RPT - Maintenance - 2023.09.05
TAHOMA TERRA COMMERCIAL
22-005
Maintenance & Source Control Manual
Prepared for: Tahoma Terra Holdings, LLC
PO Box 73790
Puyallup, WA 98373
(253) 820-7835
evan@soundbuilthomes.com
Report Date: September 5, 2023
Prepared by: Augustus Brinckmeyer, EIT
Reviewed by: Chloe McIntyre, P.E.
HATTON GODAT PANTIER
3910 Martin Way E., Suite B
Olympia, WA 98506
(360) 943-1599
Project No: 22-005
Project Name: TAHOMA TERRA COMMERCIAL
H:\Office\JOBS\2022\22-005 Tahoma Commercial\PERMIT\Drainage\Facility Maintenance
Guide\RPT - Stormwater Facility Maintenance Guide.docx
TABLE OF CONTENTS
Introduction ................................................................................................................... 1
What Is Stormwater Runoff? ............................................................................................................ 1
What Is a Storm Drain System and How Does It Work? ................................................................. 1
What Does Stormwater Runoff Have to Do With Water Quality? .................................................... 1
Section 1 – Project Description ................................................................................... 1
Section 2 – Maintenance Importance and Intent ........................................................ 2
Section 3 – Responsible Parties .................................................................................. 2
Section 4 – Facilities Requiring Maintenance ............................................................. 3
Section 5 – Maintenance Instructions ......................................................................... 4
How to Use the Stormwater Facility Maintenance Guide ................................................................ 4
Included in This Guide ..................................................................................................................... 4
Facility Key ....................................................................................................................................... 4
Site Plan ........................................................................................................................................... 5
Quick List ......................................................................................................................................... 6
Resource Listing .............................................................................................................................. 7
Section 6 – Vegetation Management ........................................................................... 8
Landscape Design and Maintenance ............................................................................................... 8
Pest Control ................................................................................................................................... 11
Pesticide Management................................................................................................................... 11
Section 7 – Pollution Source Control Measures ....................................................... 13
Purpose .......................................................................................................................................... 13
Materials Used and Wastes Generated ......................................................................................... 13
General Principals of Pollution Prevention..................................................................................... 13
Appendix A – Maintenance Covenant ....................................................................... 17
Appendix B – Maintenance Checklists ...................................................................... 18
Log Sheet ....................................................................................................................................... 33
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 1
Introduction
What Is Stormwater Runoff?
When urban and suburban development covers the land with buildings, streets and parking lots,
much of the native topsoil, duff, trees, shrubs and grass are replaced by asphalt and concrete.
Rainfall that would have soaked directly into the ground instead stays on the surface as stormwater
runoff making its way into storm drains (including man-made pipes, ditches or swale networks),
stormwater ponds, surface and groundwater and, eventually, to Puget Sound.
What Is a Storm Drain System and How Does It Work?
The storm drain system for most developments includes measures to carry, store, cleanse and
release the stormwater. Components work together to reduce the impacts of development on the
environment. Impacts can include flooding that results in property damage and blocked emergency
routes, erosion that can cause damage to salmon spawning habitat and pollution that harms fish
and/or drinking water supplies.
The storm drain system provides a safe method to carry stormwater to the treatment and storage
area. Filter Strips and ponds filter pollutants from the stormwater by physically settling out
particles, chemically binding pollutants to pond sediments and biologically converting pollutants to
less harmful compounds. Ponds also store treated water, releasing it gradually to a nearby stream
or to groundwater.
What Does Stormwater Runoff Have to Do With Water Quality?
Stormwater runoff must be treated because it carries litter, oil, gasoline, fertilizers, pesticides, pet
wastes, sediments and anything else that can float, dissolve or be swept along by moving water.
Left untreated, polluted stormwater can reach nearby waterways where it can harm and even kill
aquatic life. It can also pollute groundwater to the extent that it requires treatment before it is
suitable for drinking. Nationally, stormwater is recognized as a major threat to water quality.
Remember to keep everything out of stormwater systems except the rainwater they are designed
to collect.
Section 1 – Project Description
The Tahoma Terra Commercial project is located northwest of Tahoma Blvd SE and west of Berry
Valley Rd. in the City of Yelm in Section 24, Township 17, Range 1 East, Quarter NW SW & NE
SW on tax parcel number 78640000012 W.M. The project proposes to construct nine, 5,500
square feet, multifamily apartment buildings for a total of 49,800 square feet, and 11,900 square
feet of storage units and mixed use commercial across 15 buildings. The Retail portion of the site
includes two retail buildings for a total of 6,990 square feet. A 176,400 square foot permeable
pavement parking lot and drive aisle serves as access for the site. The project also proposes
required drainage, landscaping, sewer, and water service improvements.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 2
Section 2 – Maintenance Importance and Intent
The importance of maintenance for the proper functioning of stormwater control facilities cannot be
over-emphasized. A substantial portion of failures (clogging of filters, resuspension of sediments,
loss of storage capacity, etc.) are due to inadequate maintenance. Stormwater BMP maintenance
is essential to ensure that BMPs function as intended throughout their full life cycle.
The fundamental goals of maintenance activities are to ensure the entire flow regime and treatment
facilities designed for this site continue to fully function. For this site these include:
• Maintain designed stormwater infiltration capacity
• Maintain designed stormwater detention/retention volume
• Maintain ability of storm facility to attenuate flow rates
• Maintain ability to safely convey design stormwater flows
• Maintain ability to treat stormwater runoff quality
• Preserve soil and plant health, as well as stormwater flow contact with plant and soil
systems
• Clearly identify systems so they can be protected
• Keep maintenance costs low
• Prevent large-scale or expensive stormwater system failures
• Prevent water quality violations or damage to downstream properties
The intent of this section and manual is to pass on to the responsible party(s) all the information
critical to understand the design of the system, risks and considerations for proper use,
suggestions for maintenance frequencies, and cost so that realistic budgets can be established.
Section 3 – Responsible Parties
All stormwater facilities require maintenance. Regular maintenance ensures proper functioning and
preserves visual appeal. The property owner is responsible for many of the mitigation measures
discussed herein. This Maintenance and Source Control Plan is recorded against the title this
property. Enforcement of the recommendations lies with the underlying jurisdictions, and the
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 3
property owners should strive to incorporate them in their daily activities. All parties below shall
read this Maintenance and Source Control Plan:
Specific Responsibilities
Landscape Maintenance Developer / Maintenance Contractors / Property Owners
Common Facilities Developer / Maintenance Contractors / Property Owners
Stormwater Facilities Developer / Maintenance Contractors / Property Owners
Section 4 – Facilities Requiring Maintenance
This Maintenance and Source Control Manual was designed to explain how stormwater facilities
work and provide user-friendly, straightforward guidance on facility maintenance.
Private stormwater facilities on this site include permeable pavement facilities, catch basins, pipes,
infiltration trenches, and energy disspaters.
All stormwater facilities located in the public right-of-way are maintained by city of Yelm.
The property owner is responsible for all private stormwater facilities.
Permeable pavement facilities accept water from downspouts and catch basins where the flow is
distributed via a perforated pipe, into the storage/infiltration layer of the permeable pavement
facility for infiltration. All other flows either fall directly onto the permeable pavement surface or
flows as predeveloped conditions. Due to the nature of the permeable pavement the flow through
the porous asphalt is vital in the performance of the facility. Debris must stay clear of all
conveyance piping and the pores of the asphalt.
