HomeMy WebLinkAboutNPDES
Issuance Date: November 18, 2020
Effective Date: January 1, 2021
Expiration Date: December 31, 2025
CONSTRUCTION STORMWATER
GENERAL PERMIT
National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge
General Permit for Stormwater Discharges Associated with Construction Activity
State of Washington
Department of Ecology
Olympia, Washington 98504
In compliance with the provisions of Chapter 90.48 Revised Code of Washington (State of Washington Water Pollution Control Act) and Title 33 United States Code, Section 1251 et seq. The Federal Water Pollution Control Act (The Clean Water Act)
Until this permit expires, is modified, or revoked, Permittees that have properly obtained coverage under this general permit are authorized to discharge in accordance with the special and general conditions that follow.
__________________________________ Vincent McGowan, P.E. Water Quality Program Manager Washington State Department of Ecology
Construction Stormwater General Permit Page i
TABLE OF CONTENTS
LIST OF TABLES .................................................................................................................................. ii
SUMMARY OF PERMIT REPORT SUBMITTALS ...................................................................................... 1
SPECIAL CONDITIONS ......................................................................................................................... 3
S1. Permit Coverage .............................................................................................................................. 3
S2. Application Requirements ............................................................................................................... 7
S3. Compliance with Standards ............................................................................................................. 9
S4. Monitoring Requirements, Benchmarks, and Reporting Triggers ................................................. 10
S5. Reporting and Recordkeeping Requirements ................................................................................ 17
S6. Permit Fees .................................................................................................................................... 20
S7. Solid and Liquid Waste Disposal .................................................................................................... 20
S8. Discharges to 303(D) or TMDL Waterbodies ................................................................................. 20
S9. Stormwater Pollution Prevention Plan .......................................................................................... 23
S10. Notice Of Termination ................................................................................................................... 32
GENERAL CONDITIONS ..................................................................................................................... 34
G1. Discharge Violations....................................................................................................................... 34
G2. Signatory Requirements ................................................................................................................ 34
G3. Right of Inspection and Entry ......................................................................................................... 35
G4. General Permit Modification and Revocation ............................................................................... 35
G5. Revocation of Coverage Under tPermit ......................................................................................... 35
G6. Reporting a Cause for Modification ............................................................................................... 36
G7. Compliance with Other Laws and Statutes .................................................................................... 36
G8. Duty to Reapply.............................................................................................................................. 36
G9. Removed Substance ....................................................................................................................... 36
G10. Duty to Provide Information .......................................................................................................... 36
G11. Other Requirements of 40 CFR ...................................................................................................... 37
G12. Additional Monitoring .................................................................................................................... 37
G13. Penalties for Violating Permit Conditions ...................................................................................... 37
G14. Upset .............................................................................................................................................. 37
G15. Property Rights .............................................................................................................................. 37
G16. Duty to Comply .............................................................................................................................. 37
G17. Toxic Pollutants .............................................................................................................................. 38
G18. Penalties for Tampering ................................................................................................................. 38
G19. Reporting Planned Changes ........................................................................................................... 38
G20. Reporting Other Information ......................................................................................................... 38
G21. Reporting Anticipated Non-Compliance ........................................................................................ 38
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G22. Requests to Be Excluded From Coverage Under the Permit ......................................................... 39
G23. Appeals........................................................................................................................................... 39
G24. Severability..................................................................................................................................... 39
G25. Bypass Prohibited .......................................................................................................................... 39
APPENDIX A – DEFINITIONS .............................................................................................................. 42
APPENDIX B – ACRONYMS ................................................................................................................ 50
LIST OF TABLES
Table 1 Summary of Required Submittals ................................................................................................ 1
Table 2 Summary of Required On-site Documentation ........................................................................... 2
Table 3 Summary of Primary Monitoring Requirements ....................................................................... 12
Table 4 Monitoring and Reporting Requirements ................................................................................. 14
Table 5 Turbidity, Fine Sediment & Phosphorus Sampling and Limits for
303(d)-Listed Waters ................................................................................................................ 22
Table 6 pH Sampling and Limits for 303(d)-Listed Waters ..................................................................... 22
Construction Stormwater General Permit Page 1
SUMMARY OF PERMIT REPORT SUBMITTALS
Refer to the Special and General Conditions within this permit for additional submittal requirements.
Appendix A provides a list of definitions. Appendix B provides a list of acronyms.
Table 1 Summary of Required Submittals
Permit Section Submittal Frequency First Submittal Date
S5.A and
S8
High Turbidity/Transparency Phone
Reporting
As Necessary Within 24 hours
S5.B Discharge Monitoring Report Monthly* Within 15 days following the
end of each month
S5.F and S8 Noncompliance Notification – Telephone Notification As necessary Within 24 hours
S5.F Noncompliance Notification – Written
Report
As necessary Within 5 Days of
non-compliance
S9.D Request for Chemical Treatment Form As necessary Written approval from
Ecology is required prior to
using chemical treatment
(with the exception of dry ice,
CO2 or food grade vinegar to
adjust pH)
G2 Notice of Change in Authorization As necessary
G6 Permit Application for Substantive
Changes to the Discharge
As necessary
G8 Application for Permit Renewal 1/permit cycle No later than 180 days
before expiration
S2.A Notice of Permit Transfer As necessary
G19 Notice of Planned Changes As necessary
G21 Reporting Anticipated Non-compliance As necessary
NOTE: *Permittees must submit electronic Discharge Monitoring Reports (DMRs) to the Washington State
Department of Ecology monthly, regardless of site discharge, for the full duration of permit coverage. Refer
to Section S5.B of this General Permit for more specific information regarding DMRs.
Construction Stormwater General Permit Page 2
Table 2 Summary of Required On-site Documentation
Document Title
Permit Conditions
Permit Coverage Letter See Conditions S2, S5
Construction Stormwater General Permit (CSWGP) See Conditions S2, S5
Site Log Book See Conditions S4, S5
Stormwater Pollution Prevention Plan (SWPPP) See Conditions S5, S9
Site Map See Conditions S5, S9
Construction Stormwater General Permit Page 3
SPECIAL CONDITIONS
S1. PERMIT COVERAGE
A. Permit Area
This Construction Stormwater General Permit (CSWGP) covers all areas of Washington State,
except for federal operators and Indian Country as specified in Special Condition S1.E.3 and 4.
B. Operators Required to Seek Coverage Under this General Permit
1. Operators of the following construction activities are required to seek coverage under
this CSWGP:
a. Clearing, grading and/or excavation that results in the disturbance of one or more
acres (including off-site disturbance acreage related to construction-support activity
as authorized in S1.C.2) and discharges stormwater to surface waters of the State;
and clearing, grading and/or excavation on sites smaller than one acre that are part
of a larger common plan of development or sale, if the common plan of
development or sale will ultimately disturb one acre or more and discharge
stormwater to surface waters of the State.
i. This category includes forest practices (including, but not limited to, class IV
conversions) that are part of a construction activity that will result in the
disturbance of one or more acres, and discharge to surface waters of the State
(that is, forest practices that prepare a site for construction activities); and
b. Any size construction activity discharging stormwater to waters of the State that the
Washington State Department of Ecology (Ecology):
i. Determines to be a significant contributor of pollutants to waters of the State
of Washington.
ii. Reasonably expects to cause a violation of any water quality standard.
2. Operators of the following activities are not required to seek coverage under this CSWGP
(unless specifically required under Special Condition S1.B.1.b, above):
a. Construction activities that discharge all stormwater and non-stormwater to
groundwater, sanitary sewer, or combined sewer, and have no point source
discharge to either surface water or a storm sewer system that drains to surface
waters of the State.
b. Construction activities covered under an Erosivity Waiver (Special Condition S1.F).
c. Routine maintenance that is performed to maintain the original line and grade,
hydraulic capacity, or original purpose of a facility.
C. Authorized Discharges
1. Stormwater Associated with Construction Activity. Subject to compliance with the terms
and conditions of this permit, Permittees are authorized to discharge stormwater
associated with construction activity to surface waters of the State or to a storm sewer
system that drains to surface waters of the State. (Note that “surface waters of the
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State” may exist on a construction site as well as off site; for example, a creek running
through a site.)
2. Stormwater Associated with Construction Support Activity. This permit also authorizes
stormwater discharge from support activities related to the permitted construction site
(for example, an on-site portable rock crusher, off-site equipment staging yards, material
storage areas, borrow areas, etc.) provided:
a. The support activity relates directly to the permitted construction site that is
required to have an NPDES permit; and
b. The support activity is not a commercial operation serving multiple unrelated
construction projects, and does not operate beyond the completion of the
construction activity; and
c. Appropriate controls and measures are identified in the Stormwater Pollution
Prevention Plan (SWPPP) for the discharges from the support activity areas.
3. Non-Stormwater Discharges. The categories and sources of non-stormwater discharges
identified below are authorized conditionally, provided the discharge is consistent with
the terms and conditions of this permit:
a. Discharges from fire-fighting activities.
b. Fire hydrant system flushing.
c. Potable water, including uncontaminated water line flushing.
d. Hydrostatic test water.
e. Uncontaminated air conditioning or compressor condensate.
f. Uncontaminated groundwater or spring water.
g. Uncontaminated excavation dewatering water (in accordance with S9.D.10).
h. Uncontaminated discharges from foundation or footing drains.
i. Uncontaminated or potable water used to control dust. Permittees must minimize
the amount of dust control water used.
j. Routine external building wash down that does not use detergents.
k. Landscape irrigation water.
