2021.0325.PR0009 Stor-House Yelm stormwater preliminary TIR 06-04-2021
Stormwater Site Plan
Stor-House Yelm
Yelm, WA 98597
Prepared For:
Gilroy Family Five, LLC
1614 – 118th Avenue SE
Bellevue, WA 98005
Report Prepared By:
J.E. Gibson Engineering and Consulting Inc.
PO Box 178
Tenino, WA 98589
360.951.1454
Date Prepared
June 2021
PROJECT ENGINEER'S CERTIFICATION
The technical material and data contained in these documents were prepared under the supervision and
direction of the undersigned, whose seal, as a professional engineer to practice as such, is affixed below.
Cvyrcb E " �---+ (a— 7— 2 -oz -1
�Kibson, PE
ncipal
3of6
Date
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SECTION 1: PROJECT OVERVIEW
This Stormwater Site Plan was prepared for the proposed self-storage facility that will be located
adjacent to Creek Street SE in Yelm. The Stormwater Site Plan was prepared to comply with the
minimum technical standards and requirements that are set forth in the 2012 Department of Ecology
Stormwater Management Manual for Western Washington (SWMMWW) as amended in December
2014. The proposed self-storage commercial development improvements will be constructed on Unit 1,
Unit 2, and Tract A of the amended Creek Road Binding Site Plan. Specifically, the proposed site
improvements and construction activities include the following:
Site preparation, grading, and erosion control activities
Construction of a 3-story self-storage facility
Replacement/reconfiguration of the existing impervious surface parking lot
Construction of on-site stormwater facilities
Reconnection/extension of utilities (water, sewer, storm, power, etc.)
The proposed project improvements will result in more than 2,000 ft2, but less than 5,000 ft2 of “net-
new” impervious surface area. According to the SWMMWW, Minimum Requirements 1-5 need to be
addressed. The following table summarizes how each requirement will be met.
MINIMUM REQUIREMENT COMPLIANCE WITH MINIMUM REQUIREMENT
#1 - Stormwater Site Plan The contents of this report and the enclosed plans are intended to
satisfy this requirement.
#2 - Construction SWPPP A Construction SWPPP has been prepared and is enclosed as an
appendix.
#3 - Source Control of Pollution If required, a Source Control Pollution Prevention Plan will be recorded
against the property prior to certificate of occupancy.
#4 - Drainage Path Preservation Preservation of the site’s previously established natural drainage paths
will be maintained to the maximum extent practicable.
#5 - Stormwater Management A below-grade infiltration trench is being proposed; the LID
Performance Standard will be met.
Table 1: Compliance with Minimum Technical Requirements
SECTION 2: SITE CONDITIONS
Existing Site Conditions
The Threshold Discharge Area (TDA), which consists of Unit 1, Unit 2, and Tract A of the amended Creek
Road Binding Site Plan, is approximately 1.56 acres in size and is developed; an existing parking lot,
landscaping area, and two building pads currently reside on the TDA. The proposed site improvements
will disturb approximately 95% of the TDA area. The site, generally, slopes in a west-to-east direction.
According to Thurston County GIS mapping, there are no on-site wetlands, and the subject area is not
positioned in the floodplain. City of Yelm water and sewer facilities will be extended to the proposed
storage facility and power will be provided by PSE. At the time of the project survey, there wasn’t any
evidence to suggest that the site was or is being used as a solid waste dump site. The TDA is bordered by
other commercial development enterprises.
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The TDA was developed back in the late 2000s and was a part of a bigger development (Creek Road
Mixed Use) with master planned water quality and flow control facilities for multiple businesses. The
Stormwater Report for the project is enclosed as an appendix. The TDA’s parking lot was constructed,
but the two building pads have remained vacant. The proposed parking lot will be reconfigured, and the
proposed self-storage facility will be positioned closer to NE Creek Street. Currently, on-site generated
stormwater from the TDA is routed to the east and discharged through Contech StormFilters for water
quality treatment and then released to below-grade infiltration rock galleries. The existing stormwater
facilities were designed in accordance with the 2005 Department of Ecology Stormwater Management
Manual for Western Washington. An equivalent amount of landscaping and impervious surface area
from the proposed development will be routed to the existing off-site stormwater infrastructure for
treatment and infiltration after construction activities are completed.
Soils Information
A geotechnical report was finalized by Earth Solutions NW, LLC in May 2021. The geotechnical engineer
classified the in-situ soil along the vertical profile of the infiltration stratum as poorly graded gravel with
sand. Groundwater was not encountered in the test pits. The geotechnical engineer recommended a
long-term design infiltration rate of 5 inches per hour for proposed stormwater facilities. The
geotechnical report is enclosed as an appendix.
SECTION 3: OFF-SITE ANALYSIS AND REPORT
A majority of on-site generated stormwater runoff from the proposed project will continue to be routed
off-site to the existing water quality and flow control facilities. The “net-new” increase in impervious
surface area from the proposed site improvements will be conveyed to an on-site Aqua-Swirl AS-2 unit
for water quality treatment and then discharged to a below-grade rock infiltration gallery for 100%
infiltration. Off-site discharge from the “net-new” increase in impervious surface area is not proposed.
Historic off-site drainage courses will not be altered. Consequently, downstream impacts are not
anticipated.
SECTION 4: PERMANENT STORMWATER CONTROL PLAN
Summary Section
The following tables identifies the different land-type designations & their respective areas for the TDA:
LAND TYPE DESIGNATIONS EXISTING CONDITIONS PROPOSED CONDITIONS
Threshold Discharge Area 67,934 sq. ft.67,934 sq. ft
Asphalt Area 28,739 sq. ft 26,045 sq. ft
Building Area 18,082 sq. ft 27,016 sq. ft
Sidewalk Area 7,336 sq. ft 3,480 sq. ft
Landscaping Area 13,777 f sq. ft 11,393 sq. ft
Table 2: Land Type Designations Summary Table
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The “net-new” increase in impervious surface area from the existing conditions to the proposed
conditions is 2,384 ft2. A 4,018 ft2 area of the proposed parking lot will be conveyed to an on-site Aqua
Swirl AS-2 unit for water quality treatment and then discharged to a 5’ wide x 50’ long x 4’ deep below-
grade rock gallery for 100% infiltration; stormwater from the remaining impervious and pervious site
improvements will be collected and routed off-site to the existing water quality and flow control
infrastructure that was constructed/installed in the late 2000s.
Low Impact Development Features
The LID performance standard will be met for this project. Consequently, the construction of
bioretention facilities, rain gardens, permeable pavement, etc. are not required for this project.
Water Quality System
Stormwater from the parking lot area that will not be routed off-site (4,018 ft2) will be conveyed to an
on-site Aqua-Swirl AS-2 unit. Clear Creek’s Western Washington Hydrologic Modeling (WWHM) software
was used to size the Aqua-Swirl unit. According to the analysis, the water quality flow rate from the
“net-new” parking lot area is 0.02 cfs. Aqua-Swirl AS-2 units have a maximum water quality flow rate of
approximately 0.55 cfs.
Flow Control System
After treatment, on-site generated stormwater will be discharged to a below-grade infiltration rock
gallery. According to a completed WWHM model, a 5’ wide x 50’ long x 4’ deep (includes 1’ of
freeboard) rock gallery is required to infiltrate 100% of the influent runoff file. Refer to the enclosed
WWHM report for calculations and design parameters of the proposed infiltration facility.
SECTION 5: PERMITS
Building and Right-of-Way permits will need to be secured from the City of Yelm prior to beginning
construction activities.
SECTION 6: CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN
A Construction Stormwater Pollution Prevention Plan has been prepared in accordance with Volume II of
the SWMMWW and is enclosed as an appendix.
END OF STORMWATER SITE PLAN
APPENDIX 1
SITE VICINITY MAP
N
THRESHOLD
DISCHARGE AREA
APPENDIX 2
DESIGN CALCULATIONS
WWHM2012
PROJECT REPORT
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General Model Information
Project Name:default[0]
Site Name:
Site Address:
City:
Report Date:6/6/2021
Gage:Lake Lawrence
Data Start:1955/10/01
Data End:2008/09/30
Timestep:15 Minute
Precip Scale:0.857
Version Date:2019/09/13
Version:4.2.17
POC Thresholds
Low Flow Threshold for POC1:50 Percent of the 2 Year
High Flow Threshold for POC1:50 Year
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Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass:No
GroundWater:No
Pervious Land Use acre
A B, Forest, Flat 0.092
Pervious Total 0.092
Impervious Land Use acre
Impervious Total 0
Basin Total 0.092
Element Flows To:
Surface Interflow Groundwater
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Mitigated Land Use
Basin 1
Bypass:No
GroundWater:No
Pervious Land Use acre
Pervious Total 0
Impervious Land Use acre
PARKING FLAT 0.092
Impervious Total 0.092
Basin Total 0.092
Element Flows To:
Surface Interflow Groundwater
Gravel Trench Bed 1 Gravel Trench Bed 1
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Routing Elements
Predeveloped Routing
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Mitigated Routing
Gravel Trench Bed 1
Bottom Length:50.00 ft.
Bottom Width:5.00 ft.
Trench bottom slope 1:0.0000001 To 1
Trench Left side slope 0:0.0000001 To 1
Trench right side slope 2:0.0000001 To 1
Material thickness of first layer:4
Pour Space of material for first layer:0.4
Material thickness of second layer:0
Pour Space of material for second layer:0
Material thickness of third layer:0
Pour Space of material for third layer:0
Infiltration On
Infiltration rate:5
Infiltration safety factor:1
Total Volume Infiltrated (ac-ft.):16.026
Total Volume Through Riser (ac-ft.):0
Total Volume Through Facility (ac-ft.):16.026
Percent Infiltrated:100
Total Precip Applied to Facility:0
Total Evap From Facility:0
Discharge Structure
Riser Height:3 ft.
Riser Diameter:6 in.
Element Flows To:
Outlet 1 Outlet 2
Gravel Trench Bed Hydraulic Table
Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs)
0.0000 0.005 0.000 0.000 0.000
0.0444 0.005 0.000 0.000 0.028
0.0889 0.005 0.000 0.000 0.028
0.1333 0.005 0.000 0.000 0.028
0.1778 0.005 0.000 0.000 0.028
0.2222 0.005 0.000 0.000 0.028
0.2667 0.005 0.000 0.000 0.028
0.3111 0.005 0.000 0.000 0.028
0.3556 0.005 0.000 0.000 0.028
0.4000 0.005 0.000 0.000 0.028
0.4444 0.005 0.001 0.000 0.028
0.4889 0.005 0.001 0.000 0.028
0.5333 0.005 0.001 0.000 0.028
0.5778 0.005 0.001 0.000 0.028
0.6222 0.005 0.001 0.000 0.028
0.6667 0.005 0.001 0.000 0.028
0.7111 0.005 0.001 0.000 0.028
0.7556 0.005 0.001 0.000 0.028
0.8000 0.005 0.001 0.000 0.028
0.8444 0.005 0.001 0.000 0.028
0.8889 0.005 0.002 0.000 0.028
0.9333 0.005 0.002 0.000 0.028
0.9778 0.005 0.002 0.000 0.028
1.0222 0.005 0.002 0.000 0.028
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1.0667 0.005 0.002 0.000 0.028
1.1111 0.005 0.002 0.000 0.028
1.1556 0.005 0.002 0.000 0.028
1.2000 0.005 0.002 0.000 0.028
1.2444 0.005 0.002 0.000 0.028
1.2889 0.005 0.003 0.000 0.028
1.3333 0.005 0.003 0.000 0.028
1.3778 0.005 0.003 0.000 0.028
1.4222 0.005 0.003 0.000 0.028
1.4667 0.005 0.003 0.000 0.028
1.5111 0.005 0.003 0.000 0.028
1.5556 0.005 0.003 0.000 0.028
1.6000 0.005 0.003 0.000 0.028
1.6444 0.005 0.003 0.000 0.028
1.6889 0.005 0.003 0.000 0.028
1.7333 0.005 0.004 0.000 0.028
1.7778 0.005 0.004 0.000 0.028
1.8222 0.005 0.004 0.000 0.028
1.8667 0.005 0.004 0.000 0.028
1.9111 0.005 0.004 0.000 0.028
1.9556 0.005 0.004 0.000 0.028
2.0000 0.005 0.004 0.000 0.028
2.0444 0.005 0.004 0.000 0.028
2.0889 0.005 0.004 0.000 0.028
2.1333 0.005 0.004 0.000 0.028
2.1778 0.005 0.005 0.000 0.028
2.2222 0.005 0.005 0.000 0.028
2.2667 0.005 0.005 0.000 0.028
2.3111 0.005 0.005 0.000 0.028
2.3556 0.005 0.005 0.000 0.028
2.4000 0.005 0.005 0.000 0.028
2.4444 0.005 0.005 0.000 0.028
2.4889 0.005 0.005 0.000 0.028
2.5333 0.005 0.005 0.000 0.028
2.5778 0.005 0.005 0.000 0.028
2.6222 0.005 0.006 0.000 0.028
2.6667 0.005 0.006 0.000 0.028
2.7111 0.005 0.006 0.000 0.028
2.7556 0.005 0.006 0.000 0.028
2.8000 0.005 0.006 0.000 0.028
2.8444 0.005 0.006 0.000 0.028
2.8889 0.005 0.006 0.000 0.028
2.9333 0.005 0.006 0.000 0.028
2.9778 0.005 0.006 0.000 0.028
3.0222 0.005 0.006 0.017 0.028
3.0667 0.005 0.007 0.090 0.028
3.1111 0.005 0.007 0.184 0.028
3.1556 0.005 0.007 0.277 0.028
3.2000 0.005 0.007 0.346 0.028
3.2444 0.005 0.007 0.385 0.028
3.2889 0.005 0.007 0.423 0.028
3.3333 0.005 0.007 0.454 0.028
3.3778 0.005 0.007 0.484 0.028
3.4222 0.005 0.007 0.511 0.028
3.4667 0.005 0.008 0.537 0.028
3.5111 0.005 0.008 0.562 0.028
3.5556 0.005 0.008 0.586 0.028
3.6000 0.005 0.008 0.609 0.028
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3.6444 0.005 0.008 0.632 0.028
3.6889 0.005 0.008 0.653 0.028
3.7333 0.005 0.008 0.674 0.028
3.7778 0.005 0.008 0.694 0.028
3.8222 0.005 0.008 0.714 0.028
3.8667 0.005 0.008 0.733 0.028
3.9111 0.005 0.009 0.751 0.028
3.9556 0.005 0.009 0.769 0.028
4.0000 0.005 0.009 0.787 0.028
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Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area:0.092
Total Impervious Area:0
Mitigated Landuse Totals for POC #1
Total Pervious Area:0
Total Impervious Area:0.092
Flow Frequency Method:Log Pearson Type III 17B
Flow Frequency Return Periods for Predeveloped. POC #1
Return Period Flow(cfs)
2 year 0.00014
5 year 0.000387
10 year 0.000714
25 year 0.001458
50 year 0.002394
100 year 0.003829
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0
5 year 0
10 year 0
25 year 0
50 year 0
100 year 0
Annual Peaks
Annual Peaks for Predeveloped and Mitigated. POC #1
Year Predeveloped Mitigated
1956 0.000 0.000
1957 0.000 0.000
1958 0.000 0.000
1959 0.000 0.000
1960 0.000 0.000
1961 0.000 0.000
1962 0.000 0.000
1963 0.000 0.000
1964 0.000 0.000
1965 0.000 0.000
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1966 0.000 0.000
1967 0.000 0.000
1968 0.000 0.000
1969 0.000 0.000
1970 0.000 0.000
1971 0.001 0.000
1972 0.001 0.000
1973 0.000 0.000
1974 0.000 0.000
1975 0.000 0.000
1976 0.000 0.000
1977 0.000 0.000
1978 0.000 0.000
1979 0.000 0.000
1980 0.000 0.000
1981 0.000 0.000
1982 0.000 0.000
1983 0.000 0.000
1984 0.000 0.000
1985 0.000 0.000
1986 0.000 0.000
1987 0.000 0.000
1988 0.000 0.000
1989 0.000 0.000
1990 0.001 0.000
1991 0.001 0.000
1992 0.000 0.000
1993 0.000 0.000
1994 0.000 0.000
1995 0.000 0.000
1996 0.001 0.000
1997 0.001 0.000
1998 0.000 0.000
1999 0.000 0.000
2000 0.000 0.000
2001 0.000 0.000
2002 0.000 0.000
2003 0.000 0.000
2004 0.005 0.000
2005 0.001 0.000
2006 0.003 0.000
2007 0.001 0.000
2008 0.000 0.004
Ranked Annual Peaks
Ranked Annual Peaks for Predeveloped and Mitigated. POC #1
Rank Predeveloped Mitigated
1 0.0047 0.0036
2 0.0033 0.0000
3 0.0014 0.0000
4 0.0011 0.0000
5 0.0010 0.0000
6 0.0008 0.0000
7 0.0008 0.0000
8 0.0007 0.0000
9 0.0006 0.0000
10 0.0005 0.0000
11 0.0005 0.0000
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12 0.0005 0.0000
13 0.0005 0.0000
14 0.0003 0.0000
15 0.0003 0.0000
16 0.0002 0.0000
17 0.0002 0.0000
18 0.0002 0.0000
19 0.0002 0.0000
20 0.0002 0.0000
21 0.0001 0.0000
22 0.0001 0.0000
23 0.0001 0.0000
24 0.0001 0.0000
25 0.0001 0.0000
26 0.0001 0.0000
27 0.0001 0.0000
28 0.0001 0.0000
29 0.0001 0.0000
30 0.0001 0.0000
31 0.0001 0.0000
32 0.0001 0.0000
33 0.0001 0.0000
34 0.0001 0.0000
35 0.0001 0.0000
36 0.0001 0.0000
37 0.0001 0.0000
38 0.0001 0.0000
39 0.0001 0.0000
40 0.0001 0.0000
41 0.0001 0.0000
42 0.0001 0.0000
43 0.0001 0.0000
44 0.0001 0.0000
45 0.0001 0.0000
46 0.0001 0.0000
47 0.0001 0.0000
48 0.0001 0.0000
49 0.0001 0.0000
50 0.0001 0.0000
51 0.0001 0.0000
52 0.0001 0.0000
53 0.0001 0.0000
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Duration Flows
The Facility PASSED
Flow(cfs)Predev Mit Percentage Pass/Fail
0.0001 665 3 0 Pass
0.0001 148 3 2 Pass
0.0001 120 3 2 Pass
0.0001 98 3 3 Pass
0.0002 80 3 3 Pass
0.0002 61 3 4 Pass
0.0002 52 3 5 Pass
0.0002 48 3 6 Pass
0.0003 44 3 6 Pass
0.0003 38 3 7 Pass
0.0003 37 3 8 Pass
0.0003 33 3 9 Pass
0.0004 32 3 9 Pass
0.0004 30 3 10 Pass
0.0004 29 3 10 Pass
0.0004 27 3 11 Pass
0.0004 26 3 11 Pass
0.0005 22 3 13 Pass
0.0005 19 3 15 Pass
0.0005 18 3 16 Pass
0.0005 16 3 18 Pass
0.0006 16 3 18 Pass
0.0006 14 3 21 Pass
0.0006 13 3 23 Pass
0.0006 11 3 27 Pass
0.0007 9 3 33 Pass
0.0007 9 3 33 Pass
0.0007 9 3 33 Pass
0.0007 9 3 33 Pass
0.0008 8 3 37 Pass
0.0008 6 3 50 Pass
0.0008 5 3 60 Pass
0.0008 5 3 60 Pass
0.0008 5 3 60 Pass
0.0009 5 3 60 Pass
0.0009 5 3 60 Pass
0.0009 5 3 60 Pass
0.0009 5 3 60 Pass
0.0010 5 3 60 Pass
0.0010 4 3 75 Pass
0.0010 4 3 75 Pass
0.0010 4 3 75 Pass
0.0011 4 2 50 Pass
0.0011 4 2 50 Pass
0.0011 4 2 50 Pass
0.0011 3 2 66 Pass
0.0011 3 2 66 Pass
0.0012 3 2 66 Pass
0.0012 3 2 66 Pass
0.0012 3 2 66 Pass
0.0012 3 2 66 Pass
0.0013 3 2 66 Pass
0.0013 3 2 66 Pass
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0.0013 3 2 66 Pass
0.0013 3 2 66 Pass
0.0014 3 2 66 Pass
0.0014 3 2 66 Pass
0.0014 3 2 66 Pass
0.0014 3 2 66 Pass
0.0015 2 2 100 Pass
0.0015 2 2 100 Pass
0.0015 2 2 100 Pass
0.0015 2 2 100 Pass
0.0015 2 2 100 Pass
0.0016 2 2 100 Pass
0.0016 2 2 100 Pass
0.0016 2 2 100 Pass
0.0016 2 2 100 Pass
0.0017 2 2 100 Pass
0.0017 2 2 100 Pass
0.0017 2 2 100 Pass
0.0017 2 2 100 Pass
0.0018 2 2 100 Pass
0.0018 2 2 100 Pass
0.0018 2 2 100 Pass
0.0018 2 2 100 Pass
0.0019 2 2 100 Pass
0.0019 2 2 100 Pass
0.0019 2 2 100 Pass
0.0019 2 2 100 Pass
0.0019 2 2 100 Pass
0.0020 2 2 100 Pass
0.0020 2 2 100 Pass
0.0020 2 2 100 Pass
0.0020 2 2 100 Pass
0.0021 2 2 100 Pass
0.0021 2 2 100 Pass
0.0021 2 2 100 Pass
0.0021 2 2 100 Pass
0.0022 2 2 100 Pass
0.0022 2 2 100 Pass
0.0022 2 2 100 Pass
0.0022 2 2 100 Pass
0.0023 2 2 100 Pass
0.0023 2 2 100 Pass
0.0023 2 2 100 Pass
0.0023 2 2 100 Pass
0.0023 2 2 100 Pass
0.0024 2 2 100 Pass
0.0024 2 2 100 Pass
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Water Quality
Water Quality BMP Flow and Volume for POC #1
On-line facility volume:0 acre-feet
On-line facility target flow:0 cfs.
Adjusted for 15 min:0 cfs.
Off-line facility target flow:0 cfs.
Adjusted for 15 min:0 cfs.
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LID Report
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Model Default Modifications
Total of 0 changes have been made.
PERLND Changes
No PERLND changes have been made.
IMPLND Changes
No IMPLND changes have been made.