See the Drainage Report submitted as part of the Drainage Control Plan for a more detailed
explanation of the onsite stormwater facility design and operation.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 4
Section 5 – Maintenance Instructions
The stormwater system owner(s) must review and apply the maintenance requirements contained
in the Stormwater Maintenance Agreement. The owner shall inspect all stormwater facilities
annually and maintain them at their own expense. The owner shall complete and file an inspection
and maintenance form with the city following inspection and maintenance. When inspections
indicate a maintenance need, the owner shall complete all maintenance within one year for typical
maintenance of facilities, within six months for catch basins, and within two years for maintenance
that requires capital construction of greater than $25,000.
How to Use the Stormwater Facility Maintenance Guide
This Maintenance & Source Control Manual includes a Site Plan specific to your development and
a Facility Key that identifies the private stormwater facilities you are responsible for maintaining. A
“Quick List” of maintenance activities has also been included to help you identify the more routi ne
needs of your facility.
Included in This Guide
• Comprehensive Maintenance Checklists that provide specific details on required
maintenance located in Appendix B
• Pollution Prevention Tips that list ways to protect water quality and keep storm drain
systems functioning smoothly
• Resources to provide more information and technical assistance
Facility Key
The stormwater facilities in your neighborhood are comprised of the following elements:
Type of Feature and Checklist Name Location on Site Plan
Permeable Pavement Facility 1
Conveyance Pipe
2
Catch Basin 3
Overflow Trench 4
Energy Dissipaters 5
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 5
Site Plan
C
PERMEABLE
PAVEMENT
(TYP)
TYPE 1 CATCH
BASIN (TYP)
ROOF DRAIN (TYP)
N
HATTON
GODAT
PANTIERN.T.S.
6" PERFORATED
PIPE DISTRIBUTION
TO PERMEABLE
PAVEMENT (TYP)
SITE PLAN
ROOF DRAIN
CLEANOUT (TYP)
ROOF DRAINS TO PERMEABLE
PAVEMENT (TYP)TAHOMA BLVD SETA+20A TE55A &200E5&IAL
BERRY
VALLEY
RD SET5A&T
A
L2T
L2T
L2T
L2T
L2T
T+20A %L9' SE <EL0 :A
%E55< 9ALLE< 5' SE <EL0 :A
PERMEABLE
PAVEMENT
(TYP)
6" PERFORATED
PIPE DISTRIBUTION
TO PERMEABLE
PAVEMENT (TYP)
C2
1
FACILITY MAINTENANCE MAP - NORTHN HATTONGODATPANTIERN.T.S.TAHOMA TERRA COMMERCIAL
3
2
3
TAHOMA %L9' SE YELM :A
%ERRY 9ALLEY R' SE YELM :A
5 MATCH LINEMATCH LINEBERRY
VALLEY
RD SETAHOMABLVD SE
2
3
1
4
2
55
3
3
FACILITY MAINTENANCE MAP - SOUTH
N
HATTON
GODAT
PANTIERN.T.S.
TAHOMA TE55A COMME5CIAL
2
1
2
TAHOMA %L9' SE YELM :A
%E55Y 9ALLEY 5' SE YELM :A
4
5
5
5
MATCH LINEMATCH LINE
3
TAHOMABLVD SE
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 6
Quick List
The following is an abbreviated checklist of the most common types of maintenance required.
Please go over this checklist after heavy rains. The list represents minimum maintenance to be
performed and should be completed in conjunction with the other checklists for an effective
maintenance program. More comprehensive maintenance checklists specific to each onsite
stormwater facility are included in Appendix B.
❑ Inspect catch basin grates to see that they are not clogged or broken. Remove twigs,
leaves or other blockages. Contact the local jurisdiction to replace the grate if it is broken.
❑ Inspect inlet and outlet pipes for blockages. Clear all blockages.
❑ Inspect filter strip, swale and pond walls for erosion or caved in areas.
❑ Inspect riprap (rocks) at the inlets and outlets of culverts and other pipes. If they are silted
in or eroded away, replace them.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 7
Resource Listing
If you suspect a problem exists, please contact your local jurisdiction at one of the numbers below
and ask for Technical Assistance.
CONTACT NUMBERS
Yelm Public Works Department (360) 458-8406
City of Yelm Spill Reporting Hotline (360) 458-8406
Thurston County Environmental Health –
Hazardous Waste Disposal
(360) 754-4111
Thurston County Environmental Health –
Solid Waste Disposal
(360) 789-5136
WSU Thurston Co. Extension (360) 786-5445
DEVELOPER INFORMATION
Tahoma Terra Holdings, LLC
PO Box 73790
Puyallup, WA 98373
(253) 820-7835
ENGINEER’S INFORMATION
Hatton Godat Pantier
3910 Martin Way E., Suite B
Olympia, WA 98506
(360) 943-1599
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 8
Section 6 – Vegetation Management
The property owners and Landscape Maintenance Contractors are responsible for applying
integrated pest management control techniques to maintain landscaped areas. This includes pest
control, pesticide management, and watering. Reference the construction drawings in the Drainage
Control Plan for detailed information on landscaping throughout the site.
Landscape Design and Maintenance
The following techniques shall be applied:
1. Native Plants: One of the best methods of reducing impacts to water resources is by using
landscaping materials that do not require extensive care. Native plants have adapted
themselves to our region, particularly their root structure and water needs. Thes e plants
have also built tolerances over the centuries to local pests and disease. By using native
plants in the landscape, we are less likely to need fertilizers, herbicides, and pesticides.
Native plants are also more tolerant of drought conditions and typically require less water.
The Developer shall install the native plant materials called out on the Landscape Plan.
Additional plantings may be installed by individual homeowners /property owners.
Native plants come in all shapes and sizes so there is probably one that will fit into your
landscape plans. There are deciduous and evergreen varieties of trees, shrubs and
groundcovers. Some suggested species of native plants are listed below. Contact your
local garden supply store for more ideas on use of native plants in your garden.
Evergreen Plants:
Trees: Western red cedar, Douglas-fir, Western hemlock
Shrubs: rhododendron, evergreen huckleberry, tall Oregon-grape
Ferns: lady fern, sword fern, dear fern
Groundcover: manzanita, kinnikinnik, common juniper
Deciduous Plants:
Trees: big leaf maple, Pacific dogwood, bitter cherry
Shrubs: western azalea, Nootka rose, red huckleberry
2. Grasses for Lawns: Both the developer and individual homeowners /property owners will
install lawns. The lawn is a major component of the landscape. Selection of a grass well
suited to our area is an important step in reducing the impact to water resources. The
National Turfgrass Evaluation studies various types of grasses for their resistance to
insects, drought tolerance, seasonal appearance, density, the strength of their sod and leaf
texture. Based upon these characteristics, specific grass types are recommended for
specific areas throughout the country. Fescue and perennial rye grass are recommended
for this area.
3. Mulching: Use of native plants will greatly reduce the need for fertilizer. Use of mulch may
eliminate the need altogether. Mulch acts as a physical barrier to weeds and is an
excellent alternative to herbicides. Mulch can be compost, bark or wood chip s, or leaves
and grass clippings. It should be spread around the base of plants and within flowerbeds.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 9
The recommended depth of mulch varies between plant varieties but should typically be 2 -
to 4 inches.
4. Use of Fertilizers: Proper use of fertilizers yields better plants and reduces negative
impacts to our water resources. Fertilizers typically contain high levels of nitrogen and
phosphorus, both of which can damage ground and surface waters. The following are a
few tips to optimize the use of fertilizers in your garden.