The SWPPP must adequately address all authorized non-stormwater discharges, except for
discharges from fire-fighting activities, and must comply with Special Condition S3. At a
minimum, discharges from potable water (including water line flushing), fire hydrant system
flushing, and pipeline hydrostatic test water must undergo the following: dechlorination to a
concentration of 0.1 parts per million (ppm) or less, and pH adjustment to within 6.5 – 8.5
standard units (su), if necessary.
D. Prohibited Discharges
The following discharges to waters of the State, including groundwater, are prohibited:
Construction Stormwater General Permit Page 5
1. Concrete wastewater
2. Wastewater from washout and clean-up of stucco, paint, form release oils, curing
compounds and other construction materials.
3. Process wastewater as defined by 40 Code of Federal Regulations (CFR) 122.2 (See
Appendix A of this permit).
4. Slurry materials and waste from shaft drilling, including process wastewater from shaft
drilling for construction of building, road, and bridge foundations unless managed
according to Special Condition S9.D.9.j.
5. Fuels, oils, or other pollutants used in vehicle and equipment operation and
maintenance.
6. Soaps or solvents used in vehicle and equipment washing.
7. Wheel wash wastewater, unless managed according to Special Condition S9.D.9.
8. Discharges from dewatering activities, including discharges from dewatering of trenches
and excavations, unless managed according to Special Condition S9.D.10.
E. Limits on Coverage
Ecology may require any discharger to apply for and obtain coverage under an individual permit
or another more specific general permit. Such alternative coverage will be required when
Ecology determines that this CSWGP does not provide adequate assurance that water quality
will be protected, or there is a reasonable potential for the project to cause or contribute to a
violation of water quality standards.
The following stormwater discharges are not covered by this permit:
1. Post-construction stormwater discharges that originate from the site after completion of
construction activities and the site has undergone final stabilization.
2. Non-point source silvicultural activities such as nursery operations, site preparation,
reforestation and subsequent cultural treatment, thinning, prescribed burning, pest and
fire control, harvesting operations, surface drainage, or road construction and
maintenance, from which there is natural runoff as excluded in 40 CFR Subpart 122.
3. Stormwater from any federal operator.
4. Stormwater from facilities located on Indian Country as defined in 18 U.S.C.§1151,
except portions of the Puyallup Reservation as noted below.
Indian Country includes:
a. All land within any Indian Reservation notwithstanding the issuance of any patent,
and, including rights-of-way running through the reservation. This includes all
federal, tribal, and Indian and non-Indian privately owned land within the
reservation.
b. All off-reservation Indian allotments, the Indian titles to which have not been
extinguished, including rights-of-way running through the same.
c. All off-reservation federal trust lands held for Native American Tribes.
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Puyallup Exception: Following the Puyallup Tribes of Indians Land Settlement Act of
1989, 25 U.S.C. §1773; the permit does apply to land within the Puyallup
Reservation except for discharges to surface water on land held in trust by the
federal government.
5. Stormwater from any site covered under an existing NPDES individual permit in which
stormwater management and/or treatment requirements are included for all stormwater
discharges associated with construction activity.
6. Stormwater from a site where an applicable Total Maximum Daily Load (TMDL)
requirement specifically precludes or prohibits discharges from construction activity.
F. Erosivity Waiver
Construction site operators may qualify for an Erosivity Waiver from the CSWGP if the following
conditions are met:
1. The site will result in the disturbance of fewer than five (5) acres and the site is not a
portion of a common plan of development or sale that will disturb five (5) acres or
greater.
2. Calculation of Erosivity “R” Factor and Regional Timeframe:
a. The project’s calculated rainfall erosivity factor (“R” Factor) must be less than five
(5) during the period of construction activity, (See the CSWGP homepage
http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html for a
link to the EPA’s calculator and step by step instructions on computing the “R”
Factor in the EPA Erosivity Waiver Fact Sheet). The period of construction activity
starts when the land is first disturbed and ends with final stabilization. In addition:
b. The entire period of construction activity must fall within the following timeframes:
i. For sites west of the Cascades Crest: June 15 – September 15.
ii. For sites east of the Cascades Crest, excluding the Central Basin:
June 15 – October 15.
iii. For sites east of the Cascades Crest, within the Central Basin: no timeframe
restrictions apply. The Central Basin is defined as the portions of Eastern
Washington with mean annual precipitation of less than 12 inches. For a map of
the Central Basin (Average Annual Precipitation Region 2), refer to:
http://www.ecy.wa.gov/programs/wq/stormwater/construction/resourcesguida
nce.html.
3. Construction site operators must submit a complete Erosivity Waiver certification form at
least one week before disturbing the land. Certification must include statements that the
operator will:
a. Comply with applicable local stormwater requirements; and
b. Implement appropriate erosion and sediment control BMPs to prevent violations of
water quality standards.
4. This waiver is not available for facilities declared significant contributors of pollutants as
defined in Special Condition S1.B.1.b or for any size construction activity that could
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reasonably expect to cause a violation of any water quality standard as defined in Special
Condition S1.B.1.b.ii.
5. This waiver does not apply to construction activities which include non-stormwater
discharges listed in Special Condition S1.C.3.
6. If construction activity extends beyond the certified waiver period for any reason, the
operator must either:
a. Recalculate the rainfall erosivity “R” factor using the original start date and a new
projected ending date and, if the “R” factor is still under 5 and the entire project
falls within the applicable regional timeframe in Special Condition S1.F.2.b,
complete and submit an amended waiver certification form before the original
waiver expires; or
b. Submit a complete permit application to Ecology in accordance with Special
Condition S2.A and B before the end of the certified waiver period.
S2. APPLICATION REQUIREMENTS
A. Permit Application Forms
1. Notice of Intent Form
a. Operators of new or previously unpermitted construction activities must submit a
complete and accurate permit application (Notice of Intent, or NOI) to Ecology.
b. Operators must apply using the electronic application form (NOI) available on Ecology’s
website (http://ecy.wa.gov/programs/wq/stormwater/construction/index.html).
Permittees unable to submit electronically (for example, those who do not have an
internet connection) must contact Ecology to request a waiver and obtain instructions
on how to obtain a paper NOI.
Department of Ecology
Water Quality Program - Construction Stormwater
PO Box 47696
Olympia, Washington 98504-7696
c. The operator must submit the NOI at least 60 days before discharging stormwater
from construction activities and must submit it prior to the date of the first public
notice (See Special Condition S2.B, below, for details). The 30-day public comment
period begins on the publication date of the second public notice. Unless Ecology
responds to the complete application in writing, coverage under the general permit
will automatically commence on the 31st day following receipt by Ecology of a
completed NOI, or the issuance date of this permit, whichever is later; unless Ecology
specifies a later date in writing as required by WAC173-226-200(2). See S8.B for
Limits on Coverage for New Discharges to TMDL or 303(d)-Listed Waters.
d. If an applicant intends to use a Best Management Practice (BMP) selected on the
basis of Special Condition S9.C.4 (“demonstrably equivalent” BMPs), the applicant
must notify Ecology of its selection as part of the NOI. In the event the applicant
selects BMPs after submission of the NOI, the applicant must provide notice of the
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selection of an equivalent BMP to Ecology at least 60 days before intended use of
the equivalent BMP.
e. Applicants must notify Ecology if they are aware of contaminated soils and/or
groundwater associated with the construction activity. Provide detailed information
with the NOI (as known and readily available) on the nature and extent of the
contamination (concentrations, locations, and depth), as well as pollution
prevention and/or treatment BMPs proposed to control the discharge of soil and/or
groundwater contaminants in stormwater. Examples of such detail may include, but
are not limited to:
i. List or table of all known contaminants with laboratory test results showing
concentration and depth,
ii. Map with sample locations,
iii. Related portions of the Stormwater Pollution Prevention Plan (SWPPP) that
address the management of contaminated and potentially contaminated
construction stormwater and dewatering water,
iv. Dewatering plan and/or dewatering contingency plan.
2. Transfer of Coverage Form
The Permittee can transfer current coverage under this permit to one or more new
operators, including operators of sites within a Common Plan of Development, provided:
i. The Permittee submits a complete Transfer of Coverage Form to Ecology,
signed by the current and new discharger and containing a specific date for
transfer of permit responsibility, coverage and liability (including any
Administrative Orders associated with the permit); and
ii. Ecology does not notify the current discharger and new discharger of intent to
revoke coverage under the general permit. If this notice is not given, the
transfer is effective on the date specified in the written agreement.
When a current discharger (Permittee) transfers a portion of a permitted site, the current
discharger must also indicate the remaining permitted acreage after the transfer.
Transfers do not require public notice.
3. Modification of Coverage Form
Permittees must notify Ecology regarding any changes to the information provided on
the NOI by submitting an Update/Modification of Permit Coverage form in accordance
with General Conditions G6 and G19. Examples of such changes include, but are not
limited to:
i. Changes to the Permittee’s mailing address,
ii. Changes to the on-site contact person information, and
iii. Changes to the area/acreage affected by construction activity.
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B. Public Notice
For new or previously unpermitted construction activities, the applicant must publish a public
notice at least one time each week for two consecutive weeks, at least 7 days apart, in a
newspaper with general circulation in the county where the construction is to take place. The
notice must be run after the NOI has been submitted and must contain:
1. A statement that “The applicant is seeking coverage under the Washington State
Department of Ecology’s Construction Stormwater NPDES and State Waste Discharge
General Permit.”
2. The name, address, and location of the construction site.
3. The name and address of the applicant.
4. The type of construction activity that will result in a discharge (for example, residential
construction, commercial construction, etc.), and the total number of acres to be
disturbed over the lifetime of the project.
