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Drainage Report (3)Drainage and Erosion Control Report for Sunshine Cafe Yelm, WA May 21, 2024 PO Box 12690 Olympia WA 98508 360.705.2474 www.olyeng.com ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 1 COVER SHEET SUNSHINE CAFE Yelm, Washington May 21, 2024 Owner/Applicant Prepared for: Yelm Carlson, LLC Contact: Marian Licxandru 7310 Onyx Dr. SW Lakewood, WA 98498 (360) 960-0165 Reviewing Agency Jurisdiction: City of Yelm, Washington Project Number: ____________ Project Contact: ____________ (360) 458-8496 Contractor Contact: References WSDOE Stormwater Management Manual for Western Washington (SWMMWW), 2019 edition, with Errata Project Engineer Prepared by: Olympic Engineering, Inc. PO Box 12690 Olympia, WA 98508 (360) 705-2474 Contact: Chris Merritt, PE Project Number: 22074 5/21/2024 "I hereby certify that this Drainage and Erosion Control Plan and Report and Construction SWPPP for the Sunshine Cafe project has been prepared by me or under my supervision and meets the requirements of the City of Yelm Stormwater Standards and the standards of care and expertise which is usual and customary in this community for professional engineers. I understand that the City of Tumwater does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities prepared by me.” ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 2 TABLE OF CONTENTS COVER SHEET ........................................................................................................................ 1 TABLE OF CONTENTS ........................................................................................................... 2 SECTION 1 – PROPOSED PROJECT DESCRIPTION .......................................................... 3 Permit ................................................................................................................................................ 3 Project Location ................................................................................................................................. 3 Property Boundaries & Zoning ........................................................................................................... 3 Project Description ............................................................................................................................. 3 Minimum Requirements ..................................................................................................................... 3 Timing of the Project .......................................................................................................................... 5 SECTION 2 – EXISTING SITE CONDITIONS ......................................................................... 5 Topography ........................................................................................................................................ 5 Ground Cover .................................................................................................................................... 5 Drainage ............................................................................................................................................ 5 Soils ................................................................................................................................................... 5 Critical Areas ..................................................................................................................................... 5 Adjacent Areas .................................................................................................................................. 6 Precipitation Records ......................................................................................................................... 6 Reports and Studies .......................................................................................................................... 6 SECTION 3 – GEOTECHNICAL REPORT .............................................................................. 6 SECTION 4 – WELLS AND SEPTIC SYSTEMS ..................................................................... 6 SECTION 5 – FUEL TANKS .................................................................................................... 6 SECTION 6 – ANALYSIS OF THE 100-YEAR FLOOD .......................................................... 6 SECTION 7 – AESTHETIC CONSIDERATIONS FOR FACILITIES ....................................... 6 SECTION 8 – FACILITY SIZING AND OFF-SITE ANALYSIS ................................................ 6 Proposed Permanent BMP’s ............................................................................................................. 7 Off-Site Analysis ................................................................................................................................ 8 SECTION 9 – COVENANTS, DEDICATIONS, EASEMENTS ................................................ 8 SECTION 10 – PROPERTY OWNERS ASSOCIATION ARTICLES OF INCORPORATION 8 APPENDICES Appendix 1 - Drainage Plan Appendix 2 - Drainage Calculations Appendix 3 - Soils Reports ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 3 SECTION 1 – PROPOSED PROJECT DESCRIPTION Permit The applicant is applying for permits to construct a drive thru coffee stand and an axe throwing venue building (or possibly general retail/office space). Project Location See Vicinity Map on plans for reference. Site Address: 407 Yelm Ave. E Yelm, WA 98597 Tax Parcel Number(s): 22719342700 Section, Township, Range: Section 19 Township 17 North Range 02 East, W.M. Property Boundaries & Zoning The eastern portion of the parcel is zoned C-1 and the eastern portion is located in UGA of Thurston County and is zoned RR 1/5. The parcel boundaries are shown on the site/drainage plan (see Appendix). Project Description The proposal is to construct a 480 sf drive-thru coffee stand and a 2,400 sf proposed an axe throwing venue building) with associated access, parking lot, storm drainage, and public and private utility improvements. Minimum Requirements The Minimum Requirements for stormwater development and redevelopment sites are listed in Section I-2.4 of Volume I of the SWMMWW. The proposed project creates and/or replaces more than 5,000 square-feet of new hard surface area; therefore, the proposed project must address Minimum Requirements #1 through #9. The Minimum Requirements have been addressed as follows: Minimum Requirement #1 – Preparation of Stormwater Site Plans Drainage Plans have been prepared for this project (see Appendix). Minimum Requirement #2 – Construction Stormwater Pollution Prevention (C- SWPP) A Construction Stormwater Pollution Prevention (C-SWPP) Plan will be provided with the final Drainage Report. Minimum Requirement #3 – Source Control of Pollution A Permanent Source Control Plan will be provided with the storm drainage maintenance agreement prior to final project approval. ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 4 Minimum Requirement #4 – Preservation of Natural Drainage Systems and Outfalls There are no existing natural drainage systems or outfalls located on or near the subject parcel; therefore, this Minimum Requirement is not applicable. Minimum Requirement #5 – On-Site Stormwater Management This project will meet the LID Performance Standard. The proposed BMPs are as follows: Lawn and Landscape Areas: • All disturbed and/or new lawn and landscape areas will contain soils meeting the Post-Construction Soil Quality and Depth (BMP T5.13) requirements. Roof Areas: • Stormwater runoff from the roof areas will be routed to a Bioretention Facility (BMP T7.30). Other Hard Surface Areas: • Stormwater runoff from the new driveway, parking lot, and sidewalk areas will be routed to a Bioretention Facility (BMP T7.30). See Section 8 and the drainage plans for additional information. Minimum Requirement #6 – Runoff Treatment This project will create/replace more than 5,000 square-feet of new total effective pollution-generating hard surface (PGHS) area; therefore, Runoff Treatment is required. Runoff treatment will be provided in the Bioretention Facility (BMP T7.30). See Minimum Requirement #5 above and Section 8 below for additional information along with the WWHM modeling results in the Appendix. Minimum Requirement #7 – Flow Control This project will have less than 10,000 square-feet of “effective” impervious surface area; will convert less than ¾-acre of vegetation to lawn/landscape; convert less than 2.5-acres of native vegetation to pasture; and cause less than a 0.15-cfs increase in the 100-year flow frequency; therefore, Flow Control is not required. Per WWHM, this project will meet the LID Performance Standard. See Minimum Requirement #5 above and Section 8 below for additional information along with the WWHM modeling results in the Appendix for infiltration trench sizing. ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 5 Minimum Requirement #8 – Wetlands Protection There are no known wetlands located on-site or within the immediate vicinity; therefore, this Minimum Requirement is not applicable. Minimum Requirement #9 – Operation and Maintenance A storm drainage maintenance agreement, including a pollution source control plan, will be prepared and recorded prior to final project approval. Optional Guidance #1 – Financial Liability A Financial Guarantee will be provided prior to final project approval, if required. Optional Guidance #2 – Off-Site Analysis and Mitigation See Section 8 below. No downstream impacts are anticipated as a result of this project. Timing of the Project It is anticipated that site work construction will begin in spring 2024 with substantial completion by summer 2024 and with building construction complete by winter 2024. SECTION 2 – EXISTING SITE CONDITIONS Topography Site topography slopes down from the southwest and northeast towards the middle of the parcel (proposed Bioretention Facility location). The proposed project and surrounding areas are generally flat. Ground Cover Site vegetation consists mainly of field grass with some brush. Drainage See drainage plan and Section 8 below. Soils The Natural Resources Conservation Service (NRCS) Soil Survey of Thurston County classifies the on-site soils as Nisqually Loamy Fine Sand (HSG A). A Geotechnical Report prepared by Mud Bay Geotechnical Services (MBGS) (see Appendix) classified the on-site soils as sand with silt overlying gravel with sand. Seasonal groundwater was encountered at 16’ below-grade. MBGS recommends a long-term infiltration rate of 4”/hr for infiltration facilities down to 72” below-grade and a 6”/hr rate for facilities below 72”. Critical Areas There are no known critical areas (i.e. wetlands, landslide hazards, streams, etc.) located on-site or within the immediate vicinity of the site based on review of Thurston County critical areas maps and a site visit. The project is located within a Category I Critical Aquifer Recharge Area (CARA) and a 1-year time of travel zone of ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 6 a wellhead protection area. Adjacent Areas The project site is bounded by a carwash to the northwest; by a bank to the southeast; by Yelm Ave. to the northeast; and by a single-family parcel to the southeast. Precipitation Records Precipitation data is included within the WWHM model. Reports and Studies A Geotechnical Report has been prepared by MBGS, dated July 2, 2023 (see Appendix). SECTION 3 – GEOTECHNICAL REPORT A Geotechnical Report has been prepared by MBGS, dated July 2, 2023 (see Appendix). SECTION 4 – WELLS AND SEPTIC SYSTEMS One on-site well was located during the survey work and this well will be decommissioned , if needed. There are no other known on-site wells or off-site wells within 200-feet of this project’s boundaries. SECTION 5 – FUEL TANKS No fuel tanks were located