5. Soil Testing: The first step in fixing a problem is to know what that problem is. Therefore,
before applying any fertilizer, test your soil. Existing soil conditions, particularly nitrogen,
phosphorus, potassium and pH levels, can be easily determined by using kits available at
garden stores or from the WSU Cooperative Extension. Applying fertilizer before knowing
the components of the soil could lead to over loading certain areas that may impact our
water resources.
6. Proper Fertilization: Proper fertilization is important in maintaining a healthy lawn that
resists environmental stress, including competition with weeds and moss and drought
stress. Because Spring and Fall are periods of optimal growth, these are the most
important times to fertilize. The use of slow release fertilizers is recommended. Natural
organic and synthetic organic fertilizers (such as IBDU, sulfur or polymer coated urea, or
methylene urea) behave similarly once they are applied to the soil.
Although some people feel that natural organic fertilizers provide added benefits to soil
health, research has not shown this to be true as a general rule. The natural organic
nutrient sources in these products are often supplemented with synthetic plant nutrients
anyway. The most important thing to remember is to use a slow release fertilizer.
Extensive research around the country has shown that when these materials are applied
properly there is very little risk of surface or groundwater contamination, and they provide
an even feeding, which is better for your lawn. Remember to sweep granules off pavement
to prevent washing into storm drains.
Many soils can benefit from the use of organic fertilizers such as compost or peat. These
substances add nutrients to soil and increase the porosity of the soil as well as its ability to
hold water.
For lots with additional restrictions regarding phosphorus contamination to stormwater
runoff, phosphorus-free fertilizers must be used for all lawn and landscaping activities.
7. Fertilizing the Lawn: Turf fertilization practices for the entire year are built around what is
done in the fall. Apply fertilizer in early to mid-September to promote regrowth from
summer stress. Another application in November is important in keeping the grass
competitive with moss through the winter. If you fertilize in November, you probably don't
need an early spring fertilization. If not, your lawn will probably be ready for fertilizer in the
spring. Again, use a slow release fertilizer so that you don't promote a big flush of growth.
Fertilize again in early June so that the grass has the nutrients it needs to grow at a
moderate rate through the summer stress period.
If you want to maintain a lawn of moderate quality, a minimum of three fertilizations through
the year is needed. Additional light fertilizations can be added if you are looking for a
higher quality lawn. In general, you should apply no more than one pou nd of actual
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 10
fertilizer nitrogen per 1000 square feet at a time, although this rate can be increased to 1.5
pounds in the fall when using slow release products. (If the fertilizer analysis is 24 -4-12,
for example, it contains 24% nitrogen. To apply 1 pound of Nitrogen per 1,000 square feet,
apply 4.2 pounds of fertilizer: 1 ÷ 0.24 = 4.2).
Return clippings (grasscycle) when you mow to recycle nutrients into the lawn. Use
mulching mowers to return grass clippings directly to the lawn. Essential nutrients from the
decomposed grass can then be retained in the soil thereby reducing the need fo r fertilizer.
8. Water Before Fertilizing: Water plants and lawns before fertilizing. Water enough to
dampen the ground thoroughly, but not enough to cause surface runoff. Dampening the
soil prevents fertilizer from being washed from the surface of dry soil in the first rain or
watering after application.
9. Proper Watering: Proper watering can help build strong plants resistant to drought, pests
and disease. Water infrequently but enough to dampen soil down to 10 inches. Be careful
not to water so rapidly that water runs off the surface. Infrequent watering promotes
shallow root depths making the plants susceptible to damage during periods of drought.
Unhealthy plants are easy targets for pests and disease. Also, water during early morning
hours rather than during the day or at night. Irrigating during the day loses a sizable
amount of water to the atmosphere through evaporation. Watering at night can lead to
mold and fungi growth on plants left damp over a cool night.
The irrigation system should be programmed to provide about 1” of water per week during
the growing season. This includes normal precipitation. The system shall be provided with
rain sensors which can suspend watering, and soil moisture sensors which can
automatically adjust watering intervals and run times (e.g. Cycle-Soak).
10. Weed Control: Use of mechanical means for weed control is typically less attractive due to
the cost. However, non-chemical controls for transient and invasive weed problems shall
be emphasized in the IPM program in efforts to reduce overall environmental impacts. The
quick establishment of a thick, healthy, native or ornamental groundcover planting will
reduce the need for weed control. Implement measures to reduce this establishment time
by increasing plant spacing, adding/replacing groundcovers, and using groundcover
species that are spreading or widely-mounding. Reduce compaction to mulch to
encourage groundcover establishment and cover-rate.
The initial establishment of groundcovers may require more weed control. When the need
for chemical treatment is necessary over woody groundcovers, carefully determine the
target broadleaf or grass species, and choose a selective herbicide that specifically labeled
for application over the type of planting. Use labeled rates and ensure proper training for
applicators and handlers for proper coverage.
Reduce the need for selective broadleaf herbicide treatments in lawn areas by using clean
soil amendment and turf seed, proper installation, and appropriate nutrient applications for
the lawn area. Use selective mechanical measures to remove broadleaf weeds in newly
seeded lawn areas. Proper watering and mowing height will increase vigor and reduce
broadleaf pressure in lawn areas established with turf.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 11
Pest Control
Some of the tactics that can be used to decrease or eliminate the use of pesticides include:
1. Use of Natural Predators or Pathogens: Because chemical sprays generally kill many
beneficial insects instead of just the target pest, it may be necessary to introduce natural
predators back into the garden. Ladybugs, lacewings, predatory wasps and nematodes
are all commercially available. Garter snakes and toads are also predators and should not
be eliminated from the garden.
There are some bacteria, viruses and insect parasites that are specific to pests and will not
harm other insects or animals. A commonly used bacterium in the Puget Sound area is
Bacillus thuringiensis (Bt), which is intended to control infestations of tent caterpillars.
2. Habitat Changes: Many times a change of habitat can control pest infestations. Removal
of any item that will pond water, like buckets or tires, can cut down on the mosquito
population by removing a convenient location for them to breed in. Removing last year’s
leaves from under rose bushes can cut down on the incidence of mildew and blackspot, as
these fungi overwinter in dead leaves.
3. Timing: Crops that can overwinter (such as leeks or carrots) should be planted in the fall.
This gives them time to become established before pests arrive in the spring.
4. Mechanical: Many eggs, larvae, cocoons and adult insects can be removed by hand. Be
sure that the insect is properly identified prior to removing it so those beneficial insects are
not destroyed in error. Drowning insects in plain water or spraying them with soapy water
are alternatives to squashing them.
5. Resistant Plants: Plants that are native to this area are often more resistant to pests and
tolerant of the climate than are introduced plants. Many plant cultivars have been
developed which are resistant to such diseases as verticilium wilt and peach leaf curl.
Grass seed mixes are also available for lawns that need much less watering, mowing and
chemical use.
6. Growing Conditions: Plants, such as hostas, that require some shade are more
susceptible to pests when they are growing in the sun. Improperly fertilized or watered
plants are less vigorous in growth and tend to attract pests. Plants that prefer an acid soil,
such as azaleas, will perform better and be less susceptible to pests when they are grown
in soil with the proper pH.
7. Chemicals: Chemicals are a small part of the IPM plan and should be applied only as
needed after reviewing all other alternatives. Avoid the use of broad-spectrum pesticides
which may kill beneficial insects.
Pesticide Management
When use of a chemical is the best or only option, follow the basic guidelines below. Maintenance
Contractors shall be licensed commercial applicators and shall always follow the Pesticide Label.