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Appendix
Predeveloped Schematic
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Mitigated Schematic
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Predeveloped UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1955 10 01 END 2008 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1
END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>***
<-ID-> ***
WDM 26 default[0].wdm
MESSU 25 Predefault[0].MES
27 Predefault[0].L61
28 Predefault[0].L62
30 POCdefault[0]1.dat
END FILES
OPN SEQUENCE
INGRP INDELT 00:15
PERLND 1
COPY 501
DISPLY 1
END INGRP
END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND
1 Basin 1 MAX 1 2 30 9
END DISPLY-INFO1
END DISPLY
COPY
TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1
END TIMESERIES
END COPY
GENER
OPCODE
# # OPCD ***
END OPCODE
PARM
# # K ***
END PARM
END GENER
PERLND
GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer ***
# - # User t-series Engl Metr ***
in out ***
1 A/B, Forest, Flat 1 1 1 1 27 0
END GEN-INFO
*** Section PWATER***
ACTIVITY
<PLS > ************* Active Sections *****************************
# - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ***
1 0 0 1 0 0 0 0 0 0 0 0 0
END ACTIVITY
PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR
# - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *********
1 0 0 4 0 0 0 0 0 0 0 0 0 1 9
END PRINT-INFO
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PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags ***
# - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT ***
1 0 0 0 0 0 0 0 0 0 0 0
END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC
1 0 5 2 400 0.05 0.3 0.996
END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP
1 0 0 2 2 0 0 0
END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 ***
# - # CEPSC UZSN NSUR INTFW IRC LZETP ***
1 0.2 0.5 0.35 0 0.7 0.7
END PWAT-PARM4
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS
1 0 0 0 0 3 1 0
END PWAT-STATE1
END PERLND
IMPLND
GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer ***
# - # User t-series Engl Metr ***
in out ***
END GEN-INFO
*** Section IWATER***
ACTIVITY
<PLS > ************* Active Sections *****************************
# - # ATMP SNOW IWAT SLD IWG IQAL ***
END ACTIVITY
PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********
END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags ***
# - # CSNO RTOP VRS VNN RTLI ***
END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
END IWAT-PARM2
IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
END IWAT-STATE1
default[0]6/6/2021 1:07:02 PM Page 21
END IMPLND
SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK ***
<Name> # <-factor-> <Name> # Tbl# ***
Basin 1***
PERLND 1 0.092 COPY 501 12
PERLND 1 0.092 COPY 501 13
******Routing******
END SCHEMATIC
NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> ***
<Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***
COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> ***
<Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***
END NETWORK
RCHRES
GEN-INFO
RCHRES Name Nexits Unit Systems Printer ***
# - #<------------------><---> User T-series Engl Metr LKFG ***
in out ***
END GEN-INFO
*** Section RCHRES***
ACTIVITY
<PLS > ************* Active Sections *****************************
# - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG ***
END ACTIVITY
PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR
# - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR *********
END PRINT-INFO
HYDR-PARM1
RCHRES Flags for each HYDR Section ***
# - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each
FG FG FG FG possible exit *** possible exit possible exit
* * * * * * * * * * * * * * ***
END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 ***
<------><--------><--------><--------><--------><--------><--------> ***
END HYDR-PARM2
HYDR-INIT
RCHRES Initial conditions for each HYDR section ***
# - # *** VOL Initial value of COLIND Initial value of OUTDGT
*** ac-ft for each possible exit for each possible exit
<------><--------> <---><---><---><---><---> *** <---><---><---><---><--->
END HYDR-INIT
END RCHRES
SPEC-ACTIONS
END SPEC-ACTIONS
FTABLES
END FTABLES
EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> ***
<Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # ***
WDM 2 PREC ENGL 0.857 PERLND 1 999 EXTNL PREC
WDM 2 PREC ENGL 0.857 IMPLND 1 999 EXTNL PREC
default[0]6/6/2021 1:07:02 PM Page 22
WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP
WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP
END EXT SOURCES
EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd ***
<Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg***
COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL
END EXT TARGETS
MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->***
<Name> <Name> # #<-factor-> <Name> <Name> # #***
MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN
END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN
END MASS-LINK 13
END MASS-LINK
END RUN
default[0]6/6/2021 1:07:02 PM Page 23
Mitigated UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1955 10 01 END 2008 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1
END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>***
<-ID-> ***
WDM 26 default[0].wdm
MESSU 25 Mitdefault[0].MES
27 Mitdefault[0].L61
28 Mitdefault[0].L62
30 POCdefault[0]1.dat
END FILES
OPN SEQUENCE
INGRP INDELT 00:15
IMPLND 11
RCHRES 1
COPY 1
COPY 501
DISPLY 1
END INGRP
END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND
1 Gravel Trench Bed 1 MAX 1 2 30 9
END DISPLY-INFO1
END DISPLY
COPY
TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1
END TIMESERIES
END COPY
GENER
OPCODE
# # OPCD ***
END OPCODE
PARM
# # K ***
END PARM
END GENER
PERLND
GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer ***
# - # User t-series Engl Metr ***
in out ***
END GEN-INFO
*** Section PWATER***
ACTIVITY
<PLS > ************* Active Sections *****************************
# - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ***
END ACTIVITY
PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR
# - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *********
END PRINT-INFO
PWAT-PARM1
default[0]6/6/2021 1:07:02 PM Page 24
<PLS > PWATER variable monthly parameter value flags ***
# - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT ***
END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC
END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP
END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 ***
# - # CEPSC UZSN NSUR INTFW IRC LZETP ***
END PWAT-PARM4
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS
END PWAT-STATE1
END PERLND
IMPLND
GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer ***
# - # User t-series Engl Metr ***
in out ***
11 PARKING/FLAT 1 1 1 27 0
END GEN-INFO
*** Section IWATER***
ACTIVITY
<PLS > ************* Active Sections *****************************
# - # ATMP SNOW IWAT SLD IWG IQAL ***
11 0 0 1 0 0 0
END ACTIVITY
PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********
11 0 0 4 0 0 0 1 9
END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags ***
# - # CSNO RTOP VRS VNN RTLI ***
11 0 0 0 0 0
END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
11 400 0.01 0.1 0.1
END IWAT-PARM2
IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
11 0 0
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
11 0 0
END IWAT-STATE1
default[0]6/6/2021 1:07:02 PM Page 25
END IMPLND
SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK ***
<Name> # <-factor-> <Name> # Tbl# ***
Basin 1***
IMPLND 11 0.092 RCHRES 1 5
******Routing******
IMPLND 11 0.092 COPY 1 15
RCHRES 1 1 COPY 501 17
END SCHEMATIC
NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> ***
<Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***
COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> ***
<Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***
END NETWORK
RCHRES
GEN-INFO
RCHRES Name Nexits Unit Systems Printer ***
# - #<------------------><---> User T-series Engl Metr LKFG ***
in out ***
1 Gravel Trench Be-007 2 1 1 1 28 0 1
END GEN-INFO
*** Section RCHRES***
ACTIVITY
<PLS > ************* Active Sections *****************************
# - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG ***
1 1 0 0 0 0 0 0 0 0 0
END ACTIVITY
PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR
# - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR *********
1 4 0 0 0 0 0 0 0 0 0 1 9
END PRINT-INFO
HYDR-PARM1
RCHRES Flags for each HYDR Section ***
# - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each
FG FG FG FG possible exit *** possible exit possible exit
* * * * * * * * * * * * * * ***
1 0 1 0 0 4 5 0 0 0 0 0 0 0 0 2 2 2 2 2
END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 ***
<------><--------><--------><--------><--------><--------><--------> ***
1 1 0.01 0.0 0.0 0.5 0.0
END HYDR-PARM2
HYDR-INIT
RCHRES Initial conditions for each HYDR section ***
# - # *** VOL Initial value of COLIND Initial value of OUTDGT
*** ac-ft for each possible exit for each possible exit
<------><--------> <---><---><---><---><---> *** <---><---><---><---><--->
1 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
END HYDR-INIT
END RCHRES
SPEC-ACTIONS
END SPEC-ACTIONS
default[0]6/6/2021 1:07:02 PM Page 26
FTABLES
FTABLE 1
92 5
Depth Area Volume Outflow1 Outflow2 Velocity Travel Time***
(ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)***
0.000000 0.005739 0.000000 0.000000 0.000000
0.044444 0.005739 0.000102 0.000000 0.028935
0.088889 0.005739 0.000204 0.000000 0.028935
0.133333 0.005739 0.000306 0.000000 0.028935
0.177778 0.005739 0.000408 0.000000 0.028935
0.222222 0.005739 0.000510 0.000000 0.028935
0.266667 0.005739 0.000612 0.000000 0.028935
0.311111 0.005739 0.000714 0.000000 0.028935
0.355556 0.005739 0.000816 0.000000 0.028935
0.400000 0.005739 0.000918 0.000000 0.028935
0.444444 0.005739 0.001020 0.000000 0.028935
0.488889 0.005739 0.001122 0.000000 0.028935
0.533333 0.005739 0.001224 0.000000 0.028935
0.577778 0.005739 0.001326 0.000000 0.028935
0.622222 0.005739 0.001428 0.000000 0.028935
0.666667 0.005739 0.001530 0.000000 0.028935
0.711111 0.005739 0.001632 0.000000 0.028935
0.755556 0.005739 0.001735 0.000000 0.028935
0.800000 0.005739 0.001837 0.000000 0.028935
0.844444 0.005739 0.001939 0.000000 0.028935
0.888889 0.005739 0.002041 0.000000 0.028935
0.933333 0.005739 0.002143 0.000000 0.028935
0.977778 0.005739 0.002245 0.000000 0.028935
1.022222 0.005739 0.002347 0.000000 0.028935
1.066667 0.005739 0.002449 0.000000 0.028935
1.111111 0.005739 0.002551 0.000000 0.028935
1.155556 0.005739 0.002653 0.000000 0.028935
1.200000 0.005739 0.002755 0.000000 0.028935
1.244444 0.005739 0.002857 0.000000 0.028935
1.288889 0.005739 0.002959 0.000000 0.028935
1.333333 0.005739 0.003061 0.000000 0.028935
1.377778 0.005739 0.003163 0.000000 0.028935
1.422222 0.005739 0.003265 0.000000 0.028935
1.466667 0.005739 0.003367 0.000000 0.028935
1.511111 0.005739 0.003469 0.000000 0.028935
1.555556 0.005739 0.003571 0.000000 0.028935
1.600000 0.005739 0.003673 0.000000 0.028935
1.644444 0.005739 0.003775 0.000000 0.028935
1.688889 0.005739 0.003877 0.000000 0.028935
1.733333 0.005739 0.003979 0.000000 0.028935
1.777778 0.005739 0.004081 0.000000 0.028935
1.822222 0.005739 0.004183 0.000000 0.028935
1.866667 0.005739 0.004285 0.000000 0.028935
1.911111 0.005739 0.004387 0.000000 0.028935
1.955556 0.005739 0.004489 0.000000 0.028935
2.000000 0.005739 0.004591 0.000000 0.028935
2.044444 0.005739 0.004693 0.000000 0.028935
2.088889 0.005739 0.004795 0.000000 0.028935
2.133333 0.005739 0.004897 0.000000 0.028935
2.177778 0.005739 0.004999 0.000000 0.028935
2.222222 0.005739 0.005102 0.000000 0.028935
2.266667 0.005739 0.005204 0.000000 0.028935
2.311111 0.005739 0.005306 0.000000 0.028935
2.355556 0.005739 0.005408 0.000000 0.028935
2.400000 0.005739 0.005510 0.000000 0.028935
2.444444 0.005739 0.005612 0.000000 0.028935
2.488889 0.005739 0.005714 0.000000 0.028935
2.533333 0.005739 0.005816 0.000000 0.028935
2.577778 0.005739 0.005918 0.000000 0.028935
2.622222 0.005739 0.006020 0.000000 0.028935
2.666667 0.005739 0.006122 0.000000 0.028935
2.711111 0.005739 0.006224 0.000000 0.028935
2.755556 0.005739 0.006326 0.000000 0.028935
2.800000 0.005739 0.006428 0.000000 0.028935
2.844444 0.005739 0.006530 0.000000 0.028935
default[0]6/6/2021 1:07:02 PM Page 27
2.888889 0.005739 0.006632 0.000000 0.028935
2.933333 0.005739 0.006734 0.000000 0.028935
2.977778 0.005739 0.006836 0.000000 0.028935
3.022222 0.005739 0.006938 0.017558 0.028935
3.066667 0.005739 0.007040 0.090096 0.028935
3.111111 0.005739 0.007142 0.184914 0.028935
3.155556 0.005739 0.007244 0.277515 0.028935
3.200000 0.005739 0.007346 0.346488 0.028935
3.244444 0.005739 0.007448 0.385798 0.028935
3.288889 0.005739 0.007550 0.423219 0.028935
3.333333 0.005739 0.007652 0.454610 0.028935
3.377778 0.005739 0.007754 0.483969 0.028935
3.422222 0.005739 0.007856 0.511647 0.028935
3.466667 0.005739 0.007958 0.537902 0.028935
3.511111 0.005739 0.008060 0.562934 0.028935
3.555556 0.005739 0.008162 0.586899 0.028935
3.600000 0.005739 0.008264 0.609923 0.028935
3.644444 0.005739 0.008366 0.632109 0.028935
3.688889 0.005739 0.008469 0.653543 0.028935
3.733333 0.005739 0.008571 0.674296 0.028935
3.777778 0.005739 0.008673 0.694428 0.028935
3.822222 0.005739 0.008775 0.713993 0.028935
3.866667 0.005739 0.008877 0.733036 0.028935
3.911111 0.005739 0.008979 0.751597 0.028935
3.955556 0.005739 0.009081 0.769711 0.028935
4.000000 0.005739 0.009183 0.787408 0.028935
4.044444 0.005739 0.009438 0.804715 0.028935
END FTABLE 1
END FTABLES
EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> ***
<Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # ***
WDM 2 PREC ENGL 0.857 PERLND 1 999 EXTNL PREC
WDM 2 PREC ENGL 0.857 IMPLND 1 999 EXTNL PREC
WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP
WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP
END EXT SOURCES
EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd ***
<Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg***
RCHRES 1 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL
RCHRES 1 HYDR O 1 1 1 WDM 1001 FLOW ENGL REPL
RCHRES 1 HYDR O 2 1 1 WDM 1002 FLOW ENGL REPL
RCHRES 1 HYDR STAGE 1 1 1 WDM 1003 STAG ENGL REPL
COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL
COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL
END EXT TARGETS
MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->***
<Name> <Name> # #<-factor-> <Name> <Name> # #***
MASS-LINK 5
IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL
END MASS-LINK 5
MASS-LINK 15
IMPLND IWATER SURO 0.083333 COPY INPUT MEAN
END MASS-LINK 15
MASS-LINK 17
RCHRES OFLOW OVOL 1 COPY INPUT MEAN
END MASS-LINK 17
END MASS-LINK
END RUN
default[0]6/6/2021 1:07:02 PM Page 28
default[0]6/6/2021 1:07:02 PM Page 29
Predeveloped HSPF Message File
default[0]6/6/2021 1:07:02 PM Page 30
Mitigated HSPF Message File
default[0]6/6/2021 1:07:02 PM Page 31
Disclaimer
Legal Notice
This program and accompanying documentation is provided 'as-is' without warranty of any kind. The
entire risk regarding the performance and results of this program is assumed by the user. Clear Creek
Solutions, Inc. disclaims all warranties, either expressed or implied, including but not limited to
implied warranties of program and accompanying documentation. In no event shall Clear Creek
Solutions, Inc. be liable for any damages whatsoever (including without limitation to damages for
loss of business profits, loss of business information, business interruption, and the like) arising
out of the use of, or inability to use this program even if Clear Creek Solutions, Inc. has been
advised of the possibility of such damages.
Clear Creek Solutions, Inc.
6200 Capitol Blvd. Ste F
Olympia, WA. 98501
Toll Free 1(866)943-0304
Local (360)943-0304
www.clearcreeksolutions.com
EarthSolutionsNWLLC
EarthSolutions
NW LLC
15365 N.E.90th Street,Suite 100 Redmond,WA 98052
(425)449-4704 Fax (425)449-4711
www.earthsolutionsnw.com
Geotechnical Engineering
Construction Observation/Testing
Environmental Services
GEOTECHNICAL ENGINEERING STUDY
STOR-HOUSE YELM
10520 CREEK STREET SOUTHEAST
YELM,WASHINGTON
ES-1259.03
PREPARED FOR
GILORY FAMILY FIVE, LLC
May 28, 2021
_________________________
Adam Z. Shier, L.G.
Project Geologist
_________________________
Keven D. Hoffmann, P.E.
Geotechnical Engineering Services Manager
GEOTECHNICAL ENGINEERING STUDY
STOR-HOUSE YELM
10520 CREEK STREET SOUTHEAST
YELM, WASHINGTON
ES-1259.03
Earth Solutions NW, LLC
15365 Northeast 90th Street, Suite 100
Redmond, Washington 98052
Phone: 425-449-4704 | Fax: 425-449-4711
www.earthsolutionsnw.com
05/28/2021
Geotechnical-Engineering Report
Important Information about This
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
While you cannot eliminate all such risks, you can manage them. The following information is provided to help.
The Geoprofessional Business Association (GBA)
has prepared this advisory to help you – assumedly
a client representative – interpret and apply this
geotechnical-engineering report as effectively as
possible. In that way, you can benefit from a lowered
exposure to problems associated with subsurface
conditions at project sites and development of
them that, for decades, have been a principal cause
of construction delays, cost overruns, claims,
and disputes. If you have questions or want more
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer.
Active engagement in GBA exposes geotechnical
engineers to a wide array of risk-confrontation
techniques that can be of genuine benefit for
everyone involved with a construction project.
Understand the Geotechnical-Engineering Services
Provided for this Report
Geotechnical-engineering services typically include the planning,
collection, interpretation, and analysis of exploratory data from
widely spaced borings and/or test pits. Field data are combined
with results from laboratory tests of soil and rock samples obtained
from field exploration (if applicable), observations made during site
reconnaissance, and historical information to form one or more models
of the expected subsurface conditions beneath the site. Local geology
and alterations of the site surface and subsurface by previous and
proposed construction are also important considerations. Geotechnical
engineers apply their engineering training, experience, and judgment
to adapt the requirements of the prospective project to the subsurface
model(s). Estimates are made of the subsurface conditions that
will likely be exposed during construction as well as the expected
performance of foundations and other structures being planned and/or
affected by construction activities.
The culmination of these geotechnical-engineering services is typically a
geotechnical-engineering report providing the data obtained, a discussion
of the subsurface model(s), the engineering and geologic engineering
assessments and analyses made, and the recommendations developed
to satisfy the given requirements of the project. These reports may be
titled investigations, explorations, studies, assessments, or evaluations.
Regardless of the title used, the geotechnical-engineering report is an
engineering interpretation of the subsurface conditions within the context
of the project and does not represent a close examination, systematic
inquiry, or thorough investigation of all site and subsurface conditions.
Geotechnical-Engineering Services are Performed
for Specific Purposes, Persons, and Projects,
and At Specific Times
Geotechnical engineers structure their services to meet the specific
needs, goals, and risk management preferences of their clients. A
geotechnical-engineering study conducted for a given civil engineer
will not likely meet the needs of a civil-works constructor or even a
different civil engineer. Because each geotechnical-engineering study
is unique, each geotechnical-engineering report is unique, prepared
solely for the client.
Likewise, geotechnical-engineering services are performed for a specific
project and purpose. For example, it is unlikely that a geotechnical-
engineering study for a refrigerated warehouse will be the same as
one prepared for a parking garage; and a few borings drilled during
a preliminary study to evaluate site feasibility will not be adequate to
develop geotechnical design recommendations for the project.
Do not rely on this report if your geotechnical engineer prepared it:
• for a different client;
• for a different project or purpose;
• for a different site (that may or may not include all or a portion of
the original site); or
• before important events occurred at the site or adjacent to it;
e.g., man-made events like construction or environmental
remediation, or natural events like floods, droughts, earthquakes,
or groundwater fluctuations.
Note, too, the reliability of a geotechnical-engineering report can
be affected by the passage of time, because of factors like changed
subsurface conditions; new or modified codes, standards, or
regulations; or new techniques or tools. If you are the least bit uncertain
about the continued reliability of this report, contact your geotechnical
engineer before applying the recommendations in it. A minor amount
of additional testing or analysis after the passage of time – if any is
required at all – could prevent major problems.
Read this Report in Full
Costly problems have occurred because those relying on a geotechnical-
engineering report did not read the report in its entirety. Do not rely on
an executive summary. Do not read selective elements only. Read and
refer to the report in full.
You Need to Inform Your Geotechnical Engineer
About Change
Your geotechnical engineer considered unique, project-specific factors
when developing the scope of study behind this report and developing
the confirmation-dependent recommendations the report conveys.
Typical changes that could erode the reliability of this report include
those that affect:
• the site’s size or shape;
• the elevation, configuration, location, orientation,
function or weight of the proposed structure and
the desired performance criteria;
• the composition of the design team; or
• project ownership.
As a general rule, always inform your geotechnical engineer of project
or site changes – even minor ones – and request an assessment of their
impact. The geotechnical engineer who prepared this report cannot accept
responsibility or liability for problems that arise because the geotechnical
engineer was not informed about developments the engineer otherwise
would have considered.
Most of the “Findings” Related in This Report
Are Professional Opinions
Before construction begins, geotechnical engineers explore a site’s
subsurface using various sampling and testing procedures. Geotechnical
engineers can observe actual subsurface conditions only at those specific
locations where sampling and testing is performed. The data derived from
that sampling and testing were reviewed by your geotechnical engineer,
who then applied professional judgement to form opinions about
subsurface conditions throughout the site. Actual sitewide-subsurface
conditions may differ – maybe significantly – from those indicated in
this report. Confront that risk by retaining your geotechnical engineer
to serve on the design team through project completion to obtain
informed guidance quickly, whenever needed.
This Report’s Recommendations Are
Confirmation-Dependent
The recommendations included in this report – including any options or
alternatives – are confirmation-dependent. In other words, they are not
final, because the geotechnical engineer who developed them relied heavily
on judgement and opinion to do so. Your geotechnical engineer can finalize
the recommendations only after observing actual subsurface conditions
exposed during construction. If through observation your geotechnical
engineer confirms that the conditions assumed to exist actually do exist,
the recommendations can be relied upon, assuming no other changes have
occurred. The geotechnical engineer who prepared this report cannot assume
responsibility or liability for confirmation-dependent recommendations if you
fail to retain that engineer to perform construction observation.
This Report Could Be Misinterpreted
Other design professionals’ misinterpretation of geotechnical-
engineering reports has resulted in costly problems. Confront that risk
by having your geotechnical engineer serve as a continuing member of
the design team, to:
• confer with other design-team members;
• help develop specifications;
• review pertinent elements of other design professionals’ plans and
specifications; and
• be available whenever geotechnical-engineering guidance is needed.
You should also confront the risk of constructors misinterpreting this
report. Do so by retaining your geotechnical engineer to participate in
prebid and preconstruction conferences and to perform construction-
phase observations.
Give Constructors a Complete Report and Guidance
Some owners and design professionals mistakenly believe they can shift
unanticipated-subsurface-conditions liability to constructors by limiting
the information they provide for bid preparation. To help prevent
the costly, contentious problems this practice has caused, include the
complete geotechnical-engineering report, along with any attachments
or appendices, with your contract documents, but be certain to note
conspicuously that you’ve included the material for information purposes
only. To avoid misunderstanding, you may also want to note that
“informational purposes” means constructors have no right to rely on
the interpretations, opinions, conclusions, or recommendations in the
report. Be certain that constructors know they may learn about specific
project requirements, including options selected from the report, only
from the design drawings and specifications. Remind constructors
that they may perform their own studies if they want to, and be sure to
allow enough time to permit them to do so. Only then might you be in
a position to give constructors the information available to you, while
requiring them to at least share some of the financial responsibilities
stemming from unanticipated conditions. Conducting prebid and
preconstruction conferences can also be valuable in this respect.
Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do
not realize that geotechnical engineering is far less exact than other
engineering disciplines. This happens in part because soil and rock on
project sites are typically heterogeneous and not manufactured materials
with well-defined engineering properties like steel and concrete. That
lack of understanding has nurtured unrealistic expectations that have
resulted in disappointments, delays, cost overruns, claims, and disputes.
To confront that risk, geotechnical engineers commonly include
explanatory provisions in their reports. Sometimes labeled “limitations,”
many of these provisions indicate where geotechnical engineers’
responsibilities begin and end, to help others recognize their own
responsibilities and risks. Read these provisions closely. Ask questions.
Your geotechnical engineer should respond fully and frankly.
Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an
environmental study – e.g., a “phase-one” or “phase-two” environmental
site assessment – differ significantly from those used to perform a
geotechnical-engineering study. For that reason, a geotechnical-engineering
report does not usually provide environmental findings, conclusions, or
recommendations; e.g., about the likelihood of encountering underground
storage tanks or regulated contaminants. Unanticipated subsurface
environmental problems have led to project failures. If you have not
obtained your own environmental information about the project site,
ask your geotechnical consultant for a recommendation on how to find
environmental risk-management guidance.
Obtain Professional Assistance to Deal with
Moisture Infiltration and Mold
While your geotechnical engineer may have addressed groundwater,
water infiltration, or similar issues in this report, the engineer’s
services were not designed, conducted, or intended to prevent
migration of moisture – including water vapor – from the soil
through building slabs and walls and into the building interior, where
it can cause mold growth and material-performance deficiencies.
Accordingly, proper implementation of the geotechnical engineer’s
recommendations will not of itself be sufficient to prevent
moisture infiltration. Confront the risk of moisture infiltration by
including building-envelope or mold specialists on the design team.
Geotechnical engineers are not building-envelope or mold specialists.
Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly
prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of
GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind.
Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.
Telephone: 301/565-2733
e-mail: info@geoprofessional.org www.geoprofessional.org
May 28, 2021
ES-1259.03
Gilroy Family Five, LLC
1614 – 118th Avenue Southeast
Bellevue, Washington 98005
Attention: Mr. Patrick Gilroy
Dear Mr. Gilroy:
Earth Solutions NW, LLC (ESNW) is pleased to present this geotechnical report to support the
subject project. Based on the results of the geotechnical investigation, construction of the
proposed storage facility and related infrastructure improvements is feasible from a geotechnical
standpoint. Our study indicates the site is underlain by about two to four feet of compact fill, with
native recessional outwash deposits below.
the proposed self-storage building structure may be supported on conventional continuous and
spread footing foundations bearing on either compact structural fill (including suitable or re-
compacted fill placed during past grading activities) or competent native soil. In general,
competent soils suitable for support of the new foundation should be encountered within the
upper two to three feet of existing grades. In any case, where loose or unsuitable soil conditions
are exposed at foundation subgrade elevations, mechanical compaction of the soils to the
specifications of structural fill or overexcavation and replacement with suitable structural fill may
be necessary.
For sizing and design considerations, it is our opinion a preliminary long-term design rate of 5
inches per hour may be considered in the native recessional outwash deposits. The native
outwash deposits have the potential to successfully facilitate the implementation of infiltration
facilities on site, provided that proper separation from the groundwater table is maintained. A
higher infiltration rate may be feasible following infiltration facility placement and targeted in-situ
infiltration testing. As part of any infiltration proposal, monitoring of seasonal high groundwater
levels (through at least one wet season) may also be prudent and/or required by the presiding
jurisdiction.
Pertinent geotechnical recommendations are provided in this report. The opportunity to be of
service to you is appreciated. Should you have any questions regarding the content of this
geotechnical engineering study, please call.
Sincerely,
EARTH SOLUTIONS NW, LLC
Adam Z. Shier, L.G.