during a site inspection or during the soils evaluation work. Olympic Engineering reviewed the latest “LUST” list (Leaking Underground Storage Tank) and found no listing for the subject site. SECTION 6 – ANALYSIS OF THE 100-YEAR FLOOD According to FEMA FIRM #53067C0353E dated October 16, 2012, the project site and surrounding area are located in Zone X, an area of minimal flood hazard. SECTION 7 – AESTHETIC CONSIDERATIONS FOR FACILITIES The proposed Bioretention facility (BMP T7.30) will be landscaped. All disturbed pervious areas will be vegetated and/or landscaped and will contain soils that meet the Post- Construction Soil Quality and Depth (BMP T5.13) requirements. SECTION 8 – FACILITY SIZING AND OFF-SITE ANALYSIS Parcel Area: 56,770 sf (1.303 ac) Existing Development Coverage Land Coverage Table – Pre-Developed (Acres) Pasture 1.303 Total 1.303 ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 7 Proposed Development Coverage Land Coverage Table – Post-Developed (Acres) Roof 0.087 Driveway/Parking 0.388 Walkways/Solid Waste Pad 0.029 Lawn/Landscape 0.335 Pasture 0.464 Total 1.303 38.7% Hard Surface Coverage 61.3% Landscape Coverage Proposed Permanent BMP’s The following Permanent BMP’s have been incorporated into the design (see drainage plans): 1. BMP T7.30 Bioretention Facility (for roof, drive/parking, walkways, and refuse pad) 2. BMP T5.13 Post-Construction Soil Quality and Depth (all disturbed, lawn/landscape, and stormwater dispersion areas) Flow Control & Runoff Treatment Facilities A Bioretention Facility (BMP T7.30) will provide treatment and temporary detention of stormwater runoff from all pollution generating hard surface (PGHS) areas. Per WWHM modeling results, this project will treat and infiltrate 100% of the runoff volume. The bioretention facility will provide just over 2’ of freeboard. At a maximum ponding depth of 0.95’, the facility will draw down in 3.8 hours (0.95’x12”)/3”/hr = 3.8 hours). See WWHM modeling results in the Appendix for infiltration trench sizing. Modeling & Assumptions • Stormwater runoff from the hard surface areas will be infiltrated. These areas are considered “ineffective” and can be excluded from the impervious area threshold determination of Minimum Requirement #7. • When analyzing the difference in the pre- to post-developed runoff rate, the existing ground cover can be used (typically a more conservative approach). However, the entire area to be disturbed was modeled as “forest” in the pre- developed scenario for simplicity and for use in analyzing the Low Impact Development standard. • All lawn/landscape areas that meet the Post-Construction Soil Quality and Depth (BMP T5.13) requirements have been modeled as “pasture”. • A 4”/hr design (corrected Ksat) infiltration rate has been used for the native subgrade beneath the Bioretention facility as recommended in the ________________________________________________________________________________ May 2024 Drainage and Erosion Control Report 8 Geotechnical Report. A 12”/hr rate, with a correction factor of 4, was used for the default bioretention soil mix. • The bioretention surface area in the model automatically receives rainfall; therefore, the area of the facility has been excluded from the lawn/landscape basin area. Off-Site Analysis Stormwater runoff generated from the new on-site improvements will be fully infiltrated on-site. Stormwater runoff from the Yelm Ave. frontage currently sheet flows to roadside swales containing catch basins and it is assumed this runoff is infiltrated within the swales and/or below-grade (to be confirmed by City). There does not appear to be any noticeable stormwater run-on from adjacent parcels. Due to site grades, the proposed bioretention facility does not have a means to provide for emergency overflow to a downstream release point. As a result, it has been designed to provide 2’ of freeboard. 2’ of freeboard provides an additional 2.7 times the storage volume available in the 1’ working depth of the pond and the side slopes in the freeboard area will have a slightly higher infiltration rate than the BSM; therefore, the pond has adequate capacity to accommodate premature failing/clogging. No downstream impacts, including impacts to structures, are anticipated as a result of this project. Based on the above, a quantitative off-site analysis or mitigation is not warranted. SECTION 9 – COVENANTS, DEDICATIONS, EASEMENTS No easements are required for the storm drainage system components. SECTION 10 – PROPERTY OWNERS ASSOCIATION ARTICLES OF INCORPORATION The property owner will be required to maintain the on-site stormwater systems. Appendix 1 Drainage Plan PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R VANVAN PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R SH E E T 1 O F 1 S H E E T FA B R I C ( G E O T E X T I L E ) (T Y P I C A L ) 1.2.3. (W O O D P O S T S S H O W N ) SP L I C E D F E N C E S E C T I O N S S H A L L B E C L O S E E N O U G H TO G E T H E R T O P R E V E N T S I L T L A D E N W A T E R F R O M ES C A P I N G T H R O U G H T H E F E N C E A T T H E O V E R L A P . SE E N O T E 1 SE E N O T E 1 GE O T E X T I L E F O R S I L T F E N C E ~ S E E ST A N D A R D SP E C I F I C A T I O N S E C T I O N 9- 3 3 . 2 ( 1 ) , T A B L E 6 (S T E E L P O S T S S H O W N ) (S T E E L P O S T S S H O W N ) PO S T ~ S E E ST D . SP E C . 8 - 0 1 . 3 ( 9 ) A GE O T E X T I L E FLOW BU R Y G E O T E X T I L E IN T R E N C H 4" 2' - 0" MIN. 2' - 0" MIN. FA S T E N G E O T E X T I L E T O PO S T E V E R Y 6 " ( I N . ) O . C . 4" BA C K F I L L E D & CO M P A C T E D NA T I V E S O I L FA S T E N T O P O S T EV E R Y 6 " O . C SE L F - L O C K I N G T I E ~ N Y L O N 6 / 6 ( M I N . G R A D E ) , 12 0 # M I N . T E N S I L E S T R E N G T H , U V S T A B I L I Z E D PO S T ~ W O O D O R S T E E L (T Y P I C A L ) 4. DU R I N G E X C A V A T I O N , M I N I M I Z E D I S T U R B I N G T H E G R O U N D AR OU N D T R E N C H A S M U C H A S I S F E A S I B L E , A N D S M O O T H SU R F A C E F O L L O W I N G E X C A V A T I O N T O A V O I D C O N C E N T - RA T I N G F L O W S . C O M P A C T I O N M U S T B E A D E Q U A T E T O PR E V E N T U N D E R C U T T I N G F L O W S . In s t a l l t h e e n d s o f t h e s i l t f e n c e t o p o i n t s l i g h t l y up s l o p e t o p r e v e n t se d i m e n t f r o m f l o w i n g a r o u n d t h e e n d s o f t h e f e n c e . Pe r f o r m m a i n t e n a n c e i n a c c o r d a n c e w i t h S t a n d a r d S p e c i f i c a t i o n s 8- 0 1 . 3 ( 9 ) A a n d 8 - 0 1 . 3 ( 1 5 ) . Sp l i c e s s h a l l n e v e r b e p l a c e d i n l o w s p o t s o r s u m p l o c a t i o n s . I f sp l i c e s a r e l o c a t e d i n l o w o r s u m p a r e a s , t h e f e n c e m a y n e e d t o b e re i n s t a l l e d u n l e s s t h e P r o j e c t E n g i n e e r a p p r o v e s t h e i n s t a l l a t i o n . In s t a l l s i l t f e n c i n g p a r a l l e l t o m a p p e d c o n t o u r l i n e s . 1.2.3.4. OV E R F L O W B Y P A S S 5" M A X . TR I M GR A T E F R A M E FI L T E R E D WA T E R SE D I M E N T A N D D E B R I S SH E E T 1 O F 1 S H E E T DR A I N A G E G R A T E BE L O W I N L E T G R A T E D E V I C E OV E R F L O W B Y P A S S ( T Y P . ) DR A I N A G E G R A T E ~ R E C T A N G U L A R G R A T E S H O W N RE T R I E V A L S Y S T E M ( T Y P . ) BE L O W I N L E T G R A T E D E V I C E NO T T O S C A L E VANVAN PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R VANVAN PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R · · · · · · · · · · · · · · · · · · · · · · PO B o x 1 2 6 9 0 Ol y m p i a , W A 9 8 5 0 8 36 0 . 7 0 5 . 2 4 7 4 o f f i c e ww w . o l y e n g . c o m CHRI M. M E RS T R I T HOT EP R · · · · · · · · · · · · · · · · · · · · · · · · · Appendix 2 Drainage Calculations WWHM2012 PROJECT REPORT 22074_082923 8/31/2023 1:46:31 PM Page 2 General Model Information Project Name: 22074_082923 Site Name: Sunshine Cafe Site Address: 407 Yelm Ave. E City:Yelm Report Date: 8/31/2023 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 22074_082923 8/31/2023 1:46:31 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre A B, Forest, Flat 0.831 A B, Pasture, Flat 0.472 Pervious Total 1.303 Impervious Land Use acre Impervious Total 0 Basin Total 1.303 Element Flows To: Surface Interflow Groundwater 22074_082923 8/31/2023 1:46:31 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre A B, Pasture, Flat 0.08 Pervious Total 0.08 Impervious Land Use acre ROOF TOPS FLAT 0.087 SIDEWALKS FLAT 0.029 PARKING FLAT 0.388 Impervious Total 0.504 Basin Total 0.584 Element Flows To: Surface Interflow Groundwater Surface Bioretention Surface Bioretention 22074_082923 8/31/2023 1:46:31 PM Page 5 Basin 2 Bypass:Yes GroundWater:No Pervious Land Use acre A B, Pasture, Flat 0.688 Pervious Total 0.688 Impervious Land Use acre Impervious Total 0 Basin Total 0.688 Element Flows To: Surface Interflow Groundwater 22074_082923 8/31/2023 1:46:31 PM Page 6 Routing Elements Predeveloped Routing 22074_082923 8/31/2023 1:46:31 PM Page 7 Mitigated Routing Bioretention Bottom Length: 37.00 ft. Bottom Width: 37.00 ft. Material thickness of first layer: 1.5 Material type for first layer: SMMWW 12 in/hr Material thickness of second layer: 0 Material type for second layer: Sand Material thickness of third layer: 0 Material type for third layer: GRAVEL Infiltration On Infiltration rate:4 Infiltration safety factor:1 Wetted surface area On Total Volume Infiltrated (ac-ft.):92.277 Total Volume Through Riser (ac-ft.): 0 Total Volume Through Facility (ac-ft.): 92.277 Percent Infiltrated:100 Total Precip Applied to Facility:6.231 Total Evap From Facility:2.456 Underdrain not used Discharge Structure Riser Height:1 ft. Riser Diameter:6 in. Element Flows To: Outlet 1 Outlet 2 Bioretention Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.0486 0.0000 0.0000 0.0000 0.0495 0.0484 0.0007 0.0000 0.0000 0.0989 0.0477 0.0014 0.0000 0.0000 0.1484 0.0471 0.0022 0.0001 0.0001 0.1978 0.0465 0.0029 0.0007 0.0007 0.2473 0.0459 0.0037 0.0012 0.0012 0.2967 0.0453 0.0045 0.0019 0.0019 0.3462 0.0447 0.0053 0.0028 0.0028 0.3956 0.0441 0.0061 0.0039 0.0039 0.4451 0.0435 0.0069 0.0053 0.0053 0.4945 0.0429 0.0077 0.0070 0.0070 0.5440 0.0423 0.0085 0.0089 0.0089 0.5934 0.0417 0.0094 0.0113 0.0113 0.6429 0.0412 0.0102 0.0139 0.0139 0.6923 0.0406 0.0111 0.0170 0.0170 0.7418 0.0400 0.0120 0.0204 0.0204 0.7912 0.0394 0.0129 0.0243 0.0243 0.8407 0.0389 0.0138 0.0287 0.0287 0.8901 0.0383 0.0147 0.0335 0.0335 0.9396 0.0378 0.0157 0.0389 0.0389 0.9890 0.0372 0.0166 0.0448 0.0448 1.0385 0.0367 0.0176 0.0513 0.0513 1.0879 0.0361 0.0186 0.0583 0.0583 1.1374 0.0356 0.0195 0.0660 0.0660 1.1868 0.0351 0.0206 0.0744 0.0744 22074_082923 8/31/2023 1:46:32 PM Page 8 1.2363 0.0345 0.0216 0.0835 0.0835 1.2857 0.0340 0.0226 0.0932 0.0932 1.3352 0.0335 0.0236 0.1038 0.1038 1.3846 0.0330 0.0247 0.1151 0.1151 1.4341 0.0324 0.0258 0.1271 0.1271 1.4835 0.0319 0.0269 0.1399 0.1399 1.5000 0.0314 0.0272 0.1959 0.1959 Bioretention Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)To Amended(cfs)Infilt(cfs) 1.5000 0.0486 0.0272 0.0000 0.0951 0.0025 1.5495 0.0492 0.0296 0.0000 0.0951 0.0051 1.5989 0.0498 0.0321 0.0000 0.1013 0.0077 1.6484 0.0505 0.0346 0.0000 0.1045 0.0102 1.6978 0.0511 0.0371 0.0000 0.1076 0.0128 1.7473 0.0518 0.0396 0.0000 0.1107 0.0155 1.7967 0.0524 0.0422 0.0000 0.1139 0.0181 1.8462 0.0531 0.0448 0.0000 0.1170 0.0207 1.8956 0.0537 0.0475 0.0000 0.1201 0.0234 1.9451 0.0544 0.0501 0.0000 0.1233 0.0261 1.9945 0.0550 0.0528 0.0000 0.1264 0.0288 2.0440 0.0557 0.0556 0.0000 0.1295 0.0315 2.0934 0.0564 0.0583 0.0000 0.1327 0.0342 2.1429 0.0571 0.0611 0.0000 0.1358 0.0370 2.1923 0.0577 0.0640 0.0000 0.1389 0.0397 2.2418 0.0584 0.0669 0.0000 0.1421 0.0425 2.2912 0.0591 0.0698 0.0000 0.1452 0.0453 2.3407 0.0598 0.0727 0.0000 0.1484 0.0481 2.3901 0.0605 0.0757 