5. The name of the receiving water(s) (that is, the surface water(s) to which the site will
discharge), or, if the discharge is through a storm sewer system, the name of the
operator of the system and the receiving water(s) the system discharges to.
6. The statement: Any persons desiring to present their views to the Washington State
Department of Ecology regarding this application, or interested in Ecology’s action on this
application, may notify Ecology in writing no later than 30 days of the last date of
publication of this notice. Ecology reviews public comments and considers whether
discharges from this project would cause a measurable change in receiving water quality,
and, if so, whether the project is necessary and in the overriding public interest according
to Tier II antidegradation requirements under WAC 173-201A-320. Comments can be
submitted to: Department of Ecology, PO Box 47696, Olympia, Washington 98504-7696
Attn: Water Quality Program, Construction Stormwater.
S3. COMPLIANCE WITH STANDARDS
A. Discharges must not cause or contribute to a violation of surface water quality standards
(Chapter 173-201A WAC), groundwater quality standards (Chapter 173-200 WAC),
sediment management standards (Chapter 173-204 WAC), and human health-based
criteria in the Federal water quality criteria applicable to Washington. (40 CFR Part 131.45)
Discharges that are not in compliance with these standards are prohibited.
B. Prior to the discharge of stormwater and non-stormwater to waters of the State, the
Permittee must apply All Known, Available, and Reasonable methods of prevention,
control, and Treatment (AKART). This includes the preparation and implementation of an
adequate SWPPP, with all appropriate BMPs installed and maintained in accordance with
the SWPPP and the terms and conditions of this permit.
C. Ecology presumes that a Permittee complies with water quality standards unless discharge
monitoring data or other site-specific information demonstrates that a discharge causes or
contributes to a violation of water quality standards, when the Permittee complies with the
following conditions. The Permittee must fully:
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1. Comply with all permit conditions, including; planning, sampling, monitoring,
reporting, and recordkeeping conditions.
2. Implement stormwater BMPs contained in stormwater management manuals
published or approved by Ecology, or BMPs that are demonstrably equivalent to BMPs
contained in stormwater management manuals published or approved by Ecology,
including the proper selection, implementation, and maintenance of all applicable and
appropriate BMPs for on-site pollution control. (For purposes of this section, the
stormwater manuals listed in Appendix 10 of the Phase I Municipal Stormwater Permit
are approved by Ecology.)
D. Where construction sites also discharge to groundwater, the groundwater discharges must
also meet the terms and conditions of this CSWGP. Permittees who discharge to
groundwater through an injection well must also comply with any applicable requirements
of the Underground Injection Control (UIC) regulations, Chapter 173-218 WAC.
S4. MONITORING REQUIREMENTS, BENCHMARKS, AND
REPORTING TRIGGERS
A. Site Log Book
The Permittee must maintain a site log book that contains a record of the implementation of
the SWPPP and other permit requirements, including the installation and maintenance of
BMPs, site inspections, and stormwater monitoring.
B. Site Inspections
Construction sites one (1) acre or larger that discharge stormwater to surface waters of the
State must have site inspections conducted by a Certified Erosion and Sediment Control Lead
(CESCL). Sites less than one (1) acre may have a person without CESCL certification conduct
inspections. (See Special Conditions S4.B.3 and B.4, below, for detailed requirements of the
Permittee’s CESCL.)
Site inspections must include all areas disturbed by construction activities, all BMPs, and all
stormwater discharge points under the Permittee’s operational control.
1. The Permittee must have staff knowledgeable in the principles and practices of erosion
and sediment control. The CESCL (sites one acre or more) or inspector (sites less than one
acre) must have the skills to assess the:
a. Site conditions and construction activities that could impact the quality of
stormwater; and
b. Effectiveness of erosion and sediment control measures used to control the quality
of stormwater discharges. The SWPPP must identify the CESCL or inspector, who
must be present on site or on-call at all times. The CESCL (sites one (1) acre or more)
must obtain this certification through an approved erosion and sediment control
training program that meets the minimum training standards established by Ecology.
(See BMP C160 in the manual, referred to in Special Condition S9.C.1 and 2.)
2. The CESCL or inspector must examine stormwater visually for the presence of suspended
sediment, turbidity, discoloration, and oil sheen. BMP effectiveness must be evaluated to
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determine if it is necessary to install, maintain, or repair BMPs to improve the quality of
stormwater discharges.
Based on the results of the inspection, the Permittee must correct the problems
identified, by:
a. Reviewing the SWPPP for compliance with Special Condition S9 and making
appropriate revisions within 7 days of the inspection.
b. Immediately beginning the process of fully implementing and maintaining
appropriate source control and/or treatment BMPs, within 10 days of the
inspection. If installation of necessary treatment BMPs is not feasible within 10
days, Ecology may approve additional time when an extension is requested by a
Permittee within the initial 10-day response period.
c. Documenting BMP implementation and maintenance in the site log book.
3. The CESCL or inspector must inspect all areas disturbed by construction activities, all
BMPs, and all stormwater discharge points at least once every calendar week and within
24 hours of any discharge from the site. (For purposes of this condition, individual
discharge events that last more than one (1) day do not require daily inspections. For
example, if a stormwater pond discharges continuously over the course of a week, only
one (1) inspection is required that week.) Inspection frequency may be reduced to once
every calendar month for inactive sites that are temporarily stabilized.
4. The Permittee must summarize the results of each inspection in an inspection report or
checklist and enter the report/checklist into, or attach it to, the site log book. At a
minimum, each inspection report or checklist must include:
a. Inspection date and time.
b. Weather information.
c. The general conditions during inspection.
d. The approximate amount of precipitation since the last inspection.
e. The approximate amount of precipitation within the last 24 hours.
f. A summary or list of all implemented BMPs, including observations of all
erosion/sediment control structures or practices.
g. A description of:
i. BMPs inspected (including location).
ii. BMPs that need maintenance and why.
iii. BMPs that failed to operate as designed or intended, and
iv. Where additional or different BMPs are needed, and why.
h. A description of stormwater discharged from the site. The Permittee must note the
presence of suspended sediment, turbidity, discoloration, and oil sheen, as
applicable.
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i. Any water quality monitoring performed during inspection.
j. General comments and notes, including a brief description of any BMP repairs,
maintenance, or installations made following the inspection.
k. An implementation schedule for the remedial actions that the Permittee plans to
take if the site inspection indicates that the site is out of compliance. The remedial
actions taken must meet the requirements of the SWPPP and the permit.
l. A summary report of the inspection.
m. The name, title, and signature of the person conducting the site inspection, a phone
number or other reliable method to reach this person, and the following statement:
I certify that this report is true, accurate, and complete to the best of my knowledge
and belief.
Table 3 Summary of Primary Monitoring Requirements
Size of Soil
Disturbance1
Weekly Site
Inspections
Weekly
Sampling w/
Turbidity Meter
Weekly Sampling w/
Transparency
Tube
Weekly pH
Sampling2
CESCL
Required for
Inspections?
Sites that disturb less
than 1 acre, but are
part of a larger
Common Plan of
Development
Required Not Required Not Required Not Required No
Sites that disturb 1 acre or more, but
fewer than 5 acres
Required Sampling Required –
either method3
Required Yes
Sites that disturb 5 acres or more
Required Required Not Required4 Required Yes
1 Soil disturbance is calculated by adding together all areas that will be affected by construction activity.
Construction activity means clearing, grading, excavation, and any other activity that disturbs the surface of the
land, including ingress/egress from the site.
2 If construction activity results in the disturbance of 1 acre or more, and involves significant concrete work (1,000
cubic yards of concrete or recycled concrete placed or poured over the life of a project) or the use of engineered
soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or
fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer
stormwater collection system that drains to other surface waters of the State, the Permittee must conduct pH
sampling in accordance with Special Condition S4.D.
3 Sites with one or more acres, but fewer than 5 acres of soil disturbance, must conduct turbidity or transparency
sampling in accordance with Special Condition S4.C.4.a or b.
4 Sites equal to or greater than 5 acres of soil disturbance must conduct turbidity sampling using a turbidity meter
in accordance with Special Condition S4.C.4.a.
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C. Turbidity/Transparency Sampling Requirements
1. Sampling Methods
a. If construction activity involves the disturbance of five (5) acres or more, the
Permittee must conduct turbidity sampling per Special Condition S4.C.4.a, below.
b. If construction activity involves one (1) acre or more but fewer than five (5) acres of
soil disturbance, the Permittee must conduct either transparency sampling or
turbidity sampling per Special Condition S4.C.4.a or b, below.
2. Sampling Frequency
a. The Permittee must sample all discharge points at least once every calendar week
when stormwater (or authorized non-stormwater) discharges from the site or
enters any on-site surface waters of the state (for example, a creek running through
a site); sampling is not required on sites that disturb less than an acre.
b. Samples must be representative of the flow and characteristics of the discharge.
c. Sampling is not required when there is no discharge during a calendar week.
d. Sampling is not required outside of normal working hours or during unsafe
conditions.
e. If the Permittee is unable to sample during a monitoring period, the Permittee must
include a brief explanation in the monthly Discharge Monitoring Report (DMR).
f. Sampling is not required before construction activity begins.
g. The Permittee may reduce the sampling frequency for temporarily stabilized,
inactive sites to once every calendar month.
3. Sampling Locations
a. Sampling is required at all points where stormwater associated with construction
activity (or authorized non-stormwater) is discharged off site, including where it
enters any on-site surface waters of the state (for example, a creek running through
a site).
b. The Permittee may discontinue sampling at discharge points that drain areas of the
project that are fully stabilized to prevent erosion.
c. The Permittee must identify all sampling point(s) in the SWPPP and on the site map
and clearly mark these points in the field with a flag, tape, stake or other visible
marker.
d. Sampling is not required for discharge that is sent directly to sanitary or combined
sewer systems.
e. The Permittee may discontinue sampling at discharge points in areas of the project
where the Permittee no longer has operational control of the construction activity.