Project Geologist
15365 N.E. 90th Street, Suite 100 • Redmond, WA 98052 • (425) 449-4704 • FAX (425) 449-4711
Earth Solutions NW LLC
Geotechnical Engineering, Construction
Observation/Testing and Environmental Services
Earth Solutions NW, LLC
Table of Contents
ES-1259.03
PAGE
INTRODUCTION ................................................................................. 1
General..................................................................................... 1
Project Description ................................................................. 2
SITE CONDITIONS ............................................................................. 2
Surface ..................................................................................... 2
Subsurface .............................................................................. 2
Soil Profile & Geologic Setting.................................... 2
Groundwater ................................................................. 3
Geologically Hazardous Areas Review ................................. 3
DISCUSSION AND RECOMMENDATIONS ....................................... 3
General..................................................................................... 3
Site Preparation and Earthwork ............................................. 4
Temporary Erosion Control ......................................... 4
Excavations and Slopes .............................................. 5
In-situ and Imported Soils ........................................... 5
Structural Fill ................................................................ 5
Subgrade Preparation .................................................. 6
Foundations ............................................................................ 6
Seismic Design ....................................................................... 6
Slab-on-Grade Floors ............................................................. 7
Retaining Walls ....................................................................... 8
Drainage................................................................................... 9
Preliminary Infiltration Feasibility ............................... 9
Utility Support and Trench Backfill ....................................... 9
Preliminary Pavement Sections ............................................. 10
LIMITATIONS ...................................................................................... 11
Additional Services ................................................................. 11
Earth Solutions NW, LLC
Table of Contents
Cont’d
ES-1259.03
GRAPHICS
Plate 1 Vicinity Map
Plate 2 Test Pit Location Plan
Plate 3 Retaining Wall Drainage Detail
Plate 4 Footing Drain Detail
APPENDICES
Appendix A Subsurface Exploration
Test Pit Logs
Appendix B Laboratory Test Results
Earth Solutions NW, LLC
GEOTECHNICAL ENGINEERING STUDY
STOR-HOUSE YELM
10520 CREEK STREET SOUTHEAST
YELM, WASHINGTON
ES-1259.03
INTRODUCTION
General
This geotechnical engineering study (study) was prepared for the proposed storage unit facility
to be constructed east of Creek Street Southeast, about 300 feet north of the intersection with
106th Avenue Southeast, in Yelm, Washington. The purpose of this study was to provide
geotechnical recommendations for currently proposed development plans. Our scope of services
for completing this study included the following:
Excavating test pits to characterize soil and near-surface groundwater conditions.
Laboratory testing of soil samples collected at the test pit locations.
Conducting engineering analyses.
Preparation of this report.
The following documents and maps were reviewed as part of our study preparation:
Topographic Survey, prepared by MTN2COAST, LLC, dated April 2, 2021.
Yelm Municipal Code (YMC) Chapter 18.21: Critical Areas and Resource Lands.
Surficial Hydrogeologic Units of the Puget Sound Aquifer System, Washington and British
Columbia, for the Centralia Quadrangle, by M.A. Jones, 1998.
Stormwater Management Manual for Western Washington (2019 SWMMWW), prepared
by the Washington State Department of Ecology, July 2019.
Online Web Soil Survey (WSS) resource, maintained by the Natural Resources
Conservation Service under the United States Department of Agriculture.
Geologic Information Portal, maintained by the Washington State Department of Natural
Resources (DNR).
Liquefaction Susceptibility Map of Thurston County, Washington, by Stephen P. Palmer et
al., September 2004.
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Earth Solutions NW, LLC
Project Description
We understand a new three-story storage facility and related infrastructure improvements are
proposed for the subject site. We anticipate grading activities will include a series of cuts and
fills to establish the planned finish grade elevations and building pad(s). Based on the existing
grades, we estimate cuts and fills to establish finish grades will be roughly five feet or less.
At the time of report submission, building plans were not readily available for review. However,
based on our experience with similar projects, we expect the building structure will be comprised
of concrete masonry unit (CMU) wall construction and slab-on-grade floors. As such, building
loads are anticipated to be approximately 4 to 6 kips per foot, with slab-on-grade loading of
roughly 250 to 350 pounds per square foot (psf).
If the above design assumptions either change or are incorrect, ESNW should be contacted to
review the recommendations provided in this report. ESNW should review final designs to
confirm that our geotechnical recommendations have been incorporated into the plans.
SITE CONDITIONS
Surface
The subject site is located at 10520 Creek Street Southeast, in Yelm, Washington. The
approximate location of the property is illustrated on Plate 1 (Vicinity Map). The property is
comprised of two tax parcels (Thurston County parcel numbers 64303400-404 and -405), totaling
about two-thirds acre.
The site is bordered to the north by open space, to the east by an apartment development, to the
south by a commercial warehouse building, and to the west by Creek Street Southeast. Per the
referenced survey, the site is relatively level, with about two feet of elevation change. Currently,
the site is vacant and covered with grass and a paved parking area.
Subsurface
An ESNW representative observed, logged, and sampled five test pits on April 27, 2021. The
test pits were completed using an excavator and operator retained by our firm. The approximate
locations of the test pits are depicted on Plate 2 (Test Pit Location Plan). Please refer to the test
pit logs provided in Appendix A for a more detailed description of subsurface conditions.
Representative soil samples collected at the test pit locations were evaluated in accordance with
Unified Soil Classification System (USCS) and USDA methods and procedures.
Soil Profile & Geologic Setting
Fill was encountered at all test pit locations extending to depths of about two to three-and-one-
half feet below the existing ground surface (bgs). The fill was characterized as silty gravel,
consistent with reworked native soil.
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Earth Solutions NW, LLC
Underlying the fill, native soils consisted primarily of medium dense well-graded gravel, poorly
graded gravel, and poorly graded sand (USCS: GW, GP, and SP, respectively). The native soils
were encountered in a moist condition extending to the maximum exploration depth of
approximately eight feet bgs.
The referenced geologic map identifies Vashon recessional outwash (Qvrg) as underlying the
site and surrounding area. According to the geologic map, the recessional outwash deposit is
typified by moderately to poorly sorted gravel and sand with small amounts of silt and clay. Ice-
contact deposits, glacial outwash alluvium, and minor amounts of ablation till may also be
included. The referenced WSS resource identifies Spanaway gravelly sandy loam (Map Unit
Symbol: 110) as underlying the site and immediately surrounding areas. The Spanaway series
is associated with volcanic ash over gravelly outwash. Based on our field observations, native
soil conditions observed at the test pit locations are consistent with recessional outwash deposits,
as outlined herein.
Groundwater
During our subsurface exploration completed on April 27, 2021, groundwater seepage was not
encountered at the test pit locations. Seeps are common within glacial deposits; elevations and
seepage rates depending on many factors, including precipitation duration and intensity, the time
of year, and soil conditions. In general, groundwater flow rates are higher during the winter,
spring, and early summer months.
Geologically Hazardous Areas Review
We reviewed both YMC 18.21 and a database maintained by Thurston County to assist in
characterizing potential geologically hazardous areas both on site and in the immediate vicinity
of the site. YMC 18.21.100 designates erosion, landslide, and seismic hazard areas as the
geologically hazardous areas specifically recognized by the City of Yelm. Our review indicates
that geologically hazardous areas have not been mapped on site or in proximity to the site. Based
on our field observations, it is our opinion the site is correctly mapped outside of geologically
hazardous areas.
DISCUSSION AND RECOMMENDATIONS
General
Based on the results of our investigation, construction of the proposed self-storage facility and
related infrastructure improvements is feasible from a geotechnical standpoint. The primary
geotechnical considerations associated with the proposed development include building
subgrade preparation, foundation support, slab-on-grade subgrade support, the suitability of
using on-site soils as structural fill, and infiltration facility design (where applicable).
Gilroy Family Five, LLC ES-1259.03
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Earth Solutions NW, LLC
The proposed self-storage building structure may be supported on conventional continuous and
spread footing foundations bearing on either compact structural fill (including suitable or re-
compacted fill placed during past grading activities) or competent native soil. In general,
competent soils suitable for support of the new foundation should be encountered within the
upper two to three feet of existing grades. In any case, where loose or unsuitable soil conditions
are exposed at foundation subgrade elevations, mechanical compaction of the soils to the
specifications of structural fill or overexcavation and replacement with suitable structural fill may
be necessary.
For sizing and design considerations, it is our opinion a preliminary long-term design rate of 5
inches per hour may be considered in the native recessional outwash deposits. The native
outwash deposits have the potential to successfully facilitate the implementation of infiltration
facilities on site, provided that proper separation from the groundwater table is maintained. A
higher infiltration rate may be feasible following infiltration facility placement and targeted in-situ
infiltration testing. As part of any infiltration proposal, monitoring of seasonal high groundwater
levels (through at least one wet season) may also be prudent and/or required by the presiding
jurisdiction.
Site Preparation and Earthwork
Initial site preparation activities will consist of installing temporary erosion control measures,
establishing grading limits, and clearing and stripping the site (as necessary). Subsequent
earthwork procedures will likely involve grading activities and related infrastructure
improvements.
Temporary Erosion Control
The following temporary erosion and sediment control (TESC) Best Management Practices
(BMPs) are offered:
Temporary construction entrances and drive lanes, consisting of at least six inches of
quarry spalls, should be considered to both minimize off-site soil tracking and provide a
stable access entrance surface. Placement of a geotextile fabric beneath the quarry spalls
will provide greater stability, if needed.
Silt fencing should be placed around the site perimeter.
When not in use, soil stockpiles should be covered or otherwise protected.
Temporary measures for controlling surface water runoff, such as interceptor trenches,
sumps, or interceptor swales, should be installed prior to beginning earthwork activities.
Dry soils disturbed during construction should be wetted to minimize dust.
When appropriate, permanent planting or hydroseeding will help to stabilize site soils.
Additional TESC BMPs, as specified by the project civil engineer and indicated on the plans,
should be incorporated into construction activities. TESC BMPs may be modified during
construction as site conditions require and as approved by the site erosion control lead.
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Earth Solutions NW, LLC
Excavations and Slopes
Excavation activities are likely to expose medium dense soil (both fill and native). Based on the
soil conditions observed at the test pit locations, a maximum allowable temporary slope inclination
of one-and-one-half horizontal to one vertical (1.5H:1V) inclination is recommended. Per Federal
Occupation Safety and Health Administration and Washington Industrial Safety and Health Act
guidelines, the on-site soil should be considered a Type C soil.
The presence of perched groundwater may cause localized sloughing of temporary slopes. An
ESNW representative should observe temporary and permanent slopes to confirm the slope
inclinations are suitable for the exposed soil conditions and to provide additional excavation and
slope recommendations, as necessary. If the recommended temporary slope inclinations cannot
be achieved, temporary shoring may be necessary to support excavations. Permanent slopes
should be planted with vegetation to both enhance stability and minimize erosion and should
maintain a gradient of 2H:1V or flatter.
In-situ and Imported Soils
From a geotechnical standpoint, in general, our field observations indicate on-site soils likely to
be encountered during construction will be suitable for use as structural fill, provided the soil
moisture content is at (or slightly above) the optimum level at the time of placement and
compaction. Successful use of on-site soils as structural fill will largely be dictated by the
moisture content at the time of placement and compaction. It should be noted on-site soils are
generally well drained and are not considered moisture sensitive.
Imported soil intended for use as structural fill should consist of a well-graded, granular soil with
a moisture content that is at (or slightly above) the optimum level. During wet weather conditions,
imported soil intended for use as structural fill should consist of a well-graded, granular soil with
a fines content of 5 percent or less (where the fines content is defined as the percent passing the
Number 200 sieve, based on the minus three-quarter-inch fraction).
Structural Fill
Structural fill placed and compacted during site grading activities should meet the following
specifications and guidelines:
Structural fill material Granular soil*
Moisture content At or slightly above optimum**
Relative compaction (minimum) 95 percent (Modified Proctor)
Loose lift thickness (maximum) 12 inches
* Existing on-site soil may not be suitable for use as structural fill, unless at or near the optimum moisture content
at the time of placement and compaction.
** Soil shall not be placed dry of optimum and should be evaluated by ESNW during construction.
Gilroy Family Five, LLC ES-1259.03
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Earth Solutions NW, LLC
With respect to underground utility installations and backfill, local jurisdictions may dictate the soil
type(s) and compaction requirements. We recommend removing any unsuitable material or
debris from structural areas, if encountered.
Subgrade Preparation
Foundations should be constructed on competent native soil or structural fill placed directly atop
competent native soil. Loose or unsuitable soil conditions encountered below areas of footing
and slab elements should be remedied as recommended in this report. Uniform compaction of
the foundation and slab subgrade areas will establish a relatively consistent subgrade condition
below the foundation and slab elements. ESNW should observe the foundation and slab
subgrade prior to placing formwork. Supplementary recommendations for subgrade
improvement can be provided at the time of construction and would likely include further
mechanical compaction effort and/or overexcavation and replacement with suitable structural fill.
Foundations
Based on the findings of our investigation, the proposed self-storage building structure may be
supported on conventional continuous and spread footing foundations bearing on either compact
structural fill (including suitable or re-compacted fill placed during past grading activities) or
competent native soil. In general, competent soils suitable for support of the new foundation
should be encountered within the upper two to three feet of existing grades. In any case, where
loose or unsuitable soil conditions are exposed at foundation subgrade elevations, mechanical
compaction of the soils to the specifications of structural fill or overexcavation and replacement
with suitable structural fill may be necessary. Provided foundations will be supported as
prescribed above, the following parameters may be used for design:
Allowable soil bearing capacity 3,000 psf
Passive earth pressure 300 pcf (equivalent fluid)
Coefficient of friction 0.40
A one-third increase in the allowable soil bearing capacity may be assumed for short-term wind
and seismic loading conditions. The above passive pressure and friction values include a factor-
of-safety of 1.5. With structural loading as expected, total settlement in the range of one inch and
differential settlement of about one-half inch is anticipated. Most of the anticipated settlement
should occur during construction as dead loads are applied.
Seismic Design
The 2018 International Building Code (2018 IBC) recognizes the most recent edition of the
Minimum Design Loads for Buildings and Other Structures manual (ASCE 7-16) for seismic
design, specifically with respect to earthquake loads. Based on the soil conditions encountered
at the test pit locations, the parameters and values provided below are recommended for seismic
design per the 2018 IBC.
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Earth Solutions NW, LLC
Parameter Value
Site Class D*
Mapped short period spectral response acceleration, S S (g) 1.28
Mapped 1-second period spectral response acceleration, S 1 (g) 0.462
Short period site coefficient, Fa 1.0
Long period site coefficient, Fv 1.838†
Adjusted short period spectral response acceleration, S MS (g) 1.28
Adjusted 1-second period spectral response acceleration, S M1 (g) 0.849†
Design short period spectral response acceleration, S DS (g) 0.853
Design 1-second period spectral response acceleration, S D1 (g) 0.566†
* Assumes medium dense native soil conditions, encountered to a maximum depth of eight feet bgs during the
April 2021 field exploration, remain medium dense to at least 100 feet bgs.
† Values assume Fv may be determined using linear interpolation per Table 11.4-2 in ASCE 7-16.
As indicated in the table footnote, several of the seismic design values provided above are
dependent on the assumption that site-specific ground motion analysis (per Section 11.4.8 of
ASCE 7-16) will not be required for the subject project. ESNW recommends the validity of this
assumption be confirmed at the earliest available opportunity during the planning and early
design stages of the project. Further discussion between the project structural engineer, the
project owner, and ESNW may be prudent to determine the possible impacts to the structural
design due to increased earthquake load requirements under the 2018 IBC. ESNW can provide
additional consulting services to aid with design efforts, including supplementary geotechnical
and geophysical investigation, upon request.
The referenced liquefaction susceptibility map indicates the site and surrounding areas maintain
very low liquefaction susceptibility. Liquefaction is a phenomenon where saturated and loose
soils suddenly lose internal strength and behave as a fluid. This behavior is in response to
increased pore water pressures resulting from an earthquake or other intense ground shaking.
In our opinion, site susceptibility to liquefaction can be considered low. The soil gradation, the
relative density of native soils, and the absence of a uniformly established, shallow groundwater
table were the primary bases for this opinion.
Slab-on-Grade Floors
Slab-on-grade floors for the proposed building structure should be supported on a well-
compacted, firm, and unyielding subgrade. Existing fill and native soils exposed at the slab-on-
grade subgrade level can likely be compacted in situ to the specifications of structural fill.
Unstable or yielding areas of the subgrade should be recompacted, or overexcavated and
replaced with suitable structural fill, prior to slab construction.
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Earth Solutions NW, LLC
A capillary break consisting of a minimum of four inches of free-draining crushed rock or gravel
should be placed below the slab. The free-draining material should have a fines content of 5
percent or less (where the fines content is defined as the percent passing the Number 200 sieve,
based on the minus three-quarter-inch fraction). In areas where slab moisture is undesirable,
installation of a vapor barrier below the slab should be considered. If a vapor barrier is to be
utilized, it should be a material specifically designed for use as a vapor barrier and should be
installed in accordance with the specifications of the manufacturer.
Retaining Walls
Retaining walls must be designed to resist earth pressures and applicable surcharge loads. The
following parameters may be used for design:
Active earth pressure (unrestrained condition) 35 pcf (equivalent fluid)
At-rest earth pressure (restrained condition) 55 pcf
Traffic surcharge* (passenger vehicles) 70 psf (rectangular distribution)
Passive earth pressure 300 pcf (equivalent fluid)
Coefficient of friction 0.40
Seismic surcharge 7H**
* Where applicable
** Where H equals the retained height (in feet)
The above design parameters are based on a level backfill condition and level grade at the wall
toe. Revised design values will be necessary if sloping grades are to be used above or below
retaining walls. Additional surcharge loading from adjacent foundations, sloped backfill, or other
relevant loads should be included in the retaining wall design.
Retaining walls should be backfilled with free-draining material that extends along the height of
the wall and a distance of at least 18 inches behind the wall. The upper 12 inches of the wall
backfill may consist of a less permeable soil, if desired. A perforated drain pipe should be placed
along the base of the wall and connected to an approved discharge location. A typical retaining
wall drainage detail is provided on Plate 3. If drainage is not provided, hydrostatic pressures
should be included in the wall design.
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Earth Solutions NW, LLC
Drainage
Although not encountered at the time of our subsurface exploration (April 2021), groundwater
seepage should be anticipated in deeper site excavations, particularly during the winter, spring,
and early summer months. Temporary measures to control surface water runoff and groundwater
during construction would likely involve interceptor trenches, interceptor swales, and sumps.
ESNW should be consulted during preliminary grading to both identify areas of seepage and
provide recommendations to reduce the potential for seepage-related instability.
Finish grades must be designed to direct surface drain water away from structures and slopes.
Water must not be allowed to pond adjacent to structures or slopes. In our opinion, foundation
drains should be installed along building perimeter footings. A typical foundation drain detail is
provided on Plate 4.
Preliminary Infiltration Feasibility
As indicated in the Subsurface section of this report, the native soil encountered during our
fieldwork was characterized primarily as medium dense outwash sand and gravel deposits. In
accordance with USDA textural analyses, the deposits are classified primarily as extremely
gravelly coarse sand. Disregarding gravel contents at the tested locations, fines contents within
the native gravelly sandy loam were about 2 to 8 percent, per USDA testing procedures and
methods.
For preliminary sizing and design considerations, a long-term infiltration rate was calculated using
the soil grain size analysis method, which is Ksat Determination Option 3 in the 2019 SWMMWW.
Based on the gradation analyses performed on representative soil samples collected during the
fieldwork, it is our opinion a preliminary long-term design rate of 5 inches per hour may be
considered in the native recessional outwash deposits.
The native outwash deposits have the potential to successfully facilitate the implementation of
infiltration facilities on site, provided that proper separation from the groundwater table is
maintained. A higher infiltration rate may be feasible following infiltration facility placement and
targeted in-situ infiltration testing. As part of any infiltration proposal, monitoring of seasonal high
groundwater levels (through at least one wet season) may also be prudent and/or required by the
presiding jurisdiction. In any case, ESNW should be contacted to review submittal designs and
to provide additional recommendations or consulting services, as necessary.
Utility Support and Trench Backfill
In our opinion, on-site soils will generally be suitable for support of utilities. Remedial measures
may be necessary in some areas to provide support for utilities, such as overexcavation and
replacement with structural fill and/or placement of geotextile fabric. Groundwater seepage may
be encountered within utility excavations, and caving of trench walls may occur where
groundwater is encountered. Depending on the time of year and conditions encountered,
dewatering or temporary trench shoring may be necessary during utility excavation and related
installations.
Gilroy Family Five, LLC ES-1259.03
May 28, 2021 Page 10
Earth Solutions NW, LLC
Native and existing fill soils encountered at the test pit locations may be suitable for use as
structural backfill in the utility trench excavations provided the soil is at or near the optimum
moisture content at the time of placement and compaction. Moisture conditioning of the soils will
likely be necessary at some locations prior to use as structural fill and may likely require the
addition of moisture due to the coarse nature of the native deposits. Each section of utility line
must be adequately supported in the bedding material. Utility trench backfill should be placed
and compacted to the specifications of structural fill as previously detailed in this report or to the
applicable specifications of the presiding jurisdiction.
Preliminary Pavement Sections
The performance of site pavements is largely related to the condition of the underlying subgrade.
To ensure adequate pavement performance, the subgrade should be in a firm and unyielding
condition when subjected to proofrolling with a loaded dump truck. Structural fill in pavement
areas should be compacted to the specifications previously detailed in this report. Soft, wet, or
otherwise unsuitable subgrade areas may still exist after base grading activities. Areas
containing unsuitable or yielding subgrade conditions will require remedial measures, such as
overexcavation and/or placement of thicker crushed rock or structural fill sections, prior to
pavement.
We anticipate new pavement sections will be subjected primarily to passenger vehicle traffic. For
lightly loaded pavement areas subjected primarily to passenger vehicles, the following
preliminary pavement sections may be considered:
A minimum of two inches of hot-mix asphalt (HMA) placed over four inches of crushed
rock base (CRB).
A minimum of two inches of HMA placed over three inches of asphalt-treated base (ATB).
Heavier traffic areas generally require thicker pavement sections depending on site usage,
pavement life expectancy, and site traffic. For preliminary design purposes, the following
pavement sections for occasional truck traffic and access roadways areas may be considered:
Three inches of HMA placed over six inches of CRB.
Three inches of HMA placed over four-and-one-half inches of ATB.
An ESNW representative should be requested to observe subgrade conditions prior to placement
of CRB or ATB. As necessary, supplemental recommendations for achieving subgrade stability
and drainage can be provided. If on-site roads will be constructed with an inverted crown,
additional drainage measures may be recommended to assist in maintaining road subgrade and
pavement stability.
Gilroy Family Five, LLC ES-1259.03
May 28, 2021 Page 11
Earth Solutions NW, LLC
Final pavement design recommendations, including recommendations for heavy traffic areas,
access roads, and frontage improvement areas, can be provided once final traffic loading has
been determined. Road standards utilized by the governing jurisdiction may supersede the
recommendations provided in this report. The HMA, ATB, and CRB materials should conform to
WSDOT specifications. All soil base material should be compacted to a relative compaction of
95 percent, based on the laboratory maximum dry density as determined by ASTM D1557.
LIMITATIONS
This report has been prepared for the exclusive use of Gilroy Family Five, LLC, and its
representatives. The recommendations and conclusions provided in this report are professional
opinions consistent with the level of care and skill that is typical of other members in the
profession currently practicing under similar conditions in this area. No warranty, express or
implied, is made. Variations in the soil and groundwater conditions observed at the test locations
may exist and may not become evident until construction. ESNW should reevaluate the
conclusions provided in this study if variations are encountered.
Additional Services
ESNW should have an opportunity to review final project plans with respect to the geotechnical
recommendations provided in this study. ESNW should also be retained to provide testing and
consultation services during construction.
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drwn.CAM
Checked KDH Date May 2021
Date 05/27/2021 Proj.No.1259.03
Plate 1
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
Vicinity Map
Stor-House Yelm
Yelm,Washington
Reference:
Thurston County,Washington
OpenStreetMap.org
NORTH
NOTE:This plate may contain areas of color.ESNW cannot be
responsible for any subsequent misinterpretation of the information
resulting from black &white reproductions of this plate.
Yelm
SITE
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drwn.CAM
Checked KDH Date May 2021
Date 05/27/2021 Proj.No.1259.03
Plate 2
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
TP-1
TP-2
TP-3
TP-4
TP-5creekstreets.e.Tract B
Existing
Parking Lot
Existing
Parking Lot
351351
351
351350
351
350
350
350
350
0 4 0 8 0 1 6 0
Sc ale in Feet1"=8 0 '
NOTE:This plate may contain areas of color.ESNW cannot be
responsible for any subsequent misinterpretation of the information
resulting from black &white reproductions of this plate.
NOTE:The graphics shown on this plate are not intended for design
purposes or precise scale measurements,but only to illustrate the
approximate test locations relative to the approximate locations of
existing and /or proposed site features.The information illustrated
is largely based on data provided by the client at the time of our
study.ESNW cannot be responsible for subsequent design changes
or interpretation of the data by others.
LEGEND
Approximate Location of
ESNW Test Pit,Proj.No.
ES-1259.03,April 2021
Subject Site
Proposed Building
Existing Building
TP-1
NORTH
Test Pit Location Plan
Stor-House Yelm
Yelm,Washington
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drwn.CAM
Checked KDH Date May 2021
Date 05/27/2021 Proj.No.1259.03
Plate 3
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
NOTES:
Free-draining Backfill should consist
of soil having less than 5 percent fines.
Percent passing No.4 sieve should be
25 to 75 percent.
Sheet Drain may be feasible in lieu
of Free-draining Backfill,per ESNW
recommendations.
Drain Pipe should consist of perforated,
rigid PVC Pipe surrounded with 1-inch
Drain Rock.
LEGEND:
Free-draining Structural Backfill
1-inch Drain Rock
18"Min.
Structural
Fill
Perforated Rigid Drain Pipe
(Surround in Drain Rock)
SCHEMATIC ONLY -NOT TO SCALE
NOT A CONSTRUCTION DRAW ING
Retaining Wall Drainage Detail
Stor-House Yelm
Yelm,Washington
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drwn.CAM
Checked KDH Date May 2021
Date 05/27/2021 Proj.No.1259.03
Plate 4
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
Slope
Perforated Rigid Drain Pipe
(Surround in Drain Rock)
18"Min.
NOTES:
Do NOT tie roof downspouts
to Footing Drain.
Surface Seal to consist of
12"of less permeable,suitable
soil.Slope away from building.
LEGEND:
Surface Seal:native soil or
other low-permeability material.