0.0000 0.1515 0.0510 2.4396 0.0612 0.0787 0.0000 0.1546 0.0538 2.4890 0.0619 0.0817 0.0000 0.1578 0.0567 2.5385 0.0626 0.0848 0.0000 0.1584 0.0595 2.5879 0.0633 0.0879 0.0000 0.1584 0.0624 2.6374 0.0641 0.0911 0.0000 0.1584 0.0654 2.6868 0.0648 0.0943 0.0000 0.1584 0.0683 2.7363 0.0655 0.0975 0.0000 0.1584 0.0712 2.7857 0.0662 0.1007 0.0000 0.1584 0.0742 2.8352 0.0670 0.1040 0.0000 0.1584 0.0772 2.8846 0.0677 0.1074 0.0000 0.1584 0.0802 2.9341 0.0684 0.1107 0.0000 0.1584 0.0832 2.9835 0.0692 0.1141 0.0000 0.1584 0.0862 3.0330 0.0699 0.1176 0.0000 0.1584 0.0892 3.0824 0.0707 0.1211 0.6009 0.1584 0.0923 3.1319 0.0715 0.1246 0.6259 0.1584 0.0954 3.1813 0.0722 0.1281 0.6499 0.1584 0.0984 3.2308 0.0730 0.1317 0.6731 0.1584 0.1016 3.2802 0.0738 0.1353 0.6955 0.1584 0.1047 3.3297 0.0745 0.1390 0.7172 0.1584 0.1078 3.3791 0.0753 0.1427 0.7383 0.1584 0.1110 3.4286 0.0761 0.1465 0.7588 0.1584 0.1141 3.4780 0.0769 0.1502 0.7787 0.1584 0.1173 3.5275 0.0777 0.1541 0.7982 0.1584 0.1205 3.5769 0.0785 0.1579 0.8171 0.1584 0.1238 3.6264 0.0793 0.1618 0.8357 0.1584 0.1270 3.6758 0.0801 0.1658 0.8538 0.1584 0.1302 3.7253 0.0809 0.1697 0.8716 0.1584 0.1335 3.7747 0.0817 0.1738 0.8890 0.1584 0.1368 3.8242 0.0825 0.1778 0.9061 0.1584 0.1401 22074_082923 8/31/2023 1:46:32 PM Page 9 3.8736 0.0833 0.1819 0.9229 0.1584 0.1434 3.9231 0.0841 0.1861 0.9393 0.1584 0.1468 3.9725 0.0850 0.1902 0.9555 0.1584 0.1501 4.0220 0.0858 0.1945 0.9714 0.1584 0.1535 4.0714 0.0866 0.1987 0.9871 0.1584 0.1569 4.1209 0.0875 0.2030 1.0025 0.1584 0.1603 4.1703 0.0883 0.2074 1.0177 0.1584 0.1637 4.2198 0.0892 0.2118 1.0326 0.1584 0.1671 4.2692 0.0900 0.2162 1.0473 0.1584 0.1705 4.3187 0.0909 0.2207 1.0619 0.1584 0.1740 4.3681 0.0917 0.2252 1.0762 0.1584 0.1775 4.4176 0.0926 0.2297 1.0904 0.1584 0.1810 4.4670 0.0935 0.2343 1.1043 0.1584 0.1833 4.5000 0.0940 0.2374 1.1181 0.1584 0.0000 22074_082923 8/31/2023 1:46:32 PM Page 10 Surface Bioretention Element Flows To: Outlet 1 Outlet 2 Bioretention 22074_082923 8/31/2023 1:46:32 PM Page 11 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 1.303 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.768 Total Impervious Area: 0.504 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.002976 5 year 0.010018 10 year 0.020196 25 year 0.044928 50 year 0.077529 100 year 0.129176 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.002832 5 year 0.01004 10 year 0.020285 25 year 0.044352 50 year 0.07485 100 year 0.121313 Annual Peaks 22074_082923 8/31/2023 1:47:23 PM Page 12 Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1956 0.009 0.007 1957 0.006 0.009 1958 0.002 0.003 1959 0.002 0.003 1960 0.001 0.002 1961 0.006 0.005 1962 0.001 0.001 1963 0.008 0.010 1964 0.002 0.002 1965 0.004 0.005 1966 0.001 0.001 1967 0.003 0.003 1968 0.001 0.001 1969 0.001 0.001 1970 0.001 0.001 1971 0.011 0.008 1972 0.019 0.015 1973 0.001 0.001 1974 0.005 0.004 1975 0.001 0.001 1976 0.002 0.002 1977 0.001 0.001 1978 0.005 0.006 1979 0.001 0.001 1980 0.001 0.002 1981 0.007 0.008 1982 0.005 0.006 1983 0.001 0.001 1984 0.001 0.001 1985 0.001 0.001 1986 0.006 0.007 1987 0.006 0.007 1988 0.001 0.001 1989 0.001 0.001 1990 0.025 0.029 1991 0.014 0.010 1992 0.001 0.001 1993 0.001 0.001 1994 0.001 0.001 1995 0.009 0.007 1996 0.020 0.014 1997 0.015 0.013 1998 0.014 0.019 1999 0.001 0.001 2000 0.002 0.002 2001 0.001 0.001 2002 0.008 0.005 2003 0.001 0.001 2004 0.126 0.122 2005 0.046 0.057 2006 0.063 0.048 2007 0.030 0.024 2008 0.004 0.006 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 22074_082923 8/31/2023 1:47:23 PM Page 13 Rank Predeveloped Mitigated 1 0.1261 0.1225 2 0.0630 0.0572 3 0.0460 0.0478 4 0.0295 0.0290 5 0.0247 0.0240 6 0.0196 0.0190 7 0.0193 0.0153 8 0.0154 0.0140 9 0.0140 0.0128 10 0.0138 0.0105 11 0.0112 0.0102 12 0.0093 0.0086 13 0.0088 0.0085 14 0.0080 0.0076 15 0.0076 0.0075 16 0.0068 0.0072 17 0.0062 0.0069 18 0.0061 0.0066 19 0.0060 0.0063 20 0.0059 0.0058 21 0.0052 0.0057 22 0.0052 0.0054 23 0.0048 0.0049 24 0.0043 0.0047 25 0.0038 0.0037 26 0.0031 0.0035 27 0.0025 0.0032 28 0.0022 0.0028 29 0.0021 0.0023 30 0.0020 0.0022 31 0.0015 0.0016 32 0.0015 0.0016 33 0.0014 0.0016 34 0.0013 0.0014 35 0.0012 0.0014 36 0.0010 0.0011 37 0.0009 0.0009 38 0.0009 0.0008 39 0.0009 0.0008 40 0.0009 0.0007 41 0.0008 0.0007 42 0.0008 0.0006 43 0.0008 0.0006 44 0.0008 0.0006 45 0.0008 0.0006 46 0.0008 0.0006 47 0.0008 0.0006 48 0.0008 0.0006 49 0.0008 0.0005 50 0.0008 0.0005 51 0.0008 0.0005 52 0.0008 0.0005 53 0.0007 0.0005 22074_082923 8/31/2023 1:47:23 PM Page 14 LID Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0002 22246 12894 57 Pass 0.0003 21372 12061 56 Pass 0.0003 20369 11218 55 Pass 0.0003 19532 10511 53 Pass 0.0003 18566 9857 53 Pass 0.0003 17709 9227 52 Pass 0.0003 16945 8636 50 Pass 0.0003 16126 8038 49 Pass 0.0003 15345 7451 48 Pass 0.0004 14619 6969 47 Pass 0.0004 13872 6415 46 Pass 0.0004 13223 5951 45 Pass 0.0004 12558 5505 43 Pass 0.0004 11928 5031 42 Pass 0.0004 11361 4579 40 Pass 0.0004 10811 4146 38 Pass 0.0004 10249 3739 36 Pass 0.0005 9764 3355 34 Pass 0.0005 9248 2972 32 Pass 0.0005 8776 2606 29 Pass 0.0005 8229 2213 26 Pass 0.0005 7724 1866 24 Pass 0.0005 7261 1583 21 Pass 0.0005 6754 1247 18 Pass 0.0005 6252 942 15 Pass 0.0006 5785 676 11 Pass 0.0006 5315 624 11 Pass 0.0006 4931 613 12 Pass 0.0006 4470 603 13 Pass 0.0006 4061 587 14 Pass 0.0006 3689 577 15 Pass 0.0006 3329 563 16 Pass 0.0006 3001 555 18 Pass 0.0007 2706 547 20 Pass 0.0007 2370 536 22 Pass 0.0007 2148 519 24 Pass 0.0007 2007 510 25 Pass 0.0007 1844 502 27 Pass 0.0007 1727 495 28 Pass 0.0007 1594 486 30 Pass 0.0007 1451 472 32 Pass 0.0008 1324 469 35 Pass 0.0008 1232 459 37 Pass 0.0008 1133 454 40 Pass 0.0008 1020 448 43 Pass 0.0008 909 441 48 Pass 0.0008 815 432 53 Pass 0.0008 700 425 60 Pass 0.0008 605 423 69 Pass 0.0009 532 420 78 Pass 0.0009 470 411 87 Pass 0.0009 447 402 89 Pass 0.0009 438 396 90 Pass 22074_082923 8/31/2023 1:47:23 PM Page 15 0.0009 428 389 90 Pass 0.0009 422 383 90 Pass 0.0009 414 377 91 Pass 0.0009 408 374 91 Pass 0.0010 404 373 92 Pass 0.0010 396 370 93 Pass 0.0010 392 365 93 Pass 0.0010 386 358 92 Pass 0.0010 381 356 93 Pass 0.0010 376 355 94 Pass 0.0010 373 349 93 Pass 0.0010 365 344 94 Pass 0.0011 358 339 94 Pass 0.0011 357 336 94 Pass 0.0011 355 331 93 Pass 0.0011 350 330 94 Pass 0.0011 348 327 93 Pass 0.0011 346 324 93 Pass 0.0011 341 323 94 Pass 0.0011 335 319 95 Pass 0.0012 329 316 96 Pass 0.0012 326 314 96 Pass 0.0012 320 314 98 Pass 0.0012 318 304 95 Pass 0.0012 316 300 94 Pass 0.0012 310 297 95 Pass 0.0012 306 295 96 Pass 0.0012 302 292 96 Pass 0.0013 301 289 96 Pass 0.0013 299 289 96 Pass 0.0013 296 286 96 Pass 0.0013 293 282 96 Pass 0.0013 290 278 95 Pass 0.0013 290 278 95 Pass 0.0013 286 277 96 Pass 0.0013 284 274 96 Pass 0.0014 282 274 97 Pass 0.0014 278 272 97 Pass 0.0014 276 271 98 Pass 0.0014 275 269 97 Pass 0.0014 272 267 98 Pass 0.0014 266 265 99 Pass 0.0014 264 261 98 Pass 0.0015 263 258 98 Pass 0.0015 263 254 96 Pass 0.0015 260 254 97 Pass 0.0015 257 252 98 Pass 22074_082923 8/31/2023 1:47:37 PM Page 16 Duration Flows Flow(cfs) Predev Mit Percentage Pass/Fail 0.0015 257 252 98 Pass 0.0023 157 148 94 Pass 0.0030 110 99 90 Pass 0.0038 84 75 89 Pass 0.0046 65 64 98 Pass 0.0053 50 55 110 Pass 0.0061 44 43 97 Pass 0.0069 38 36 94 Pass 0.0076 33 29 87 Pass 0.0084 31 26 83 Pass 0.0092 26 24 92 Pass 0.0099 24 22 91 Pass 0.0107 23 17 73 Pass 0.0115 21 14 66 Pass 0.0122 19 13 68 Pass 0.0130 17 12 70 Pass 0.0138 13 11 84 Pass 0.0145 10 9 90 Pass 0.0153 10 8 80 Pass 0.0161 8 8 100 Pass 0.0168 8 8 100 Pass 0.0176 8 7 87 Pass 0.0184 8 7 87 Pass 0.0192 8 6 75 Pass 0.0199 6 6 100 Pass 0.0207 6 6 100 Pass 0.0215 6 6 100 Pass 0.0222 6 6 100 Pass 0.0230 6 6 100 Pass 0.0238 6 6 100 Pass 0.0245 6 5 83 Pass 0.0253 5 5 100 Pass 0.0261 4 5 125 Fail 0.0268 4 5 125 Fail 0.0276 4 5 125 Fail 0.0284 4 5 125 Fail 0.0291 4 4 100 Pass 0.0299 3 4 133 Fail 0.0307 3 4 133 Fail 0.0314 3 4 133 Fail 0.0322 3 4 133 Fail 0.0330 3 3 100 Pass 0.0337 3 3 100 Pass 0.0345 3 3 100 Pass 0.0353 3 3 100 Pass 0.0361 3 3 100 Pass 0.0368 3 3 100 Pass 0.0376 3 3 100 Pass 0.0384 3 3 100 Pass 0.0391 3 3 100 Pass 0.0399 3 3 100 Pass 0.0407 3 3 100 Pass 0.0414 3 3 100 Pass 0.0422 3 3 100 Pass 22074_082923 8/31/2023 1:47:37 PM Page 17 0.0430 3 3 100 Pass 0.0437 3 3 100 Pass 0.0445 3 3 100 Pass 0.0453 3 3 100 Pass 0.0460 3 3 100 Pass 0.0468 2 3 150 Fail 0.0476 2 3 150 Fail 0.0483 2 2 100 Pass 0.0491 2 2 100 Pass 0.0499 2 2 100 Pass 0.0506 2 2 100 Pass 0.0514 2 2 100 Pass 0.0522 2 2 100 Pass 0.0530 2 2 100 Pass 0.0537 2 2 100 Pass 0.0545 2 2 100 Pass 0.0553 2 2 100 Pass 0.0560 2 2 100 Pass 0.0568 2 2 100 Pass 0.0576 2 1 50 Pass 0.0583 2 1 50 Pass 0.0591 2 1 50 Pass 0.0599 2 1 50 Pass 0.0606 2 1 50 Pass 0.0614 2 1 50 Pass 0.0622 2 1 50 Pass 0.0629 2 1 50 Pass 0.0637 1 1 100 Pass 0.0645 1 1 100 Pass 0.0652 1 1 100 Pass 0.0660 1 1 100 Pass 0.0668 1 1 100 Pass 0.0675 1 1 100 Pass 0.0683 1 1 100 Pass 0.0691 1 1 100 Pass 0.0698 1 1 100 Pass 0.0706 1 1 100 Pass 0.0714 1 1 100 Pass 0.0722 1 1 100 Pass 0.0729 1 1 100 Pass 0.0737 1 1 100 Pass 0.0745 1 1 100 Pass 0.0752 1 1 100 Pass 0.0760 1 1 100 Pass 0.0768 1 1 100 Pass 0.0775 1 1 100 Pass The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. 22074_082923 8/31/2023 1:47:37 PM Page 18 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. 22074_082923 8/31/2023 1:47:37 PM Page 19 LID Report 22074_082923 8/31/2023 1:47:54 PM Page 20 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. 22074_082923 8/31/2023 1:47:54 PM Page 21 Appendix Predeveloped Schematic 22074_082923 8/31/2023 1:47:55 PM Page 22 Mitigated Schematic Appendix 3 Soils Reports 1001 Cooper Point Rd SW, STE 140 PMB 108 | Olympia, WA 98502 | 360.481.9784 | CHeathman@MudBayGeotech.com July 2, 2023 Job: 2131-THU Page 1 Subject: Site Development Geotechnical Report 407 E Yelm Ave, Yelm, WA 98597 Parcel #22719342700 Dear Marian Licxandru, This report presents the results of our geotechnical investigation and contains geotechnical recommendations for the site development project located at 407 E Yelm Ave in Yelm, WA. The analyses, conclusions, and recommendations in this report are based on the information available. These informational resources include: five (5) excavated test pits completed specifically for the subject project, (2) two EPA falling head infiltration tests completed specifically for the subject project (1) one shallow groundwater monitoring well installed specifically for the subject project, laboratory testing, published geologic information for the site and vicinity and our experience with similar geologic materials. The conditions observed in the explorations are assumed to be representative of the subsurface conditions throughout the project area. If during construction, subsurface conditions differ from those described in the explorati ons, we should be advised immediately so that we may reevaluate our recommendations and provide further assistance. This is a revised report that supersedes all previous versions of the report for this project. SITE CONDITIONS AND PROJECT DESCRIPTION Parcel #22719342700 consists of a total of 1.32 acres in Yelm, Washington. The parcel location has been given the situs address of 407 E Yelm Ave, and is identified on the Site Map included as Figure 1 attached to this report. The property is located off the southwestern side of Yelm Ave E and can be accessed via the northeastern property boundary from the street. The parcel is 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |2 currently undeveloped, has been previously cleared, and is vegetated with various native shrubbery and grasses. The property grades gently downslope from northeast to south. The minimal amount of elevation loss across the subject parcel is attributed to a minor sloped bank bisecting the parcel from east to west, measuring roughly 6 feet in total height. The purpose of this report is to provide site development