1. Know your target pest before spraying. Use the pesticide according to the manufacturer's
instructions and buy only the needed quantity. Many pesticides have a limited shelf life
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 12
and may be useless or degrade into even more toxic compounds if stored for extended
periods of time.
2. Do not apply more than the specified amount. Overuse can be dangerous to your health
as well as the health of wildlife and the environment. If more than one chemical can be
used to control the pest, choose the least toxic. The word “caution” on the labe l means
that the chemical is less toxic than one that is labeled “warning”.
3. Do not spray on windy days, in the morning of what will be a very hot day or when rain is
likely. Herbicides can drift and injure valuable ornamental plants. Do not water heavily
after application. Plants should be lightly watered before application to prevent burning of
the foliage and to help evenly spread the chemical.
4. Never apply pesticides near streams, ponds or wetlands (exception: approved applications
for aquatic weeds). Do not apply pesticides to bare eroded ground. Many pesticides bind
to soil particles and can be easily carried into a stream or storm drain.
5. Pesticides should be stored well away from living areas. Ideally, the storage area should
have a cement floor and be insulated from temperature extremes. Always keep pesticides
in their original containers with labels intact. Labels often corrode and become illegible in
this climate and may have to be taped onto the container.
6. Federal law now requires that all pesticides be labeled with the appropriate disposal
method. Leftovers should never be dumped anywhere, including a landfill. Take unwanted
pesticides to Hazo House located at the former landfill at 2420 Hogum Bay Road NE ,
Lacey. Call the Thurston County Hazardous Waste Section at (360) 867-2664 for more
information.
7. Empty pesticide containers should be triple rinsed, and the rinse water used in the same
manner as the product. Once containers are rinsed, they can be disposed of as regular
garbage.
8. If a pesticide is spilled onto pavement, it can be absorbed using kitty litter or sawdust. The
contaminated absorbent should be bagged, labeled and taken to Hazo House.
9. If the pesticide is spilled onto dirt, dig up the dirt, place it in a plastic bag and take it to
Hazo House.
10. Many pest control companies and licensed applicators have access to pesticides that are
more toxic than those available to the consumer. Check with the company before they
spray indoors or outdoors to find out what spray they will be using and what precautions, if
any, are necessary after the operator leaves.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 13
Section 7 – Pollution Source Control Measures
Purpose
Pollution source controls are actions taken by a person or business to reduce the contamination of
stormwater runoff at its source. Controls, also called “best management practices” (BMPs) include:
• Altering the activity (e.g., substitute non-toxic products, recycle used oil, route floor drains
to sanitary sewer rather than storm sewer)
• Enclosing or covering the activity (e.g., building a roof)
• Segregating the activity (e.g., diverting runoff away from an area that is contaminated)
• Routing runoff from the activity to a treatment alternative (e.g., a wastewater treatment
facility, sanitary sewer, or stormwater treatment area)
A Stormwater Pollution Source Control Checklist and Worksheet has been completed and is
included in Appendix C of this Maintenance & Source Control Manual. The Stormwater Pollution
Source Control Checklist and Worksheet identifies all of the activities tha t will occur at the project
site as well as the source control BMPs which will be implemented to manage source
contamination.
Materials Used and Wastes Generated
Generally, drives and parking areas are of particular concern. Because of heavy vehicle usage,
the concentration of oil and grease in stormwater may exceed the Ecology guidelines of 10 mg/L.
Although there are no local data to confirm this view, limited research in the San Francisco Bay
area found the mean concentration of oil and grease in stormwater to exceed 10 mg/L.
General Principals of Pollution Prevention
This section describes the basic pollution prevention principles that every business and
homeowner must consider. Most of these are common sense “housekeeping” types of solutions.
With collective action by individuals and businesses throughout the region i n implementing each of
these principles, the improvement in water quality could be substantial. Although most of these
principles are aimed at commercial or industrial activities, many items apply to individual residents
as well.
AVOID THE ACTIVITY OR REDUCE ITS OCCURRENCE
If possible, avoid the activity or do it less frequently. Is there a substitute process or a
different material available to get the job done? Can a larger run of a process be performed
at one time, thus reducing the number of times per week or month it needs to be repeated?
For instance, raw materials could be delivered close to the time of use instead of being
stockpiled and exposed to the weather. Perhaps the site could avoid one solvent-washing
step altogether. Apply lawn care chemicals following directions and only as needed. Many
lawns are excessively fertilized. Do not apply herbicides right before it rains. Ecology or the
Thurston County Department of Public Health and Social Services can provide pollution
prevention assistance.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 14
MOVE ACTIVITIES UNDER SHELTER
Sometimes it is fairly easy to move an activity indoors out of the weather. The benefits of
this are twofold; preventing runoff contamination, and providing for easier, more controlled
cleanup if a spill occurs. An example would be unloading and storing ba rrels of chemicals
inside a garage area instead of doing it outside. Please be aware that moving storage
areas indoors may require installation of fire suppression equipment or other building
modifications as required by the International Building Code (IBC), the International Fire
Code or local ordinances.
CLEAN UP SPILLS QUICKLY
Promptly contain and clean up solid and liquid pollutant leaks and spills on any exposed
soil, vegetation, or paved area. Commercial spill kits are available, but readily available
absorbents such as kitty litter also work well in many cases. Promptly repa ir or replace all
leaking connections, pipes, hoses, valves, etc., which can contaminate stormwater .
USE LESS MATERIAL
Don’t buy or use more material than you really need. This not only helps keep potential
disposal, storage, and pollution problems to a minimum, but will probably save money, too.
USE THE LEAST TOXIC MATERIALS AVAILABLE
Investigate the use of materials that are less toxic than what is used now. Perhaps a
caustic-type detergent or a solvent could be replaced with a more environmentally friendly
product. Such a change might allow the site to discharge process water to the s anitary
sewer instead of paying for expensive disposal (contact the City of Yelm Wastewater Utility
to find out about allowable sanitary sewer discharges and pretreatment permits).
Remember that even if using a biodegradable product, nothing but uncontamin ated water
is allowed to enter the stormwater drainage system.
CREATE AND MAINTAIN VEGETATED AREAS NEAR ACTIVITY LOCATIONS
Vegetation of various kinds can help filter pollutants out of stormwater, so it is advisable to
route stormwater through vegetated areas located near the activity. For instance, many
parking lots contain grassy islands, typically formed in a “hump.” By creating those islands
as depressions instead of humps, they can be used to treat runoff from the parking lot or
roof. Also, don’t forget the erosion control benefits of vegetation at a site.
LOCATE ACTIVITIES AS FAR AS POSSIBLE FROM SURFACE DRAINAGE PATHS
Activities located as far as possible from known drainage paths, ditches, streams, other
water bodies, and storm drains will be less likely to pollute, since it will take longer for
material to reach the drainage feature. This gives more time to react to a spill, or if it is a
“housekeeping” issue, may protect the local waters long enough for you to clean up the
area around the activity. Don’t forget that groundwater protection is important throughout
the region, no matter where the activity is located, so the actions taken on your site on a
day-to-day basis are always important, even in dry weather.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 15
MAINTAIN STORMWATER DRAINAGE SYSTEMS
Pollutants can concentrate over time in storm drainage structures such as catch basins,
ditches, and storm drains. When a large storm event occurs, it can mobilize these
pollutants and carry them to receiving waters. Develop and implement maintenance
practices, inspections, and schedules for treatment facilities (e.g., detention ponds,
oil/water separators, vegetated swales). Clean oils, debris, sludge, etc., from all BMP
systems regularly, including catch basins, settling/detention basins, oil/water separa tors,
boomed areas, and conveyance systems, to prevent the contamination of stormwater.