Construction Stormwater General Permit Page 14
4. Sampling and Analysis Methods
a. The Permittee performs turbidity analysis with a calibrated turbidity meter
(turbidimeter) either on site or at an accredited lab. The Permittee must record the
results in the site log book in nephelometric turbidity units (NTUs).
b. The Permittee performs transparency analysis on site with a 1¾ inch diameter, 60
centimeter (cm)-long transparency tube. The Permittee will record the results in the
site log book in centimeters (cm).
Table 4 Monitoring and Reporting Requirements
Parameter Unit Analytical Method Sampling
Frequency
Benchmark
Value
Turbidity NTU SM2130 Weekly, if
discharging 25 NTUs
Transparency Cm
Manufacturer
instructions, or Ecology guidance
Weekly, if
discharging 33 cm
5. Turbidity/Transparency Benchmark Values and Reporting Triggers
The benchmark value for turbidity is 25 NTUs. The benchmark value for transparency is
33 centimeters (cm). Note: Benchmark values do not apply to discharges to segments of
water bodies on Washington State’s 303(d) list (Category 5) for turbidity, fine sediment,
or phosphorus; these discharges are subject to a numeric effluent limit for turbidity.
Refer to Special Condition S8 for more information and follow S5.F – Noncompliance
Notification for reporting requirements applicable to discharges which exceed the
numeric effluent limit for turbidity.
a. Turbidity 26 – 249 NTUs, or Transparency 32 – 7 cm:
If the discharge turbidity is 26 to 249 NTUs; or if discharge transparency is 32 to 7
cm, the Permittee must:
i. Immediately begin the process to fully implement and maintain appropriate
source control and/or treatment BMPs, and no later than 10 days of the date
the discharge exceeded the benchmark. If installation of necessary treatment
BMPs is not feasible within 10 days, Ecology may approve additional time when
the Permittee requests an extension within the initial 10-day response period.
ii. Review the SWPPP for compliance with Special Condition S9 and make
appropriate revisions within 7 days of the date the discharge exceeded the
benchmark.
iii. Document BMP implementation and maintenance in the site log book.
b. Turbidity 250 NTUs or greater, or Transparency 6 cm or less:
If a discharge point’s turbidity is 250 NTUs or greater, or if discharge transparency is
less than or equal to 6 cm, the Permittee must complete the reporting and adaptive
Construction Stormwater General Permit Page 15
management process described below. For discharges which are subject to a
numeric effluent limit for turbidity, see S5.F – Noncompliance Notification.
i. Within 24 hours, telephone or submit an electronic report to the applicable
Ecology Region’s Environmental Report Tracking System (ERTS) number (or
through Ecology’s Water Quality Permitting Portal [WQWebPortal] – Permit
Submittals when the form is available), in accordance with Special Condition S5.A.
• Central Region (Okanogan, Chelan, Douglas, Kittitas, Yakima, Klickitat,
Benton): (509) 575-2490
• Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield,
Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman):
(509) 329-3400
• Northwest Region (Kitsap, Snohomish, Island, King, San Juan, Skagit,
Whatcom): (425) 649-7000
• Southwest Region (Grays Harbor, Lewis, Mason, Thurston, Pierce, Clark,
Cowlitz, Skamania, Wahkiakum, Clallam, Jefferson, Pacific): (360) 407-6300
These numbers and a link to the ERTS reporting page are also listed at the following
website: http://www.ecy.wa.gov/programs/wq/stormwater/construction/index.html.
ii. Immediately begin the process to fully implement and maintain appropriate
source control and/or treatment BMPs as soon as possible, addressing the
problems within 10 days of the date the discharge exceeded the benchmark. If
installation of necessary treatment BMPs is not feasible within 10 days, Ecology
may approve additional time when the Permittee requests an extension within
the initial 10-day response period.
iii. Sample discharges daily until:
a) Turbidity is 25 NTUs (or lower); or
b) Transparency is 33 cm (or greater); or
c) The Permittee has demonstrated compliance with the water quality
standard for turbidity:
1) No more than 5 NTUs over background turbidity, if background is less
than 50 NTUs, or
2) No more than 10% over background turbidity, if background is 50
NTUs or greater; or
*Note: background turbidity in the receiving water must be
measured immediately upstream (upgradient) or outside of the area
of influence of the discharge.
d) The discharge stops or is eliminated.
iv. Review the SWPPP for compliance with Special Condition S9 and make
appropriate revisions within seven (7) days of the date the discharge exceeded
the benchmark.
Construction Stormwater General Permit Page 16
v. Document BMP implementation and maintenance in the site log book.
Compliance with these requirements does not relieve the Permittee from responsibility to
maintain continuous compliance with permit benchmarks.
D. pH Sampling Requirements – Significant Concrete Work or Engineered Soils
If construction activity results in the disturbance of 1 acre or more, and involves significant
concrete work (significant concrete work means greater than 1000 cubic yards placed or
poured concrete or recycled concrete used over the life of a project) or the use of engineered
soils (soil amendments including but not limited to Portland cement-treated base [CTB],
cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface
waters of the State or to a storm sewer system that drains to surface waters of the State, the
Permittee must conduct pH sampling as set forth below. Note: In addition, discharges to
segments of water bodies on Washington State’s 303(d) list (Category 5) for high pH are subject
to a numeric effluent limit for pH; refer to Special Condition S8.
1. The Permittee must perform pH analysis on site with a calibrated pH meter, pH test kit,
or wide range pH indicator paper. The Permittee must record pH sampling results in the
site log book.
2. During the applicable pH monitoring period defined below, the Permittee must obtain a
representative sample of stormwater and conduct pH analysis at least once per week.
a. For sites with significant concrete work, the Permittee must begin the pH sampling
period when the concrete is first placed or poured and exposed to precipitation, and
continue weekly throughout and after the concrete placement, pour and curing
period, until stormwater pH is in the range of 6.5 to 8.5 (su).
b. For sites with recycled concrete where monitoring is required, the Permittee must
begin the weekly pH sampling period when the recycled concrete is first exposed to
precipitation and must continue until the recycled concrete is fully stabilized with
the stormwater pH in the range of 6.5 to 8.5 (su).
c. For sites with engineered soils, the Permittee must begin the pH sampling period
when the soil amendments are first exposed to precipitation and must continue
until the area of engineered soils is fully stabilized.
3. The Permittee must sample pH in the sediment trap/pond(s) or other locations that
receive stormwater runoff from the area of significant concrete work or engineered soils
before the stormwater discharges to surface waters.
4. The benchmark value for pH is 8.5 standard units. Anytime sampling indicates that pH is
8.5 or greater, the Permittee must either:
a. Prevent the high pH water (8.5 or above) from entering storm sewer systems or
surface waters of the state; or
b. If necessary, adjust or neutralize the high pH water until it is in the range of pH 6.5 to
8.5 (su) using an appropriate treatment BMP such as carbon dioxide (CO2) sparging, dry
ice or food grade vinegar. The Permittee must obtain written approval from Ecology
before using any form of chemical treatment other than CO2 sparging, dry ice or food
grade vinegar.
Construction Stormwater General Permit Page 17
S5. REPORTING AND RECORDKEEPING REQUIREMENTS
A. High Turbidity Reporting
Anytime sampling performed in accordance with Special Condition S4.C indicates turbidity has
reached the 250 NTUs or more (or transparency less than or equal to 6 cm), high turbidity
reporting level, the Permittee must notify Ecology within 24 hours of analysis either by calling
the applicable Ecology Region’s Environmental Report Tracking System (ERTS) number by
phone or by submitting an electronic ERTS report (through Ecology’s Water Quality Permitting
Portal (WQWebPortal) – Permit Submittals when the form is available). See the CSWGP website
for links to ERTS and the WQWebPortal. (http://www.ecy.wa.gov/programs/wq/stormwater/
construction/index.html) Also, see phone numbers in Special Condition S4.C.5.b.i.
B. Discharge Monitoring Reports (DMRs)
Permittees required to conduct water quality sampling in accordance with Special Conditions
S4.C (Turbidity/Transparency), S4.D (pH), S8 (303[d]/TMDL sampling), and/or G12 (Additional
Sampling) must submit the results to Ecology.
Permittees must submit monitoring data using Ecology's WQWebDMR web application
accessed through Ecology’s Water Quality Permitting Portal.
Permittees unable to submit electronically (for example, those who do not have an internet
connection) must contact Ecology to request a waiver and obtain instructions on how to obtain
a paper copy DMR at:
Department of Ecology
Water Quality Program - Construction Stormwater
PO Box 47696
Olympia, WA 98504-7696
Permittees who obtain a waiver not to use WQWebDMR must use the forms provided to them
by Ecology; submittals must be mailed to the address above. Permittees must submit DMR
forms to be received by Ecology within 15 days following the end of each month.
If there was no discharge during a given monitoring period, all Permittees must submit a DMR
as required with “no discharge” entered in place of the monitoring results. DMRs are required
for the full duration of permit coverage (from the first full month following the effective date of
permit coverage up until Ecology has approved termination of the coverage). For more
information, contact Ecology staff using information provided at the following website:
www.ecy.wa.gov/programs/wq/permits/paris/contacts.html.