geotechnical recommendations, including bearing capacity of foundations and other site development considerations, as well as a final design infiltration rate for stormwater design. The scope of the project is to develop the parcel with a drive-thru coffee stand and associated paved surfaces. A proposed site plan has not been provided for our review prior to completion of this report. We understand based on conversations with the client and contracted engineers that stormwater infiltration facilities are proposed as a flow control and treatment BMP for the new impervious surface generated as part of the development. The parcel is located within the jurisdiction of the City of Yelm; therefore, the stormwater and infiltration design requirements of the Department of Ecology 2019 Stormwater Management Manual for Western Washington (SWMMWW) needs to be satisfied. To meet the requirements for that method, we performed one (1) deeply excavated test pit and performed laboratory testing on selected samples to further refine soil classification and to determine key soil index parameters such as grain size distribution and plasticity. Based on the laboratory testing results, we further classified selected soil samples in accordance with ASTM D2487 to characterize the infiltration rate of the site soils. Two (2) EPA falling head infiltration tests were also performed to characterize the infiltration rates of the site soils. These infiltration tests were performed within the upper ~3 to 4 feet based on the assumption that shallow infiltration trenches, basins, swales, or rock galleries may be used for treatment and flow control. The infiltration tests were performed near the location of proposed stormwater facilities. SITE GEOLOGY AND SOILS As part of this project, we reviewed available geologic data and prepared a site -specific geologic map. The project vicinity geologic map is attached as Figure 2, WA DNR Geologic Map. This figure indicates the project vicinity consists of Pleistocene continental glacial drift. The DNR describes these deposits as follows: Pleistocene till and outwash clay, silt, sand, gravel, cobbles, and boulders deposited by or originating from continental glaciers; locally includes peat, nonglacial sediments, modified land, and artificial fill. Conditions observed at the site are generally consistent with the mapped geology at the site. In addition to the site geology, site-specific soil data made available by the United States Department of Agriculture was consulted. The USDA Soil Map is attached to this report as Figure 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |3 3. This figure suggests that the parcel is underlain by No. 74 – Nisqually loamy fine sand, 3 to 15 percent slopes. The Nisqually soil series is described by the USDA as follows: a somewhat excessively draining loamy fine sand to loamy sand derived from sandy glacial outwash occurring on terraces. The soils observed in-situ are generally consistent with the mapped soils on-site. It should be noted that the slope percentages displayed on the map are estimates and do not necessarily reflect true surface topography. SUBSURFACE EXPLORATION To characterize the surface and subsurface conditions, Mud Bay Geotechnical Services, LLC performed five (5) excavated test pits designated TP-1-22, TP-2-22, EPA-1-22, EPA-2-22, and TP-3-23. The excavated test pits were completed from the existing ground surface at the approximate locations shown on Figure 4, Site Exploration Map. The excavated test pits were completed using a compact excavator and loader backhoe with Mud Bay Geotechnical Services, LLC personnel onsite to observe excavation, log the soils encountered in the pits and collect samples. In situ testing was performed at selected depths using a Humboldt Manufacturing model H-4202A dynamic cone penetrometer to estimate the density of the soil. The dynamic cone penetrometer uses a 15-lb steel mass falling a height of 20-inches onto an anvil to penetrate a 1.5-inch diameter 45-degree cone tip seated into the bottom of the hole. The penetrometer is driven 1-inch through the upper slough within the test pit and the number of blows is recorded, afterwards the number of blows required to achieve a total of ¾ inches of penetration into the undisturbed soil is recorded. The number of blows from three intervals of the ¾ inches are averaged and recorded as the field N-value. This recorded blow count is correlated to the Standard Penetration Test (SPT) field N- value blow count determined in accordance with ASTM D1586, which is the standard in situ test method for determining relative density of cohesionless soils and the consistency of cohesive soils. Samples were removed from the bottom of the hole after the dynamic cone penetration testing was performed to observe the soil material at the approximate depth the test was performed. Following the excavation of TP-1-22, a shallow groundwater monitoring well was installed in the test pit. The monitoring well consisted of a lower five (5) feet of slotted PVC pipe with a five (5) foot length of solid riser extending to the existing grade. The base of the PVC pipe was capped and placed in the center of the test pit. The void space around the well casing was backfilled with 10/20 silica sand to near the existing ground surface and a cap was placed at the top of the upper, 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |4 riser segment. The upper approximately eight (8) inches of the well was sealed using from surface water and precipitation using bentonite clay chips. The soil samples were classified visually in the field in general accordance with ASTM D2488, the Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Once transported back to the office, the samples were re-examined, and the field classifications were modified accordingly. Summary logs of the excavated test pits are included in Appendix A. Note the soil descriptions and interfaces shown on the logs are interpretive, and actual changes may be gradual. Upon completion, the test pits were backfilled to the original ground surface using excavated material from the spoil piles. Representative samples were selected for a suite of laboratory tests. The ove rall soil-testing program included cation exchange capacity, organic content testing and grain size analysis for classification purposes,. The results of these laboratory tests are presented in Appendix B. SUBSURFACE SOIL AND GROUNDWATER CONDITIONS Findings in the excavated test pits within the upper northeastern portion of the parcel suggest the subsurface consists of an upper 78-inches of very loose to loose, moist, brown, poorly-graded sand with silt (SP-SM), underlain by a very loose, moist, tan, poorly-graded sand with silt (SP- SM) to a depth of approximately 102-inches to 104-inches followed by a final unit of very loose, moist, tan, well-graded gravel with sand (GP) to a final depth of approximately 210-inches below ground surface (bgs). Findings in the excavated test pits within the middle to southwestern portion of the parcel suggest the subsurface consists of an upper, shallower, 36-inches of very loose to loose, moist, brown, poorly-graded sand with silt (SP-SM), underlain by a very loose, moist, tan, poorly-graded sand with silt (SP-SM) to a depth of approximately 72-inches followed by a final unit of very loose, moist, tan, poorly-graded gravel with sand (GP) to a final depth of approximately 96-inches bgs. Gravels and cobbles up to 24-inches in size were found throughout the base of the test pits. This final GP soil unit appeared to be fairly loose and is interpreted as recessional outwash deposits. The excavated test pits performed are assumed to be representative of the project area subsurface conditions, however, the true nature of glacial deposits can be difficult to ascertain as they are highly variable units. If conditions vary significantly during construction, we should be contacted to reassess the recommendations included in this report. 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |5 Groundwater was encountered during our subsurface exploration of the site on April 21st, 2023 at approximately 192-inches (16-feet) below the existing ground surface in TP-3-23. As a part of this project, well logs made available by the Washington State Department of Ecology for the surrounding region were consulted. These well logs suggest that the depth to groundwater in the area surrounding the subject property is approximately 30-feet below ground surface. The shallow groundwater monitoring well installed in TP-1-22, was periodically monitored for signs of groundwater over the course of the 2022-2023 rainy season. No indications of groundwater levels less than 9.5-feet below ground surface elevation were present. FIELD MEASURED INFILTRATION TESTING A total of two (2) EPA test wells, designated EPA-1-22 and EPA-2-22 were completed to further explore the subsurface conditions at the site location , and to perform field measured infiltration testing. We understand that the infiltration design needs to meet the requirements of the 2019 Department of Ecology Western Washington Stormwater Design Manual. The EPA test procedure for determining infiltration is not an allowable method in that design manual. However, the results of the tests were still useful as a comparison to the grain size method of analysis which was used to determine the final design infiltration rate, so that appropriate reduction factors could be applied to that method using engineering judgment. The approximate locations of the EPA test wells are shown on Figure 4, Site Exploration Map. Falling head percolation tests were performed by Mud Bay Geotechnical Services, LLC personnel according to the general guidelines laid out by the EPA, On-site Wastewater Treatment and Disposal Systems, 1980 publication. Excavated pits were performed at select locations and the base of the pits were cleaned out. PVC pipes 6 inches in diameter and 48-60 inches in length were placed into the excavated pits. The PVC pipes were embedded to a depth of 6 inches below the base of the pits. The void around the well casing was backfilled using material from the spoil piles by placing and tamping the material in approximately 6-inch lifts. Two inches of ½”-¾” diameter washed river rock base course was placed into the base of the pipes to prevent scouring and reduce turbidity. In sandy soils with little or no clay, soaking is not necessary. EPA-1-22 was filled twice with 12- inches of water, and the water seeped completely away in less than 10-minutes, therefore the tests were able to proceed immediately. Percolation test measurements began on January 19, 2023, at 9:30AM after it was determined that no soaking period was necessary. The EPA well designated EPA-2-22 failed the “fast test”, therefore the well was soaked for 4 hours starting at 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |6 9AM. Percolation test measurements began on January 19, 2023, at 1PM after the soaking period. The first 6-inches of water added after the soaking period seeped away in less than 30 minutes. Therefore, per protocol the water level was raised to 6 inches above the river rock and measured to the nearest 1/16” in 10-minute intervals for a 1-hour period in EPA-1-22 and EPA-2- 22. The last water level drops were used to calculate the percolation rate. A summary of the test results is presented in Table 1 below. Table 1: Falling Head Percolation Test Results EPA Falling Head Well Trial #1 in./hr. Trial #2 in./hr. Trial #3 in./hr. Trial #4 in./hr. Trial #5 in./hr. Trial #6 in./hr. EPA-1-22 36.0 36.0 36.0 36.0 36.0 36.0 EPA-2-22 12.875 12.75 12.75 12.875 12.75 12.75 The percolation rate was calculated for each test hole by dividing the time interval used between measurements by the magnitude of the last water level drop. This calculation results in a percolation rate in terms of inches per hour. To determine the perco lation rate for the area, the rates obtained from each hole were averaged. The unfactored percolation rates in EPA-1-22 and EPA-2-22 were measured at 36 in./hr. and 12.75 in./hr., respectively. The test pits were further utilized to investigate the infiltrating soil conditions, to observe the potential depth of saturation, to look for natural groundwater, and to look for a non-infiltrating hardpan. The underlying soil conditions consisted of poorly-graded sand with silt (SP-SM) and poorly-graded gravel with sand (GP), the materials observed throughout the test pits across the subject parcel. Mottling was absent within these units and the induration of the sediment was noted to be poorly to moderately indurated. The excavations indicated that water would completely infiltrate beyond the limits of excavation and no groundwater seepage was observed. An impervious layer was not encountered within the test pits nor was a lowermost limit to the coarse sand and cobble outwash sediment. Based on the explorations and testing performed for this project, we believe the on-site, native soil material to consist of well-draining glacial outwash material. The test pit excavations beyond the scope of the base of the EPA wells appears to indicate that any surface water will infiltrate vertically into the underlying, pervious strata rather than horizontally along any impervious layers. 