1-inch Drain Rock
SCHEMATIC ONLY -NOT TO SCALE
NOT A CONSTRUCTION DRAW ING
Footing Drain Detail
Stor-House Yelm
Yelm,Washington
Earth Solutions NW, LLC
Appendix A
Subsurface Exploration
Test Pit Logs
ES-1259.03
Subsurface conditions at the subject site were explored on April 27, 2021. Five test pits were
excavated using a trackhoe and operator retained by ESNW. The approximate locations of the
test pits are illustrated on Plate 2 of this study. The test pit logs are provided in this Appendix.
The test pits were advanced to a maximum depth of approximately eight feet bgs.
The final logs represent the interpretations of the field logs and the results of laboratory analyses.
The stratification lines on the logs represent the approximate boundaries between soil types. In
actuality, the transitions may be more gradual.
GRAVEL
AND
GRAVELLY
SOILS
CLAYEY GRAVELS, GRAVEL - SAND -
CLAY MIXTURES
WELL-GRADED SANDS, GRAVELLY
SANDS, LITTLE OR NO FINES
POORLY-GRADED SANDS,
GRAVELLY SAND, LITTLE OR NO
FINES
SILTY SANDS, SAND - SILT
MIXTURES
CLAYEY SANDS, SAND - CLAY
MIXTURES
INORGANIC SILTS AND VERY FINE
SANDS, ROCK FLOUR, SILTY OR
CLAYEY FINE SANDS OR CLAYEY
SILTS WITH SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TO
MEDIUM PLASTICITY, GRAVELLY
CLAYS, SANDY CLAYS, SILTY CLAYS,
LEAN CLAYS
ORGANIC SILTS AND ORGANIC
SILTY CLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS FINE SAND OR
SILTY SOILS
INORGANIC CLAYS OF HIGH
PLASTICITY
SILTS
AND
CLAYS
MORE THAN 50%
OF MATERIAL IS
LARGER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF MATERIAL IS
SMALLER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF COARSE
FRACTION
PASSING ON NO.
4 SIEVE
MORE THAN 50%
OF COARSE
FRACTION
RETAINED ON NO.
4 SIEVE
SOIL CLASSIFICATION CHART
(APPRECIABLE
AMOUNT OF FINES)
(APPRECIABLE
AMOUNT OF FINES)
(LITTLE OR NO FINES)
FINE
GRAINED
SOILS
SAND
AND
SANDY
SOILS
SILTS
AND
CLAYS
ORGANIC CLAYS OF MEDIUM TO
HIGH PLASTICITY, ORGANIC SILTS
PEAT, HUMUS, SWAMP SOILS WITH
HIGH ORGANIC CONTENTS
LETTERGRAPH
SYMBOLSMAJOR DIVISIONS
COARSE
GRAINED
SOILS
TYPICAL
DESCRIPTIONS
WELL-GRADED GRAVELS, GRAVEL -
SAND MIXTURES, LITTLE OR NO
FINES
POORLY-GRADED GRAVELS,
GRAVEL - SAND MIXTURES, LITTLE
OR NO FINES
SILTY GRAVELS, GRAVEL - SAND -
SILT MIXTURES
CLEAN
GRAVELS
GRAVELS WITH
FINES
CLEAN SANDS
(LITTLE OR NO FINES)
SANDS WITH
FINES
LIQUID LIMIT
LESS THAN 50
LIQUID LIMIT
GREATER THAN 50
HIGHLY ORGANIC SOILS
DUAL SYMBOLS are used to indicate borderline soil classifications.
The discussion in the text of this report is necessary for a proper understanding of the nature
of the material presented in the attached logs.
GW
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
Earth Solutions NW LLC
348.5
348.0
345.0
342.5
MC = 4.3%
MC = 4.0%Fines = 2.0%
MC = 3.6%
MC = 2.3%
GM
TPSL
GP
SP
2.0
2.5
5.5
8.0
Gray silty GRAVEL with sand, medium dense, moist (Fill)
Dark brown TOPSOIL
Brown poorly graded GRAVEL with sand, medium dense, moist
[USDA Classification: extremely gravelly coarse SAND]
Brown poorly graded SAND with gravel, medium dense, moist
Test pit terminated at 8.0 feet below existing grade. No groundwater encountered duringexcavation. No caving observed.
NOTES Surface Conditions: exposed soil
LOGGED BY AZS
EXCAVATION METHOD
EXCAVATION CONTRACTOR NW Excavating
CHECKED BY KDH
DATE STARTED 4/27/21 COMPLETED 4/27/21
SAMPLE TYPENUMBERDEPTH(ft)0
5
PAGE 1 OF 1
TEST PIT NUMBER TP-1
PROJECT NUMBER ES-1259.03
GENERAL BH / TP / WELL - 1259-3.GPJ - GINT STD US.GDT - 5/27/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOGHOLE SIZE
AT TIME OF DRILLING
LONGITUDE LATITUDE
GROUND WATER LEVELS:
PROJECT NAME Stor-House Yelm
GROUND ELEVATION 350.5 ft
46.93471 -122.58949
347.5
346.5
343.0
MC = 5.2%
MC = 3.4%
MC = 2.5%Fines = 1.0%
GM
TPSL
GW
3.5
4.5
8.0
Brown silty GRAVEL with sand, medium dense, moist (Fill)
Dark brown TOPSOIL
Brown well-graded GRAVEL with sand, medium dense, moist
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 8.0 feet below existing grade. No groundwater encountered duringexcavation. No caving observed.
NOTES Surface Conditions: exposed soil
LOGGED BY AZS
EXCAVATION METHOD
EXCAVATION CONTRACTOR NW Excavating
CHECKED BY KDH
DATE STARTED 4/27/21 COMPLETED 4/27/21
SAMPLE TYPENUMBERDEPTH(ft)0
5
PAGE 1 OF 1
TEST PIT NUMBER TP-2
PROJECT NUMBER ES-1259.03
GENERAL BH / TP / WELL - 1259-3.GPJ - GINT STD US.GDT - 5/27/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOGHOLE SIZE
AT TIME OF DRILLING
LONGITUDE LATITUDE
GROUND WATER LEVELS:
PROJECT NAME Stor-House Yelm
GROUND ELEVATION 351 ft
46.93511 -122.58946
347.5
343.0
MC = 4.7%
MC = 2.7%
MC = 3.1%
MC = 4.3%Fines = 1.6%
GM
GP
3.0
7.5
Dark brown silty GRAVEL with sand, medium dense, moist (Fill)
Brown poorly graded GRAVEL with sand, medium dense, moist
-slight caving from 3' to BOH
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 7.5 feet below existing grade. No groundwater encountered duringexcavation. Caving observed from 3.0 feet to BOH.
NOTES Surface Conditions: 2" asphalt
LOGGED BY AZS
EXCAVATION METHOD
EXCAVATION CONTRACTOR NW Excavating
CHECKED BY KDH
DATE STARTED 4/27/21 COMPLETED 4/27/21
SAMPLE TYPENUMBERDEPTH(ft)0
5
PAGE 1 OF 1
TEST PIT NUMBER TP-3
PROJECT NUMBER ES-1259.03
GENERAL BH / TP / WELL - 1259-3.GPJ - GINT STD US.GDT - 5/27/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOGHOLE SIZE
AT TIME OF DRILLING
LONGITUDE LATITUDE
GROUND WATER LEVELS:
PROJECT NAME Stor-House Yelm
GROUND ELEVATION 350.5 ft
46.93505 -122.58966
349.0
344.0
MC = 4.0%
MC = 4.4%Fines = 1.6%
MC = 3.9%
GM
GW
2.0
7.0
Brown silty GRAVEL with sand, medium dense, moist (Fill)
Brown well-graded GRAVEL with sand, medium dense, moist
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 7.0 feet below existing grade. No groundwater encountered duringexcavation. No caving observed.
NOTES Surface Conditions: 2" asphalt
LOGGED BY AZS
EXCAVATION METHOD
EXCAVATION CONTRACTOR NW Excavating
CHECKED BY KDH
DATE STARTED 4/27/21 COMPLETED 4/27/21
SAMPLE TYPENUMBERDEPTH(ft)0
5
PAGE 1 OF 1
TEST PIT NUMBER TP-4
PROJECT NUMBER ES-1259.03
GENERAL BH / TP / WELL - 1259-3.GPJ - GINT STD US.GDT - 5/27/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOGHOLE SIZE
AT TIME OF DRILLING
LONGITUDE LATITUDE
GROUND WATER LEVELS:
PROJECT NAME Stor-House Yelm
GROUND ELEVATION 351 ft
46.93503 -122.58982
348.5
343.5
MC = 3.5%
MC = 6.8%Fines = 1.4%
MC = 3.6%
GM
SP
2.0
7.0
Brown silty GRAVEL with sand, medium dense, moist (Fill)
Brown poorly graded SAND with gravel, medium dense, moist
-slight caving from 2' to BOH
[USDA Classification: gravelly coarse SAND]
Test pit terminated at 7.0 feet below existing grade. No groundwater encountered duringexcavation. Caving observed from 2.0 feet to BOH.
NOTES Surface Conditions: 2" asphalt
LOGGED BY AZS
EXCAVATION METHOD
EXCAVATION CONTRACTOR NW Excavating
CHECKED BY KDH
DATE STARTED 4/27/21 COMPLETED 4/27/21
SAMPLE TYPENUMBERDEPTH(ft)0
5
PAGE 1 OF 1
TEST PIT NUMBER TP-5
PROJECT NUMBER ES-1259.03
GENERAL BH / TP / WELL - 1259-3.GPJ - GINT STD US.GDT - 5/27/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOGHOLE SIZE
AT TIME OF DRILLING
LONGITUDE LATITUDE
GROUND WATER LEVELS:
PROJECT NAME Stor-House Yelm
GROUND ELEVATION 350.5 ft
46.93459 -122.58984
Earth Solutions NW, LLC
Appendix B
Laboratory Test Results
ES-1259.03
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
3
D100
140
Specimen Identification
1
fine
6
HYDROMETER
304
2.0
1.0
1.6
1.6
1.4
101/2
COBBLES
Specimen Identification
4
coarse
20 401.5 8 14
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GW with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GW with Sand.
USDA: Brown Gravelly Coarse Sand. USCS: SP with Gravel.
6 60
PERCENT FINER BY WEIGHTD10
2.766
6.641
2.279
3.506
0.564
22.908
15.313
10.49
10.68
1.115
GRAIN SIZE DISTRIBUTION
100
38.81
11.07
20.29
18.04
3.78
LL
TP-01
TP-02
TP-03
TP-04
TP-05
0.59
1.384
0.517
0.592
0.295
3/4
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
GRAVEL SAND
75
37.5
37.5
75
37.5
%Silt
0.57
2.08
0.96
1.94
0.96
TP-01
TP-02
TP-03
TP-04
TP-05
2 2003
Cc CuClassification
%Clay
16
PID60 D30
coarse SILT OR CLAYfinemedium
GRAIN SIZE IN MILLIMETERS
3/8 50
3.0ft.
8.0ft.
7.5ft.
4.0ft.
4.5ft.
3.00ft.
8.00ft.
7.50ft.
4.00ft.
4.50ft.
PL
PROJECT NUMBER ES-1259.03 PROJECT NAME Stor-House Yelm
GRAIN SIZE USDA ES-1259.03 STOR-HOUSE YELM.GPJ GINT US LAB.GDT 5/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
Earth Solutions NW, LLC
Report Distribution
ES-1259.03
EMAIL ONLY Gilroy Family Five, LLC
1614 – 118th Avenue Southeast
Bellevue, Washington 98005
Attention: Mr. Patrick Gilroy
APPENDIX 4
CONSTRUCTION SWPPP
Construction Stormwater General Permit (CSWGP)
Stormwater Pollution Prevention Plan
(SWPPP)
for
Shur – Stor Yelm
Prepared for:
Department of Ecology
Southwest Region
Permittee / Owner Developer Operator / Contractor
Shur – Stor Yelm Gilroy Family Five, LLC T.B.D.
XX Creek Street SE
Yelm, WA 98597
Certified Erosion and Sediment Control Lead (CESCL)
Name Organization Contact Phone Number
T.B.D.T.B.D.T.B.D.
SWPPP Prepared By
Name Organization Contact Phone Number
Jim Gibson, P.E.J.E. Gibson Consulting (360) 951-1454
SWPPP Preparation Date
June 2021
Project Construction Dates
Activity / Phase Start Date End Date
Commercial Construction Summer 2021 Spring 2022
List of Acronyms and Abbreviations
Acronym / Abbreviation Explanation
303(d)Section of the Clean Water Act pertaining to Impaired Waterbodies
BFO Bellingham Field Office of the Department of Ecology
BMP(s)Best Management Practice(s)
CESCL Certified Erosion and Sediment Control Lead
CO2 Carbon Dioxide
CRO Central Regional Office of the Department of Ecology
CSWGP Construction Stormwater General Permit
CWA Clean Water Act
DMR Discharge Monitoring Report
DO Dissolved Oxygen
Ecology Washington State Department of Ecology
EPA United States Environmental Protection Agency
ERO Eastern Regional Office of the Department of Ecology
ERTS Environmental Report Tracking System
ESC Erosion and Sediment Control
GULD General Use Level Designation
NPDES National Pollutant Discharge Elimination System
NTU Nephelometric Turbidity Units
NWRO Northwest Regional Office of the Department of Ecology
pH Power of Hydrogen
RCW Revised Code of Washington
SPCC Spill Prevention, Control, and Countermeasure
su Standard Units
SWMMEW Stormwater Management Manual for Eastern Washington
SWMMWW Stormwater Management Manual for Western Washington
SWPPP Stormwater Pollution Prevention Plan
TESC Temporary Erosion and Sediment Control
SWRO Southwest Regional Office of the Department of Ecology
TMDL Total Maximum Daily Load
VFO Vancouver Field Office of the Department of Ecology
WAC Washington Administrative Code
WSDOT Washington Department of Transportation
WWHM Western Washington Hydrology Model
Project Information (1.0)
Project/Site Name: Shur – Stor Yelm
Street/Location: XX Creek Street SE
City: Yelm State: WA Zip code: 98597
Subdivision: N/A
Receiving waterbody: Yelm Creek
Existing Conditions (1.1)
Total acreage (including support activities such as off-site equipment staging yards, material
storage areas, borrow areas).
Total acreage: 1.56 acres
Disturbed acreage: 1.50 acres
Existing structures: N/A
Landscape topography: Paved and flat.
Drainage patterns: On-site generated stormwater runoff is routed to binding site plan
water quality and follow control facilies.
Existing Vegetation: N/A
Proposed Construction Activities / Project Narrative (1.2)
The proposed self-storage commercial development improvements will be constructed on Unit
1, Unit 2, and Tract A of the amended Creek Road Binding Site Plan. Specifically, the proposed
site improvements and construction activities include the following:
Site preparation, grading, and erosion control activities
Construction of a 3-story self-storage facility
Replacement/reconfiguration of the existing impervious surface parking lot
Construction of on-site stormwater facilities
Reconnection/extension of utilities (water, sewer, storm, power, etc.)
There are no known groudnwater and/or soil contaminants on the site.
“Track-out” is an illicit discharge. To prevent truck “track-out,” quarry spall construction
entrances will be installed at the construction entrance for both project sites. Brooming of tires,
wheel washing, etc. may be required to prevent “track-out.” Silt fencing and/or straw wattles will
be installed along the perimeter of both project sites. The bottom of the silt fencing shall be lined
with plastic lining to prevent filtration through the silt fencing on the south site.
Contingency Planning
In the event that the previously described construction stormwater strategies or following BMPs
fail to satisfy the permit requirements, additional measures shall be taken. Additional measures
may include, but are not limited to auxiliary treatment facilities, retention or impoundment of
untreated wastes, stopping production, or transport of untreated wastes to another treatment
facility.
Construction Stormwater Best Management Practices (BMPs) (2.0)
The purpose of a Construction Stormwater Pollution Prevention Plan (SWPPP) is to describe
the potential for pollution problems during the duration of a construction project. The SWPPP
also explains and illustrates the measures that may need to be taken on the construction site to
control said problems. The SWPPP is a guideline for the Contractor to follow during the
construction process to prevent erosion and migration of sediments. Erosion control measures
are not limited to those that are identified in this SWPPP or on the temporary erosion and
sediment control plans. Construction Best Management Practices (BMPs) shall be installed as
necessary to meet the Department of Ecology’s guidelines for construction stormwater pollution
prevention and the requirements that are set forth in the National Pollutant Discharge
Elimination System (NPDES) Permit.
This SWPPP was prepared in accordance to the established guidelines and BMPs that are set
forth in Volume 2 of the 2014 Department of Ecology Stormwater Management Manual for
Western Washington (SWMMWW). The SWMMWW describes the twelve (12) elements of
construction stormwater pollution prevention. The twelve (12) elements include the following:
Element 1 – Mark Clearing Limits
Element 2 – Establish Construction Access
Element 3 – Control Flow Rates
Element 4 – Install Sediment Controls
Element 5 – Stabilize Soils
Element 6 – Protect Slopes
Element 7 – Protect Drain Inlets
Element 8 – Stabilize Channels and Outlets
Element 9 – Control Pollutants
Element 10 – Control Dewatering
Element 11 – Maintain BMPs
Element 12 – Manage the Project
Element 13 – Protection of Low Impact Development BMPs
The SWPPP is a living document reflecting current conditions and changes throughout the life
of the project. These changes may be informal (i.e. hand-written notes and deletions). Update
the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design.
The 13 Elements (2.1)
Element 1: Preserve Vegetation / Mark Clearing Limits (2.1.1)
Prior to beginning land disturbing activities, which include site clearing and grading, the
Contractor shall mark the clearing limits (including trees) that are to be preserved within the
construction zone. High-visibility fences shall be installed/erected as shown on the temporary
erosion and sediment control plan and in accordance with the landscaping plan. The following
BMPs are applicable for this project. If the following BMPs are not shown on the construction
plan set, the Engineer reserves the right to direct the Contractor to install, construct, and/or
implement said BMPs.
BMP C101: Preserving Natural Vegetation
BMP C103: High-Visibility Plastic or Metal Fence with Backup Support
BMP C104: Stake and Wire Fence
Element 2: Establish Construction Access (2.1.2)
A stabilized construction entrance shall be constructed to minimize the tracking of sediment
onto any public road. The stabilized construction entrance shall be constructed per the TESC
plans and details and in accordance with the requirements of BMP C105.
BMP C105: Stabilized Construction Entrance
Element 3: Control Flow Rates (2.1.3)
Properties and waterways downstream from the development site shall be protected from
erosion due to increases in the volume, velocity, and/or peak flow rates of stormwater runoff
from the project site. The following BMPs are applicable for this project. If the following BMPs
are not shown on the construction plan set, the Engineer reserves the right to direct the
Contractor to install, construct, and/or implement said BMPs.
BMP C240: Sediment Trap
BMP C241: Temporary Sediment Pond
Element 4: Install Sediment Controls (2.1.4)
Prior to leaving a construction site or prior to discharging into an infiltration facility, stormwater
runoff must pass through a sediment pond or some other appropriate BMP for removal of
sediments. Silt fencing and straw bale barriers shall be constructed as shown on the temporary
and erosion sediment control plans. The following BMPs are applicable for this project. If the
following BMPs are not shown on the construction plan set, the Engineer reserves the right to
direct the Contractor to install, construct, and/or implement said BMPs.
BMP C230: Straw Bale Barrier
BMP C231: Brush Barrier
BMP C232: Gravel Filter Berm
BMP C233: Silt Fence
BMP C234: Vegetated Filter Strip
BMP C235: Straw Wattles
BMP C240: Sediment Trap
BMP C241: Temporary Sediment Pond
BMP C251: Construction Stormwater Filtration
Element 5: Stabilize Soils (2.1.5)
All exposed and unworked soils shall be stabilized by application of effective BMPs, which
protect the soil from the erosive forces of raindrop impact, flowing water, and from wind erosion.
From October 01 through April 30 of each calendar year, no soils shall remain exposed and
unworked form more than two (2) days. From May 01 to September 30 of each calendar year,
no soils shall remain exposed and unworked for more than seven (7) days. This condition
applies to all on-site soils, whether at final grade or not.
In areas where the on-site soils will remain unworked for more than the aforementioned time
duration limits or have reached final grade, seeding and mulching shall be installed in
accordance with BMP C120 and C121. Sod shall be installed in accordance with BMP C124 for
disturbed areas that require immediate vegetative cover. Dust control shall be used as needed
to prevent wind transport of dust from disturbed soil surfaces and in accordance with BMP
C140. If the following BMPs are not shown on the construction plan set, the Engineer reserves
the right to direct the Contractor to install, construct, and/or implement said BMPs.
BMP C120: Temporary and Permanent Seeding
BMP C121: Mulching
BMP C123: Plastic Covering
BMP C124: Sodding
BMP C125: Topsoiling
BMP C140: Dust Control
West of the Cascade Mountains Crest
Season Dates Number of Days Soils Can
be Left Exposed
During the Dry Season May 1 – September 30 7 days
During the Wet Season October 1 – April 30 2 days
East of the Cascade Mountains Crest, except the Central Basin*
Season Dates Number of Days Soils Can
be Left Exposed
During the Dry Season July 1 – September 30 10 days
During the Wet Season October 1 – June 30 5 days
The Central Basin*, East of the Cascade Mountain Crest
Season Dates Number of Days Soils Can
be Left Exposed
During the Dry Season July 1 – September 30 30 days
During the Wet Season October 1 – June 30 15 days
*Note: The Central Basin is defined as the portions of Eastern Washington with mean annual precipitation
of less than 12 inches.
Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on
the weather forecast.
Element 6: Protect Slopes (2.1.6)
Slopes shall be constructed in such a manner that will minimize erosion. This shall include, but
is not limited to: placing excavated material on the uphill side of trenches, collecting drainage at
the top of slopes, etc. If the following BMPs are not shown on the construction plan set, the
Engineer reserves the right to direct the Contractor to install, construct, and/or implement said
BMPs.
BMP C200: Interceptor Dike and Swale
BMP C205: Subsurface Drains
BMP C206: Level Spreader
BMP C207: Check Dams
Element 7: Protect Drain Inlets (2.1.7)
All storm drain catch basins/inlets that are in use during construction, as well as all existing
structures within the project limits, shall be protected so that stormwater runoff shall not enter
any conveyance system without first being filtered or treated to remove sediment from sediment
laden runoff. Install storm drain inlet protection devices as shown on the erosion and sediment
control plans and in accordance with BMP C220.
BMP C220: Storm Drain Inlet Protection
Element 8: Stabilize Channels and Outlets (2.1.8)
All temporary on-site conveyance channels shall be constructed and stabilized to prevent
erosion. Stabilization that is adequate to prevent erosion of outlets and drainage channels shall
be provided. If the following BMPs are not shown on the construction plan set, the Engineer
reserves the right to direct the Contractor to install, construct, and/or implement said BMPs.
BMP C202: Channel Lining
BMP C209: Outlet Protection
Provide stabilization, including armoring material, adequate to prevent erosion of outlets,
adjacent stream banks, slopes, and downstream reaches, will be installed at the outlets of all
conveyance systems.
Element 9: Control Pollutants (2.1.9)
All pollutants, including waste materials and demolition of debris, that are generated or brought
on-site during construction activities shall be handled and disposed of in a manner that does not
cause contamination of stormwater. Maintenance and repair of heavy equipment and vehicles
involving oil changes, hydraulic system drawdown, solvent and degreasing cleaning operations,
fuel tank drawdown and removal, and other activities which may result in discharge or spillage
of pollutants to the ground or into stormwater runoff must be conducted using spill prevention
measures. Contaminated surfaces shall be cleaned immediately following any discharge or spill
incident. Emergency repairs may be performed on-site using temporary plastic placed beneath
and, if raining, over the vehicle. Application of agricultural chemicals, including fertilizers and
pesticides, shall be conducted in a manner and at application rates that will not result in loss of
chemical(s) to stormwater runoff. Manufacturers’ recommendations shall be followed for
application rates and procedures. The following Source Control BMPs will be
prepared/implemented by the Contractor for this project.
A Spill Prevention Plan
Maintenance of storm drainage facilities
Street sweeping at an interval that’s prescribed by the authority having jurisidction
Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches,
streets, or streams. Excess concrete must not be dumped on-site, except in designated
concrete washout areas with appropriate BMPs installed.
Element 10: Control Dewatering (2.1.10)
Clean, non-turbid dewatered water, as determined by the Certified Professional in Erosion and
Sediment Control, can be discharged to systems tributary to state surface waters, provided the
dewatering flow does not cause erosion or flooding to receiving waters.
Highly turbid or otherwise contaminated dewatered water that’s from construction equipment
operation, clamshell digging, concrete tremie pour, or work inside a cofferdam, shall be handled
separately from stormwater at the site. Some disposal options, depending on site constraints,
may include:
Transport off-site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner
that does not pollute State waters
On-site treatment using chemical treatment or other suitable treatment technologies
Sanitary sewer discharge with local sewer district’s approval if there is no other option
Element 11: Maintain BMPs (2.1.11)
All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained
and repaired as needed to ensure continued performance of their intended function.
Maintenance and repair shall be conducted in accordance with each particular BMP
specification (see Volume II of the SWMMWW or Chapter 7 of the SWMMEW).
Visual monitoring of all BMPs installed at the site will be conducted at least once every calendar
week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the
site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to
once every calendar month.
All temporary ESC BMPs shall be removed within 30 days after final site stabilization is
achieved or after the temporary BMPs are no longer needed.
Trapped sediment shall be stabilized on-site or removed. Disturbed soil resulting from removal
of either BMPs or vegetation shall be permanently stabilized.
Additionally, protection must be provided for all BMPs installed for the permanent control of
stormwater from sediment and compaction. BMPs that are to remain in place following
completion of construction shall be examined and restored to full operating condition. If
sediment enters these BMPs during construction, the sediment shall be removed and the facility
shall be returned to conditions specified in the construction documents.