C. Records Retention
The Permittee must retain records of all monitoring information (site log book, sampling
results, inspection reports/checklists, etc.), Stormwater Pollution Prevention Plan, copy of the
permit coverage letter (including Transfer of Coverage documentation) and any other
documentation of compliance with permit requirements for the entire life of the construction
project and for a minimum of five (5) years following the termination of permit coverage. Such
information must include all calibration and maintenance records, and records of all data used
to complete the application for this permit. This period of retention must be extended during
Construction Stormwater General Permit Page 18
the course of any unresolved litigation regarding the discharge of pollutants by the Permittee
or when requested by Ecology.
D. Recording Results
For each measurement or sample taken, the Permittee must record the following information:
1. Date, place, method, and time of sampling or measurement.
2. The first and last name of the individual who performed the sampling or measurement.
3. The date(s) the analyses were performed.
4. The first and last name of the individual who performed the analyses.
5. The analytical techniques or methods used.
6. The results of all analyses.
E. Additional Monitoring by the Permittee
If the Permittee samples or monitors any pollutant more frequently than required by this
permit using test procedures specified by Special Condition S4 of this permit, the sampling
results for this monitoring must be included in the calculation and reporting of the data
submitted in the Permittee’s DMR.
F. Noncompliance Notification
In the event the Permittee is unable to comply with any part of the terms and conditions of this
permit, and the resulting noncompliance may cause a threat to human health or the
environment (such as but not limited to spills or fuels or other materials, catastrophic pond or
slope failure, and discharges that violate water quality standards), or exceed numeric effluent
limitations (see S8 – Discharges to 303(d) or TMDL Waterbodies), the Permittee must, upon
becoming aware of the circumstance:
1. Notify Ecology within 24 hours of the failure to comply by calling the applicable Regional
office ERTS phone number (refer to Special Condition S4.C.5.b.i, or go to
https://ecology.wa.gov/About-us/Get-involved/Report-an-environmental-issue to find
contact information for the regional offices.)
2. Immediately take action to prevent the discharge/pollution, or otherwise stop or correct
the noncompliance, and, if applicable, repeat sampling and analysis of any noncompliance
immediately and submit the results to Ecology within five (5) days of becoming aware of
the violation (See S5.F.3, below, for details on submitting results in a report).
3. Submit a detailed written report to Ecology within five (5) days of the time the Permittee
becomes aware of the circumstances, unless requested earlier by Ecology. The report must
be submitted using Ecology’s Water Quality Permitting Portal (WQWebPortal) – Permit
Submittals, unless a waiver from electronic reporting has been granted according to S5.B.
The report must contain a description of the noncompliance, including exact dates and
times, and if the noncompliance has not been corrected, the anticipated time it is expected
to continue; and the steps taken or planned to reduce, eliminate, and prevent
reoccurrence of the noncompliance.
Construction Stormwater General Permit Page 19
The Permittee must report any unanticipated bypass and/or upset that exceeds any
effluent limit in the permit in accordance with the 24-hour reporting requirement
contained in 40 C.F.R. 122.41(l)(6).
Compliance with these requirements does not relieve the Permittee from responsibility
to maintain continuous compliance with the terms and conditions of this permit or the
resulting liability for failure to comply. Upon request of the Permittee, Ecology may waive
the requirement for a written report on a case-by-case basis, if the immediate
notification is received by Ecology within 24 hours.
G. Access to Plans and Records
1. The Permittee must retain the following permit documentation (plans and records) on
site, or within reasonable access to the site, for use by the operator or for on-site review
by Ecology or the local jurisdiction:
a. General Permit
b. Permit Coverage Letter
c. Stormwater Pollution Prevention Plan (SWPPP)
d. Site Log Book
e. Erosivity Waiver (if applicable)
2. The Permittee must address written requests for plans and records listed above (Special
Condition S5.G.1) as follows:
a. The Permittee must provide a copy of plans and records to Ecology within 14 days of
receipt of a written request from Ecology.
b. The Permittee must provide a copy of plans and records to the public when
requested in writing. Upon receiving a written request from the public for the
Permittee’s plans and records, the Permittee must either:
i. Provide a copy of the plans and records to the requester within 14 days of a
receipt of the written request; or
ii. Notify the requester within 10 days of receipt of the written request of the
location and times within normal business hours when the plans and records
may be viewed; and provide access to the plans and records within 14 days of
receipt of the written request; or
Within 14 days of receipt of the written request, the Permittee may submit a
copy of the plans and records to Ecology for viewing and/or copying by the
requester at an Ecology office, or a mutually agreed location. If plans and
records are viewed and/or copied at a location other than at an Ecology office,
the Permittee will provide reasonable access to copying services for which a
reasonable fee may be charged. The Permittee must notify the requester
within 10 days of receipt of the request where the plans and records may be
viewed and/or copied.
Construction Stormwater General Permit Page 20
S6. PERMIT FEES
The Permittee must pay permit fees assessed by Ecology. Fees for stormwater discharges covered
under this permit are established by Chapter 173-224 WAC. Ecology continues to assess permit
fees until the permit is terminated in accordance with Special Condition S10 or revoked in
accordance with General Condition G5.
S7. SOLID AND LIQUID WASTE DISPOSAL
The Permittee must handle and dispose of solid and liquid wastes generated by construction
activity, such as demolition debris, construction materials, contaminated materials, and waste
materials from maintenance activities, including liquids and solids from cleaning catch basins and
other stormwater facilities, in accordance with:
A. Special Condition S3, Compliance with Standards.
B. WAC 173-216-110.
C. Other applicable regulations.
S8. DISCHARGES TO 303(d) OR TMDL WATERBODIES
A. Sampling and Numeric Effluent Limits For Certain Discharges to 303(d)-Listed
Water Bodies
1. Permittees who discharge to segments of water bodies listed as impaired by the State of
Washington under Section 303(d) of the Clean Water Act for turbidity, fine sediment,
high pH, or phosphorus, must conduct water quality sampling according to the
requirements of this section, and Special Conditions S4.C.2.b-f and S4.C.3.b-d, and must
comply with the applicable numeric effluent limitations in S8.C and S8.D.
2. All references and requirements associated with Section 303(d) of the Clean Water Act
mean the most current listing by Ecology of impaired waters (Category 5) that exists on
January 1, 2021, or the date when the operator’s complete permit application is received
by Ecology, whichever is later.
B. Limits on Coverage for New Discharges to TMDL or 303(d)-Listed Waters
Construction sites that discharge to a TMDL or 303(d)-listed waterbody are not eligible for
coverage under this permit unless the operator:
Construction Stormwater General Permit Page 21
1. Prevents exposing stormwater to pollutants for which the waterbody is impaired, and
retains documentation in the SWPPP that details procedures taken to prevent exposure
on site; or
2. Documents that the pollutants for which the waterbody is impaired are not present at
the site, and retains documentation of this finding within the SWPPP; or
3. Provides Ecology with data indicating the discharge is not expected to cause or
contribute to an exceedance of a water quality standard, and retains such data on site
with the SWPPP. The operator must provide data and other technical information to
Ecology that sufficiently demonstrate:
a. For discharges to waters without an EPA-approved or -established TMDL, that the
discharge of the pollutant for which the water is impaired will meet in-stream water
quality criteria at the point of discharge to the waterbody; or
b. For discharges to waters with an EPA-approved or -established TMDL, that there is
sufficient remaining wasteload allocation in the TMDL to allow construction
stormwater discharge and that existing dischargers to the waterbody are subject to
compliance schedules designed to bring the waterbody into attainment with water
quality standards.
Operators of construction sites are eligible for coverage under this permit only after
Ecology makes an affirmative determination that the discharge will not cause or
contribute to the existing impairment or exceed the TMDL.
C. Sampling and Numeric Effluent Limits for Discharges to Water Bodies on the 303(d) List
for Turbidity, Fine Sediment, or Phosphorus
1. Permittees who discharge to segments of water bodies on the 303(d) list (Category 5) for
turbidity, fine sediment, or phosphorus must conduct turbidity sampling in accordance
with Special Condition S4.C.2 and comply with either of the numeric effluent limits noted
in Table 5 below.
2. As an alternative to the 25 NTUs effluent limit noted in Table 5 below (applied at the
point where stormwater [or authorized non-stormwater] is discharged off-site),
Permittees may choose to comply with the surface water quality standard for turbidity.
The standard is: no more than 5 NTUs over background turbidity when the background
turbidity is 50 NTUs or less, or no more than a 10% increase in turbidity when the
background turbidity is more than 50 NTUs. In order to use the water quality standard
requirement, the sampling must take place at the following locations:
a. Background turbidity in the 303(d)-listed receiving water immediately upstream
(upgradient) or outside the area of influence of the discharge.
b. Turbidity at the point of discharge into the 303(d)-listed receiving water, inside the
area of influence of the discharge.
3. Discharges that exceed the numeric effluent limit for turbidity constitute a violation of
this permit.
4. Permittees whose discharges exceed the numeric effluent limit must sample discharges
daily until the violation is corrected and comply with the non-compliance notification
requirements in Special Condition S5.F.
Construction Stormwater General Permit Page 22
Table 5 Turbidity, Fine Sediment & Phosphorus Sampling and Limits for 303(d)-Listed Waters
Parameter identified in
303(d) listing
Parameter
Sampled Unit Analytical
Method
Sampling
Frequency
Numeric Effluent
Limit1
• Turbidity
• Fine Sediment
• Phosphorus
Turbidity NTU SM2130 Weekly, if discharging 25 NTUs, at the point where stormwater is
discharged from the
site; OR
In compliance with
the surface water
quality standard for
turbidity (S8.C.2.a)
1 Permittees subject to a numeric effluent limit for turbidity may, at their discretion, choose either
numeric effluent limitation based on site-specific considerations including, but not limited to,
safety, access and convenience.