Promptly repair or replace all substantially cracked or otherwise damaged paved
secondary containment, high-intensity parking, and any other drainage areas that are
subjected to pollutant material leaks or spills. Also repair or replace all leaking connections,
pipes, hoses, valves, etc., which can contaminate stormwater.
Requirements for cleaning stormwater facilities are discussed in Volume IV of the 2014
Ecology Manual, specifically BMP S417. Maintenance standards can be found in Chapter
3, Appendix 3B.
REDUCE, REUSE, AND RECYCLE AS MUCH AS POSSIBLE
Always look for ways to recycle instead of just disposing. This can save money as well as
keep both hazardous and non-hazardous materials out of the landfills. Learn more about
other businesses that have made process changes allowing recycling of chemicals by
calling Ecology at 1-800-RECYCLE and requesting publications No. 92-45 and No. 90-22.
Another unique recycling opportunity for businesses is available through the Industrial
Materials Exchange. This free service acts as a waste or surplus “matchmaker,” helping
one company’s waste become another company’s asset. For instance, waste vegetable oil
can become biofuel for another business. Call Industrial Materials Exchange at (206) 625-
6232 to list potentially usable solid or chemical waste in their publication.
BE AN ADVOCATE FOR STORMWATER POLLUTION PREVENTION
Help friends, neighbors, and business associates find ways to reduce stormwater pollution
in their activities. Most people want clean water and do not pollute intentionally. Share your
ideas and the BMPs in this chapter to get them thinking about how their everyday activities
effect water quality.
REPORT PROBLEMS
We all must do our part to protect water, fish, wildlife, and our own health by implementing
proper BMPs, and reporting water quality problems that we observe. In the City of Yelm,
call the Department of Public Works at (360) 754-4150 to report dumping to sewers and to
report spills and other incidents involving storm drains or ditches. Also contact Ecology’s
Southwest Regional Office at (360) 407-6300.
PROVIDE OVERSIGHT AND TRAINING
Assign one or more individuals at your place of business to be responsible for stormwater
pollution control. Hold regular meetings to review the overall operation of BMPs. Establish
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 16
responsibilities for inspections, operation and maintenance (O&M), documentation, and
availability for emergency situations. Train all team members in the operation,
maintenance, and inspection of BMPs and reporting procedures.
DUST CONTROL
Sweep paved material handling and storage areas regularly as needed, to collect and
dispose of dust and debris that could contaminate stormwater. Do not hose down
pollutants from any area to the ground, storm drain, conveyance ditch, or receiving water.
ELIMINATE ILLICIT CONNECTIONS
An illicit connection is formally defined in the city’s NPDES Municipal Stormwater Permit,
but generally includes any connection to the city stormwater system that is not intended,
permitted, or used for collecting and conveying stormwater. A common proble m with the
stormwater drainage system for most communities is the existence of illicit connections of
wastewater to the storm drainage system. Wastewater other than stormwater runoff, such
as wash water, must be discharged to a wastewater collection system, and may not be
discharged to a storm drainage system (the storm drainage system does not drain to a
wastewater treatment plant). Many businesses and residences have internal building
drains, sump overflows, process wastewater discharges, and even sanitary sewer and
septic system pipes that were connected to the nearby storm drainage system in the past
as a matter of course.
All businesses and residences must examine their plumbing systems to determine if illicit
connections exist. Any time it is found that toilets, sinks, appliances, showers and bathtubs,
floor drains, industrial process waters, and/or other indoor activities are connected to the
stormwater drainage system, these connections must be immediately rerouted to the
sanitary or septic system, holding tanks, or a process treatment system.
DISPOSE OF WASTE PROPERLY
Every business and residence in the city must dispose of solid and liquid wastes and
contaminated stormwater properly. There are generally four options for disposal depending
on the type of materials. These options include:
• Sanitary sewer and septic systems
• Recycling facilities
• Municipal solid waste disposal facilities
• Hazardous waste treatment, storage, and disposal facilities
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 17
Appendix A – Maintenance Covenant
RESIDENTIAL
AGREEMENT TO MAINTAIN STORMWATER FACILITIES
BY AND BETWEEN
Tahoma Terra Holdings, LLC
THEIR HEIRS, SUCCESSORS, OR ASSIGNS
(HEREINAFTER “__OWNER________”)
AND
City of Yelm, Washington
HEREINAFTER “JURISDICTION”)
The upkeep and maintenance of stormwater facilities and the implementation of
pollution source control best management practices (BMPs) is essential to the protection
of water resources. All property owners are expected to conduct business in a manner
that promotes environmental protection. This Agreement contains specific provisions
with respect to maintenance of stormwater facilities and use of pollution source control
BMPs.
LEGAL DESCRIPTION:
TRACT 7 (FUTURE COMMERCIAL PARCEL) AND TRACT 9 (FUTURE PHASE) CITY OF YELM
PLAT OF TAHOMA TERRA PHASE 1, DIVISION 1, AS RECORDED MAY 11, 2006, UNDER
AUDITOR'S FILE NO. 3830707.
IN THURSTON COUNTY, WASHINGTON.
Whereas, the ___OWNER______ have constructed improvements, including but
not limited to, buildings, pavement, and stormwater facilities on the property described
above. In order to further the goals of the Jurisdiction to ensure the protection and
enhancement of water resources, the Jurisdiction and the ____ OWNER ____ hereby
enter into this Agreement. The responsibilities of each party to this Agreement are
identified below.
_____ OWNER ____ SHALL:
(1) Implement the stormwater facility maintenance program included herein.
(2) Implement the pollution source control program included herein.
(3) Maintain a record (in the form of a log book) of steps taken to implement the
programs referenced in (1) and (2) above. The log book shall be available for
inspection by appointment at 9955 Tahoma Blvd SE, Yelm WA 98597. The log
book shall catalog the action taken, who took it, when it was done, how it was
done, and any problems encountered or follow-on actions recommended.
Maintenance items (“problems”) listed in Attachment “A” shall be inspected as
specified in the attached instructions or more often if necessary. The __
OWNER __ are encouraged to photocopy the individual checklists in Appendix
“B” and use them to complete its inspections. These completed checklists would
then, in combination, comprise the log book.
(4) Submit an annual report to the Jurisdiction regarding implementation of the
programs referenced in (1) and (2) above. The report must be submitted on or
before May 15 of each calendar year and shall contain, at a minimum, the
following:
(a) Name, address, and telephone number of the businesses, the persons, or the
firms responsible for plan implementation, and the person completing the
report.
(b) Time period covered by the report.
(c) A chronological summary of activities conducted to implement the programs
referenced in (1) and (2) above. A photocopy of the applicable sections of
the log book, with any additional explanation needed, shall normally suffice.
For any activities conducted by paid parties, include a copy of the invoice for
services.
(d) An outline of planned activities for the next year.
THE JURISDICTION SHALL:
(1) Provide technical assistance to the ___ OWNER _____ in support of its
operation and maintenance activities conducted pursuant to its maintenance and
source control programs. Said assistance shall be provided upon request and as
Jurisdiction time and resources permit.
(2) Review the annual report and conduct a minimum of one (1) site visit per year to
discuss performance and problems with the ____ OWNER ___________.