Element 12: Manage the Project (2.1.12)
The project will be managed based on the following principles:
Projects will be phased to the maximum extent practicable and seasonal work limitations
will be taken into account.
Inspection and monitoring:
o Inspection, maintenance and repair of all BMPs will occur as needed to ensure
performance of their intended function.
o Site inspections and monitoring will be conducted in accordance with Special
Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map.
Sampling station(s) are located in accordance with applicable requirements of
the CSWGP.
Maintain an updated SWPPP.
o The SWPPP will be updated, maintained, and implemented in accordance with
Special Conditions S3, S4, and S9 of the CSWGP.
As site work progresses the SWPPP will be modified routinely to reflect changing site
conditions. The SWPPP will be reviewed monthly to ensure the content is current.
Table 6 – BMP Implementation Schedule
Phase of Construction
Project Stormwater BMPs Date Wet/Dry
Season
[Insert construction
activity]
[Insert BMP][MM/DD/YYYY][Insert
Season]
Phase of Construction
Project Stormwater BMPs Date Wet/Dry
Season
[Insert construction
activity]
[Insert BMP][MM/DD/YYYY][Insert
Season]
Element 13: Protect Low Impact Development (LID) BMPs (2.1.13)
Protect all biofiltration swale and detention pond BMPs from sedimentation through installation
and maintenance of erosion and sediment control BMPs on portions of the site that drain into
the biofiltration swale and/or detention pond. Restore BMPs to their fully functioning condition if
they accumulate sediment during construction. Restoring the BMP must include removal of
sediment and any sediment-laden swale and/or pond soils, and replacing the removed soils with
soils meeting the design specification.
Prevent compacting the biofiltration soil and detention pond BMPs by excluding construction
equipment and foot traffic. Protect completed lawn and landscaped areas from compaction due
to construction equipment. Keep all heavy equipment off existing soils under LID facilities that
have been excavated to final grade to retain the infiltration rate of the soils.
BMP C102: Buffer Zone
BMP C103: High Visibility Fence
BMP C200: Interceptor Dike and Swale
BMP C201: Grass-Lined Channels
BMP C207: Check Dams
BMP C208: Triangular Silt Dike
BMP C231: Brush Barrier
BMP C233: Silt Fence
BMP C234: Vegetated Strip
Pollution Prevention Team (3.0)
Table 7 – Team Information
Title Name(s)Phone Number
Certified Erosion and
Sediment Control Lead
(CESCL)
Resident Engineer
Emergency Ecology
Contact
Emergency Permittee/
Owner Contact
Non-Emergency Owner
Contact
Monitoring Personnel
Ecology Regional Office Southwest Regional Office (360) 742-9751
Monitoring and Sampling Requirements (4.0)
Monitoring includes visual inspection, sampling for water quality parameters of concern, and
documentation of the inspection and sampling findings in a site log book. A site log book will be
maintained for all on-site construction activities and will include:
A record of the implementation of the SWPPP and other permit requirements
Site inspections
Stormwater sampling data
The site log book must be maintained on-site within reasonable access to the site and be made
available upon request to Ecology or the local jurisdiction.
Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See
CSWGP Special Condition S8 and Section 5 of this template.
Complete the following paragraph for sites that discharge to impaired waterbodies for fine
sediment, turbidity, phosphorus, or pH:
Site Inspection (4.1)
Site inspections will be conducted at least once every calendar week and within 24 hours
following any discharge from the site. For sites that are temporarily stabilized and inactive, the
required frequency is reduced to once per calendar month.
The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with
the applicable requirements of the CSWGP.
Stormwater Quality Sampling (4.2)
Turbidity Sampling (4.2.1)
Requirements include calibrated turbidity meter or transparency tube to sample site discharges
for compliance with the CSWGP. Sampling will be conducted at all discharge points at least
once per calendar week.
Method for sampling turbidity:
Table 8 – Turbidity Sampling Method
Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size)
Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size)
The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency
less than 33 centimeters.
If the discharge’s turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to
or greater than 6 cm, the following steps will be conducted:
1. Review the SWPPP for compliance with Special Condition S9. Make appropriate
revisions within 7 days of the date the discharge exceeded the benchmark.
2. Immediately begin the process to fully implement and maintain appropriate source
control and/or treatment BMPs as soon as possible. Address the problems within 10
days of the date the discharge exceeded the benchmark. If installation of necessary
treatment BMPs is not feasible within 10 days, Ecology may approve additional time
when the Permittee requests an extension within the initial 10-day response period.
3. Document BMP implementation and maintenance in the site log book.
If the turbidity exceeds 250 NTU or the transparency is 6 cm or less at any time, the following
steps will be conducted:
1. Telephone or submit an electronic report to the applicable Ecology Region’s
Environmental Report Tracking System (ERTS) within 24 hours.
https://www.ecology.wa.gov/About-us/Get-involved/Report-an-environmental-issue
Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, Yakima):
(509) 575-2490
Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant,
Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400
Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish,
Whatcom): (425) 649-7000
Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis,
Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300
2. Immediately begin the process to fully implement and maintain appropriate source
control and/or treatment BMPs as soon as possible. Address the problems within 10
days of the date the discharge exceeded the benchmark. If installation of necessary
treatment BMPs is not feasible within 10 days, Ecology may approve additional time
when the Permittee requests an extension within the initial 10-day response period
3. Document BMP implementation and maintenance in the site log book.
4. Continue to sample discharges daily until one of the following is true:
Turbidity is 25 NTU (or lower).
Transparency is 33 cm (or greater).
Compliance with the water quality limit for turbidity is achieved.
o 1 - 5 NTU over background turbidity, if background is less than 50 NTU
o 1% - 10% over background turbidity, if background is 50 NTU or greater
The discharge stops or is eliminated.
pH Sampling (4.2.2)
pH monitoring is required for “Significant concrete work” (i.e. greater than 1000 cubic yards
poured concrete or recycled concrete over the life of the project).The use of engineered soils
(soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln
dust [CKD] or fly ash) also requires pH monitoring.
For significant concrete work, pH sampling will start the first day concrete is poured and
continue until it is cured, typically three (3) weeks after the last pour.
For engineered soils and recycled concrete, pH sampling begins when engineered soils or
recycled concrete are first exposed to precipitation and continues until the area is fully
stabilized.
If the measured pH is 8.5 or greater, the following measures will be taken:
1. Prevent high pH water from entering storm sewer systems or surface water.
2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate
technology such as carbon dioxide (CO2) sparging (liquid or dry ice).
3. Written approval will be obtained from Ecology prior to the use of chemical treatment
other than CO2 sparging or dry ice.
Method for sampling pH:
Table 8 – pH Sampling Method
pH meter
pH test kit
Wide range pH indicator paper
Reporting and Record Keeping (6.0)
Record Keeping (6.1)
Site Log Book (6.1.1)
A site log book will be maintained for all on-site construction activities and will include:
A record of the implementation of the SWPPP and other permit requirements
Site inspections
Sample logs
Records Retention (6.1.2)
Records will be retained during the life of the project and for a minimum of three (3) years
following the termination of permit coverage in accordance with Special Condition S5.C of the
CSWGP.
Permit documentation to be retained on-site:
CSWGP
Permit Coverage Letter
SWPPP
Site Log Book
Permit documentation will be provided within 14 days of receipt of a written request from
Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when
requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP.
Updating the SWPPP (6.1.3)
The SWPPP will be modified if:
Found ineffective in eliminating or significantly minimizing pollutants in stormwater
discharges from the site.
There is a change in design, construction, operation, or maintenance at the construction
site that has, or could have, a significant effect on the discharge of pollutants to waters
of the State.
The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine
additional or modified BMPs are necessary for compliance. An updated timeline for BMP
implementation will be prepared.
Reporting (6.2)
Discharge Monitoring Reports (6.2.1)
Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring
Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given
monitoring period the DMR will be submitted as required, reporting “No Discharge”. The DMR
due date is fifteen (15) days following the end of each calendar month.
DMRs will be reported online through Ecology’s WQWebDMR System.
https://www.ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Water-quality-
permits-guidance/WQWebPortal-guidance
Notification of Noncompliance (6.2.2)
If any of the terms and conditions of the permit is not met, and the resulting noncompliance may
cause a threat to human health or the environment, the following actions will be taken:
1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable
Regional office ERTS phone number (Regional office numbers listed below).
2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or
correct the noncompliance. If applicable, sampling and analysis of any noncompliance
will be repeated immediately and the results submitted to Ecology within five (5) days of
becoming aware of the violation.
3. A detailed written report describing the noncompliance will be submitted to Ecology
within five (5) days, unless requested earlier by Ecology.
Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6
cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as
required by Special Condition S5.A of the CSWGP.
Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat,
Okanogan, or Yakima County
Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin,
Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman
County
Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit,
Snohomish, or Whatcom County
Southwest Region at (360) 407-6300 for Clallam, Clark, Cowlitz, Grays Harbor,
Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum
Include the following information:
1. Your name and / Phone number
2. Permit number
3. City / County of project
4. Sample results
5. Date / Time of call
6. Date / Time of sample
7. Project name
In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will
be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH
water.
APPENDIX 5
2007 CREEK ROAD MIXED USE STORMWATER REPORT
SOUND ENGINEERING, INC.
civil engineers• land planners
PRELIMINARY STORMWATER
SITE PLAN
FOR
CREEK ROAD MIXED USE
TACOMA, WASHINGTON
SEPTEMBER 2007
PREPARED FOR:
YELM CREEK BUILDINGS, LLC
240 STADIUM WAY SOUTH
TACOMA, WA 98402
PREPARED BY:
JAMEY BARR, E.I., PROJECT ENGINEER
SOUND ENGINEERING, INC.
1102 COMMERCE S'PREET, SUITE 300
TACOMA, WA 98402
253) 573 -0040
i :UY 06 ,'))
PROFCe 07118.10 DATED 11.07
PRELIMINARY STORMWATER SITE PLAN
M81All
CREEK ROAD MIXED USE
YELM, WASHINGTON
November 2007
Prepared For:
Yelm Creek Buildings, LLC
240 Stadium Way South
Tacoma, WA 98402
Prepared By:
Jamey Barr, Project Engineer
Approved By:
Timothy D. Holderman, P.E., Principal
REPORT #07118.10
EXPIRES: 1023/
This analysis is based on data and records either supplied to or obtained by Sound Engineering,
Inc. These documents are referenced within the text of the analysis. This analysis has been
prepared utilizing procedures and practices within the standard accepted practices of the industry.
SOUND ENGINEERING, INC.
TABLE OF CONTENTS
t Page
1.0 Project Overview ........................................................................................ ............................... 1
1.1 Project Location and Minimum Requirements ....................................... ............................... i
1.2 Project Descript ion ................................................................................. ............................... 2
1
2.0 Existing Conditions Summary ............................................................... ............................... 3
3.0 Off -Site Analysis ........................................................................................ ............................... 4
4.0 Permanent Stormwater Control Plan .......................................................... ............................... 4
4.1 Pre- developed Site Hydrology ............................................................... ............................... 4
4.2 Developed Site Hydrology ..................................................................... ............................... 4
4.3 Performance Standards and Goals ........................................................ ................_.............. 6
4.4 Flow Control System ............................................................................. ............................... 6
4.5 Water Quality System ............................................................................ ............................... 7
4.6 Conveyance System Analysis and Design ............................................. ............................... 8
5.0 Discussion of Minimum Requirements ...................................................... ............................... 8
6.0 Operation and Maintenance Manual .......................................................... ............................... 9
7.0 Special Reports and Studies ....................................................................... ............................... 9
8.0 Bond Quantities Worksheet ....................................................................... ............................... 9
Appendix A General Exhibits
A -1 Vicinity Map
A -2 Assessors Map
A -3 Soil Map
A -4 Soils Description
1 Appendix B Geotechnical Report
1 Appendix C Water Quality Treatment
C -1 Contech Stormwater Solutions stormfilter details
Appendix D Basin and Infiltration Trench Calculations
D -1 Basin Maps
D -2 W WHM calculations
i
J
1.0 PROJECT OVERVIEW
1.1 Project Location and Minimum Requirements
This report has been prepared as part of requirements for Site Plan Review for the Creek
Road mixed use project, as submitted to the City of Yelm. The site Address is 10520
Creek Rd. SE, Yelm WA, 98567
Section 29 Township 17 Range 2E
General site located is at the northeast comer of Creek Road, and Yelm Ave. (SR 507),
the parcel numbers are PARCEL 'A'— 64303400400, and PARCEL 'B'— 64303400501.
See associated topographic boundary survey as submitted with the plan set. Also see
vicinity map provided within Appendix `A'.
All storm drainage requirements have been designed according to the 2005 Stormwater
Management Manual for Western Washington. Stormwater runoff from the developed
site will be collected and conveyed via tighlined systems to one of four infiltration trench
beds. Prior to release into the trenches, pollution generating surface runoff is designed to
be conveyed through the required "Conteeh" Stormwater Solutions stoanfilter vaults.
Minimum requirements as listed in Volume l of the 2005 Stormwater Management
Manual for Western Washington are:
1. Preparation of Stormwater Site Plans
2. Construction Stormwater Pollution Prevention (SWPPP)
t
1
1
1
1
1
1
3. Source Control of Pollution
4. Preservation of Natural Drainage Systems and Outfalls
5. On -site Stormwater Management
6. Runoff Treatment
7. Flow Control
8. Wetlands Protection
9. Basin/Watershed Planning
10. Operation and Maintenance
1.2 Project Description
The proposal is to construct a 164 -unit multi - family residential and two commercial /retail
strip buildings totaling 16,740 square feet. The total site area is approximately 11.06
acres. The development will include stormwater facilities, utilities, public and private
roadways, parking lots and open space. In addition, a commercial development of three
buildings totaling approximately 28,800 square feet and approximately 6.02 acres on the
tax parcels known as 64303400501 and 64303400502 will be incorporated in the design
of the aforementioned development.
The proposed storm drain systems onsite have been broken into 4 sub basins which will
collect and convey all pollution generating stomr water runoff from the paved areas to a
2
stomrfilter manhole or vault by Contech Stormwater Solutions, for water quality
treatment, then to the associated infiltration bed. Runoff from nonpollution generating
surfaces will be collected and conveyed directly to associated infiltration bed. Roof
runoff from several units to the east side of the site will be conveyed directly to wetland
buffer which is to remain undisturbed, via dispersal trenches. Runoff from the existing
adjacent site is designed to be treated via a bioswale then released into the existing
retention facility. Minor disturbance to the existing bioswale is required in order to
construct the adjacent site parking areas, it is to be slightly regraded and replanted in
place.
2.0 EXISTING CONDITIONS SUMMARY
The project parcels are bordered to the west by Creek Road and to the south by Yelm Ave
SR 507). An existing commercial building with associated parking areas, and runoff
treatment and infiltration facilities exists onsite to the south. To the north an existing
lumber yard, with associated access and parking exists. The eastern side of the site
development area abuts Yelm Creek. All construction is proposed outside of the buffer
zone for the creek.
The site is predominantly covered by mid sized grass and vegetation historically used as
agricultural pasture. Runoff sheet flows naturally at a slight slope of approximately 1%
from the west to the east. A couple existing residences exist onsite which are to be
demolished. A Geotechnical study was performed by GeoResources, see Appendix B'.
3
Soils onsite are mapped as Spanaway gravelly sandy loam (I10) and Spanaway stony
sandy loam (l 12) by NCRS — SCS (Thurston County Soil Conservation Survey).
3.0 OFF -SITE ANALYSIS
Runoff from the site sheet flows to the east to the Yelm Creek, where it then flows to the
south within the creek. Due to highly permeable soils found onsite it is likely that much
of the existing runoff also infiltrates and is conveyed via subsurface flows.
4.0 PERMANENT STORMWATER CONTROL PLAN
4.1 Pre - developed Site Hydrology
A roadway for access to the existing commercial building and associated parking exist on
the site to the south. A bioswale has been implemented to treat runoff from the existing
road and parking areas, and then routed to an existing infiltration pond to the south east of
the site. Runoff from the existing building is designed to be routed directly to drywells
adjacent to the building.
4.2 Developed Site Hydrology
The developed site is broken into four basins:
The first basin (Basin 1) is located to the northwest of the site, adjacent to Creek Road.
Stormwater runoff generated by roadway, sidewalk and parking areas will be collected
and conveyed to a 72" Contech Stormwater Solutions Stormfilter manhole housing 5
cartridges for water quality treatment. Flow is then conveyed to infiltration trench bed
A' which consists of 2, 125' long x 6' wide trenches hydraulically connected. See
Appendix `D' for basin exhibits, calculations, and details.
4
The second basin (Basin 2) encompasses a majority of the north parcel directly to the east
of Basin 1 and adjacent to Yelm Creek. Stormwater runoff generated by roadway,
1
sidewalk and parking areas will be collected and conveyed to one of the two 6'x12'
Stormfilter vaults housing 16 total cartridges for water quality treatment. Flow is then
conveyed to infiltration trench bed `B' which consists of 5, 150' long x 8' wide trenches
hydraulically connected. See Appendix `D' for Basin exhibits, calculations, and details.
The third Basin (Basin 3) is located directly to the south of Basin 2, and adjacent to Yetm
Creek. Stormwater runoff generated by roadway, sidewalk and parking areas will be
collected and conveyed to a Contech Stormwater Solutions 72" Stormfitter manhole
housing 5 cartridges for water quality treatment. Flow is then conveyed to infiltration
trench bed `C' which consists of 3, 125' tong x 6' wide trenches hydraulically connected.
See Appendix `D' for basin exhibits, calculations, and details.
The fourth basin (Basin 4) is located to the south and west of the existing access road
constructed through the site, 160'" Avenue SE. Stormwater runoff generated by roadway,
1 sidewalk and parking areas will be collected and conveyed to a Contech Stormwater
Solutions 72" Stormfitter manhole housing 4 cartridges for water quality treatment. Is
then conveyed to infiltration trench bed `d' which consists of 1, 125' long x 6' wide
trench. See Appendix `D' for basin exhibits, calculations, and details.
Additional roof runoff from the eastern most apartments, #5 & 6, and the apartment office
building have been designed to disperse runoff to their natural discharge location via
appropriately sized dispersal trenches located along the wetland boundary. Per Vol. III
sec. 3.1.2 of the 2005 D.O.E. Stormwater Management Manual for Western Washington.
i 5
SL
4.3 Performance Standards and Goals
Infiltration trench bed facilities and dispersion trenches for roof drainage will be
implemented in accordance with minimum requirement #5 On -site Stormwater
Management Vol. I sec. 2.5.5 of the 2005 D.O.E. Stormwater Management Manual for
Western Washington.
Contech Stormwater Solutions Stormfilter facilities will be implemented in accordance
with minimum requirement #6, Runoff Treatment Vol. 1 sec 2.5.6 of the above
referenced manual. This satisfies the required `Basic treatment" facilities per Vol. 1 sec.
4.2.
4.4 Flow Control System
Storm runoff generated by proposed impervious surfaces onsite is designed to be
infiltrated within the previously discussed infiltration trench beds. Doing so satisfies on-
site Stormwater Management requirements for flow control.
Several test pits were dug to accurately analyze the groundwater elevations throughout
the site. Careful consideration and design of the infiltration facilities was done in order to
maintain the minimum 5' separation from the bottom of the trenches to the seasonal high
water mark. See Appendix `B' for Geotechnical analysis of test pit findings, and refer to
preliminary grading and drainage plans for trench elevations.
6
The infiltration beds were sized using the Western Washington Hydrology
Model Version 3 (WWHM3), see Appendix 'E'. The designed flow rate of 60
in /hr was provided by GeoResources, see Appendix 'B'. The long term
infiltration rate used to size the trenches was achieved by applying a safety factor
of 5 to the actual rate. Per Table 3.9 Vol. III p. 3 -80 of the 2005 D.O.E Stormwater
Management Manual jar Western Washington.
Long term rate = 60 in/hr (1/5.5) = 10.9 in/hr
Due to high permeability of the existing soils, the infiltration trenches are designed for
flow control only, see the water quality system section for treatment facility design.
4.5 Water Quality System
Contech Stormwater Solutions stormfilter structures were chosen to treat the storm water
runoff from the traveled area (travelways, puking stalls, sidewalks) of the developed site.
Each of the infiltration trenches is preceded by a stormfilter structure for the pollution
generating surface runoff. Storm filter cartridge counts were calculated using W WHM3
to generate the target water quality 15 minute flow rate, then by applying the equation:
Treatment flow)(449gpm/cfs / 15 gpm/cart.) _ # cartridges
The results are as follows:
Basin 1: Treatment flow= 0.17 cfs
Number of Required Cartridges = 5 Cartridges
Size of Stormfilter Vault =72" stormfilter manhole
7
Basin 2: Treatment flow= 0.53 cfs
Number of Required Cartridges = 16 Cartridges (total)
Size of Stormfilter Vault = (2) 6' x 12' Precast Stormfilter
Basin 3: Treatment Flow= 0.19 cfs
Number of Required Cartridges = 6 Cartridges
Size of Stormfilter Vault= 72" stormfilter manhole
Basin 4: Treatment flow= 0.08 cfs
Number of Required Cartridges = 3 Cartridges
Size of Stormfilter Vault = 48" stormfilter manhole
See Appendix 'D' for a more complete breakdown of calculations)
Runoff collected from roofs is proposed to bypass the water quality system and be routed directly
to the infiltration trench beds.
4.6 Conveyance System Analysis and Design
Conveyance calculations to be submitted with final Stormwater Site Plan.
5.0 DISCUSSION OF MINIMUM REQUIREMENTS
The Minimum Requirements have been addressed as discussed below.
1. Preparation of Stormwater Site Plans: Included herein.
2. Construction Stormwater Pollution Prevention Plan (SWPPP): To be submitted with
construction document plans.
3. Source Control of Pollution: To be submitted with construction document plans.
S4
4. Preservation of Natural Drainage Systems and Outfalls: The project does not abut a
natural drainage system or outfall, flow control is designed as infiltration.
5. On -Site Stormwater Management: Onsite infiltration trenches have been sized in
accordance with the 2005 Stormwater Management Manual for Western
Washington.
6. Runoff Treatment: Stormfiher vaults and manholes will be provided
7. Flow Control: Runoff is designed to infiltrate onsite.
8. Wetlands Protection: All development is outside the 50 buffer zone of the existing
wedand
9. Basin/Watershed Planning: NA
10. Operation and Maintenance: To be submitted with final Stormwater Site Plan.
6.0 OPERATION AND MAINTENANCE MANUAL
To be submitted with final Stormwater Site Plan,
7.0 SPECIAL REPORTS AND STUDIES
To be submitted with final Stormwater Site Plan.
8.0 BOND QUANTITIES WORKSHEET
To be submitted with final Stormwater Site Plan.
SOUND ENGINEERING, INC.
Jamey Barr
Project Engineer
APPENDIX A
General Exhibits
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III. Spanaway gravelly sandy loam, 3 to 15 percent slope., continued.
This soil is suited to year -round logging. Unsurfaced roads and skid trails are slippery when wet. Logging roads
require suitable surfacing material for year -round use. Rounded pebbles and cobbles for road construction are
readily available on this unit. Disturbance of the protective layer of duff can be minimized by the careful use of
wheeled and tracked equipment.
Seedling establishment and seedling mortality are the main concerns in the production of timber. Reforestation
can be accomplished by planting Douglas -fir seedlings. If the stand includes seed trees, natural reforestation of
cutover areas by Oregon white oak and lodgepole pine occurs infrequently, Droughtiness in the surface layer re-
duces the seedling survival rate. When openings are made in the canopy, invading brushy plants can delay the
establishment of planted Douglas -fir seedlings.
Common forest understory plants are cascade Oregon - grape, salal, western brackenfern, western swordfem, In-
dian plum, and Scotch - broom.
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112- Spanaway stony sandy loam, 0 to 3 percent slopes.
This very deep, somewhat excessively drained soil is on terraces. It is formed in glacial outwash and volcanic ash. The
native vegetation is mainly grasses, fems, and a few conifers. Elevation is 200 to 400 feet. The average annual pre-
cipitation is 40 to 50 inches, the average annual air temperature is about 51 degrees F, and the average frost -free period
is 150 to 200 days.
Typically, the surface layer is black stony sandy loam about 16 inches thick. The subsoil is very dark brown gravelly
sandy loam about 6 inches thick. The substratum to a depth of 60 inches or more is grayish brown extremely gravelly
sand.
Included in this unit are small areas of Aldersood soils on till plains, Baldhill soils on terminal moraines, and Event,
Indianola, and Nisqually soils on terraces. Also included are small areas of Spanaway soils that have a gravelly sandy
loam surface layer and small areas of Spanaway stony sandy loam that have slopes of 3 to 15 percent. Included areas
make up about 15 percent ofthe total acreage.
Permeability is moderately rapid in the subsoil of the Spanaway soil and very rapid in the substratum. Available water
capacity is low. Effective rooting depth is 60 inches or more. Runoff is slow, and the hazard of water erosion is slight.
This unit is used mainly for hayland, pasture or homesites. The main limitations affecting hay and pasture are the low
available water capacity and the stones on the surface. Proper grazing practices, weed control, and fertilizer are needed
to ensure maximum quality of forage. Rotation grazing helps to maintain the quality of the forage. Because of the sur-
face stones, spreading animal manure, mowing, and seeding are difficult. In summer, irrigation is needed for maximum
production of most forage crops. Sprinkler irrigation is the best method of applying water. The amount of water ap-
plied should be sufficient to wet the root zone but small enough to minimize the leaching of plant nutrients.