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |7 GEOLOGIC HAZARD ASSESSMENT Landslide Hazard We performed a cursory review of the available online site information to determine the potential for landslide hazards at the site. The Landslide Map available from the Washington State Department of Natural Resources revealed no mapped landslide deposits near the project vicinity. No indications of deep-seated landslide activity, past or present, were observed during our on - site investigation nor during our review of online resources. The landslide hazard map has been omitted from this report. A map of liquefaction susceptibility developed by the Department of Natural Resources is attached as Figure 5, Liquefaction Hazard Map. Soil liquefaction is a phenomenon whereby saturated soil deposits temporarily lose strength and behave as a viscous fluid in response to cyclic loading. These behaviors are most common in saturated, loose, sandy soils with lesser impacts occurring in silty soils. Figure 5 indicates that the glacial deposits mapped across the parcel are at very low risk of soil liquefaction. The geomorphology (shape of the land) was analyzed during the site evaluation and compared to the Light Detection and Ranging images (LiDAR) from the Washington State LiDAR portal. LiDAR is a remote sensing method were light is pulsed down to the surface of the Earth and back to a sensor. This methodology enables bare earth images of the surface to be analyzed for the presence of geologic landforms. The most recent available LiDAR imagery of this site is included as Figure 6 attached to this report, WA LiDAR Map (2019). The bare earth imagery highlights the gently grading topography of the parcel and surrounding region, along with moderate urban grading activities. We conclude the onsite landslide hazard risk to be low. GEOTECHNICAL RECOMMENDATIONS Stormwater Infiltration Onsite stormwater infiltration facilities are proposed to address the excess runoff due to increased impervious surface. Shallow infiltration may occur within the moist, tan-brown, poorly-graded sand with silt (SP-SM) that was observed in the test pits. Deep infi ltration may occur within the moist, brown, poorly-graded gravel with sand (GP). Laboratory testing for grain size distribution was performed on selected samples within the infiltrating soils below the proposed infiltration facility subgrade. The results from the gradation tests were applied to the Massmann equation to estimate the saturated hydraulic conductivity and infiltration rate to be used for design. A groundwater depth of 16-feet was assumed, based on the depth to groundwater observed during 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |8 the deeply excavated test pit. Based on the time of year the explorations were performed, this likely represents close to the maximum groundwater level for a seasonal recharge aquifer. Based on the analysis and with consideration given to the results of the EPA falling head testing, we recommend a long-term infiltration rate of 4 inches per hour for shallow infiltration at the site from 18-72 inches below the existing ground surface which will primarily occur within the poorly graded sand with silt (SP-SM) that was observed in the test pits. We recommend a long termin filtration rate of 6 inches per hour for deeper infiltration used to design flow control and treatment facilities that are currently planned at 7 to 8 feet below the ground surface where infiltration will occur within or be heavily influenced by the poorly graded sand (GP) that was observed deeper below the existing ground. The design infiltration rate assumes that moderate level of maintenance in order to reduce the potential for biofouling. We recommend that the treatment areas undergo regular inspection and maintenance so that the system is not significantly clogged due to biofouling. The dimensions of the pond should be sized to an aspect ratio (width/length) of no less than 0.5. The treatment areas should be sized accordingly. The design infiltration rate can be increased depending on the actual aspect ratio used in the final design of the facility. It should also be noted that the infiltration rates at ALL DEPTHS can likely be improved with small PIT infiltration testing. The correction factors assume a moderate amount of maintenance over the lifetime of the infiltration facility. Based on the infiltration rates within the grain size analysis, EPA falling head percolation tests, onsite soil conditions, and our experience with similar geologic conditions, we conclude that the site is well-draining and that on-site infiltration is feasible. This infiltration rate assumes that the groundwater level during the design storm event is a minimum of 4 feet below the bottom of the infiltration. The bottom of the infiltrating facilities subgrade should be verified at the time of construction to ensure that the anticipated soils are present throughout. Pavement Section Design Asphalt pavement (both pervious or impervious) may be used for the development, with primarily passenger vehicle travel and anticipated light use (a few times per week) travel from a greater than 10,000 pound gross weight commercial vehicle. For this type of usage, we recommend a n asphalt pavement section consisting of a minimum of 0.5 feet (6 inches) of crushed surface base course (CSBC), overlain by hot mix asphalt (HMA) with a minimum thickness of 0.25 feet (3 inches). A thicker section could be used depending on the desired life cycle, with as much as 0.67 feet of CSBC and 0.33 feet of HMA. The aggregates for HMA and the HMA design, an d field testing, should be completed in accordance with the criteria in Section 9-03.8 of the WSDOT 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |9 Standard Specifications, based on an Equivalent Single Axle Load (ESAL) of less than 0.3 million. The CSBC material should meet the criteria of Section 9-03.9(3) of the WSDOT Standard Specifications. Prior to construction of the pavement section, the subgrade should be cleared and grubbed and the exposed native subgrade soils should be compacted in place. The CSBC should be placed in layers no greater than 3-inches and compacted to at least 95 percent of the maximum dry density. Concrete pavement may be used as part of the development. We recommend using a concrete pavement section consisting of a minimum of 6 inches of crushed surface base course (CSBC), overlain by concrete pavement with a minimum thickness of 8 inches. The CSBC material should meet the criteria of Section 9-03.9(3) of the WSDOT Standard Specifications. Concrete pavement mix design and construction should be done in accordance with the requirements in Section 5-05 of the WSDOT Standard Specifications. Prior to construction of the concrete pavement section, the subgrade should be cleared and grubbed and the exposed native subgrade soils should be compacted in place. The CSBC should be placed in layers no greater than 3-inches and compacted to at least 95 percent of the maximum dry density. We recommend subgrade preparation and crushed surfacing placement and compaction be evaluated by Mud Bay Geotechnical Services, LLC prior to the construction of the pavement. Subgrade preparation should not be performed during periods of wet weather. We recommend staging the subgrade excavation, compaction of native subgrade soils, and placement of CSBC to limit the time the pavement subgrade is exposed to weather. Foundation Support Shallow strip footings or mat/slab foundations are anticipated to support the new structure. Based on the observed soil conditions, we recommend locating the bottom of the new footings and mat/slab foundations on the native soil deposits at a minimum depth of approximately 6 inches below the existing ground surface. Prior to placement of concrete, the footing subgrade should be cleared and grubbed, and the exposed native subgrade soils should be compacted in place. The subgrade should be inspected for any pockets of loose material. Loose material should be compacted in place to a firm and unyielding condition or removed and replaced with a minimum of 6 -inches of CSBC. The CSBC should be placed in layers no greater than 6-inches and compacted to at least 95 percent of the maximum dry density. 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |10 Footings bearing on a subgrade prepared as described above can be designed using a maximum allowable bearing pressure of 1,500 psf. The maximum allowable bearing pressure may be increased by up to one-third for short-term transient loading conditions such as wind and seismic loading. We anticipate that total settlement will not exceed one inch, and differential settlement along an equivalent 50-foot length of footing will not exceed half of the total settlement. The settlement is expected to be elastic and will occur as the footings are loaded. We recommend footing subgrade preparation be evaluated by Mud Bay Geotechnical Services, LLC prior to placement of concrete. Foundation subgrade preparation should not be performed during periods of wet weather. We recommend staging the foundation subgrade excavation, compaction of native subgrade soils, and placement of CSBC to limit the time the foundation subgrade is exposed to weather. RECOMMENDED ADDITIONAL SERVICES Before construction begins, we recommend a copy of the draft plans and specifications prepared for the project are made available for review so that we can ensure that the geotechnical recommendations in this report are included in the Contract. Mud Bay Geotechnical Services, LLC is also available to provide geotechnical engineering and construction monitoring services throughout the remainder of the design and construction of the project. The integrity of the geotechnical elements of a project depend on proper site preparation and construction procedures. In addition, engineering decisions may need to be made in the field if conditions are encountered that differ from those described in this report. During the construction phase of the project, we recommend that Mud Bay Geotechnical Services, LLC be retained to review construction proposals and submittals, excavation and fill placement, drainage installation, foundation subgrade preparation, and provide recommendations for any other geotechnical considerations that may arise during construction. INTENDED USE AND LIMITATIONS This report was prepared based on observations of the surface and subsurface conditions at the site, review of geology and other information available for the site, and conversations with the property owner about the soil and surface water conditions on the p roperty and the nature of the proposed development. The geotechnical recommendations in this report are based on the current site conditions and understanding of the proposed development as described previously. Any modification of the current property conditions or the nature of the proposed development beyond what is described in this report would render these geotechnical recommendations invalid. 