D. Discharges to Water Bodies on the 303(d) List for High pH
1. Permittees who discharge to segments of water bodies on the 303(d) list (Category 5) for
high pH must conduct pH sampling in accordance with the table below, and comply with
the numeric effluent limit of pH 6.5 to 8.5 su (Table 6).
Table 6 pH Sampling and Limits for 303(d)-Listed Waters
Parameter identified in 303(d)
listing
Parameter
Sampled/Units
Analytical
Method
Sampling
Frequency
Numeric Effluent
Limit
High pH pH /Standard Units pH meter Weekly, if discharging In the range of 6.5 – 8.5 su
2. At the Permittee’s discretion, compliance with the limit shall be assessed at one of the
following locations:
a. Directly in the 303(d)-listed waterbody segment, inside the immediate area of
influence of the discharge; or
b. Alternatively, the Permittee may measure pH at the point where the discharge
leaves the construction site, rather than in the receiving water.
3. Discharges that exceed the numeric effluent limit for pH (outside the range of 6.5 – 8.5 su)
constitute a violation of this permit.
4. Permittees whose discharges exceed the numeric effluent limit must sample discharges
daily until the violation is corrected and comply with the non-compliance notification
requirements in Special Condition S5.F.
E. Sampling and Limits for Sites Discharging to Waters Covered by a TMDL or another
Pollution Control Plan
Construction Stormwater General Permit Page 23
1. Discharges to a waterbody that is subject to a Total Maximum Daily Load (TMDL) for
turbidity, fine sediment, high pH, or phosphorus must be consistent with the TMDL. Refer
to http://www.ecy.wa.gov/programs/wq/tmdl/TMDLsbyWria/TMDLbyWria.html for
more information on TMDLs.
a. Where an applicable TMDL sets specific waste load allocations or requirements for
discharges covered by this permit, discharges must be consistent with any specific
waste load allocations or requirements established by the applicable TMDL.
i. The Permittee must sample discharges weekly, unless otherwise specified by
the TMDL, to evaluate compliance with the specific waste load allocations or
requirements.
ii. Analytical methods used to meet the monitoring requirements must conform
to the latest revision of the Guidelines Establishing Test Procedures for the
Analysis of Pollutants contained in 40 CFR Part 136.
iii. Turbidity and pH methods need not be accredited or registered unless
conducted at a laboratory which must otherwise be accredited or registered.
b. Where an applicable TMDL has established a general waste load allocation for
construction stormwater discharges, but has not identified specific requirements,
compliance with Special Conditions S4 (Monitoring) and S9 (SWPPPs) will constitute
compliance with the approved TMDL.
c. Where an applicable TMDL has not specified a waste load allocation for construction
stormwater discharges, but has not excluded these discharges, compliance with
Special Conditions S4 (Monitoring) and S9 (SWPPPs) will constitute compliance with
the approved TMDL.
d. Where an applicable TMDL specifically precludes or prohibits discharges from
construction activity, the operator is not eligible for coverage under this permit.
S9. STORMWATER POLLUTION PREVENTION PLAN
The Permittee must prepare and properly implement an adequate Stormwater Pollution
Prevention Plan (SWPPP) for construction activity in accordance with the requirements of this
permit beginning with initial soil disturbance and until final stabilization.
A. The Permittee’s SWPPP must meet the following objectives:
1. To identify best management practices (BMPs) which prevent erosion and sedimentation,
and to reduce, eliminate or prevent stormwater contamination and water pollution from
construction activity.
2. To prevent violations of surface water quality, groundwater quality, or sediment
management standards.
3. To control peak volumetric flow rates and velocities of stormwater discharges.
Construction Stormwater General Permit Page 24
B. General Requirements
1. The SWPPP must include a narrative and drawings. All BMPs must be clearly referenced in
the narrative and marked on the drawings. The SWPPP narrative must include
documentation to explain and justify the pollution prevention decisions made for the
project. Documentation must include:
a. Information about existing site conditions (topography, drainage, soils, vegetation, etc.).
b. Potential erosion problem areas.
c. The 13 elements of a SWPPP in Special Condition S9.D.1-13, including BMPs
used to address each element.
d. Construction phasing/sequence and general BMP implementation schedule.
e. The actions to be taken if BMP performance goals are not achieved—for example,
a contingency plan for additional treatment and/or storage of stormwater that
would violate the water quality standards if discharged.
f. Engineering calculations for ponds, treatment systems, and any other designed
structures. When a treatment system requires engineering calculations, these
calculations must be included in the SWPPP. Engineering calculations do not need to
be included in the SWPPP for treatment systems that do not require such calculations.
2. The Permittee must modify the SWPPP if, during inspections or investigations conducted
by the owner/operator, or the applicable local or state regulatory authority, it is
determined that the SWPPP is, or would be, ineffective in eliminating or significantly
minimizing pollutants in stormwater discharges from the site. The Permittee must then:
a. Review the SWPPP for compliance with Special Condition S9 and make appropriate
revisions within 7 days of the inspection or investigation.
b. Immediately begin the process to fully implement and maintain appropriate source
control and/or treatment BMPs as soon as possible, addressing the problems no later
than 10 days from the inspection or investigation. If installation of necessary treatment
BMPs is not feasible within 10 days, Ecology may approve additional time when an
extension is requested by a Permittee within the initial 10-day response period.
c. Document BMP implementation and maintenance in the site log book.
The Permittee must modify the SWPPP whenever there is a change in design,
construction, operation, or maintenance at the construction site that has, or could have,
a significant effect on the discharge of pollutants to waters of the State.
C. Stormwater Best Management Practices (BMPs)
BMPs must be consistent with:
1. Stormwater Management Manual for Western Washington (most current approved
edition at the time this permit was issued), for sites west of the crest of the Cascade
Mountains; or
Construction Stormwater General Permit Page 25
2. Stormwater Management Manual for Eastern Washington (most current approved
edition at the time this permit was issued), for sites east of the crest of the Cascade
Mountains; or
3. Revisions to the manuals listed in Special Condition S9.C.1 & 2, or other stormwater
management guidance documents or manuals which provide an equivalent level of
pollution prevention, that are approved by Ecology and incorporated into this permit in
accordance with the permit modification requirements of WAC 173-226-230; or
4. Documentation in the SWPPP that the BMPs selected provide an equivalent level of
pollution prevention, compared to the applicable stormwater management manuals,
including:
a. The technical basis for the selection of all stormwater BMPs (scientific, technical studies,
and/or modeling) that support the performance claims for the BMPs being selected.
b. An assessment of how the selected BMP will satisfy AKART requirements and the
applicable federal technology-based treatment requirements under 40 CFR part 125.3.
D. SWPPP – Narrative Contents and Requirements
The Permittee must include each of the 13 elements below in Special Condition S9.D.1-13 in
the narrative of the SWPPP and implement them unless site conditions render the element
unnecessary and the exemption from that element is clearly justified in the SWPPP.
1. Preserve Vegetation/Mark Clearing Limits
a. Before beginning land-disturbing activities, including clearing and grading, clearly
mark all clearing limits, sensitive areas and their buffers, and trees that are to be
preserved within the construction area.
b. Retain the duff layer, native topsoil, and natural vegetation in an undisturbed state
to the maximum degree practicable.
2. Establish Construction Access
a. Limit construction vehicle access and exit to one route, if possible.
b. Stabilize access points with a pad of quarry spalls, crushed rock, or other equivalent
BMPs, to minimize tracking sediment onto roads.
c. Locate wheel wash or tire baths on site, if the stabilized construction entrance is not
effective in preventing tracking sediment onto roads.
d. If sediment is tracked off site, clean the affected roadway thoroughly at the end of
each day, or more frequently as necessary (for example, during wet weather).
Remove sediment from roads by shoveling, sweeping, or pickup and transport of the
sediment to a controlled sediment disposal area.
e. Conduct street washing only after sediment removal in accordance with Special
Condition S9.D.2.d.
f. Control street wash wastewater by pumping back on site or otherwise preventing it
from discharging into systems tributary to waters of the State.
Construction Stormwater General Permit Page 26
3. Control Flow Rates
a. Protect properties and waterways downstream of construction sites from erosion
and the associated discharge of turbid waters due to increases in the velocity and
peak volumetric flow rate of stormwater runoff from the project site, as required by
local plan approval authority.
b. Where necessary to comply with Special Condition S9.D.3.a, construct stormwater
infiltration or detention BMPs as one of the first steps in grading. Assure that
detention BMPs function properly before constructing site improvements (for
example, impervious surfaces).
c. If permanent infiltration ponds are used for flow control during construction,
protect these facilities from sedimentation during the construction phase.
4. Install Sediment Controls
The Permittee must design, install and maintain effective erosion controls and sediment
controls to minimize the discharge of pollutants. At a minimum, the Permittee must:
a. Construct sediment control BMPs (sediment ponds, traps, filters, infiltration
facilities, etc.) as one of the first steps in grading. These BMPs must be functional
before other land disturbing activities take place.
b. Minimize sediment discharges from the site. The design, installation and
maintenance of erosion and sediment controls must address factors such as the
amount, frequency, intensity and duration of precipitation, the nature of resulting
stormwater runoff, and soil characteristics, including the range of soil particle sizes
expected to be present on the site.
c. Direct stormwater runoff from disturbed areas through a sediment pond or other
appropriate sediment removal BMP, before the runoff leaves a construction site or
before discharge to an infiltration facility. Runoff from fully stabilized areas may be
discharged without a sediment removal BMP, but must meet the flow control
performance standard of Special Condition S9.D.3.a.
d. Locate BMPs intended to trap sediment on site in a manner to avoid interference
with the movement of juvenile salmonids attempting to enter off-channel areas or
drainages.
e. Provide and maintain natural buffers around surface waters, direct stormwater to
vegetated areas to increase sediment removal and maximize stormwater
infiltration, unless infeasible.
f. Where feasible, design outlet structures that withdraw impounded stormwater
from the surface to avoid discharging sediment that is still suspended lower in the
water column.