This unit is well suited to homesites. Pebbles, cobbles, and stones should be removed, particularly in areas used for
lawns. In summer, irrigation is needed for lawn grasses, shrubs, vines, shade trees, and ornamental trees. Mulch, fertil-
izer, and irrigation are needed to establish lawn grasses and other small- seeded plants. Cutbanks are not stable and are
subject to sloughing.
The main limitation affecting septic tank absorption fields is a poor filtering capacity in the substratum. If the density
of housing is moderate or high, community sewage systems are needed to prevent the contamination of water supplies
caused by seepage from onsite sewage disposal systems.
This map unity is in capability subclass IVs.
A 4-111
APPENDIX B
Geotechnical Report
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GeoResources, LLC
Ph, 255. 896 -1011 5007 Pacific Hwy. E., Ste, 20
Px. 253. 896 -2633 Fife, Washington 90424 -2648
Sound Engineering, Inc.
1102 Commerce Street, Ste. 300
Tacoma, WA 98402
Mr. Jeremy Haug
August 29, 2007
Preliminary Geotechnical Report
Creek Road Residential
Development
NE Creek Road SE
Yelm, Washington
JobNo:Avila.CreekRd. RG
INTRODUCTION
This preliminary report presents the results of our geotechnical engineering and
hydrogeologic services for the proposed Creek Road Residential site to be constructed
east of NE Creek Road and north of SR 507 in Yelm, Washington. The location of the
site is illustrated on the Vicinity Map, Figure 1.
Our understanding of the project is based on our discussions with you, our
review of the documents provided and our experience in the site area. We understand
that the site will be developed as a multi - family development with access from both
Creek Road and SR 507. The site development will include typical roadways, parking
areas, and utilities. We further understand that stormwater infiltration systems are
proposed for the site. The exact number and locations of the stormwater systems have
not been determined at this time. This report provides preliminary geotechnical
engineering recommendations and design criteria, and preliminary storm water
infiltration rates for the site. A site plan was not available at the time of our report. We
have included a general site layout as Figure 2.
Our services were provided at your request. The purpose of our services is to
evaluate the subsurface conditions at the site to develop geotechnical recommendations
and design criteria for the proposed site development, and to determine a preliminary
design infiltration rate for on -site stormwater infiltration. Specifically, our scope of services
includes the following:
1. Review the available geologic, hydrogeologic and geotechnical data for the site
area.
2. Explore the shallow subsurface conditions at the site by monitoring the
completion of a series of trackhoe test pits at the site.
3. Collect select soils samples from the explorations, several of which will be
submitted for laboratory testing.
4. Address the appropriate geotechnical regulatory requirements for the proposed
site development, per any Pierce County requirements.
S. Provide geotechnical recommendations for site grading including site
preparation, subgrade preparation, fill placement criteria, suitability of on -site
soils for use as structural fill, temporary and permanent cut and fill slopes, and
drainage and erosion control measures.
bi
nr..T I 0 1007
Avila - creek Ri
August 29, 2007
Page 2
S. Provide recommendations and design criteria for conventional foundation and
floor slab support, including allowable bearing capacity, subgrade modulus,
lateral resistance values and estimates of settlement. Specific criteria can be
provided based on your building design loads, if provided.
7. Provide recommendations and design criteria for the design of conventional
subgrade /retaining walls, including backfill and drainage requirements, lateral
design loads, and lateral resistance values.
S. Provide recommendations for pavement subgrade preparation.
9. Provide our opinion with regard to the feasibility of on -site stormwater
infiltration /dispersal, and if appropriate provide individual infiltration rates for each
system.
10. Provide appropriate IBC seismic design parameters for the proposed residential
structures.
SITE CONDITIONS
Surface Conditions
The project site is located in the central portion of the Yelm glacial oulwash plain.
The site is currently developed with a single family residence and trailer in the west,
commercial buildings in the southeast with the remaining portions as pasture land. A
BPA transmission line traverses the east portion of the site. The area is bounded by
existing commercial and residential development and vacant lots.
The site has been historically used as agricultural pasture. The southeast portion
of the site was recently developed as a commercial building with a infiltration pond to the
north. The storm water facilities are approximately 4 to 5 feet below grade. A paved
roadway traverses the south portion of the site, related to several commercial properties.
Several stockpiles of waste materials are located in the south portion of the site, likely
related to previous construction activities.
The ground surface at the site is generally flat. We observed a broad drainage
swale with localized surface water in the east portion of the site at the time of our
reconnaissance. The swale is identified as Yelm Creek which flows to the south. We
understand that a wetland area has been mapped adjacent to the creek.
The site is vegetated with pasture grass with scattered brush and isolated
evergreen trees. The northwest portion of the site has a cluster of trees. A larger
number of trees also occurs along the east drainage swale area.
Geologic Conditions
The site is situated in the central portion of the Yelm glacial oulwash plain. The
existing topography, as well as the surficial and shallow subsurface soils in the area, are
the result of the most recent Vashon stade of the Fraser glaciation that occurred
between about 12,000 and 15,000 years ago, and weathering and erosion that has
occurred since that time. A description of the surficial soils is included in the "Site
Soils" section of this report.
In general the site is underlain by Vashon glacial recessional outwash. The
recessional outwash material consists of sandy gravel with cobbles and occasional
boulders, and minor silt. The oulwash material is in a loose to medium dense condition
near the surface (0.5 feet to approximately 2 feet) and becomes medium dense to dense
below that depth. Based on our experience in the area, we expect that the site area is
underlain by glacial till at depth, likely several 10s of feet.
61
Avila — Creek Road
August 29, 2007
Page 3
Site Solis
The NCRS - SCS (Thurston County Soil Conservation Survey) has mapped the
soils in the site area as Spanaway gravelly sandy loam (110) and Spanaway stony
sandy loam (112). Both these soils are described as having a rapid permeability with a
1 "slight' erosion hazard. An isolated area of McKenna gravelly silt (65) is mapped in the
Yelm Creek area. The McKenna soils have little or no erosion hazard. A copy of the
SCS map is included as Figure 3. We observed no activeorosion in the site area during
our reconnaissance. Based on our observations, the site soils appear to have little or no
susceptibility to erosion, particularly where vegetation is established.
Subsurface Conditions
The subsurface conditions in the site area were evaluated by reviewing the
geologic maps and and monitoring the excavation of test pits at random locations across
the site. In general, recessional outwash was encountered to the full depth explored in
the ten test pit explorations that extended up to 14.0 feet. The outwash material
consisted of sandy gravel with cobbles and occasional boulders. The soil classification
method used is included as Figure 4. Copies of the test pit logs area are included Figure
I 5. Based on our site observations and experience, the soils at the site are generally
consistent.
A grain size test were performed on a soil sample collected at the likely location
and depth of an infiltration system. The grain size tests indicate the soils are poorly
graded gravelly sand (SP) with cobbles and boulders. A copy of the grain size test is
included in Appendix A.
CONCLUSIONS AND RECOMMENDATIONS
GENERAL
Based on our site observations, explorations and laboratory test results, we
conclude that the site is suitable for the proposed high density residential development. It
is also our opinion that the native site soils are suitable for the infiltration of stormwater,
provided additional explorations are completed in the proposed infiltration areas, and the
infiltration rates provided herein are confirmed. The Type A soils encountered at the site
will allow infiltration of stormwater from both the paved areas and the roof areas of the
structures.
Based on the soils encountered in the subsurface explorations at the site and our
understanding of the proposed site development, conventional earthwork and foundation
support is feasible for the project.
Pertinent conclusions and preliminary geotechnical recommendations regarding the
design and construction of the proposed residential development are presented below.
Landslide Hazards
No slopes over 15 percent occur at the site. No evidence of soil movement was
observed at the site.
Seismic Hazards
According to the Seismic Zone Map of the United States contained in Figure 16 -2
of the 1997 UBC (Uniform Building Code) and IBC (International Building Code), the
project site is located within Seismic Risk Zone 3. Based on the subsurface conditions
observed at the site, we interpret the structural site conditions to corresponds with a
seismic Soil Profile type So, (Site Class "D ") as defined by Table 16 -J (UBC) and Table
1615.1.1 in the 2003 IBC documents, respectively. These conditions were assumed to
7J
1
Avila - Creek Road
1
August 29, 2007
Page d
be representative for the conditions beyond the depths explored. Structures located at
the site that are constructed in accordance with the appropriate seismic criteria will have
the same risk as other designed structures in the Puget Sound area.
1
Erosion Hazards
Erosion hazard areas are defined by the City of Yelm as those areas defined by the
USDA Soil Conservation Service (SCS) soil survey maps as having a "slight to
moderate" erosion hazard.
The subject property is located in an area mapped by the SCS as Spanaway
stoney and gravelly sandy loam (110 and 112). It is our opinion that any potential
erosion hazard of the site soils during site development is not a limiting factor for the
proposed development. Temporary and permanent erosion control measures should be
installed and maintained during construction or as soon as practical thereafter to limit the
influx of additional water to exposed or disturbed areas.
Erosion control measures may include, but should not be limited to, berms and
swales with check dams to direct surface water runoff, ground cover /protection in
exposed areas and silt fences where appropriate. Graded areas should be shaped to
avoid concentrations of runoff onto cut or fill slopes, natural slopes or other erosion -
sensitive areas. Temporary ground cover /protection such as jute matting, excelsior
matting, wood chips or clear plastic sheeting may be used until the permanent erosion
protection is established.
EARTHWORK
The following section of this report addresses our general conclusions and
recommendations regarding site preparation, structural fill, and the re -sue of onsite soils.
Site Preparation
Areas to be graded should be cleared of deleterious matter including any existing
structures, foundations, abandoned utility lines, debris and vegetation. The portions of
the site still covered with vegetation should be stripped of any organic -laden soils. We
anticipate stripping depths to be on the order of 2 to 6 inches, although localized areas
of deeper organics may occur in areas of heavy organics or low lying areas. The
stripped topsoil may be stockpiled and later used for erosion control and
landscaping /revegetation. The areas of stockpiled material on the south portion of the
site should be considered unsuitable. Materials that cannot be used for landscaping or
erosion control should be removed from the project site.
Where placement of fill material is required, the stripped /exposed subgrade
areas should be compacted to a firm and unyielding surface prior to placement of any fill.
We recommend that trees be removed by overturning in fill areas so that a majority of
the roots are removed. Excavations for tree stump removal should be backfilled with
structural fill compacted to the densities described in the Structural Fill section of this
report.
We recommend that a member of our staff evaluate the exposed subgrade
conditions after removal of vegetation and topsoil stripping is completed and prior to
placement of structural fill. The exposed subgrade soil should be proofrolled with heavy
rubber -tired equipment during dry weather or probed with a 1/2- inch - diameter steel rod
during wet weather conditions.
Any soft, loose or otherwise unsuitable areas delineated during proofrolling or
probing should be recompacted, if practical, or over - excavated and replaced with
structural fill, based on the recommendations of our site representative.
b
Avila - Creek Road
August 29, 2007
Page 5
Structural Fill
All material placed as fill associated with mass grading or as utility trench backfill
should be placed as structural fill. The structural fill should be placed in horizontal lifts of
appropriate thickness to allow adequate and uniform compaction of each lift. Fill should
be compacted to at least 95 percent of MDD (maximum dry density as determined in,
accordance with ASTM D- 1557).
The appropriate lift thickness will depend on the fill characteristics and
compaction equipment used. We recommend that the appropriate lift thickness be
evaluated by our field representative during construction. We recommend that our
representative be present during site grading activities to observe the work and perform
field density tests.
The suitability of material for use as structural fill will depend on the gradation
and moisture content of the soil. As the amount of fines (material passing US No. 200
sieve) increases, soil becomes increasingly sensitive to small changes in moisture
content and adequate compaction becomes more difficult to achieve. During wet
weather, we recommend use of well - graded sand and gravel with less than 5 percent (by
weight) passing the US No. 200 sieve based on that fraction passing the 3/4 -inch sieve.
If prolonged dry weather prevails during the earthwork and foundation installation phase
of construction, higher fines content (up to 10 to 12 percent) will be acceptable.
Material placed for structural fill should be free of debris, organic matter, trash
and cobbles greater than 6- inches in diameter. The moisture content of the fill material
should be adjusted as necessary for proper compaction.
Suitability of On -Site Materials as Fill
During dry weather construction, any nonorganic on -site soil may be considered
for use as structural fill; provided it meets the criteria described above in the structural fill
section and can be compacted as recommended. If the material is over - optimum
moisture content when excavated, it will be necessary to aerate or dry the soil prior to
placement as structural fill. We generally did not observe the site soils to be excessively
moist at the time of our subsurface exploration program. However, laboratory test
results indicated that many of our samples had moisture contents above optimum
moisture.
The soils at the site generally consist of a fine to coarse sand with gravel,
cobbles and boulders. These soils are generally comparable to "common borrow'
material and will be suitable for use as structural fill provided the moisture content is
maintained within 2 percent of optimum moisture. However, the outwash does appear to
have a significant amount of cobbles and boulders, which may require removal in the
upper two feet of fill. Care should be taken when placing and compacting granular
material over 3 inches in size near utility lines. Fill material within 2 feet of the
foundation, slab or roadway subgrades should contain no material greater than 6 inches
in size. This will result in localize pressure points and potential cracks in the concrete.
All fill material in building and driveway areas should be placed as described in
the "Structural Fill" section of this report and compacted to at least 95 percent of the
MDD. If fill material is imported to the site for wet weather construction, we recommend
that it be clean sand and gravel mixture, such as high quality pit run with less than
5 percent fines, or crushed rock.
Cut and Fill Slopes.
Pj C
1
Avila — Creek Road
August 29, 2007
Page 5
All job site safety issues and precautions are the responsibility of the contractor
providing services /work. The following cut/fill slope guidelines are provided for planning
purposes only.
Temporary cut slopes will likely be necessary during grading operations or utility
installation. As a general guide, temporary slopes of 1.51-1:1 V (Horizontal:Vertical) or
flatter may be used for temporary cuts in the upper 3 to 4 feet of the soils that are
weathered to a loose /medium dense condition. Where ground water seepage is
encountered, flatter temporary slopes may be required. These guidelines assume that
all surface loads are kept at a minimum distance of at least one half the depth of the cut
away from the top of the slope and that significant seepage is not present on the slope
face. Flatter cut slopes will be necessary where significant raveling or seepage occurs.
We recommend a maximum slope of 2H:1 V for permanent cut and fill slopes in
areas of medium dense sand and gravel. Where 2H:1 V slopes are not feasible in these
soils, retaining structures should be considered. Where retaining structures are greater
than 4 -feet in height (bottom of footing to top of structure) or have slopes of greater than
15 percent above them, they should be engineered. It should be recognized that slopes
of this nature do ravel and require occasional maintenance. Where raveling or
maintenance is unacceptable, we recommend that flatter slopes or retaining systems be
considered.
Foundation Support
Based on the encountered subsurface soil conditions encountered across the
site, we recommend that spread footings for the new residences be founded on medium
dense native outwash soils or on structural fill that extends to suitable native soils.
The soil at the base of the excavations should be disturbed as little as possible.
All loose, soft or unsuitable material should be removed or recompacted, as appropriate.
A representative from our firm should observe the foundation excavations to determine if
suitable bearing surfaces have been prepared, particularly in the areas where the
foundation will be situated in fill material.
We recommend a minimum width of 2 feet for isolated footings and at least 16
inches for continuous wall footings for structures of two stories or less. Where taller
structures are considered, site specific recommendations for the proposed loads can be
developed.
All footing elements should be embedded at least 18 inches below grade for frost
protection. We recommend a minimum width of 2 feet for isolated footings and at least
16 inches for continuous wall footings. Footings founded as described above can be
designed using an allowable soil bearing capacity of 2,500 psf (pounds per square foot)
for combined dead and long -term live loads. The weight of the footing and any overlying
backfill may be neglected. The allowable bearing value may be increased by one -third
for transient loads such as those induced by seismic events or wind loads.
Lateral loads may be resisted by friction on the base of footings and floor slabs
and as passive pressure on the sides of footings. We recommend that an allowable
coefficient of friction of 0.35 be used to calculate friction between the concrete and the
underlying soil. Passive pressure may be determined using an allowable equivalent fluid
density of 300 pcf (pounds per cubic foot). Factors of safety have been applied to these
values.
We estimate that settlements of footings designed and constructed as
recommended will be less than 1 inch, for the anticipated load conditions, with
differential settlements between comparably loaded footings of 1/2 inch or less. Most of
the settlements should occur essentially as loads are being applied. However,
bic,
Avila — Creek Roatl
August 29, 2007
Page 7
disturbance of the foundation subgrade during construction could result in larger
settlements than predicted.
Floor Slab Support
Slabs -on- grade, if constructed, should be supported on the medium dense native
outwash soils or on structural fill prepared as described above. We recommend that
floor slabs be directly underlain by a capillary break material with minimum 6 -inch
thickness of coarse sand, pea gravel, or gravel containing less than 3 percent fines. The
drainage material should be placed in one lift and compacted to an unyielding condition.
A synthetic vapor barrier is recommended to control moisture migration through
the slabs. This is of particular importance where the foundation elements are underlain
by the silty till or lake sediments, or where moisture migration through the slab is an
issue, such as where adhesives are used to anchor carpet or tile to the slab. A thin layer
of sand may be placed over the vapor barrier and immediately below the slab to protect
the liner during steel and /or concrete placement.
A subgrade modulus of 400 kcf (kips per cubic foot) may be used for floor slab
design. We estimate that settlement of the floor slabs designed and constructed as
recommended, will be 1/2 inch or less over a span of 50 feet.
Pavement and Driveway Subgrade
We understand that asphalt pavements will likely be used for the driveways and
parking areas. All structural fill should be compacted according to our recommendations
given in the "Structural Fill" section. Specifically, the upper 2 feet of soils underlying
pavement section should be compacted to at least 95 percent of ASTM: 0 -1557, and all
soils below 2 feet should be compacted to at least 90 percent. The subgrade areas
should be proof- rolled with a loaded dump truck or heavy compactor to verify that a firm
and unyielding surface has been achieved. Any areas where this proof - rolling operation
reveals soft, organic, or pumping soils at or closely beneath the pavement subgrade
should be overexcavated to a maximum depth of 8 inches and replaced with a suitable
structural fill material.
Stormwater Infiltration Rates
Based on the soils encountered in our preliminary explorations and the results of
the grain size tests, we conclude that the infiltration of storm water is feasible at the site.
The thick underlying deposits of recessional outwash soils have adequate permeability
and storage capacity to infiltrate storm water from the site, provided adequate design,
construction and maintenance practices are used.
Preliminary storm water infiltration rates for the site soils were determined in
accordance with the Yelm/Thurston County Stormwater Manual guidelines, Table 1. Grain
size distribution tests were performed on select soil samples collected from the test pits.
The results of the grain size test are included in Appendix A.
Based on the soils observed in the test pits and the laboratory test results, it is our
opinion that a design infiltration rate of 60 inches per hour may be used for the infiltration
system if located in the shallow soils, less and 12 feet below the existing site grades. An
appropriate factor of safety should be applied to this value.
Once the locations of the infiltration systems are determined, additional
explorations will be required to verify the soils and the depths. Suspended solids could
eventually clog the soil and reduce the infiltration rate for retention ponds or trenches.
Because of the potential for clogging, we recommend that an appropriate factor of safety
be utilized in the design. To reduce potential clogging of the infiltration systems, the
0
Avila - Creek Road
August 29. 2007
Page 8
infiltration ponds or galleries should not be connected to the stormwater runoff system until
after construction is complete and the site areas are landscaped and paved. Temporary
systems may be utilized through construction, or the pond /trench bottom left a minimum of
9 -foot high during construction and later excavated to the design grade. Periodic
sweeping of the paved areas will help extend the life of the infiltration system.
LIMITATIONS
We have prepared this report for Mr. Mike Avila and the project consultants for use
in design and construction of the various components of this project. The data and report
can be utilized for bidding or estimating purposes, but our report, conclusions and
recommendations should not be construed as a warranty of the subsurface conditions, as
they may vary both vertically and laterally.
If there are changes in the locations or assumptions stated for this project, the
conclusions and recommendations presented may not be fully applicable. If design
changes are made, we should review the proposed changes to verify the applicability of
our conclusions and recommendations. Additional explorations will be required in the
stormwater infiltration areas.
Variations in subsurface conditions are possible between the explorations and
may also occur with time. Sufficient monitoring, testing and consultation should be
provided by our firm during construction to confirm that the conditions encountered are
consistent with those.indicated by the explorations, to provide recommendations for
design changes should the conditions revealed during the work differ from those antici-
pated, and to evaluate whether earthwork and foundation installation activities comply
with contract plans and specifications.
Within the limitations of scope, schedule and budget, our services have been
executed in accordance with generally accepted practices in this area at the time this
report was prepared. No other conditions, expressed or implied, should be understood.
We appreciate the opportunity to be of service to you on this project. Please call if
you have any questions regarding this submittal, or if we can provide additional services.
Yours very truly,
GeoResources, Li
SPB: GC: bite
Deco Avila,Creek$CPRG 131/0Attachments: Figure Figure 2 Site Plan
Figure 3 NRCS SCS Map
Figure 4 Sail Classification System
Figure 5 Test Pit Logs
Appendix A - Grain Size Analysis
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GeoResources, LLC Site Vicinity Map5007PacificHighwayEast, Suite 20 NE Creek RoadFife, Washington 98424
Phone: 253 - 896 -1011 Yelm, Washington
Fax: 253 - 896 -2633
File: Avlla.CreekRd September 2007 Flgure 1
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GeoResources, LLC
20 to 39 PERCENT SLOPE AREA
APPROXIMATE LOCATION TP -1 40 PERCENT OR GREATER SLOPE AREA 5007 Pacific Highway East, Suite 20
OF TEST PIT Fife, Washington 98424
Scale: 1 100'
Ph: 253-896-1011 Fax: 253-896-2633
FIGURE 2Q- Site Plan
Project : Creek Road Residential Development
Location : Yelm, Washington
Client : Mike Avila
Date : October 2007 Job #: Avila.CreakRd.SP
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eaaan naa eraw.a
GeoResources, LLC
5007 Pacific Highway East, Suite 20
Fife, Washington 98424
Phone: 253 - 896 -1011
Fax: 253 - 896 -2633
Site Layout
NE Creek Road
Yelm, Washington
Approximate Site Location
Not to Scale I
GeoResources, LLC MRCS SCS Solis Map5007PacificHighwayEast, Suite 20
NE Creek RoadFife, Washington 98424
Phone: 253 -896 -1077 Yelm, Washington
Fax: 253- 896 -2633
File: Avlla.CrsakNd.SCS September 2007 Figure 3
0.12
SOIL Oi[_ASSWiGATI6N q@/i
MAJOR DIVISIONS GROUP GROUP NAME
SYMBOL
GRAVEL CLEAN GW WELL - GRADED GRAVEL, FINE TO COARSE
GRAVEL GRAVEL
GP POORLY - GRADED GRAVELCOARSEGRAINEDMorethan50%
GRAVELWITHFINES GM SILTY GRAVEL
SOILS Of Coarse Fraction
Retained on
No, 4 Sieve
GC CLAYEY GRAVEL
More than 50% SAND CLEAN SAND SW WELL - GRADED SAND, FINE TO COARSE SAND
Retained on
No. 200 Sieve SP POORLY GRADED SAND
More than 50%
Of Coarse Fraction SAND SM SILTY SAND
Passes WITH FINES
SC CLAYEY SAND
No, 4 Sieve
SILT AND CLAY INORGANIC ML SILT
FINEGRAINED CL CLAY
SOILS Liquid Limit
Less than 50 ORGANIC OL ORGANIC SILT, ORGANIC CLAY
SILT AND CLAY INORGANIC MH SILT OF HIGH PLASTICITY, ELASTIC SILT
More than 50%
Passes CH CLAY OF HIGH PLASTICITY, FAT CLAY
No. 200 Sieve
Liquid Limit
50 or more ORGANIC OH ORGANIC CLAY, ORGANIC SILT
HIGHLY ORGANIC SOILS
I PT PEAT
NOTES:
1. Field classification is based on visual examination of 5011
in general accordance vrth ASTM D2458-90.
2. Soil classification using laboratory tests is based on
ASTM 02407 -90.
1 Description of soil density or consistency are based on
intergretaticn of blow count data visual appearance of
soils, and or test data.
SOIL MOISTURE MODIFIERS:
Dry- Absence of moisture, dry to the touch
Moist- Damp, but no v,.,,f. water
Wet- Visible free water or saturated, usually soil is
obtained from below water table
GeoResources, LLC I Soil Classification System
5007 Pacific Highway East, Suite 20 3477 Harris Road SE
Fife, Washington 98424
p County, gPhone: 253- 896 -1011 y, Washin ton
Fax: 253- 896 -2633
JOB# WilleyEstates.HarrisFid.USCS August 2007 Figure 4
1
1
1
1
t
Test Pit TP -1
Location: South center of site, south of roadway (See Figure 2)
Depth (ft.) Soil Type Description
0.0-0.5 TS Sod over Topsoil w/ gravel
0.5- 1.0 SM Dk Brn si SAND w/ gravel, cobbles (loose, moist)
1.0 - 3.0 SP Brown cobbly SAND w/ gravel, (loose to med. dense, moist)
3.0-7.0 GP Brn sdy GRAVEL w/ cobbles, boulders (med. dense to dense, moist)
7.0-12.0 SP Brn gravelly SAND w/ occ. cobbles (dense, moist)
Terminated at 12.0 feet below ground surface
Minor caving observed
No groundwater seepage observed
Test Pit TP -2
Location: Bottom of existing pond, north of commercial site (See Figure 2)
Depth (ft.) Soil Type Description
0.0 - 4.0 GP Brn sdy GRAVEL w/ cobbles, occ. boulders (dense, moist)
4.0-7.0 GP Brn sdy GRAVEL w/ cobbles, boulders (FeO Staining)(dense, moist)
7.0-11.0 SP Bin SAND w/ gravel, occ. cobbles (dense, moist to damp)
Terminated at 11.0 feet below the ground surface
Minor caving observed
No groundwater seepage observed
Test Pit TP -3
Location: South Center, North of roadway by fence (See Figure 2)
Depth (tt) Soil Type Description
0.0 - 1.0 TS Sod over Topsoil w/ gravel
1.0-2.0 SM Dk Bin si SAND w/ gravel, cobbles (loose, moist)
2.0 - 8.0 GP Brown cobbly GRAVEL w/ sand, boulders (loose to dense, moist)
8.0 - 12.5 SP Brn gravelly SAND w/ occ. cobbles (dense, moist to damp)
Terminated at 12/5 feet below the ground surface
Moderate caving observed .