2131-T H U : 4 0 7 E Y e l m A v e , Y e l m W A P a g e |11 It should not be used, in part or in whole for other purposes without contacting Mud Bay Geotechnical Services, LLC for a review of the applicability of such reuse. We have enjoyed the opportunity to work with you and serve your geotechnical needs for the permitting phase of this project. Please contact me at your earliest convenience if you have any questions or would like to discuss any of the content of this report. Sincerely, Chris Heathman, P.E. Mud Bay Geotechnical Services, LLC 7/2/2023 Legend Approximate Site Location Figure 1: Site Map 407 E Yelm Ave Yelm, WA 98597 Geotechnical Report Job #:2131-THU Date:April, 2023 Approximate Parcel Boundary Legend Figure 2: WA DNR Geologic Map 407 E Yelm Ave Yelm, WA 98597 Geotechnical Report Job #:2131-THU Date:April, 2023 Geologic Units 100k Pleistocene continental glacial drift Sources: Esri, USGS | WA State Parks GIS, Esri, HERE, Garmin, FAO, NOAA, USGS, Bureau of Land Management, EPA, NPS | Washington Geological Survey, 2019, Surface geology, 1:24,000--GIS data, November 2019: Washington Geological Survey Digital Data Series DS-10, version 3.1. N Approximate Parcel Boundary Legend Figure 3: USDA Soil Map 407 E Yelm Ave Yelm, WA 98597 Geotechnical Report Job #:2131-THU Date:April, 2023 Approximate Parcel Boundary Legend Approximate Test Pit Locations EPA-1-22 Figure 4: Site Exploration Map 407 E Yelm Ave Yelm, WA 98597 Geotechnical Report Job #:2131-THU Date:April, 2023 Approximate Parcel Boundary Approximate EPA Well Locations EPA-2-22 TP-1-22 TP-2-22 TP-3-22 Figure 5: Liquefaction Hazard Map 407 E Yelm Ave Yelm, WA 98597 Geotechnical Report Job #:2131-THU Date:April, 2023 Legend Approximate Parcel Boundary Liquefaction Susceptibility Moderate Low to Moderate Moderate to High Low High Very Low to Low Very Low Bedrock Peat Sources: Esri, USGS | WA State Parks GIS, Esri, HERE, Garmin, FAO, NOAA, USGS, Bureau of Land Management, EPA, NPS | Palmer, Stephen P.; Magsino, Sammantha L.; Bilderback, Eric L.; Poelstra, James L.; Folger, Derek S.; Niggemann, Rebecca A., 2007, Liquefaction susceptibility and site class maps of Washington State, by county: Washington Division of Geology and Earth Resources Open File Report 2004-20, [78 plates, 45 p. text]. N Figure 6: WA DNR LiDAR Map 407 E Yelm Ave Yelm, WA 98597 Geotechnical Report Job #:2131-THU Date:April, 2023 Sources: Esri, USGS | WA State Parks GIS, Esri, HERE, Garmin, FAO, NOAA, USGS, Bureau of Land Management, EPA, NPS | Washington Geological Survey Legend Approximate Parcel Boundary N APPENDIX A – FINAL TEST PIT LOGS Completed:Hammer Type: Hammer Weight: Groundwater Depth: Lithology Gravel content and coarseness increasing with depth. Very loose, moist, tan, poorly-graded sand with silt and gravel (SP-SM). Gravel content and coarseness increasing with depth. Transition: Very loose, moist, tan, poorly-graded gravel with sand (GP). Groundwater monitoring well installed into base of test pit. Test Pit and Boring Log Symbols Standard Penetration Slit Spoon Sampler (SPT) California Sampler Blows/3/4"Density Shelby Tube 0-4 Very Loose CPP Sampler 5-10 Loose StabIlized Ground water 11-24 Medium Dense Groundwater At time of Drilling 25-50 Dense Bulk/ Bag Sample REF Very Dense TP-1-22 Project Number: Contractor: Equipment: Loose, moist, brown, poorly-graded sand with silt (SP-SM). Loose, moist, brown, poorly-graded sand with silt (SP-SM). Very loose, moist, brown, poorly-graded sand with silt (SP-SM). 2131-THU n/a Compact Excavator Address: Da t e Started:Bit Type:Diameter: 407 E Yelm Ave, Yelm, WA 98597 11/30/2022 Project:Client:Test Pit No. 1 of 5: Site Development Marian Licxandru n/a n/a Fluid: 11/30/2022 Humboldt H-4202A n/a Logged By:Backfilled:Hammer Drop: Hannah Anderson 11/30/2022 15 lbs 20 inches Helper:Elevation:Total Depth of Test Pit: n/a n/a Existing Surface 114 inches GPS Method:GPS Coordinates:GPS Elevation: n/a (± __ ft.)(± __ ft.) De p t h ( i n . ) Sa m p l e T y p e Sa m p l e N u m b e r Bl o w C o u n t s (b l o w s / 3 / 4 " ) Gr a p h i c L o g Blows/3/4"Consistency Mo i s t u r e C o n t e n t (% ) Ad d i t i o n a l T e s t Soil Group Name: modifier, color, moisture, density/consistency, grain size, other descriptors Rock Description: modifier, color, hardness/degree of concentration, bedding and joint characteristics, solutions, void conditions.Dr y D e n s i t y ( p c f ) Soil Density Modifiers Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays 0-1 Very Soft 2-4 Soft 5-8 Medium Stiff >60 Very Hard 9-15 Stiff 16-30 Very Stiff 31-60 Hard 24"S-1 72''S-3 6 3 48'' 96'' S-2 S-4 5 4 108''S-5 4 78'' 114'' Completed:Hammer Type: Hammer Weight: Groundwater Depth: Lithology Transition: Moist, tan, poorly-graded sand with silt (SP-SM). Gravel content and coarseness increasing with depth. Test Pit and Boring Log Symbols Standard Penetration Slit Spoon Sampler (SPT) California Sampler Blows/3/4"Density Shelby Tube 0-4 Very Loose CPP Sampler 5-10 Loose StabIlized Ground water 11-24 Medium Dense Groundwater At time of Drilling 25-50 Dense Bulk/ Bag Sample REF Very Dense TP-2-22 Project Number: Contractor: Equipment: Moist, brown, poorly-graded sand with silt (SP-SM). 2131-THU n/a Compact Excavator Address: Da t e Started:Bit Type:Diameter: 407 E Yelm Ave, Yelm, WA 98597 11/30/2022 Project:Client:Test Pit No. 2 of 5: Site Development Marian Licxandru n/a n/a Fluid: 11/30/2022 Humboldt H-4202A n/a Logged By:Backfilled:Hammer Drop: Hannah Anderson 11/30/2022 15 lbs 20 inches Helper:Elevation:Total Depth of Test Pit: n/a n/a Existing Surface 96 inches GPS Method:GPS Coordinates:GPS Elevation: n/a (± __ ft.)(± __ ft.) De p t h ( i n . ) Sa m p l e T y p e Sa m p l e N u m b e r Bl o w C o u n t s (b l o w s / 3 / 4 " ) Gr a p h i c L o g Mo i s t u r e C o n t e n t (% ) Ad d i t i o n a l T e s t Soil Group Name: modifier, color, moisture, density/consistency, grain size, other descriptors Rock Description: modifier, color, hardness/degree of concentration, bedding and joint characteristics, solutions, void conditions.Dr y D e n s i t y ( p c f ) 5-8 Medium Stiff Soil Density Modifiers Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays Blows/3/4"Consistency >60 Very Hard Moist, tan, poorly-graded sand with silt (SP-SM). Transition: Moist, tan, poorly-graded gravel with sand (GP). Moist, tan, poorly-graded gravel with sand (GP). 9-15 Stiff 16-30 Very Stiff 31-60 Hard 0-1 Very Soft 2-4 Soft 24"S-1 72'' S-3 n/a n/a96'' S-2 n/a 36" 48" Completed:Hammer Type: Hammer Weight: Groundwater Depth: Lithology Moist, tan, poorly-graded sand with silt (SP-SM). Base of falling head infiltration test, designated EPA-1-22. Test Pit and Boring Log Symbols Standard Penetration Slit Spoon Sampler (SPT) California Sampler Blows/3/4"Density Shelby Tube 0-4 Very Loose CPP Sampler 5-10 Loose StabIlized Ground water 11-24 Medium Dense Groundwater At time of Drilling 25-50 Dense Bulk/ Bag Sample REF Very Dense EPA-1-22 Project Number: Contractor: Equipment: 2131-THU n/a Compact Excavator Address: Da t e Started:Bit Type:Diameter: 407 E Yelm Ave, Yelm, WA 98597 11/30/2022 Project:Client:Test Pit No. 3 of 5: Site Development Marian Licxandru n/a n/a Fluid: 11/30/2022 Humboldt H-4202A n/a Logged By:Backfilled:Hammer Drop: Hannah Anderson 11/30/2022 15 lbs 20 inches Helper:Elevation:Total Depth of Test Pit: n/a n/a Existing Surface 48 inches GPS Method:GPS Coordinates:GPS Elevation: n/a (± __ ft.)(± __ ft.) De p t h ( i n . ) Sa m p l e T y p e Sa m p l e N u m b e r Bl o w C o u n t s (b l o w s / 3 / 4 " ) Gr a p h i c L o g Soft Mo i s t u r e C o n t e n t (% ) Ad d i t i o n a l T e s t Soil Group Name: modifier, color, moisture, density/consistency, grain size, other descriptors Rock Description: modifier, color, hardness/degree of concentration, bedding and joint characteristics, solutions, void conditions. Soil Density Modifiers Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays Dr y D e n s i t y ( p c f ) 31-60 Hard >60 Very Hard Transition: Moist, tan, poorly-graded sand with silt (SP-SM). 5-8 Medium Stiff 9-15 Stiff 16-30 Very Stiff Blows/3/4"Consistency 0-1 Very Soft 2-4 36" S-1 n/a48" Completed:Hammer Type: Hammer Weight: Groundwater Depth: Lithology Moist, brown, poorly-graded sand with silt (SP-SM). Base of falling head infiltration test, designated EPA-2-22. Test Pit and Boring Log Symbols Standard Penetration Slit Spoon Sampler (SPT) California Sampler Blows/3/4"Density Shelby Tube 0-4 Very Loose CPP Sampler 5-10 Loose StabIlized Ground water 11-24 Medium Dense Groundwater At time of Drilling 25-50 Dense Bulk/ Bag Sample REF Very Dense EPA-2-22 Project Number: Contractor: Equipment: 2131-THU n/a Compact Excavator Address: Da t e Started:Bit Type:Diameter: 407 E Yelm Ave, Yelm, WA 98597 11/30/2022 Project:Client:Test Pit No. 4 of 5: Site Development Marian Licxandru n/a n/a Fluid: 11/30/2022 Humboldt H-4202A n/a Logged By:Backfilled:Hammer Drop: Hannah Anderson 11/30/2022 15 lbs 20 inches Helper:Elevation:Total Depth of Test Pit: n/a n/a Existing Surface 36 inches GPS Method:GPS Coordinates:GPS Elevation: n/a (± __ ft.)(± __ ft.) Mo i s t u r e C o n t e n t (% ) Ad d i t i o n a l T e s t Soil Group Name: modifier, color, moisture, density/consistency, grain size, other descriptors Rock Description: modifier, color, hardness/degree of concentration, bedding and joint characteristics, solutions, void conditions.De p t h ( i n . ) Sa m p l e T y p e Sa m p l e N u m b e r Bl o w C o u n t s (b l o w s / 3 / 4 " ) Gr a p h i c L o g Dr y D e n s i t y ( p c f ) Soil Density Modifiers Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays Blows/3/4"Consistency 0-1 Very Soft 2-4 Soft 5-8 Medium Stiff >60 Very Hard 9-15 Stiff 16-30 Very Stiff 31-60 Hard 36"S-1 n/a Completed:Hammer Type: Hammer Weight: Groundwater Depth: Lithology Moist, brown, poorly-graded sand with silt (SP-SM). Sample 1 - CEC & Organic Matter testing at MTC. Transition: Moist, brown, poorly-graded sand with silt (SP-SM). Moist, brown, poorly-graded sand with silt (SP-SM). Sample 3 - Sieve Analysis testing at MTC. Gravel content and coarseness increasing with depth. Transition: Moist, tan, poorly-graded gravel with sand (GP). Sample 5 - Sieve Analysis testing at MTC. Test Pit and Boring Log Symbols Standard Penetration Slit Spoon Sampler (SPT) California Sampler Blows/3/4"Density Shelby Tube 0-4 Very Loose CPP Sampler 5-10 Loose StabIlized Ground water 11-24 Medium Dense Groundwater At time of Drilling 25-50 Dense Bulk/ Bag Sample REF Very Dense >60 Very Hard Moist, brown, poorly-graded sand with silt (SP-SM). TP-3-23 terminated due to excessive sidewall caving. Groundwater encountered at approximately 16-feet bgs. 9-15 Stiff 16-30 Very Stiff 31-60 Hard 0-1 Very Soft 2-4 Soft 5-8 Medium Stiff Soil Density Modifiers Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays Blows/3/4"Consistency Mo i s t u r e Co n t e n t ( % ) Ad d i t i o n a l T e s t Soil Group Name: modifier, color, moisture, density/consistency, grain size, other descriptors Rock Description: modifier, color, hardness/degree of concentration, bedding and joint characteristics, solutions, void conditions.De p t h ( i n . ) Sa m p l e T y p e Sa m p l e N u m b e r Bl o w C o u n t s (b l o w s / 3 / 4 " ) Gr a p h i c L o g Dr y D e n s i t y ( p c f ) GPS Method:GPS Coordinates:GPS Elevation: n/a (± __ ft.)