5. Stabilize Soils
a. The Permittee must stabilize exposed and unworked soils by application of effective
BMPs that prevent erosion. Applicable BMPs include, but are not limited to:
temporary and permanent seeding, sodding, mulching, plastic covering, erosion
Construction Stormwater General Permit Page 27
control fabrics and matting, soil application of polyacrylamide (PAM), the early
application of gravel base on areas to be paved, and dust control.
b. The Permittee must control stormwater volume and velocity within the site to
minimize soil erosion.
c. The Permittee must control stormwater discharges, including both peak flow rates
and total stormwater volume, to minimize erosion at outlets and to minimize
downstream channel and stream bank erosion.
d. Depending on the geographic location of the project, the Permittee must not allow
soils to remain exposed and unworked for more than the time periods set forth
below to prevent erosion.
West of the Cascade Mountains Crest
During the dry season (May 1 - September 30): 7 days
During the wet season (October 1 - April 30): 2 days
East of the Cascade Mountains Crest, except for Central Basin*
During the dry season (July 1 - September 30): 10 days
During the wet season (October 1 - June 30): 5 days
The Central Basin*, East of the Cascade Mountains Crest
During the dry Season (July 1 - September 30): 30 days
During the wet season (October 1 - June 30): 15 days
*Note: The Central Basin is defined as the portions of Eastern Washington
with mean annual precipitation of less than 12 inches.
e. The Permittee must stabilize soils at the end of the shift before a holiday or
weekend if needed based on the weather forecast.
f. The Permittee must stabilize soil stockpiles from erosion, protected with sediment
trapping measures, and where possible, be located away from storm drain inlets,
waterways, and drainage channels.
g. The Permittee must minimize the amount of soil exposed during construction activity.
h. The Permittee must minimize the disturbance of steep slopes.
i. The Permittee must minimize soil compaction and, unless infeasible, preserve topsoil.
6. Protect Slopes
a. The Permittee must design and construct cut-and-fill slopes in a manner to minimize
erosion. Applicable practices include, but are not limited to, reducing continuous
length of slope with terracing and diversions, reducing slope steepness, and
roughening slope surfaces (for example, track walking).
b. The Permittee must divert off-site stormwater (run-on) or groundwater away from
slopes and disturbed areas with interceptor dikes, pipes, and/or swales. Off-site
stormwater should be managed separately from stormwater generated on the site.
c. At the top of slopes, collect drainage in pipe slope drains or protected channels to
prevent erosion.
Construction Stormwater General Permit Page 28
i. West of the Cascade Mountains Crest: Temporary pipe slope drains must handle
the peak 10-minute flow rate from a Type 1A, 10-year, 24-hour frequency storm
for the developed condition. Alternatively, the 10-year, 1-hour flow rate
predicted by an approved continuous runoff model, increased by a factor of 1.6,
may be used. The hydrologic analysis must use the existing land cover condition
for predicting flow rates from tributary areas outside the project limits. For
tributary areas on the project site, the analysis must use the temporary or
permanent project land cover condition, whichever will produce the highest flow
rates. If using the Western Washington Hydrology Model (WWHM) to predict
flows, bare soil areas should be modeled as "landscaped area.”
ii. East of the Cascade Mountains Crest: Temporary pipe slope drains must handle
the expected peak flow rate from a 6-month, 3-hour storm for the developed
condition, referred to as the short duration storm.
d. Place excavated material on the uphill side of trenches, consistent with safety and
space considerations.
e. Place check dams at regular intervals within constructed channels that are cut down
a slope.
7. Protect Drain Inlets
a. Protect all storm drain inlets made operable during construction so that stormwater
runoff does not enter the conveyance system without first being filtered or treated
to remove sediment.
b. Clean or remove and replace inlet protection devices when sediment has filled one-
third of the available storage (unless a different standard is specified by the product
manufacturer).
8. Stabilize Channels and Outlets
a. Design, construct and stabilize all on-site conveyance channels to prevent erosion
from the following expected peak flows:
i. West of the Cascade Mountains Crest: Channels must handle the peak 10-
minute flow rate from a Type 1A, 10-year, 24-hour frequency storm for the
developed condition. Alternatively, the 10-year, 1-hour flow rate indicated by
an approved continuous runoff model, increased by a factor of 1.6, may be
used. The hydrologic analysis must use the existing land cover condition for
predicting flow rates from tributary areas outside the project limits. For
tributary areas on the project site, the analysis must use the temporary or
permanent project land cover condition, whichever will produce the highest
flow rates. If using the WWHM to predict flows, bare soil areas should be
modeled as "landscaped area.”
ii. East of the Cascade Mountains Crest: Channels must handle the expected peak
flow rate from a 6-month, 3-hour storm for the developed condition, referred
to as the short duration storm.
b. Provide stabilization, including armoring material, adequate to prevent erosion of
outlets, adjacent stream banks, slopes, and downstream reaches at the outlets of all
conveyance systems.
Construction Stormwater General Permit Page 29
9. Control Pollutants
Design, install, implement and maintain effective pollution prevention measures to
minimize the discharge of pollutants. The Permittee must:
a. Handle and dispose of all pollutants, including waste materials and demolition
debris that occur on site in a manner that does not cause contamination of
stormwater.
b. Provide cover, containment, and protection from vandalism for all chemicals, liquid
products, petroleum products, and other materials that have the potential to pose a
threat to human health or the environment. Minimize storage of hazardous
materials on-site. Safety Data Sheets (SDS) should be supplied for all materials
stored. Chemicals should be kept in their original labeled containers. On-site fueling
tanks must include secondary containment. Secondary containment means placing
tanks or containers within an impervious structure capable of containing 110% of
the volume of the largest tank within the containment structure. Double-walled
tanks do not require additional secondary containment.
c. Conduct maintenance, fueling, and repair of heavy equipment and vehicles using
spill prevention and control measures. Clean contaminated surfaces immediately
following any spill incident.
d. Discharge wheel wash or tire bath wastewater to a separate on-site treatment
system that prevents discharge to surface water, such as closed-loop recirculation
or upland land application, or to the sanitary sewer with local sewer district
approval.
e. Apply fertilizers and pesticides in a manner and at application rates that will not
result in loss of chemical to stormwater runoff. Follow manufacturers’ label
requirements for application rates and procedures.
f. Use BMPs to prevent contamination of stormwater runoff by pH-modifying sources.
The sources for this contamination include, but are not limited to: bulk cement,
cement kiln dust, fly ash, new concrete washing and curing waters, recycled
concrete stockpiles, waste streams generated from concrete grinding and sawing,
exposed aggregate processes, dewatering concrete vaults, concrete pumping and
mixer washout waters. (Also refer to the definition for "concrete wastewater" in
Appendix A – Definitions.)
g. Adjust the pH of stormwater or authorized non-stormwater if necessary to prevent
an exceedance of groundwater and/or surface water quality standards.
h. Assure that washout of concrete trucks is performed off-site or in designated
concrete washout areas only. Do not wash out concrete truck drums onto the
ground, or into storm drains, open ditches, streets, or streams. Washout of small
concrete handling equipment may be disposed of in a formed area awaiting
concrete where it will not contaminate surface or groundwater. Do not dump excess
concrete on site, except in designated concrete washout areas. Concrete spillage or
concrete discharge directly to groundwater or surface waters of the State is
Construction Stormwater General Permit Page 30
prohibited. At no time shall concrete be washed off into the footprint of an area
where an infiltration BMP will be installed.
i. Obtain written approval from Ecology before using any chemical treatment, with
the exception of CO2, dry ice or food grade vinegar, to adjust pH.
j. Uncontaminated water from water-only based shaft drilling for construction of
building, road, and bridge foundations may be infiltrated provided the wastewater is
managed in a way that prohibits discharge to surface waters. Prior to infiltration,
water from water-only based shaft drilling that comes into contact with curing
concrete must be neutralized until pH is in the range of 6.5 to 8.5 (su).
10. Control Dewatering
a. Permittees must discharge foundation, vault, and trench dewatering water, which
have characteristics similar to stormwater runoff at the site, in conjunction with BMPs
to reduce sedimentation before discharge to a sediment trap or sediment pond.
b. Permittees may discharge clean, non-turbid dewatering water, such as well-point
groundwater, to systems tributary to, or directly into surface waters of the State, as
specified in Special Condition S9.D.8, provided the dewatering flow does not cause
erosion or flooding of receiving waters. Do not route clean dewatering water through
stormwater sediment ponds. Note that “surface waters of the State” may exist on a
construction site as well as off site; for example, a creek running through a site.
c. Other dewatering treatment or disposal options may include:
i. Infiltration
ii. Transport off site in a vehicle, such as a vacuum flush truck, for legal disposal in
a manner that does not pollute state waters.
iii. Ecology-approved on-site chemical treatment or other suitable treatment
technologies (See S9.D.9.i, regarding chemical treatment written approval).
iv. Sanitary or combined sewer discharge with local sewer district approval, if
there is no other option.
v. Use of a sedimentation bag with discharge to a ditch or swale for small
volumes of localized dewatering.
d. Permittees must handle highly turbid or contaminated dewatering water separately
from stormwater.