No groundwater seepage observed
GeoResources, LLC Test Pit Logs
5007 Pacific Highway East, Suite 20 NW Corner Yelm Avenue SE & Creek StreetFife, Washington 98424
Phone: 253 - 896 -1011 Yelm Washingtons
Fax: 253 - 896 -2633
JOB: DevelopmentatYelm .Yelm5CornersRetail.TP May 2007 Figure 5
Test Pit TP -4
Location: Ctr east pasture area (SEE Figure 2)
Depth (ft) Soil Type Description
0.0-1.0 TS Sod over Topsoil w/ gravel
1.0 - 1.5 SM Dk Brn at SAND w/ gravel, cobbles (loose, moist)
1.5-7.0 GP Brown sdy GRAVEL w/ c bibles, boulders (loose to dense, moist)
7.0-11.5 SP rg Bm gravelly SAND ox. cobbles (Min. FeO Stain)(dense, moist to damp)
v
Terminated at 11.5 feet below the ground surface
Minor caving observed
No groundwater seepage observed, but FeO staining 8 to Oft.
VIO
Test Pit TP -5
Location: NE corner by wetland area (SEE Figure 2)
Depth (ft.) Soil Type Description
0,0 - 1.0 TS Sod over Topsoil w/ gravel, occ. cobbles
1.0 - 4.0 SM Drk Brn si SAND w/ gravel, cobbles, boulders (12 — 16 inches)
loose to m. dense, moist to wet) (appears to perch water t east)
4,0 - 14.0 SP rdrg Bm SAND w/ gravel, occ. cobbles (med. dense to dense, moist)
Terminated at 14.0 feet below the ground surface
Minor to moderate caving observed
No groundwater seepage observed, but wet 0 1.5 to 2.5 ft.
r.i!
Test Pit TP -6
Location: NW corner of east pasture (SEE Figure 2)
Depth (ft.) Soil Tvoe De ' t'on
0.0-0.8 TS Sod over Topsoil w/ gravel, occ. cobbles
0.8-2.0 GM Dk Brn si GRAVEL w/ cobbles, occ. boulders (loose to m. dense, moist) 2.0-5.0 GP Brn sdy GRAVEL w/ occ. cobbles/boulders (med. dense to dense, moist)
5.0-11.5 SP Brn gravelly SAND w/ ox. cobbles (dense, moist to damp)
Terminated at 11.5 feet below the ground surface
Minor to moderate caving observed
No groundwater seepage observed
Logged by BPB
GeoResources, LLC Test Pit Logs
5007 Pacific Highway East, Suite 20 Creek Street DevelopmentFife, Washington 98424
Phone: 253- 896 -1011 Yelm, Washington /
Fax: 253 -896 -2633 VV6—
JOB: Avila.CreekSt.TP August 2007 Figure 5
1
1
Tes¢ P1I TP° I
Location: East of trailer house, NE corner of site (SEE Figure 2)
Depth (ft.) Soil Type Description
0.0 - 1.0 TS Sod over Topsoil w/ gravel, occ. cobbles
1.0 - 2.0 SM Drk Brn si SAND w/ gravel, cobbles, boulders (12 — 16 inches)
loose to m. dense, moist)
2.0-65 GP Ong Brn sdy GRAVEL w/ occ. cobbles (dense, moist to damp)
6.5-10.6 SP Brn gravelly SAND w/ cobbles, occ. boulders (dense, moist)
Terminated at 10.5 feet below the ground surface
Minor to moderate caving observed
No groundwater seepage observed.
Test Pit TP -8
Location: NW corner of site, pasture (SEE Figure 2)
Depth ft. Soil Type Description
0.0 - 1.0 TS Sod over Topsoil w/ gravel, occ. cobbles
1.0 - 1.5 SM Drk Brn si SAND w/ gravel, cobbles, boulders (12 inches) (m. dense, moist)
1.5-55 GP Brn sdy GRAVEL w/ occ. cobbles (dense, moist to damp)
5.5-9.5 SP Brn gravelly SAND w/ cobbles, occ. boulders (dense, moist to damp)
Terminated at 9.5 feet below the ground surface
Minor to moderate caving observed
No groundwater seepage observed
Test Pit TP -9
Location: Southwest pasture area, 100 feet from house (SEE Figure 2)
Depth (ft.) Soil Type Description
0.0 - 1.0 TS Sod over Topsoil w/ gravel, occ. cobbles
1.0 - 1.5 SM Drk Brn si SAND w/ gravel, cobbles, boulders (loose to m. dense, moist)
1 . 5 - 5 0 GP Brn sdy GRAVEL w/ occ. cobbles (dense, moist to damp)
5.0 - 9.0 SP Bm gravelly SAND w/ cobbles, occ. boulders (dense, moist to damp)
Terminated at 9.5 feet below the ground surface
Minor to moderate caving observed
No groundwater seepage observed
GeoResources, LLC Test Pit Logs
5007 Pacific Highway East, Suite 20 NW Corner Yelm Avenue SE & Creek StreetFife, Washington 98424
Phone: 253 -896 -1011 Yelm , Washington
Fax: 253- 896 -2633
JOB: DevelopmentatYelm .YelmSComersRetail.TP May 2007 1 Figure 5
Test P11 TP -10
Terminated at 9.5 feet below the ground surface
Minor to moderate caving observed
No groundwater seepage observed
GeoResources, LLC Test Pit Logs
5007 Pacific Highway East, Suite 20 NW Corner Yelm Avenue SE & Creek StreetFife, Washington 98424
Phone: 253 -896 -1011 Yelm, Washington
Fax: 253- 896 -2633 yA
JOB: Developmentatyalm .yelm5ComersRstail.TP May 2007 1 Figure 5
APPENDIX "As'
5007 Pacific Highway E, Suite 20
Fiie, WA. 98424
Office (253)896 -1011 Fax (253) 696 -2633
Screen
Grain Size Analysis
Percentage
Project Number: Avila.CreekSt Date Sampled: 8/17/2007
Project Name: Creek Street Residential Plat Sampled by: BPB
Client: Mike Avila Date Tested 812212007
Sample ID: S -1 Tested by: bpb
Description: Test p8 sample, bag TP 3
rem 0.0
Mo,.". %
Screen Weight Reteinetl Percentage Spec#ication
Db =
Summa,/
InGivldual Cumulative Retainetl Passetl Max. in.
C rem 0.0 100.0%
70.2% Coarse
109_% Fine
Bid %. - _G_rab_1-
3' rem 0.0
Mo,.". %
100.0%
71/2' rem 0.0 100.0%
14' 932.5 932.5 70.2% 29.8%
W. 100.1 1032e A.7% 22.3%
4 45.3 1077.9 81.1% 18.9%
10 26.2 1104.1 83.1% 18.9% 20% Coarse
114% Medium
4.1% Fine
17.6 %4 nand
20 66.3 1170.4 0&1% 11.9%
40 85.7 1256.1 948% 5.4%
60 36.0 1292.1 97.3% 2 .7%
100 13.1 1305.2 98.3% 1.7
200 5.0 13102 98.6% 1 1.4% 1.4% Fi rIM
an
II
D. = 33.55 Deo = 24.324 Dm = 1.5671
Da, = 26.959 Db = 19.053 one = 0.7257
Cu= 37.2 Cc= 18.56
USCS Classification
Dust Ratio 0.251
Mo,.". % 2.9%
Sand Equivalent
90%
1000/6
1 34' 3/8' #4 10 #20 #00 060 0100 #200
90%
II
70% I'
r
c 50% C I'
1
rt
140%
30%
I
zz
10%
1
0%
100 10 1 0.1 0.01
Grain Sim In millimeters
Inpu4 ®eta:
Wet +Tare 1551.1
Dry +Tare 1512.7
arree 184.4
AW + Tare 1497.9
After Wash 1313.5
200 % 17
Dry Weight 1328.3
Depth:
20
Moisture 2.99/.
eve Sizes
D60 1 050
3" 75
1 -1/2" 37.5
3/4" 19
3/8" 9.5
4 4.75
10 2
20 0.85
40 0.425
60 0.25
100 0.15
200 0.075
Gravel- Sand
4.75 0
4.75 00
Sand - Silt
0.075 0
0.075 100
Parameters;
D85 D60 1 050 1 D30 D15 D10
33.54715 26.95907 24.32383 19.053371I
1.567146
0.725674
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APPENDIX C
Water Quality Treatment
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LOCAFION I I`, F,
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5EE NOTE 2) MANIFOLD
6' x 12' STORMFILTER- SECTION VIEW A T,r M111G_F1r1T
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STANDARD DETAILSpLDTIpNS_
Onl¢C SIOfmw21B'.CORi OPR.0912 &OS S O E NONE FILE NAME:SFSI 2CC -0TL CXECKEO:ARG
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GENERAL NOTES
I) 5TORMFILTER BY CON TECH 5TORMWATFR SOLUTIONS, PORTLAND, OR SOT) 5454GG7: 5CARBOROUGII. ME (877) 9075675:
ELKRIDGE, MID (065) 740 -33. B.
2) FILTER CARTMDGE(5) TO BE MPY-ON- ACTUATED AND SELF-CLEAN ING. STANDARD DETAIL DR4WING SHOWS MAXIMUM NUMBER
OF CARTRIDGES. ACTUAL NUMBER RE OUIREU TO BE SPECIFIED ON SITE PLANS OR IN DATA TABLE BELOW.
3) PRECAST VAULT TO BE CONSTRUCTED IN ACCORDANCE WITH ASTM CC 57 AND C656 . DETAIL DRAWING RFFLFCT5 GESIGN
INTENT ONLY. ACTUAL DIMENSIONS AND CONFIGURATION OF 5TRUCTURE WILL BE SHOWN ON PRODUCTION STOP DRAWING.
4) 5TRUCTURF AND ACCE55 COVERS TO MEET AA5HT0 H -20 LOAD RATING.
5) 5TORMFILTER REQUIRES 2.3 FEET OF DROP FROM INLET TO OUTLET IF LE55 DROP IS AVAILABLE , CONTACT CONTECH
5TORMWATER SOLUTIONS -
G) INLET AND OUTLET PIPING TO BE 5PEQFIFD BY ENGINEER AND PROVIDED BY CONTRACTOR. PRECAST 5TORMFILTER VAULT
EQUIPPED'01TT EITHER GORED OPENINGS OR KNOCKOUTS AT INLET AND OUTLET LOCATIONS.
7) PRO )DE MINIMUM CLEARANCE FOR MAINTENANCE ACCESS. IF A SHALLOWER 5YSTFM 15 REQUIRED. CONTACT OONTKd
5TORM WATER 50LUTION5 FOR OTHER OPTIONS.
5) ANTLFLOTATION BALLAST TO BE SPECIFIED BY ENGINEER AND PROVIDED BY CONTRACTOR, IF DECLARED, BALLAST TO OF SET
ALONG ENTIRE LENGTH OF BOTN SIDE5 OF THE STRUCTURE.
9) ALL 5TORMFILTERS REQUIRE REGULAR MAIITF ENANCE. REFER TO OPERATION AND MAINTENANCE GUIDELINES FOR MORE
INFORMATION.
30'0 FRAME AND COVER
TYP) (SEE NOTE 4)
BAFFLEWALL
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BALLASTSEENOTE B)
UNDERDRAINMANIFOLD WIDTH
6'x 12' STORMFILTER - SECTION VIEW B
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BAI AST
5EE NOTE b)
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WIDTH
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AND COVER (57C)
5EE NOTE 4)
HUPP OUTLET
R15EK WITH
SCUM BAFFLE
4' -0" MIN
SEE NOTE 7)
31
UNOERDRAINMANIFOLD
MANHOLE STORMFILTER - SECTION VIEW A
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A ITCALJ'° PRECAST 48" MANHOLE STORMFILTER
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PLAN AND SECTION VIEWS
STORMWATER
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w
COnIecM1StormWater. COm pATE1096 &55 BCALE:NONE FILE NAME:MMSF3- i0FC -0iL I pRAYVNON NJ I CuFCNFn Paf.
CA
GENERAL NOTES
1) 5TOR 011 -YER BY CONTECH 5TORMW4TER SOLUTIONS', PORTLAND. OR (8C0) 545 -4667 5CARE0ROUGF, ME Lt 77) 907 -8676.
ELKRI WE, MD (ECG) 940-331 B.
2) FILTER CARTEIEGF(5) TO BE SIPHON ACTUATED AND 5ELFCLEANIING, STANDARD DETAIL SHOWS MAXIMUM NUMBER OF
CARTRIDGES. ACTUAL NUMBER REQUIRED TO BE SPECIFIED ON SITE PLANS OR IN DATA TABIE BELOW.
3) PRECAST MANHOLE STRUCTURE TO BE CONST.RUCTEO IN ACCORDANCE WTH A5T M C478. DETAIL KEFLECT5 DESIGN INTENT
ONLY. ACTUAL DIMENSIONS AND CONFIGURATION OF STRUCTURE WILL BE SHOWN ON PRODUCTION SHOP DRAWING.
4) STRUCTURE AND ACCESS COVERS TO MEET PASHTO H -20 LOAD RATING.
5) 5TQRD PILTER REOUIRE5 2.3 FEET OF DROP FROM INLET TO OU rLET. IF LP55 DROP 15 AVAILABLE, CON FACT CONTECH
5TORMWA(E.R 5OLUTION5. MINIMUM ANGLE BETWEEN INLET AND OUTLET 1545 °.
6) INLET PIPING TO BE SPECIFIED BY ENGINEER AMC PROVIDED BY CONTRACTOR. PRECAST MANHOLE 57ORN ILTER EQUIPPED
WITH A DUAL DIAMETER HDPE OUTLET STUB AND 5AND COLLAR. EIGHT INCH DIAMETER OUTLET SECTION MAY BE SEPARATED
FROM OUTLET 5TUB AT MOLDED IN CUT LINE TO ACCOMMOCATF A 12 INCH OUTLET PIPE. CONNECTION TO DOWN5TREAM
PIPING TO BE MADE USING A FLEXIBLE COUPLING OR ECCENTRIC REDUCER, A5 REQUIRED. COUPLING BY FERNCO OR EQUAL AND
PROVIDED EY CONTRACTOR.
7) PROVIDE MINIMUM CLEARANCE FOR MAINTENANCE ACCF55. IF A SHALLOWER 5YSTEM 15 REQUIRED, CONTACT OONTECH
STORM WATER 50LUTION5 FOR O eER OPTIONS.
B) ANTI FLOTATION BALLAST TO 6E SPECIFIED BY ENGINEER AND PROVIDED BY CONTRACTOR. IF REQUIRED, BALLAST TO BE SET
AROUND THE PERIMETER OF THE STRUCTURE.
9) ALL 5TORMELTER5 REQUIRE REGULAR MAINTENANCE. REFER TO OPERATION AND MAINTENANCE GUIDELINES FOR MORE
INFORMATION.
PRECAST MANHOLE
3010 FRAME_ STORMFILTEIR DATA
AND COVER (STD) STRUCTURE 10 XXX
WATER QUALITY FLOW RATE Icfsl x.XX
F} PEAK FLOW RATE (<I Cfs) T xxx
r <I' • ETRETURN PERIOD OF PEAK FLOW (rs) X
a OF CARTRIDGES REQUIRED xr)'.{
e..(,. CARTRIDGE FLOW RATE (15 or 7.5 m) xx
R W_ MEDIA TYPE (C5F, PERUTE. ZPG) I XXXXX
RIM ELEVATION XXX. XX' D F;.'
PIPE DATA: LE ORIENTATION MATERIAL DIAMETER
INLET PIPE NI XX.XX' XX° xX% XX"
INLET XXX.XX x° x
MANHOLE STORMFILTER- TOP VIEW I A OUTLET STUDOUTLETSNB Xx%_%X' C° XX% RAM B' / 12"
2 ECCENTRIC REDUCER i YE5W0 SIZE
BY CONTRACTOR) xXX XX' r XX°
OUTLET 5AND COLLAR ANTI FLOTATION BALLA5T WIDTH HEIGHT
R15FR 12G) OUTLET 5TUB
XX" XX"
a' MOLDED CUT LINE NOTE5 /5PECIAL REQUIREMENT5: PIPE ORIENTATION KEY:
90°
5'0 OUTLET STUD I
BO° —O —C
OUTLET PIPE
BY CONTRACTOR)
COUPLING
BY CONTRACTOR)
SEE NOTE 6)
EALLA5T
GROUT (SEE NOTE 8)
BY CONTRACTOR) o-f BTORMWArR NANAQNICNT
u®
MANHOLE STORMFILTER - OUTLET DETAIL 2 , 5,7075iz 1.. )V, 34
Nc 6 G4? ,048, Fo. 5 9D4 576
2 AND mnEA J s. AND FCUIGN
92006 GONTECH Stormwater Solutions 1ADN15 '[BONS
ITCAIJ
01' 401` i I&W w-m
PRECAST 48" MANHOLE STORMFILTER
unA.NG
STORMWATER
TOP AND SECTION VIEWS, NOTES AND DATA 2
STANDARD DETAIL
y2
COnt¢CM1SIO rtiWdlB[COT OATEeW26M5 I SCALE'. NONE I FILE NA.ME:MMSF3-08PCUTL I DRXNN:MNI I CbECKE9:ARG
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SEE
72'0
INLET GE \/ \ ' af(/ / / /l/ /y / STUB ((5EE NOTES
5E
G)
MANHOLE STORMFILTER - PLAN VIEW 1
1
30 '0 FRAME AND
CONCRETE
COVER(STD)
5EE NOTE 41
GRADE RING
STEP (iYP)
INLET PIPE NUPE OUTLET
SEE NOTES 5 e G) R15ER MTh
SCUM DAPPLE
d 4' -G' MIN
5EE NOTE 7)
eALTFST
e
EE NOT_ 5T
HEIGHT
WIDTH F— d SEE DETAIL 2J2
UNDER:RAIN 5TORMFILTER CARTRIDGE
MANIFOLD (ttP) (SEE NOTE 2)
MANHOLE STORMFILTER - SECTION VIEW A
1
ihf SrCR MAN PGfM[N i
5."T a® V S. PATENT o29
No. 5.90],5b N. G.027.GL 9
Nc. 6 649 09 B, M1o. ID RTI IANDOr1u! 05_ aND FGkfIGu2@1fiSiOMfOfiOarnwaterSolutionsPnrervTSF:vo Nc
PRECAST 72" MANHOLE STORMFILTER
STORMWATMWAT ER
PLAN AND SECTION VIEWS
SOLDrI NS STANDARD DETAIL
2
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GENERAL NOTES
I) STORMFILTER BY CONTECH STORMWATER SOLUTIONS, PORTLAND, OR (500) 548-46G7; SCARBOROUGH. ME (877)
907 - 8676, ELKRIDGE, MD (8G6) 740 -3318.
2) FILTER CARTRIDGF(5) TO BE 51PHOMAOTUATED AND SELF CLEANING, STANDARD DETAIL SHOWS MAXIMUM NUMBER OF
CARTRIDGFS, ACTUAL NUMBER REQUIRED TO BE SPECIFIED ON 51TE PLANS OR IN DATA TABLE BELOW.
3) PRECAST MANHOLE STRUCTURE TO BE CONST.RUCTEO IN ACCORDANCE WITH ASTM 0478, DETAIL REFLECTS DE51GN INTENT
ONLY. ACTUAL DIMFN510N5 AND CONFIGURATION OF STRUCTURE WILL BE SHOWN ON PRODUCTION SHOP DRAWING.
4) STRUCTURE AND ACCE55 COVERS TO MEET AASHTO H -20 LOAD RATING.
5) STORMPLTER REQUIRES 23 FEET OF DROP FROM INLET TO OUTLET. IF LE55 DROP 15 AVAILABLE, CONTACT CON *ECM
STORMWATER SOLUTIONS. MINIMUM ANGLE BETWEEN INLET AND OUTLET 15 45°
6) INLET PIPING TO BE SPECIFIED BY ENGINEER AND PROVIDED BY CONTRACTOR, PRECAST MANHOLE STORMFILTER EQUIPPED
WITH A DUAL DIAMETER HOPE OUTLET STUB AND SAND COLLAR, EIGHT INCH DIAMETER OUTLET SECTION MAY BE SEPARATED
FROM OUTLET STUB AT MOLDED -IN CUT LINE TO ACCOMMODATE A 12 INCH OUTLET PIPE. CONNECTION TO DOWNSTREAM
PIPING TO BE MADE U51NG A FLEXIBLE COUPLING OR ECCENTIBC REDUCER. AS REQUIRED. COUPLING BY FERNCO OR EQUAL
AND PROVIDED BYCONTRACTOR.
7) PROVIDE MINIMUM CLEARANCE FOR MAINTENANCE ACCESS. IF A SHAUOWERSYSTFM 15 REQUIRED, CONTACT CONTECH
STORMWATER SOLUTIONS FOR OTHER OPTIONS.
5) ANTI- FLOTATION BALLAST TO BE SPECIFIED BY ENGINEER AND PROVIDED BY CONTRACTOR, IF REQUIRED. BALLAST TO BE SET
AROUND THE PERIMETER OF THE STRUCTURE.
9) ALL STORMNLTERS REQUIRE REGULAR MAINTENANCE. REFER TO OPERATION AND MAINTENANCE GUIDELINES FOR MORE
30'0 FRAME
AND COVER (51D)
MANHOLE STORMFILTER -TOPVIEW 11
2
OUTLET SAND COLLAR
RISERB OUTLET STUB
e MOLDED-IN GUT LINE
8 "0 OUTLET SNB
OUTLET PIPE
BY CONTRACTOR)
COUPLING
Br coNrRACrow
SEE NOTE G
BALLAST
GROUT f5BF NOTE 8)
BY CONTRACTOR)
MANHOLE STORMFILTER - OUTLET DETAIL /21
2mID63tb>mTfe[n960urmwater Solutions 2
w4(4--uvrwu®
I I sue
STORMWATER
SOWTI 5_
TMf 5TORAOVT_3 MANAGEMENT
5 -11" A
U.S. PATENT No 5,322,629,
No 5,707, 527. No.', 027.639
u 6,699.098, No. 5.624376.
AND OTHER U5. AND 'CRE!Gu
PATE,NT5 PEND'NG
PRECAST 72' MANHOLE STORMFILTER
TOP AND SECTION VIEWS, NOTES AND DATA
STANDARD DETAIL
LW
APPENDIX D
Basin and Infiltration Trench Calculations
BASIN 1 AREAS
TOTAL TRIB AREA 70,469 SF (1.62 AC)
IMPERMOUS AREA: 52,590 SF (1.21 AC)
TILL GRASS AREA 17,880 SF (0.41 AC)
WATER OUAUTY TREATMENT AREA
35,850 SF (062 AC)
CREEK ROAD MIXED USE
PROPOSED BASIN
GRAPHIC SCALE
100 o so im 2W 400
IN FEET )
1 inch - 100 It
BASIN 2 AREAS
TOTAL TRIB AREA 270,190 SF (6.20 AC)
I WMMOUS AREAS IMPERMLIS AREA 200,603 SF (4.61 AC)
TILL GRASS AREA: 52,423 SF (1.20 AC)
WATER 01JALJTY TREATMENT AREA
148,381] SF (3.41 AC)
mm nao \
Mr 0YJ \
1
I
j
SOUND ENGINEERING, INC.
CIVIL ENGINEERS - LAND MANNERS
1101 COMMERCE ST, SUITE 3D0
TAOJMA, WA 98402
VNINE:(m) Slime .W(m) S IQ
SCALE: 1' =100'
DATE: PROJECT M: 07118.10
SHEET NAME:
PROPOSED 6ASIN
SHEET: 1 OF J
BASIN 4 AREAS
TOTAL TRIB AREA 23,345 SF (054 AC)
RRERMOIS AREA 21035 SF (0.53 AC)
TILL GRASS AREA: 310 SF SF (0.01 AC)
WATER WAUTY TREATMENT AREA
15,235 SF (0.50 AC)
CMVO(JS AREAS
CREEK ROAD MIXED USE
DEV BASINS 3,4 E)(HIBTT
67.N - 1N:''+i rrA A6iDi
BASIN 3 AREAS
TOTAL TRB AREA 75,664 SF (1.74 AC)
01PERMOUS AREA: 71,067 SF (1.63 AC)
TILL GRASS AREA 4,617 SF (0.11 AC)
WATER QUAL TY TREATMENT AREA
52,200 SF (11 AC)
GRAPHIC SCALE
IN Feet )
I Inch = 100 (E.
k`!A1 SEI I
SOUND ENGINEERING, INC.