(3) Review this agreement with the ________ OWNER _______ and modify it as
necessary at least once every three (3) years.
REMEDIES:
(1) If the Jurisdiction determines that maintenance or repair work is required to be
done to the stormwater facilities located in the subdivision, the Jurisdiction shall
give the ____ OWNER ____ notice of the specific maintenance and/or repair
required. The Jurisdiction shall set a reasonable time in which such work is to be
completed by the persons who were given notice. If the above required
maintenance and/or repair is not completed within the time set by the
Jurisdiction, written notice will be sent to the ___ OWNER ____ stating the
Jurisdiction’s intention to perform such maintenance and bill the ____ OWNER
_____ for all incurred expenses.
(2) If at any time the Jurisdiction determines that the existing system creates any
imminent threat to public health or welfare, the Jurisdiction may take immediate
measures to remedy said threat. No notice to the persons listed in Remedies (1),
above, shall be required under such circumstances. All other ___ OWNER
______ responsibilities shall remain in effect.
(3) The ___ OWNER ___ grant unrestricted authority to the Jurisdiction for access to
any and all stormwater system features for the purpose of performing
maintenance or repair as may become necessary under Remedies (1) and/or (2).
(4) The ___ OWNER ___ shall assume responsibility for the cost of maintenance
and repairs to the stormwater facility, except for those maintenance actions
explicitly assumed by the Jurisdiction in the preceding section. Such
responsibility shall include reimbursement to the Jurisdiction within 90 days of the
receipt of the invoice for any such work performed. Overdue payments will
require payment of interest at the current legal rate for liquidated judgments. If
legal action ensues, any costs or fees incurred by the Jurisdiction will be borne
by the parties responsible for said reimbursements.
This Agreement is intended to protect the value and desirability of the real property
described above and to benefit all the citizens of the Jurisdiction. It shall run with the
land and be binding on all parties having or acquiring any right, title, or interest, or any
part thereof, of real property in the subdivision. They shall inure to the benefit of each
present or future successor in interest of said property or any part thereof, or interest
therein, and to the benefit of all citizens of the Jurisdiction.
Owner
Owner
Dated this day day of ____________, 2023
Public Services Director, City of Yelm
STATE OF WASHINGTON )
) ss
COUNTY OF THURSTON )
On this day and year above personally appeared before me, _____________________,
known to be the individual(s) described, and who executed the foregoing instrument and
acknowledge that they signed the same as their free and voluntary act and deed for the
uses and purposes therein mentioned.
Given under my hand and official seal this _____ day of __________, 2023.
Notary Public in and for the State of
Washington, residing in
My commission expires
STATE OF WASHINGTON )
) ss
COUNTY OF THURSTON )
On this day and year above personally appeared before me, _____________________,
known to be the individual(s) described, and who executed the foregoing instrument and
acknowledge that they signed the same as their free and voluntary act and deed for the
uses and purposes therein mentioned.
Given under my hand and official seal this _____ day of __________, 2023.
Notary Public in and for the State of
Washington, residing in
My commission expires
STATE OF WASHINGTON )
) ss
COUNTY OF THURSTON )
On this day and year above personally appeared before me, _____________________,
who executed the foregoing instrument and acknowledge the said instrument to be the
free and voluntary act and deed of said Municipal Corporation for the uses and purposes
therein mentioned and on oath states he is authorized to execute the said instrument.
Given under my hand and official seal this _____ day of __________, 2023.
Notary Public in and for the State of
Washington, residing in
My commission expires
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 18
Appendix B – Maintenance Checklists
The Maintenance Checklists in this packet are for your use when inspecting the stormwater
facilities on your property. This packet has been customized so that only the checklists for your
facilities are included. If you feel you are missing a checklist, or you have additional facilities not
identified or addressed in this packet, please contact your local jurisdiction.
The checklists are in tabular format for ease of use. Each describes the area to inspect, inspection
frequency, what to look for and what action to take. A log sheet is included after the appropriate
maintenance checklists to help you track maintenance of your storm drainage system.
Although it is not intended for the maintenance survey to involve anything too difficult or strenuous,
there are a few tools that will make the job easier and safer including:
• A flashlight
• A long pole or broom handle
• Some kind of pry bar or lifting tool for pulling manhole and grate covers
• Gloves
A resource list is included on page 7 of this Maintenance & Source Control Manual. There you will
find the phone numbers of the agencies referenced in the tables, as well as the contractors and
consultants who designed and constructed your facilities.
SAFETY WARNING: In keeping with OSHA regulations, you should never
stick your head or any part of your body into a manhole or other type of
confined space. When looking into a manhole or catch basin, stand above it
and use the flashlight to help you see. Use a long pole or broom handle to
check sediment depths in confined spaces. NO PART OF YOUR BODY
SHOULD BREAK THE PLANE OF THE OPEN HOLE.
!
Sto rmwater Faci liti es Ma in ten ance Standards
Group 1 – Fl ow Control and Tr eatment Facil ities
1p. Perme able Pave ment
Permeable pavement is a stormwater infiltration facility that is designed to accommodate pedestrian,
bicycle, and auto traffic while allowing infiltration and storage of stormwater. Permeable pavement
includes porous asphalt; pervious concrete; permeable pavers and aggregate pavers; and grid
systems.
Permeable Pavement
Drainage
System Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed All Pavement
Types
Leaf and Debris
Accumulation
Fallen leaves or debris. Removed/disposed.
All Pavement
Types
Sediment or debris
accumulation between paver
blocks, on surface of
pavement, or in grid voids.
Sediment at surface does not inhibit
infiltration. Remove/dispose of
sediment.
Facility –
General
Requirements
Unstable
Adjacent
Area
Runoff from adjacent pervious
areas deposits soil, mulch, or
sediment on paving.
No deposited soil or other materials on
permeable pavement or other adjacent
surfacing. All exposed soils that may
erode to pavement surface mulched
and/or planted.
Wearing
Course
Covered by
Adjacent
Vegetation
Vegetation growing beyond
facility edge onto sidewalks,
paths, and street edge.
Vegetation does not impede function
of adjacent facilities or pose as safety
hazard. Groundcovers and shrubs
trimmed to avoid overreaching the
sidewalks, paths and street edge.
Porous
Asphalt or
Pervious
Cement
Concrete
NA None. Maintenance to prevent
clogging with fine sediment.
Conventional street sweepers
equipped with vacuums, water, and
brushes or pressure washer used to
restore permeability. Vacuum or
pressure wash the pavement two to
three times annually.
NA None. Maintenance to prevent
clogging with fine sediment.
Use of sand and sealant application
prohibited. Protect from construction
runoff.
Cracks Major cracks or trip hazards. Potholes or small cracks filled with
patching mixes. Large cracks and
settlement addressed by cutting and
replacing the pavement section.
Permeable Pavement
Drainage
System Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed NA Utility cuts. Any damage or change due to utility
cuts replaced in kind.
Interlocking
Concrete
Paver Blocks
Missing or
Damaged
Paver Block
Interlocking paver block
missing or damaged.
Individual damaged paver blocks
removed and replaced or repaired per
manufacturer’s recommendations.
Settlement Settlement of surface. When
deviation from original grade
impedes function.
Original grade re-established. May
require resetting.
Void Material
is Missing or
Low
Loss of aggregate material
between paver blocks.
Refill per manufacturer’s
recommendations.
Open-Celled
Paving Grid with
Gravel
Loss of
Aggregate
Material in
Paving Grid
Loss of aggregate material in
grid.