(± __ ft.) Helper:Elevation:Total Depth of Test Pit: n/a 192 inches Existing Surface 210 inches Logged By:Backfilled:Hammer Drop: Hannah Anderson 4/21/2023 n/a n/a n/a n/a Fluid: 4/21/2023 n/a n/a 2131-THU n/a Case 580 Super N Address: Da t e Started:Bit Type:Diameter: 407 E Yelm Ave, Yelm, WA 98597 4/21/2023 Project:Client:Test Pit No. 5 of 5: Site Development Marian Licxandru TP-3-23 Project Number: Contractor: Equipment: 24"S-1 66''S-4 n/a n/a 48''S-3 n/a S-5 n/a114'' 21"S-2 n/a 210'' 192'' APPENDIX B – LABORATORY TEST RESULTS Lab Test(s) Performed:Test(s) Performed: X X Respectfully Submitted, Mark W. Peterson Laboratory Manager Sulfate SoundnessSieve Proctor Sand Equivalent Bulk Density & Voids WSDOT Degradation Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net If you have any questions concerning the test results, the procedures used, or if we can be of any further assistance please call on us at the number below. Rice Density Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Atterberg Limits Asphalt Extraction/Gradation Hydrometer Analysis Specific Gravity, Fine Specific Gravity, Coarse 2.30%See Test Report Organic Content Fracture Count CEC Moisture Content Test Results Chris Heathman May 4, 2023 S23-0484 Q.C. Mud Bay Geoech 2023 / 2131-THU Date Sampled:April 21, 2023 23S021 Date: Project: Project #: Sample #: As requested MTC, Inc. has performed the following test(s) on the sample referenced above. The testing was performed in accordance with current applicable AASHTO or ASTM standards as indicated below. The results obtained in our laboratory were as follows below or on the attached pages: Test Results Mud Bay Geotech Attn: Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Address: Client: Project:Date Received: Project #:Date Sampled: Client:Sampled By: Source:Date Tested: Sample#:Tested By: Sample #Location Tare Wet + Tare Dry + Tare Wgt. Of Moisture Wgt. Of Soil % Moisture S23-0484 Native, Sample 1 @ 21"639.9 2380.7 2178.2 202.5 1538.3 12.8% 0.0 0.0 #DIV/0! 0.0 0.0 #DIV/0! 0.0 0.0 #DIV/0! 0.0 0.0 #DIV/0! 0.0 0.0 X 0.0 0.0 #DIV/0! 0.0 0.0 #DIV/0! 0.0 0.0 #DIV/0! 0.0 0.0 #DIV/0! Sample #Location Tare % Organics S23-0484 Native, Sample 1 @ 21"169.7 2.3% #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! Reviewed by: Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting 229.8 228.4 Moisture Content - ASTM C-566, ASTM D-2216 & AASHTO T-265 Organic Content - ASTM D-2974, AASHTO T-267 Soil + Tare, Pre-Ignition Soil + Tare, Post Ignition April 21, 2023 Client Q.C. Mud Bay Geotech 2023 23S021 April 21, 2023 Mud Bay Geotech Native, Sample 1 @ 21" S23-0484 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval. Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Madison Miller April 26, 2023 Lab Test(s) Performed:Test(s) Performed: X Respectfully Submitted, Mark W. Peterson Laboratory Manager Sulfate SoundnessSieve Proctor Sand Equivalent Bulk Density & Voids See Test Report WSDOT Degradation Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net If you have any questions concerning the test results, the procedures used, or if we can be of any further assistance please call on us at the number below. Rice Density Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Atterberg Limits Asphalt Extraction/Gradation Hydrometer Analysis Specific Gravity, Fine Specific Gravity, Coarse Organic Content Fracture Count CEC Moisture Content Test Results Chris Heathman April 26, 2023 S23-0450 Q.C. Mud Bay Geo-2023-2131-THU Date Sampled:April 21, 2023 23S021 Date: Project: Project #: Sample #: As requested MTC, Inc. has performed the following test(s) on the sample referenced above. The testing was performed in accordance with current applicable AASHTO or ASTM standards as indicated below. The results obtained in our laboratory were as follows below or on the attached pages: Test Results Mud Bay Geo Tech Attn: Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Address: Client: Project:DateSampled: Project #:Date Received: Client:Sampled By:Client Source:Date Tested: Sample#:S23-0450 Tested By:Madison Miller D(5) =0.061 mm % Gravel =3.4%Coeff. of Curvature, CC =1.18 Specifications 0.144 mm % Sand =90.5%Coeff. of Uniformity, CU =3.24 No Specs 0.194 mm % Silt & Clay =6.1%Fineness Modulus =2.05 Sample Meets Specs ?N/A 0.281 mm Liquid Limit =0.0%Plastic Limit =0.0% 0.389 mm Plasticity Index =0.0%Moisture %, as sampled =10.5% D(60) =0.467 mm Sand Equivalent =n/a Req'd Sand Equivalent = D(90) =0.894 mm Fracture %, 1 Face =0.0%Req'd Fracture %, 1 Face =75 Min. % Dust Ratio =4/37 Fracture %, 2+ Faces =n/a Req'd Fracture %, 2+ Faces = Actual Interpolated See Test Report Cumulative Cumulative Sieve Size Percent Percent Specs Specs US Metric Passing Passing Max Min 12.00"300.00 100%100.0%0.0% 10.00"250.00 100%100.0%0.0% 8.00"200.00 100%100.0%0.0% 6.00"150.00 100%100.0%0.0% 4.00"100.00 100%100.0%0.0% 3.00"75.00 100%100.0%0.0% 2.50"63.00 100%100.0%0.0% 2.00"50.00 100%100.0%0.0% 1.75"45.00 100%100.0%0.0% 1.50"37.50 100%100.0%0.0% 1.25"31.50 100%100.0%0.0% 1.00"25.00 100%100%100.0%0.0% 3/4"19.00 99%99%100.0%0.0% 5/8"16.00 98%100.0%0.0% 1/2"12.50 98%98%100.0%0.0% 3/8"9.50 97%97%100.0%0.0% 1/4"6.30 97%100.0%0.0% #4 4.75 97%97%100.0%0.0% #8 2.36 96%96%100.0%0.0% #10 2.00 96%96%100.0%0.0% #16 1.18 92%100.0%0.0% #20 0.850 90%90%100.0%0.0% #30 0.600 70%100.0%0.0% #40 0.425 57%57%100.0%0.0% #50 0.300 33%100.0%0.0% #60 0.250 24%24%100.0%0.0% #80 0.180 13%13%100.0%0.0% #100 0.150 10%10%100.0%0.0% #140 0.106 8%100.0%0.0% #170 0.090 7%100.0%0.0% #200 0.075 6.1%6.1%100.0%0.0% Copyright Spears Engineering & Technical Services PS, 1996-98 Comments: Reviewed by: Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Q.C. Mud Bay Geo-2023-2131-THU 23S021 Mud Bay Geo Tech April 26, 2023 Sample Color: JP-1-23 3 @ 4ft April 21, 2023 April 25, 2023 Materials Testing & Consulting, Inc. Visit our website: www.mtc-inc.net All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval. Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 ASTM D-2487 Unified Soils Classification System ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821 Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Sieve Report ASTM C-136, ASTM D-6913 SP-SM, Poorly graded Sand with Silt Brown 8"6"4"2"3" 1½ " 1¼ " 10 " 1" ¾" 5/ 8 " ½" 3/ 8 " ¼" #4 #8 #1 0 #1 6 #2 0 #3 0 #4 0 #5 0 #6 0 #8 0 #1 0 0 #1 4 0 #1 7 0 #2 0 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 0.0010.0100.1001.00010.000100.000 % P a s s i n g % P a s s i n g Particle Size (mm) Grain Size Distribution Sieve Sizes Max Specs Min Specs Sieve Results Lab 23S021 Test(s) Performed:Test(s) Performed: X Respectfully Submitted, Mark W. Peterson Laboratory Manager Attn: Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Address: Client: Test Results Chris Heathman April 26, 2023 S23-0449 Q.C. Mud Bay Geo-2023-2131-THU Date Sampled:April 21, 2023 23S021 Date: Project: Project #: Sample #: As requested MTC, Inc. has performed the following test(s) on the sample referenced above. The testing was performed in accordance with current applicable AASHTO or ASTM standards as indicated below. The results obtained in our laboratory were as follows below or on the attached pages: Test Results Mud Bay Geo Tech Specific Gravity, Coarse Organic Content Fracture Count CEC Moisture Content Atterberg Limits Asphalt Extraction/Gradation Hydrometer Analysis Specific Gravity, Fine Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net If you have any questions concerning the test results, the procedures used, or if we can be of any further assistance please call on us at the number below. Rice Density Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Sulfate SoundnessSieve Proctor Sand Equivalent Bulk Density & Voids See Test Report WSDOT Degradation Project:DateSampled: Project #:Date Received: Client:Sampled By:Client Source:Date Tested: Sample#:S23-0449 Tested By:Madison Miller D(5) =0.261 mm % Gravel =76.1%Coeff. of Curvature, CC =3.85 Specifications 0.495 mm % Sand =22.6%Coeff. of Uniformity, CU =85.67 No Specs 1.105 mm % Silt & Clay =1.3%Fineness Modulus =6.82 Sample Meets Specs ?N/A 8.992 mm Liquid Limit =0.0%Plastic Limit =0.0% 31.037 mm Plasticity Index =0.0%Moisture %, as sampled =8.2% D(60) =42.430 mm Sand Equivalent =n/a Req'd Sand Equivalent = D(90) =#####mm Fracture %, 1 Face =0.0%Req'd Fracture %, 1 Face =75 Min. % Dust Ratio =7/51 Fracture %, 2+ Faces =n/a Req'd Fracture %, 2+ Faces = Actual Interpolated See Test Report Cumulative Cumulative Sieve Size Percent Percent Specs Specs US Metric Passing Passing Max Min 12.00"300.00 100%100.0%0.0% 10.00"250.00 100%100.0%0.0% 8.00"200.00 100%100.0%0.0% 6.00"150.00 100%100%100.0%0.0% 4.00"100.00 85%85%100.0%0.0% 3.00"75.00 79%100.0%0.0% 2.50"63.00 77%77%100.0%0.0% 2.00"50.00 69%69%100.0%0.0% 1.75"45.00 63%100.0%0.0% 1.50"37.50 54%54%100.0%0.0% 1.25"31.50 50%100.0%0.0% 1.00"25.00 46%46%100.0%0.0% 3/4"19.00 41%41%100.0%0.0% 5/8"16.00 38%100.0%0.0% 1/2"12.50 34%34%100.0%0.0% 3/8"9.50 31%31%100.0%0.0% 1/4"6.30 26%100.0%0.0% #4 4.75 24%24%100.0%0.0% #8 2.36 19%19%100.0%0.0% #10 2.00 18%18%100.0%0.0% #16 1.18 15%100.0%0.0% #20 0.850 14%14%100.0%0.0% #30 0.600 11%100.0%0.0% #40 0.425 9%9%100.0%0.0% #50 0.300 6%100.0%0.0% #60 0.250 5%5%100.0%0.0% #80 0.180 3%3%100.0%0.0% #100 0.150 2%2%100.0%0.0% #140 0.106 2%100.0%0.0% #170 0.090 1%100.0%0.0% #200 0.075 1.3%1.3%100.0%0.0% Copyright Spears Engineering & Technical Services PS, 1996-98 Comments: Reviewed by: Materials Testing & Consulting, Inc. Visit our website: www.mtc-inc.net All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval. Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 ASTM D-2487 Unified Soils Classification System ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821 Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Sieve Report ASTM C-136, ASTM D-6913 GP, Poorly graded Gravel with Sand Brown Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Q.C. Mud Bay Geo-2023-2131-THU 23S021 Mud Bay Geo Tech April 26, 2023 Sample Color: JP-1-23 5 @ 9.5ft April 21, 2023 April 25, 2023 8"6"4"2"3" 1½ " 1¼ " 10 " 1" ¾" 5/ 8 " ½" 3/ 8 " ¼" #4 #8 #1 0 #1 6 #2 0 #3 0 #4 0 #5 0 #6 0 #8 0 #1 0 0 #1 4 0 #1 7 0 #2 0 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% 0.0010.0100.1001.00010.000100.000 % P a s s i n g % P a s s i n g Particle Size (mm) Grain Size Distribution Sieve Sizes Max Specs Min Specs Sieve Results Sample No. Description Location Sampled Spectra Labs - Tacoma received samples from Mud Bay Geotechnical Services on Tuesday, April 25, 2023 at 11:58 am. Unless otherwise noted, all samples were received in good condition and were tested in accordance with the laboratory's quality control procedures. A summary of the samples received are outlined below. 306206-01 04/21/2023 11:00S1 @ 21" This report package contains laboratory sample results and any attachments listed below. If you have any questions please call (253) 272-4850 or email us at office@spectra-lab.com. Attachments Analytical Report: Analytical Resources, LLC.01) Approved By Randa Ross Project Manager This report is issued solely for the use of the person or company to whom it is addressed. Any use, copying or disclosure other than by the intended recipient is unauthorized. If you have received this report in error, please notify the sender immediately at 253-272-4850 and destroy this report promptly. These results relate only to the items tested and the sample(s) as received by the laboratory. This report shall not be reproduced except in full, without prior express written approval by Spectra Laboratories. 