M ENGINEERS - LAND PLANNERS
1101 COMMERCE ST., SUITE 300
TACOMA, WA 98902
2S1) 5]3 W IO - FNL(2Si) SRd192
xx xnWm9ircmm ^ niW@mwdaNic
TEL:7 FAV
DRAWN:
BY
SCAIE: 1" =100'
DATE: PRO ECr z: 07116.10
SHEET NAME:
PROPOSED BASIN
SHEET. OF
21
PREDEVELOPED LAND. USE
Name BASIN 1
Bypass: No
GroundWater: No
Pervious Land Use Acres
C, Pasture, Flat 1.59
Impervious Land Use Acres
DEVELOPED LAND USE
Pervious Land Use Acres
C, Lawn, Flat .41
Impervious Land Use Acres
PARKING FLAT 1.21
Element Flows To:
Surface Interflow
Gravel Trench Bed 1,
Flow Frequency Prede,
Flow(CFS) 0501
2 Year = 0.0234
5 Year = 0.0474
10 Year = 0.0684
25 Year = 0.1013
50 Year = 0.1305
100 Year = 0.1639
Flow Frequency Developed
Flow(CFS) 0701
2 Year = 0.3115
5 Year = 0.3814
10 Year = 0.4248
25 Year = 0.4774
50 Year = 0.5153
100 Year = 0.5524
Name Gravel Trench Bed A
Bottom Length: 250ft.
Bottom Width : 6ft.
Trench bottom slope 1: 0.005 To 1
Trench Left side slope 0: 0 To 1
Trench right side slope 2: 0 To 1
Material thickness of first layer : 4
Groundwater
I
Gravel
Pour Space of material for first layer
Table
Material thickness of second layer : 0
Stage(ft)
Pour Space of material for second layer
Material thickness of third layer : 0
Pour Space of material for third layer
0.000
Infiltration On
0.000
Infiltration rate : 60
Infiltration sa£tey factor 0.18
Discharge Structure
Riser Height: 3 £c.
Riser Diameter: 24 in.
0.375
0.089
0.3
0
Gravel Trench Bed Hydraulic Table
Stage(ft) Area(acr) Volume(aer -ft) Dschrc(c£s) Infilt(cfs)
0.000 0.034 0.000 0.000 0.000
0.044 0.034 0.000 0.000 0.375
0.089 0.034 0.001 0.000 0.375
0.133 0.034 0.001 0.000 0.375
0.178 0.034 0.002 0.000 0.375
0.222 0.034 0.002 0.000 0.375
0.267 0.034 0.003 0.000 0.375
0.311 0.034 0.003 0.000 0.375
0.356 0.034 0.004 0.000 0.375
0.400 0.034 0.004 0.000 0.375
0.444 0.034 0.005 0.000 0.375
0.409 0.034 0.005 0.000 0,375
0.533 0.034 0.006 0.000 0.375
0.578 0.034 0.006 0.000 0.37510.622 0.034 0.006 0.000 0.375
0.667 0.034 0.007 0.000 0.375
0.711 0.034 0.007 0.000 0.375
0.756 0.034 0.008 0.000 0.375
0.800 0.034 0.008 0.000 0.375
0,844 0.034 0.009 0.000 0.375
0.889 0.034 0.009 0.000 0.375
0.9331 0.034 0.010 0.000 0.375
0,978 0.034 0.010 0.000 0.375
1.022 0.034 0.011 0.000 0.375
1.067 0.034 0.011 0.000 0.375
1.111 0.034 0.01i 0.000 0.375
1.156 0.034 0.012 0.000 0.375
1.200 0.034 0.012 0.000 0.375
1.244 0.034 0.013 0.000 0.375
1.289 0.034 0.013 0.000 0.375
1.333 0.034 0.014 0.000 0.375
1.378 0.034 0.014 0.000 0.375
1.422 0.034 0.015 0.000 0.375
1.467 0.034 0.015 0.000 0.375
i.511 0.034 0.016 0.000 0.375
1.556 0.034 0.016 0.000 0.375
1.600 0.034 0.017 0.000 0.375
1.644 0.034 0.017 0.000 0.375
1.669 0.034 0.017 0.000 0.375
1.733 0.034 0.018 0.000 0.375
1.778 0.034 0.018 0.000 0.375
1.822 0.034 0.019 0.000 0.375
1.867 0.034 0.019 0.000 0.375
1.911 0.034 0.020 0.000 0.375
1.956 0.034 0.020 0.000 0.375
2.000 0.034 0.021 0.000 0.375
2.044 0.034 0.021 0.000 0.375
2.089 0.034 0.022 0.000 0.375
2.133 0.034 0.022 0.000 0.375
2.178 0.034 0.022 0.000 0.375
2.222 0.034 0.023 0.000 0.375
2.267 0.034 0.023 0.000 0.375
2.311 0.034 0.024 0.000 0.375
2.356 0.034 0.024 0.000 0.375
2.400 0.034 0.025 0.000 0.375
2.444 0.034 0.025 0.000 0.375
2.489 0.034 0.026 0.000 0.375
2.533 0.034 0.026 0.000 0.375
2.578 0.034 0.027 0.000 0.375
2.622 0.034 0.027 0.000 0.375
2.667 0.034 0.028 0.000 0.375
2.711 0.034 0.028 0.000 0.375
2.756 0.034 0.028 0.000 0.375
2.800 0.034 0.029 0.000 0.375
2.844 0.034 0.029 0.000 0.375
2.889 0.034 0.030 0.000 0.375
2.933 0.034 0.030 0.000 0.375
2.978 0.034 0.031 0.000 0.375
3.022 0.034 0.031 0.065 0.375
3.067 0.034 0.032 0.335 0.375
3.111 0.034 0.032 0.721 0.375
3.156 0.034 0.033 1.195 0.375
3.200 0.034 0.033 1.742 0.375
3.244 0.034 0.034 2.354 0.375
3.289 0.034 0.034 3.024 0.375
3.333 0.034 0.034 3.749 0.375
3.378 0.034 0.035 4.523 0.375
3.422 0.034 0.035 5.344 0.375
3.467 0.034 0.036 6.209 0.375
3.511 0.034 0.036 7.117 0.375
3.556 0.034 0.037 8.066 0.375
3.600 0.034 0.037 9.053 0.375
3.644 0.034 0.038 10.08 0.375
3.689 0.034 0.038 11.14 0.375
3.733 0.034 0.039 12.23 0.375
3.778 0.034 0.039 13.36 0.375
3.822 0.034 0.039 14.52 0.375
3.867 0.034 0.040 15.72 0.375
3.911 0.034 0.040 16.94 0.375
3.956 0.034 0.041 18.19 0.375
4.000 0.034 0.041 19.48 0.375
P
Water Quality B Flow and Volume for POO 1.
On -line facility volume: 0.1066 acre -feet
On -line facility target flow: 0.01 cfs.
Adjusted for 15 min: 0.127 cfs.
Off -line facility target flow: 0.0639 cfs.
Adjusted for 15 min: 0.0722 cfs.
1
tPREDEVELOPED LAND USE
Name BASIN 2
Bypass: No
Groundwater: No
Pervious Land Use Acres
C, Pasture, Mod 6.99
Impervious Land Use Acres
DEVELOPED LAND USE
Name Basin. 2
Bypass: No
GroundWater: No
Pervious Land Use Acres
C, Lawn, Flat 2.03
Impervious Land Use Acres
PARKING FLAT 4.96
Element Flows To:
Surface Interflow Groundwater
Gravel Trench Bed 2,
Flow Frequency PREDEV.
Flow(CFS) 0502
2 Year 0.0667
5 Year = 0.1285
10 Year 0.1799
25 Year 0.2559350Year0.3204
100 Year = 0.3914
tFlow Frequency DEVELOPED
Flow(CFS) 0702
2 Year = 1.2823
5 Year = 1.5776
10 Year = 1.7662
25 Year = 1.9992
50 Year = 2.1700
100 Year = 2.3392i
A
Name Gravel Trench Bed 2
Bottom Length: 750£t.
Bottom Width : 8ft.
Trench bottom slope 1: 0.005 To 1
Trench Left side slope 0: 0 To 1
Trench right side slope 2: 0 To 1
Material thickness of first layer : 4
Pour Space of material for first layer
Material thickness of second layer : 0
Pour Space of material for second layer
Material thickness of third layer : 0
Pour Space of material for third layer
Infiltration On
Infiltration rate :o0
Infiltration saftey factor : 0.18
Discharge Structure
Riser Height: 3 ft.
Riser Diameter: 24 in.
Element Flows To:
Outlet 1 Outlet 2
0.3
0
1
Gravel Trench Bed Hydraulic Table
Stage(ft) Area(acr) Volu (acr -ft) Dachrq(cfe) Snfilt(cfs)
0.000 0.138 0.000 0.000 0.000
0.044 0.138 0.002 0.000 1.500
0.089 0.138 0.004 0.000 1.500
0.133 0.138 0.006 0.000 1.500
0.178 0.13E 0.007 0.000 1.500
0.222 0.138 0.009 0.000 1.500
0.267 0.13E 0.011 0.000 1.500
0.311 0.138 0.013 0.000 1.500
0.356 0.136 0.015 0.000 1.500
0.400 0.138 0.017 0.000 1.500
0.444 0.138 0.018 0.000 1.500
0.489 0.136 0.020 0.000 1.500
0.533 0.138 0.022 0.000 1.500
0.578 0.138 0.024 0.000 1.500
0.622 0.138 0.026 0.000 1.500
0.667 0.138 0.028 0.000 1.500
0.711 0.138 0.029 0.000 1.500
0.756 0.138 0.031 0.000 1.500
0.800 0.138 0.033 0.000 1.500
0.844 0.138 0.035 0.000 1.500
0.889 0.138 0.037 0.000 1.500
0.933 0.138 0.039 0.000 1.500
0.978 0.138 0.040 0.000 1.500
1.022 0.138 0.042 0.000 1.500
1.067 0.138 0.044 0.000 1.500
1.111 0.138 0.046 0.000 1.500
1.156 0.138 0.048 0.000 1.500
1
1.200 0.138 0.050 0.000 1.E00
1.244 0.138 0.051 0.000 1.500
1.289 0.138 0.053 0.000 1.300
1.333 0.138 0.055 0.000 1.500
1.378 0.138 0.057 0.000 1.500
L.422 0.133 0.059 0.000 1.500
1.467 0.138 0.061 0.000 1.500
1.511 0.138 0.062 0.000 1.500
1.556 0.138 0.064 0.000 1.500
1.600 0..138 0.066 0.000 1.500
1.644 0.138 0.068 0.000 1.500
1.689 0.138 0.070 0.000 1.500
1.733 0.138 0.072 0.000 1.500
1.778 0.138 0.073 0.000 1.500
1.822 0.138 0.075 0.000 1.500
1.867 0.138 0.077 0.000 1.500
1.911 0.138 0.079 0.000 1.500
1.956 0.138 0.081 0.000 1.500
2.000 0.138 0.083 0.000 1.500
2.044 0.138 0.084 0.000 1.500
2.089 0.138 0.086 0.000 1.500
2.133 0.136 0.088 0.000 1.500
2.178 0.138 0.090 0.000 1.500
2.222 0.138 0.092 0.000 1.500
2.267 0.138 0.094 0.000 1.500
2.311 0.138 0.096 0.000 1.500
2.356 0.138 0.097 0.000 1.500
2.400 0.138 0.099 0.000 1.500
2.444 0.138 0.101 0.000 1.500
2.489 0.138 0.103 0.000 1.500
2.533 0.138 0.105 0.000 1.500
2.578 0.138 O.io7 0.000 i.500
2.622 0.138 0.108 0.000 1.500
2.667 0.138 0.110 0.000 1.500
2.711 0.138 0.112 0.000 1.500
2.756 0.138 0.114 0.000 1.500
2.800 0.136 0.116 0.000 1.500
2.844 0.138 0.118 0.000 1.500
2.689 0.138 0.119 0.000 1.500
2.933 0.138 0.121 0.000 1.500
2.978 0.138 0.123 0.000 1.500
3.022 O.i38 0.125 0.065 1.500
3.067 0.138 0.127 0.335 i.500
3.111 0.138 0.129 0.721 1.500
3.156 0.138 0.130 1.195 1.500
3.200 0.138 0.132 1.742 1.500
3.244 0.138 0.134 2.354 1.500
3.289 0.136 0.136 3.024 1.500
3.333 0.136 0.138 3.749 1.500
3.378 0.138 0.140 4.523 1,590
3.422 0.138 0.141 5.344 1.500
3.467 0.138 0.143 6.209 1.500
3.511 0.138 0.145 7.117 1.500
3.556 0.138 0.147 8.066 1.500
3.600 0.138 0.149 9.053 1.500
3.644 0.138 0.151 10.08 1.500
3.689 0.138 0.152 11.14 1.500
v `
3.733 0.138 0.154 12.23 1.500
3.778 0.138 0.156 13.36 1.500
3.822 0.138 0.158 i4.52 1.500
3.867 0.138 0.160 15.72 1.500
3.911 0.138 0.162 16.94 1.500
3.956 0.138 0.163 18.19 1.500
4.000 0.138 0.165 19.48 1.500
Water Quality Bb8 Flow and Volume for POC 2.
On -line facility volume: 0.4442 ac =e -feet
On -line facility target flow: 0.01 efa.
Adjusted for 15 min: 0.5284 cfs.
Off -line facility target flow: 0.2659 cfs.
Adjusted for 15 min: 0.3005 cfs.
Name Basln 3
Bypass: No
GroundWater: No
DEVELOPED
Pervious Land Use Acres
C, Lawn, Flat .11
Impervious Land Use Acres
PARKING FLAT 1763
Element Flows To:
Surface Interflow Groundwater
Gravel Trench Bed C,
Flow Frequency PREDEV.
Flow(CFS)
2 Year =
0503
2 Year = 0.0127
0.4929
5 Year = 0.0257
0.5463
10 Year = 0.0371
0.6106
25 Year = 0.0549
0.6567
50 Year = 0.0707
0.7016
100 Year = 0.0888
Flow Frequency DEVELOPED
Flow(CFS) 0703
2 Year = 0.4065
5 Year = 0.4929
10 Year = 0.5463
25 Year = 0.6106
50 Year = 0.6567
100 Year = 0.7016
Name Gravel Trench Bed C
Bottom Length: 375ft.
Bottom Width : 6ft.
Trench bottom slope 1: 0.005 To 1
Trench Left side slope 0: 0 To 1
Trench right side slope 2: 0 To 1
Material thickness of first layer : 4
Pour Space of material for first layer 0.3
Material thickness of second layer : 0
Pour Space of material for second layer 0
Material thickness of third layer : 0
Pour Space of material for third layer : 0
Infiltration On
Infiltration rate : 60
Infiltration saftey factor : 0.18
Discharge Structure
Riser Height: 3 `_t.
Riser Diameter: 24 in.
Element Flows To:
Outlet 1 Outlet 2
V \/
Gravel Trench Bad Hydraulic Table
Stage(ft) A aa(acr) Volumelacr -ft) Dachtg(cfs) tnfilt(cfs)
0.000 0.052 0.000 0.000 0.000
0.044 0.052 0.001 0.000 0.563
0.089 0.052 0.001 0.000 0.563
0.133 0.052 0.002 0.000 0.563
0.178 0.052 0.003 0.000 0.563
0.222 0.052 0.003 0.000 0.563
0.267 0.052 0.004 0.000 0.563
0.311 0.052 0.005 0.000 0.563
0.356 0.052 0.006 0.000 0.563
0.400 0.052 0.006 0.000 0.563
0.444 0.052 0.007 0.000 0.563
0.489 0.052 0.008 0.000 0.563
0.533 0.052 0.008 0.000 0.563
0.578 0.052 0.009 0.000 0.563
0.622 0.052 0.010 0.000 0.563
0.667 0.052 0.010 0.000 0.563
0.711 0.052 0.011 0.000 0.563
0.756 0.052 0.012 0.000 0.563
0.800 0.052 0.012 0.000 0.563
0.644 0.052 0.013 0.000 0.563
0.889 0.052 0.014 0.000 0.563
0.933 0.052 0.014 0.000 0.563
0.978 0.052 0.015 0.000 0.563
1.022 0.052 0.016 0.000 0.563
1.067 0.052 0.017 0.000 0.563
1.111 0.052 0.017 0.000 0.563
1.156 0.052 0.018 0.000 0.563
1.200 0.052 0.019 0.000 0.563
1.244 0.052 0.019 0.000 0.563
1.289 0.052 0.020 0.000 0.563
1.333 0.052 0.021 0.000 0.563
1.378 0.052 0.021 0.000 0.563
1.422 0.052 0.022 0.000 0.563
1.467 0.052 0.023 0.000 0.563
1.511 0.052 0.023 0.000 0.563
1.556 0.052 0.024 0.000 0.563
1.600 0.052 0.025 0.000 0.563
1.644 0.052 0.025 0.000 0.563
1.689 0.052 0.026 0.000 0.563
1.733 0.052 0.027 0.000 0.563
1.778 0.052 0.028 0.000 0.563
1.822 0.052 0.026 0.000 0.563
1.967 0.052 0.029 0.000 0.563
1.911 0.052 0.030 0.000 0.563
1.956 0.052 0.030 0.000 0.563
V \/
2.000 0.052 0.031 0.000 0.563
2.044 0.052 0.032 0.000 0.563
2.089 0.052 0.032 0.000 0.563
2.133 0.052 0.033 0.000 0.563
2.178 0.052 0.034 0.000 0.563
2.222 0.052 0.034 0.000 0.563
2.267 0.052 0.035 0.000 0.563
2.311 0.052 0.036 0.000 0.563
2.356 0.052 0.037 0.000 0.563
2.400 0.052 0.037 0.000 0.563
2.444 0.052 0.038 0.000 0.5663
2.489 0.052 0.039 0.000 0.563
2.533 0.052 0.039 0.000 0.563
2.578 0.052 0.040 0.000 0.563
2.622 0.052 0.041 0.000 0.563
2.667 0.052 0.041 0.000 0.563
2.711 0.052 0.042 0.000 0.563
2.756 0.052 0.043 0.000 0.563
2.800 0.052 0.043 0.000 0.563
2.844 0.052 0.044 0.000 0.563
2.889 0.052 0.045 0.000 0.563
2.933 0.052 0.045 0.000 0.563
2.978 0.052 0.046 0.000 0.563
3.022 0.052 0.047 0.065 0.563
3.067 0.052 0.048 0.335 0.563
3.111 0.052 0.048 0.721 0.563
3.156 0.052 0.049 1.195 0.563
3.200 0.052 0.050 1.742 0.563
3.244 0.052 0.050 2.354 0.563
3.289 0.052 0.051 3.024 0.563
3.333 0.052 0.052 3.749 0.563
3.378 0.052 0.052 4.523 0.563
3.422 0.052 0.053 5.344 0.563
3.467 0.052 0.054 6.209 0.563
3.511 0.052 0.054 7.117 0.563
3.556 0.052 0.055 8.066 0.563
3.600 0.052 0.056 9.053 0.563
3.644 0.052 C.056 10.08 0.563
3.689 0.052 0.057 11.14 0.563
3.733 0.052 0.058 12.23 0.563
3.778 0.052 0.059 13.36 0.563
3.822 0.052 0.059 14.52 0.563
3.867 0.052 0.060 15.72 0.563
3.911 0.052 0.061 16.94 0.563
3.956 0.052 0.061 18.19 0.563
4.000 0.052 0.062 19.48 0.563
Water Quality EMP Flow and Volume for POC 3.
On -line facility volume: 0.1564 acre -feet
On -line facility target flow: 0.01 cfs.
Adjusted for 15 min: O.i859 cfs.
Off -line facility target flow: 0.0935 cfs.
Adjusted for 15 min: O.1037 cfs.
Name Basin 4
Bypass: No
Groundwater: No
Pervious Land Use Acres
C, Lawn, Flat .01
Impervious Land Use Acres
PARKING FLAT 0.53
Element Flows To:
Surface Interflow Groundwater
Gravel Trench Bed D,
Flow Frequency PREDEV.
Flow(CFS) 0504
2 Year = 0.0039
5 Year = 0.0080
10 Year = 0.0115
25 Year = 0.0170
50 Year = 0.0219
IOD Year = 0.0276
Flow Frequency DEVELOPED
Flow(CFS) 0704
2 Year = 0.1314
5 Year = 0.1591
10 Year = 0.1761
25 Year = 0.1967
50 Year = 0.2114
100 Year = 0.2257
Name Gravel Trench Bed D
Bottom Length: 125ft.
Bottom Width : 6ft.
Trench bottom slope 1: 0.005 To 1
Trench Left side slope 0: 0 To 1
Trench right side slope 2: 0 To 1
Material thickness of first layer : 4
Pour Space of material for first layer 0.3
Material thickness of second layer : 0
Pour Space of material for second layer 0
Material thickness of third layer : 0
Pour Space of material for third layer 0
Infiltration On
Infiltration rate : 60
Infiltration saftey factor : 0.18
Discharge Structure
LX
Riser Height: 3 ft.
Riser Diameter: 24 in.
Element Flows To:
Outlet 1 Outlet 2
yam\ J
Gravel Trench Bad Hydraulic Table
StaVe(fy A ea(acr) vole (acr -ft) Dschrc(cfs) InfIlt(cfs)
0.000 O.Oi7 0.000 0.000 0.000
0.044 0.017 0.000 0.000 0.188
0.089 0.017 0.000 0.000 0.188
0.133 0.017 0.001 0.000 0.188
0.178 0.017 0.001 0.000 0.188
0.222 0.017 0,001 0.000 0.188
0.267 0.017 0.001 0.000 0.188
0.311 0.017 0.002 0.000 0.188
0.35E 0.017 0.002 0.000 0.168
0.400 0.017 0.002 0.000 0.188
0.444 0.017 0.002 0.000 0.188
0.489 0.017 0.003 0.000 0.188
0.533 0.017 0.003 0.000 0.188
0.578 0.017 0.003 0.000 0.188
0.622 0.017 0.003 0.000 0.188
0.667 0.017 0.003 0.000 0.188
0.711 0,017 0.004 0.000 0.188
0.756 0.017 0.004 0.000 0.188
0.800 0.017 0.004 0.000 0.188
0.844 0.017 0.004 0.000 0.18E
0.689 0.017 0.005 0.000 0.188
0.933 0.017 0.005 0.000 0.188
0.978 0.017 0.005 0.000 0.188
1.022 0.017 0.005 0.000 0.188
1.067 0.017 0.006 0.000 0.188
1.111 0.017 0.006 0.000 0.189
1.155 0.017 0.006 0.000 0.188
1.200 0.017 0.006 0.000 0.188
1.244 0.017 0.006 0.000 O.i88
1.289 0.017 0.007 0.000 0.196
1.333 0.017 0.007 0.000 0.198
1.378 0.017 0.007 0.000, 0.188
1.422 0.017 0.007 0.000 0.188
1.467 0,017 0.008 0.000 0.188
1.511 0.017 0.008 0.000 0.188
1.556 0.017 0.008 0.000 0.188
1.600 0.017 0.008 0.000 0.188
1.644 0.017 0.008 0.000 0.188
1.689 0.017 0.009 0.000 0.188
1.733 0.017 0.009 0.000 0.188
1.778 0.017 0.009 0.000 0.188
1.822 0.017 0.009 0.000 0.188
1.867 0.017 0.010 0.000 O.i88
1.911 0.017 0.010 0.000 0.138
1.956 0.017 0.010 0.000 0.188
2.000 0.017 0.010 0.000 0.188
yam\ J
2.044 0.017 0.0il 0.000 0.188
2.089 0.017 0.011 0.000 0.188
2.i33 0.017 0.011 0.000 0.136
2.178 0.017 0.011 0.000 0.188
2.222 0.017 0.011 0.000 O.i88
2.267 O.Oi7 0.012 0.000 0.183
2.311 0.017 0.012 0.000 0.168
2.356 0.017 0.012 0.000 0.188
2.400 0.017 0.012 0.000 0.188
2.444 0.017 0.013 0.000 0.188
2.489 0.017 0.013 0.000 0.188
2.533 0.017 0.013 0.000 0.188
2.578 0.017 0.013 0.000 0.188
2.622 0.017 0.014 0.000 0.168
2.667 0.017 0.014 0.000 0.188
2.711 0.017 0.014 0.000 0.188
2.756 0.017 0.014 0.000 0.188
2.800 0.017 0.014 0.000 0.188
2.844 0.011 0.015 0.000 0.18B
2.869 0.017 0.015 0.000 0.183
2.933 0.017 0.015 0.000 0.1B8
2.973 0.017 0.015 0.000 0.188
3.022 0.017 0.016 0.065 0.188
3.067 0.017 0.016 0.335 0.188
3.111 0.017 0.016 0.721 0.186
3.156 0.017 0.016 1.195 0.188
3.200 0.017 0.017 1.742 0.188
3.244 0.017 0.017 2.354 0.188
3.289 0.017 0.017 3.024 0.188
3.333 0.017 0.017 3.749 0.188
3.378 0.017 0.017 4.523 0.188
3.422 0.017 0.016 5.344 0.188
3.467 0.017 0.018 6.209 0.188
3.511 0.017 0.018 7.117 0.188
3.556 0.017 0.018 6.066 0.188
3.600 0.017 0.019 9.053 0.188
3.644 0.017 0.019 10.08 0.186
3.689 0.017 0.019 11.14 0.188
3.733 0.017 0.019 12.23 0.188
3.779 0.017 0.020 13.36 0.188
3.822 0.017 0.020 14.52 0.188
3.867 0.017 0.020 15.72 0.168
3.911 0.017 0.020 16.94 0.168
3.956 0.017 0.020 18.19 0.188
4.000 0.017 0.021 19.48 0.188
Water Quality B Flow and Volume for 20C 4.
On -line facility volume: 0.0652 acre -feet
On -line facility target flow: 0.01 cfs.
Adjusted for 15 min: 0.0774 cfs.
Off -line facility target flow: 0.0389 cfs.
Adjusted for 15 min: 0.044 cfs.