Aggregate gravel level maintained at
the same level as the plastic rings or
no more than 0.25 inch above the top
of rings. Refill per manufacturer’s
recommendations.
Open-Celled
Paving Grid with
Grass
Lack of
Grass
Coverage
Loss of soil and/or grass
material in grid.
Refill and/or replant per
manufacturer’s recommendations.
Growing medium restored, facility
aerated, and reseeded or planted,
and vegetated area amended as
needed.
Inlet/Outlet
Pipe
Pipe is
Damaged
Pipe is damaged. Pipe is repaired/replaced.
Pipe is Clogged Pipe is clogged. Roots or debris is removed.
Erosion Native soil exposed or other
signs of erosion damage
present.
No eroded or scoured areas Cause
of erosion or scour is
addressed.
Underdrain
Pipe
Blocked
Underdrain
Plant roots, sediment or debris
reducing capacity of underdrain
(may cause prolonged
drawdown period).
Underdrains and orifice free of
sediment and debris. Jet clean or
rotary cut debris/roots from
underdrain(s). If underdrains are
equipped with a flow restrictor (e.g.,
orifice) to attenuate flows, the orifice
must be cleaned regularly.
Permeable Pavement
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Spill
Prevention
and
Response
NA Storage or use of potential
contaminants in the vicinity of
facility.
Spill prevention measures exercised
whenever handling or storing
potential contaminants.
Release of
Pollutants
Any evidence of contaminants
such as oil, gasoline, concrete
slurries, paint, etc.
Spills are cleaned up as soon as
possible to prevent contamination of
stormwater. No contaminants or
pollutants present. (Coordinate
source control, removal, and/or
cleanup with City of Yelm Spill
Reporting Hotline 360-754-4150,
Moderate Risk Waste Program at
Thurston County Environmental
Health 360-754–4111, and/or Dept.
of Ecology Spill Response
800-424-8802.)
Group 2 – Str uctur es a nd Pr etreatment
2b. Ca tch B asins
These structures are typically located in the streets. The City of Yelm is responsible for routine
maintenance of the pipes and structures in the public rights-of-way, while the property owner or
homeowners’ association is responsible for maintenance of pipes and catch basins in private areas
and for keeping the grates clear of debris in all areas.
Catch Basins
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed General Trash and
Debris
Trash, leaves, or debris which is
located immediately in front of the
catch basin opening or is
blocking inflow capacity of the
basin by more than 10 percent.
Remove trash, leaves and debris
located directly in front of catch
basin or on grate.
Trash or debris (in basin) that
exceeds 60 percent of the sump
depth as measured from bottom
of basin to invert of the lowest
pipe into or out of the basin, but
in no case less than a minimum
of 6 inches of clearance from the
debris surface to the invert of the
lowest pipe.
No trash or debris present. Remove
and properly dispose of all trash and
debris.
Trash or debris in any inlet or
outlet pipe blocking more than
33 percent (one-third) of its
height.
Inlet and outlet pipes free of trash or
debris. Remove and properly dispose
of all trash and debris.
Dead animals or vegetation that
could generate odors that could
cause complaints or dangerous
gases (e.g., methane).
Remove dead animals, etc., present
within the catch basin.
Sediment Sediment (in basin) exceeds 60
percent of sump depth as
measured from the bottom of
basin to invert of lowest pipe
into or out of basin, but in no
case less than a minimum of 6
inches of clearance from the
sediment surface to the invert of
lowest pipe.
No sediment in the catch basin.
Catch Basins
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed General
(continued)
Structure
Damage to
Frame and/or
Top Slab
Top slab has holes larger than 2
square inches or cracks wider
than 0.25 inch (intent is to make
sure no material is running into
basin).
Top slab is free of holes and cracks.
Structure
Damage to
Frame and/or
Top Slab
(continued)
Frame not sitting flush on top
slab, i.e., separation of more than
0.75 inch of the frame from the
top slab. Frame not securely
attached.
Frame is sitting flush on the riser
rings or top slab and firmly attached.
Fractures or
Cracks in
Basin Walls/
Bottom
Maintenance person determines
structure is unsound.
Basin replaced or repaired to design
standard.
Grout fillet has separated or
cracked wider than 0.5 inch and
longer than 1 foot at the joint of
any inlet/outlet pipe, or any
evidence of soil entering basin.
Pipe re-grouted and secure at basin
wall.
Settlement/
Misalignment
If failure of basin has created a
safety, function, or design
problem.
Replaced or repair to design
standards.
Vegetation Vegetation growing across and
blocking more than 10 percent of
the basin opening.
Remove vegetation blocking opening
to basin.
Vegetation growing in inlet/outlet
pipe joints that is more than
6 inches tall and less than
6 inches apart.
No vegetation or root growth
present.
Contamination
and Pollution
Presence of contaminants such
as oil, gasoline, concrete
slurries, paint, obnoxious color,
odor, or sludge.
Locate the source of the pollution
and remove contaminants or
pollutants present. Report and
coordinate source control, removal,
and/or cleanup with City of Yelm
Spill Reporting Hotline 360-754-
4150, Moderate Risk Waste
Program at Thurston County
Environmental Health 360-754–
4111, and/or Dept. of Ecology Spill
Response 800-424-8802.
Catch Basins
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Catch
Basin
Cover
Cover Not in
Place
Cover is missing or only partially in
place. Any open catch basin
requires maintenance.
Catch basin cover is in place and
secured.
Locking
Mechanism
Not Working
Mechanism cannot be opened by
one maintenance person with
proper tools. Bolts into frame
have less than 0.5 inch of thread.
Mechanism opens with proper tools.
Cover Difficult to
Remove
One maintenance person cannot
remove lid after applying normal
lifting pressure.
(Intent is keep cover from
sealing off access to
maintenance.)
Cover can be removed by one
maintenance person.
Ladder Ladder Rungs
Unsafe
Maintenance person judges that
ladder is unsafe due to missing
rungs, misalignment, rust, or
cracks. Ladder must be fixed or
secured immediately.
Ladder meets design standards and
allows maintenance persons safe
access.
Metal
Grates
(if
applicable)
Grate Opening
Unsafe
Grate with opening wider than
0.875 (7/8) inch.
Grate opening meets design
standards.
Trash and Debris Trash and debris that is blocking
more than 20 percent of grate
surface inlet capacity.
Grate free of trash and debris. Remove
and properly dispose of all trash and
debris.
Damaged or
Missing
Grate missing or broken
member(s) of the grate.
Grate is in place and meets design
standards.
2d. E ne rgy Dissipa t ors
Typically a rock splash pad at a pipe end or other discharge location, to reduce the velocity and
energy of flowing water and prevent erosion. Other means of energy dissipation include drop
manholes, stilling basins, and check dams.
Energy Dissipators
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed External:
Rock Pad Missing or
Moved Rock
Only one layer of rock exists
above native soil in area
5 square feet or larger, or any
exposure of native soil.
Rock pad replaced to design standards.
Erosion Soil erosion in or adjacent to rock
pad.
Rock pad replaced to design standards.
Dispersion
Trench
Pipe Plugged
with Sediment
Accumulated sediment that
exceeds 20 percent of the design
depth.
Pipe cleaned/flushed so it matches
design.
Not
Discharging
Water
Properly
Visual evidence of water
discharging at concentrated
points along trench (normal
condition is a “sheet flow” of
water along trench). Intent is to
prevent erosion damage.
Trench redesigned or rebuilt to
standards. Water discharges from
feature by sheet flow.