06/02/2023 Page 1 of 2 MUD BAY GEO Accounts Payable 1001 Cooper Point Rd SW Suite 140 PMB 108 Olympia, WA 98502 Date Received 04/25/2023 Project 1721-THY Analytical Report PO Number 1721-THY Lab No:306206-01 Sample Date: 04/21/23 11:00 Units AnalystAnalysis DateMethodResultAnalyte Client ID:S1 @ 21" QualifiersPQL mEq/100g1.70 ARL5/25/2023EPA 9080Cation Echange Capcity D0.27 Lab Qualifiers Comments: This report is issued solely for the use of the person or company to whom it is addressed. Any use, copying or disclosure other than by the intended recipient is unauthorized. If you have received this report in error, please notify the sender immediately at 360-443-7845 and destroy this report promptly. These results relate only to the items tested and the sample(s) as received by the laboratory. This report shall not be reproduced except in full, without prior express written approval by Spectra Laboratories. ARL = Analyzed by Analytical Resources. See complete report provided. D = The reported value is from a dilution 06/02/2023 Page 2 of 2 SPECIAL INSTRUCTIONS/COMMENTS: 1 2 3 4 E E i E c 1C SPECTRA Laboratories 2221 Ross Way, Tacoma, WA 98421 (253) 272-4850 Fax (253) 572-9838 www.spectra-lab.com info@spectra-lab.com Return Samples: Y N Page of CHAIN OF CUSTODY SPECTRA PROJECT #eJ STANDARD 4..nL.+O gQ�t (a.c�"�►a1-i�¢J�+c� AD E ' CLIENT: 'bize--J ADDRESS: CHANGE PROJECT: W w Z z 0 LL O w m z HYDROCARBONS ORGANICS METALS OTHER CONTACT- p U = a r z w m = z= w m IL x a a ~ w cn `o o LL w 2 `O ¢ N= co o Nw FCo W p O U 0 a a > g rn N¢ co 6 Co z a. a o" C11 m a Co 0 0 W v Q¢ W H �� r - a W H M L) J F a H LL a Cl) F s H � o o M a� O R O o m Cl H O a = N g p- M } U W N O J J .. SAMPLED BY: PHONE:3��`��'Z1e� FAX: Prefer FAX e-MAIL: w.�tdp�gi+� w G%,o,.c 5=4—A or a - MAIL 0 PURCHASE ORDER # SAMPLE ID DATE SAMPLED TIME SAMPLED MATRIX LAB USE ONLY SIGNATURE PRINTED NAME COMPANY DATE TIME RELINQUISHED BYA7� �NtaF� 1.� gt T 1 RECEIVED BY �� r f"r y� �� 6 • sa RELINQUISHED BY RECEIVED BY Payment Terms: Net 30 days. Past due accounts subject to 1 1/2% per month interest. Customer agrees to pay all costs of collection including reasonable attorney's fees and all other costs of collection regardless of whether suit is filed in Pierce Co., WA venue. Spectra Laboratories, LLC Spectra Laboratories RE: General Analyses (306206) Tacoma, WA 98421 2221 Ross Way Randa Ross Please find enclosed sample receipt documentation and analytical results for samples from the project referenced above. Sample analyses were performed according to ARI's Quality Assurance Plan and any provided project specific Quality Assurance Plan. Each analytical section of this report has been approved and reviewed by an analytical peer, the appropriate Laboratory Supervisor or qualified substitute, and a technical reviewer. Should you have any questions or problems, please feel free to contact us at your convenience. 02 June 2023 Associated Work Order(s) Associated SDG ID(s) 23D0627 N/A ----- I certify that this data package is in compliance with the terms and conditions of the contract, both technically and for completeness, for other than the conditions detailed in the enclose Narrative. ARI, an accredited laboratory, certifies that the report results for which ARI is accredited meets all the requirements of the accrediting body. A list of certified analyses, accreditations, and expiration dates is included in this report. Release of the data contained in this hardcopy data package has been authorized by the Laboratory Manager or his/her designee, as verified by the following signature. 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Phillip Bates, Project Manager Cert# 100006-012 Page 1 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Page 2 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report ANALYTICAL REPORT FOR SAMPLES Sample ID Laboratory ID Matrix Date Sampled Date Received 306206-01 23D0627-01 Solid 21-Apr-2023 11:00 26-Apr-2023 12:45 Page 3 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report Client: Spectra Laboratories Project: General Analyses Project Number: 306206 Work Order: 23D0627 Sample receipt Samples as listed on the preceding page were received 26-Apr-2023 12:45 under ARI work order 23D0627. For details regarding sample receipt, please refer to the Cooler Receipt Form. Wet Chemistry The sample(s) were prepared and analyzed within the recommended holding times. Initial and continuing calibrations were within method requirements. The method blank(s) were clean at the reporting limits. The blank spike (BS) percent recoveries were within control limits. The matrix spike (MS) percent recoveries and the duplicate (DUP) relative percent difference (RPD) were within advisory control limits except for the CEC duplicate RPD which was above the advisory control limits, data reported as-is. Work Order Case Narrative Page 4 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Page 5 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report 306206-01 23D0627-01 (Solid) Sampled: 04/21/2023 11:00Method: EPA 9080 Wet Chemistry Instrument: Accumet XL60 Analyst: BF Analyzed: 05/25/2023 15:15 Analysis by: Analytical Resources, LLC Dry Weight:14.00 g % Solids: 88.95 Preparation Batch: BLE0015 Prepared: 05/01/2023 Final Volume: 250 mL Preparation Method: EPA 9080Sample Preparation: Sample Size: 15.74 g (wet) Extract ID: 23D0627-01 A Limit Reporting Result Notes UnitsDilutionAnalyte Detection LimitCAS Number 5 meq/100 g0.270.27 DCation Exchange Capacity 1.70 Page 6 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report 306206-01 23D0627-01 (Solid) Sampled: 04/21/2023 11:00Method: SM 2540 G-97 Wet Chemistry Instrument: BAL2 Analyst: UW Analyzed: 04/27/2023 12:00 Analysis by: Analytical Resources, LLC Dry Weight:4.45 g % Solids: 88.95 Preparation Batch: BLD0773 Prepared: 04/27/2023 Final Volume: 5 g Preparation Method: No Prep Wet ChemSample Preparation: Sample Size: 5 g (wet) Extract ID: 23D0627-01 Limit Reporting Result Notes UnitsDilutionAnalyte Detection LimitCAS Number 1 %0.040.04Total Solids 88.95 Page 7 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report Analysis by: Analytical Resources, LLC Batch BLD0773 - SM 2540 G-97 Wet Chemistry - Quality Control Instrument: BAL2 Analyst: UW Result Limit Reporting Units Level Spike Result Source %REC %REC Limits RPD RPD Limit Notes QC Sample/Analyte Detection Limit Prepared: 27-Apr-2023 Analyzed: 27-Apr-2023 12:00Blank (BLD0773-BLK1) 0.04ND %U0.04Total Solids Page 8 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report Analysis by: Analytical Resources, LLC Batch BLE0015 - EPA 9080 Wet Chemistry - Quality Control Instrument: Accumet XL60 Analyst: BF Result Limit Reporting Units Level Spike Result Source %REC %REC Limits RPD RPD Limit Notes QC Sample/Analyte Detection Limit Prepared: 01-May-2023 Analyzed: 25-May-2023 15:15Blank (BLE0015-BLK1) 0.25ND meq/100 g U0.25Cation Exchange Capacity Prepared: 01-May-2023 Analyzed: 25-May-2023 15:15Source: 23D0627-01Duplicate (BLE0015-DUP1) 0.287.42 1.70 20125.00meq/100 g *, D0.28Cation Exchange Capacity Page 9 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report Certified Analyses included in this Report CertificationsAnalyte EPA 9080 in Solid NELAP,WADOECation Exchange Capacity Code Description Number Expires 17-015Alaska Dept of Environmental Conservation 03/28/2025ADEC 66169DoD-Environmental Laboratory Accreditation Program, PJLA Testing 02/28/2025DoD-ELAP WA100006-012ORELAP - Oregon Laboratory Accreditation Program 05/12/2023NELAP C558WA Dept of Ecology 06/30/2023WADOE C558Ecology - Drinking Water 06/30/2023WA-DW Page 10 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 Project: Project Number: Project Manager: Reported: Spectra Laboratories 2221 Ross Way 306206 Randa Ross General Analyses 02-Jun-2023 09:02Tacoma WA, 98421 Analytical Report Notes and Definitions Flagged value is not within established control limits.* The reported value is from a dilutionD This analyte is not detected above the reporting limit (RL) or if noted, not detected above the limit of detection (LOD).U Sample results reported on a dry weight basis Relative Percent DifferenceRPD dry Not ReportedNR Analyte NOT DETECTED at or above the reporting limitND Analyte DETECTEDDET [2C]Indicates this result was quantified on the second column on a dual column analysis. Page 11 of 11 23D0627 ARISample FINAL 02 Jun 2023 0902 United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Thurston County Area, Washington 407 Yelm Ave. E Natural Resources Conservation Service August 30, 2023 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 Soil Map..................................................................................................................5 Soil Map................................................................................................................6 Legend..................................................................................................................7 Map Unit Legend..................................................................................................8 Map Unit Descriptions..........................................................................................8 Thurston County Area, Washington................................................................10 74—Nisqually loamy fine sand, 3 to 15 percent slopes...............................10 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 6 Custom Soil Resource Report Soil Map 51 9 8 3 4 0 51 9 8 3 6 0 51 9 8 3 8 0 51 9 8 4 0 0 51 9 8 4 2 0 51 9 8 4 4 0 51 9 8 4 6 0 51 9 8 4 8 0 51 9 8 5 0 0 51 9 8 5 2 0 51 9 8 3 4 0 51 9 8 3 6 0 51 9 8 3 8 0 51 9 8 4 0 0 51 9 8 4 2 0 51 9 8 4 4 0 51 9 8 4 6 0 51 9 8 4 8 0 51 9 8 5 0 0 51 9 8 5 2 0 530180 530200 530220 530240 530260 530280 530300 530320 530200 530220 530240 530260 530280 530300 530320 46° 56' 22'' N 12 2 ° 3 6 ' 1 2 ' ' W 46° 56' 22'' N 12 2 ° 3 6 ' 5 ' ' W 46° 56' 16'' N 12 2 ° 3 6 ' 1 2 ' ' W 46° 56' 16'' N 12 2 ° 3 6 ' 5 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 45 90 180 270Feet 0 10 20 40 60Meters Map Scale: 1:947 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Thurston County Area, Washington Survey Area Data: Version 16, Sep 8, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 18, 2020—Jul 20, 2020 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 7 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 74 Nisqually loamy fine sand, 3 to 15 percent slopes 1.0 100.0% Totals for Area of Interest 1.0 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 8 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 9 Thurston County Area, Washington 74—Nisqually loamy fine sand, 3 to 15 percent slopes Map Unit Setting National map unit symbol: 2ndc9 Elevation: 160 to 1,310 feet Mean annual precipitation: 40 to 60 inches Mean annual air temperature: 50 degrees F Frost-free period: 150 to 200 days Farmland classification: Farmland of statewide importance Map Unit Composition Nisqually and similar soils:85 percent Minor components:5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Nisqually Setting Landform:Terraces Parent material:Sandy glacial outwash Typical profile H1 - 0 to 5 inches: loamy fine sand H2 - 5 to 31 inches: loamy fine sand H3 - 31 to 60 inches: loamy sand Properties and qualities Slope:3 to 15 percent Depth to restrictive feature:More than 80 inches Drainage class:Somewhat excessively drained Capacity of the most limiting layer to transmit water (Ksat):High (1.98 to 5.95 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Low (about 4.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: A Ecological site: R002XA006WA - Puget Lowlands Prairie Forage suitability group: Droughty Soils (G002XS401WA) Other vegetative classification: Droughty Soils (G002XS401WA) Hydric soil rating: No Minor Components Yelm Percent of map unit:3 percent Hydric soil rating: No Norma Percent of map unit:2 percent Custom Soil Resource Report 10 Landform:Depressions Other vegetative classification:Wet Soils (G002XS101WA) Hydric soil rating: Yes Custom Soil Resource Report 11