Perforations
Plugged
Over half of perforations in pipe
are plugged with debris and
sediment.
Perforated pipe cleaned or replaced.
Perforations freely discharge flow.
Water Flows
Out Top of
“Distributor”
Catch Basin
Maintenance person observes or
receives credible report of water
flowing out during any storm less
than the design storm or its
causing or appears likely to cause
damage.
Facility rebuilt or redesigned to
standards. No flow discharges from
distributor catch basin.
Receiving
Area Over-
Saturated
Water in receiving area is causing
or has potential of causing
landslide problems.
No danger of landslides.
Energy Dissipators
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Internal:
Manhole/
Chamber
Worn or
Damaged
Post, Baffles,
Side of
Chamber
Structure dissipating flow
deteriorates to 50 percent of
original size or any concentrated
worn spot exceeding 1 square
foot, which would make structure
unsound.
Structure replaced to design standards.
Structure in no danger of failing.
Trash and
Debris
Trash or debris (in basin) that
exceeds 60 percent of the sump
depth as measured from bottom
of basin to invert of the lowest
pipe into or out of the basin, but in
no case less than a minimum of 6-
inch clearance from the debris
surface to the invert of the lowest
pipe.
No trash or debris present. Remove
and properly dispose of all trash and
debris.
Trash or debris in any inlet or
outlet pipe blocking more than
33 percent of its height.
Inlet and outlet pipes free of trash or
debris. Remove and properly dispose
of all trash and debris.
Dead animals or vegetation that
could generate odors that could
cause complaints or dangerous
gases (e.g., methane).
Remove dead animals, etc., present
within the catch basin.
Sediment Sediment (in basin) exceeds
60 percent of sump depth as
measured from the bottom of
basin to invert of lowest pipe into
or out of basin, but in no case less
than a minimum of 6-inch
clearance from the sediment
surface to the invert of lowest
pipe.
No sediment in the catch basin.
Structure
Damage to
Frame and/or
Top Slab
Top slab has holes larger than 2
square inches or cracks wider
than 0.25 inch (Intent is to make
sure no material is running into
basin).
Top slab is free of holes and cracks.
Energy Dissipators
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Manhole/
Chamber
(continued)
Structure
Damage to
Frame and/or
Top Slab
(continued)
Frame not sitting flush on top
slab, i.e., separation of more than
0.75 inch of the frame from the
top slab. Frame not securely
attached
Frame is sitting flush on the riser rings
or top slab and firmly attached.
Fractures or
Cracks in
Basin Walls/
Bottom
Maintenance person determines
structure is unsound.
Basin replaced or repaired to design
standard
Grout fillet has separated or
cracked wider than 0.5 inch and
longer than 1 foot at the joint of
any inlet/outlet pipe, or any
evidence of soil entering basin.
Pipe re-grouted and secure at basin
wall.
Settlement/
Misalignment
If failure of basin has created a
safety, function, or design
problem.
Replaced or repair to design
standards.
Contamination
and Pollution
Presence of contaminants such
as oil, gasoline, concrete
slurries, paint, obnoxious color,
odor, or sludge.
Locate the source of the pollution
and remove contaminants or
pollutants present. Report and
coordinate source control, removal,
and/or cleanup with City of Yelm
Spill Reporting Hotline 360-754-
4150, Moderate Risk Waste
Program at Thurston County
Environmental Health 360-754–
4111, and/or Dept. of Ecology Spill
Response 800-424-8802.
Catch
Basin
Cover
Cover Not in
Place
Cover is missing or only partially in
place. Any open catch basin
requires maintenance.
Catch basin cover is in place and
secured.
Locking
Mechanism
Not Working
Mechanism cannot be opened by
one maintenance person with
proper tools. Bolts into frame
have less than 0.5 inch of thread.
Mechanism opens with proper tools.
Energy Dissipators
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Catch Cover Difficult One maintenance person cannot Cover can be removed by one
Basin to Remove remove lid after applying normal maintenance person.
Cover lifting pressure.
(continued) (Intent is keep cover from
sealing off access to
maintenance.)
Group 3 – Mi scellane ou s Facil iti es a nd Featur es
3a. Conveyance P ipes, C ulver ts , Di tche s, and Swales
These features contain and direct the flow of water from one location to another.
Conveyance Pipes, Culverts, Ditches, and Swales
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Pipes Sediment,
Debris, and
Vegetation
Accumulated sediment should not
exceed 20 percent of the diameter
of the pipe. Vegetation should not
reduce free movement of water
through pipes. Ensure that the
protective coating is not damaged
or rusted. Dents should not
significantly impede flow. Pipe
should not have major cracks or
flaws allowing water to leak out.
Clean out pipes of all sediment and
debris. Remove all vegetation so that
water flows freely through pipes.
Repair or replace pipe.
Open
Ditches
Trash and
Debris
There should not be any yard
waste or litter in the ditch.
No trash or debris present. Remove
and properly dispose of all trash and
debris.
Sediment
Buildup
Accumulated sediment should not
exceed 20 percent of the depth of
the ditch.
Clean out ditch of all sediment and
debris.
Open
Ditches and
Swales
Overgrowth
of
Vegetation
Check for vegetation (e.g., weedy
shrubs or saplings) that reduces the
free movement of water through
ditches or swales.
Clear blocking vegetation so that
water moves freely through the
ditches. Grassy vegetation should be
left alone.
Erosion Check around inlets and outlets for
signs of erosion. Check slopes for
signs of sloughing or settling.
Action is needed where eroded
damage is over 2 inches deep and
where there is potential for
continued erosion.
Eliminate causes of erosion.
Stabilize slopes by using the
appropriate erosion control
procedure (e.g., compact the soil,
plant grass, reinforce with rock).
Missing
Rocks
Native soil beneath the rock
splash pad, check dam, or lining
should not be visible.
Replace rocks to design standard.
Conveyance Pipes, Culverts, Ditches, and Swales
Drainage
System
Feature
Problem or
Defect
Conditions to Check For Maintenance Required (Y/N)
What To Do for Desired Condition Date Maintenance Completed Swales Vegetation Grass cover is sparse and weedy,
or areas are overgrown with woody
vegetation.
Aerate soils and re-seed and mulch
bare areas. Keep grass less than
8 inches high. Remove woody
growth, re-contour and re-seed as
necessary.
Homeowner
Conversion
Swale has been filled in or blocked
by shed, woodpile, shrubbery, etc.
Speak with the homeowner and
request that the swale area be
restored. Contact the city to report
the problem if not rectified
voluntarily.
Swale Does
Not Drain
Water stands in the swale, or flow
velocity is very slow. Stagnation
occurs.
A survey may be needed to check
grades. Grades should be in 1 to
5 percent range if possible. If grade
is less than 1 percent, underdrains
may need to be installed.
TAHOMA TERRA COMMERCIAL 09.05.2023 PAGE 33
Log Sheet
Use log sheets to track maintenance checks and what items, if any, are repaired or altered. Make copies
of this page; use a fresh copy for each inspection. The completed sheets will serve as a record of
maintenance activity and will provide valuable information about how your facilities are operating. Log
sheets should be kept in a dry, readily accessible place.
INSPECTION DATE:
PERFORMED BY:
PHONE NUMBER: ADDRESS:
POSITION ON HOA: CITY,
ST, ZIP:
PART OF FACILITY
INSPECTED
OBSERVATIONS
(LIST REQUIRED MAINTENANCE
ACTIVITIES) ACTION TAKEN
DATE OF
ACTION