11. Maintain BMPs
a. Permittees must maintain and repair all temporary and permanent erosion and
sediment control BMPs as needed to assure continued performance of their
intended function in accordance with BMP specifications.
b. Permittees must remove all temporary erosion and sediment control BMPs within
30 days after achieving final site stabilization or after the temporary BMPs are no
longer needed.
Construction Stormwater General Permit Page 31
12. Manage the Project
a. Phase development projects to the maximum degree practicable and take into
account seasonal work limitations.
b. Inspect, maintain and repair all BMPs as needed to assure continued performance
of their intended function. Conduct site inspections and monitoring in accordance
with Special Condition S4.
c. Maintain, update, and implement the SWPPP in accordance with Special Conditions
S3, S4, and S9.
13. Protect Low Impact Development (LID) BMPs
The primary purpose of on-site LID Stormwater Management is to reduce the disruption of
the natural site hydrology through infiltration. LID BMPs are permanent facilities.
a. Permittees must protect all LID BMPs (including, but not limited to, Bioretention and
Rain Garden facilities) from sedimentation through installation and maintenance of
erosion and sediment control BMPs on portions of the site that drain into the
Bioretention and/or Rain Garden facilities. Restore the BMPs to their fully
functioning condition if they accumulate sediment during construction. Restoring
the facility must include removal of sediment and any sediment-laden bioretention/
rain garden soils, and replacing the removed soils with soils meeting the design
specification.
b. Permittees must maintain the infiltration capabilities of LID BMPs by protecting
against compaction by construction equipment and foot traffic. Protect completed
lawn and landscaped areas from compaction due to construction equipment.
c. Permittees must control erosion and avoid introducing sediment from surrounding
land uses onto permeable pavements. Do not allow muddy construction equipment
on the base material or pavement. Do not allow sediment-laden runoff onto
permeable pavements or base materials.
d. Permittees must clean permeable pavements fouled with sediments or no longer
passing an initial infiltration test using local stormwater manual methodology or the
manufacturer’s procedures.
e. Permittees must keep all heavy equipment off existing soils under LID BMPs that
have been excavated to final grade to retain the infiltration rate of the soils.
E. SWPPP – Map Contents and Requirements
The Permittee’s SWPPP must also include a vicinity map or general location map (for example,
a USGS quadrangle map, a portion of a county or city map, or other appropriate map) with
enough detail to identify the location of the construction site and receiving waters within one
mile of the site.
The SWPPP must also include a legible site map (or maps) showing the entire construction site.
The following features must be identified, unless not applicable due to site conditions.
1. The direction of north, property lines, and existing structures and roads.
2. Cut and fill slopes indicating the top and bottom of slope catch lines.
Construction Stormwater General Permit Page 32
3. Approximate slopes, contours, and direction of stormwater flow before and after major
grading activities.
4. Areas of soil disturbance and areas that will not be disturbed.
5. Locations of structural and nonstructural controls (BMPs) identified in the SWPPP.
6. Locations of off-site material, stockpiles, waste storage, borrow areas, and
vehicle/equipment storage areas.
7. Locations of all surface water bodies, including wetlands.
8. Locations where stormwater or non-stormwater discharges off-site and/or to a surface
waterbody, including wetlands.
9. Location of water quality sampling station(s), if sampling is required by state or local
permitting authority.
10. Areas where final stabilization has been accomplished and no further construction-phase
permit requirements apply.
11. Location or proposed location of LID facilities.
S10. NOTICE OF TERMINATION
Partial terminations of permit coverage are not authorized.
A. The site is eligible for termination of coverage when it has met any of the following
conditions:
1. The site has undergone final stabilization, the Permittee has removed all temporary
BMPs (except biodegradable BMPs clearly manufactured with the intention for the
material to be left in place and not interfere with maintenance or land use), and all
stormwater discharges associated with construction activity have been eliminated; or
2. All portions of the site that have not undergone final stabilization per Special Condition
S10.A.1 have been sold and/or transferred (per Special Condition S2.A), and the
Permittee no longer has operational control of the construction activity; or
3. For residential construction only, the Permittee has completed temporary stabilization
and the homeowners have taken possession of the residences.
B. When the site is eligible for termination, the Permittee must submit a complete and
accurate Notice of Termination (NOT) form, signed in accordance with General
Condition G2, to:
Department of Ecology
Water Quality Program - Construction Stormwater
PO Box 47696
Olympia, WA 98504-7696
Construction Stormwater General Permit Page 33
When an electronic termination form is available, the Permittee may choose to submit a
complete and accurate Notice of Termination (NOT) form through the Water Quality Permitting
Portal rather than mailing a hardcopy as noted above.
The termination is effective on the 31st calendar day following the date Ecology receives a
complete NOT form, unless Ecology notifies the Permittee that termination request is denied
because the Permittee has not met the eligibility requirements in Special Condition S10.A.
Permittees are required to comply with all conditions and effluent limitations in the permit
until the permit has been terminated.
Permittees transferring the property to a new property owner or operator/Permittee are
required to complete and submit the Notice of Transfer form to Ecology, but are not required
to submit a Notice of Termination form for this type of transaction.
Construction Stormwater General Permit Page 34
GENERAL CONDITIONS
G1. DISCHARGE VIOLATIONS
All discharges and activities authorized by this general permit must be consistent with the terms
and conditions of this general permit. Any discharge of any pollutant more frequent than or at a
level in excess of that identified and authorized by the general permit must constitute a violation of
the terms and conditions of this permit.
G2. SIGNATORY REQUIREMENTS
A. All permit applications must bear a certification of correctness to be signed:
1. In the case of corporations, by a responsible corporate officer.
2. In the case of a partnership, by a general partner of a partnership.
3. In the case of sole proprietorship, by the proprietor.
4. In the case of a municipal, state, or other public facility, by either a principal executive
officer or ranking elected official.
B. All reports required by this permit and other information requested by Ecology (including
NOIs, NOTs, and Transfer of Coverage forms) must be signed by a person described above
or by a duly authorized representative of that person. A person is a duly authorized
representative only if:
1. The authorization is made in writing by a person described above and submitted to
Ecology.
2. The authorization specifies either an individual or a position having responsibility for
the overall operation of the regulated facility, such as the position of plant manager,
superintendent, position of equivalent responsibility, or an individual or position
having overall responsibility for environmental matters.
C. Changes to authorization. If an authorization under paragraph G2.B.2 above is no longer
accurate because a different individual or position has responsibility for the overall
operation of the facility, a new authorization satisfying the requirements of paragraph
G2.B.2 above must be submitted to Ecology prior to or together with any reports,
information, or applications to be signed by an authorized representative.
D. Certification. Any person signing a document under this section must make the following
certification:
I certify under penalty of law, that this document and all attachments were
prepared under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gathered and evaluated the
information submitted. Based on my inquiry of the person or persons who
manage the system, or those persons directly responsible for gathering
information, the information submitted is, to the best of my knowledge and
belief, true, accurate, and complete. I am aware that there are significant
penalties for submitting false information, including the possibility of fine and
imprisonment for knowing violations.
Construction Stormwater General Permit Page 35
G3. RIGHT OF INSPECTION AND ENTRY
The Permittee must allow an authorized representative of Ecology, upon the presentation of
credentials and such other documents as may be required by law:
A. To enter upon the premises where a discharge is located or where any records are kept
under the terms and conditions of this permit.
B. To have access to and copy, at reasonable times and at reasonable cost, any records
required to be kept under the terms and conditions of this permit.
C. To inspect, at reasonable times, any facilities, equipment (including monitoring and control
equipment), practices, methods, or operations regulated or required under this permit.
D. To sample or monitor, at reasonable times, any substances or parameters at any location for
purposes of assuring permit compliance or as otherwise authorized by the Clean Water Act.
G4. GENERAL PERMIT MODIFICATION AND REVOCATION
This permit may be modified, revoked and reissued, or terminated in accordance with the
provisions of Chapter 173-226 WAC. Grounds for modification, revocation and reissuance, or
termination include, but are not limited to, the following:
A. When a change occurs in the technology or practices for control or abatement of pollutants
applicable to the category of dischargers covered under this permit.
B. When effluent limitation guidelines or standards are promulgated pursuant to the CWA or
Chapter 90.48 RCW, for the category of dischargers covered under this permit.
C. When a water quality management plan containing requirements applicable to the
category of dischargers covered under this permit is approved, or
D. When information is obtained that indicates cumulative effects on the environment from
dischargers covered under this permit are unacceptable.
G5. REVOCATION OF COVERAGE UNDER THE PERMIT
Pursuant to Chapter 43.21B RCW and Chapter 173-226 WAC, the Director may terminate coverage
for any discharger under this permit for cause. Cases where coverage may be terminated include,
but are not limited to, the following:
A. Violation of any term or condition of this permit.
B. Obtaining coverage under this permit by misrepresentation or failure to disclose fully all
relevant facts.
C. A change in any condition that requires either a temporary or permanent reduction or
elimination of the permitted discharge.
D. Failure or refusal of the Permittee to allow entry as required in RCW 90.48.090.
E. A determination that the permitted activity endangers human health or the environment,
or contributes to water quality standards violations.
F. Nonpayment of permit fees or penalties assessed pursuant to RCW 90.48.465 and Chapter
173-224 WAC.
Construction Stormwater General Permit Page 36
G. Failure of the Permittee to satisfy the public notice requirements of WAC 173-226-130(5),
when applicable.
The Director may require any discharger under this permit to apply for and obtain coverage
under an individual permit or another more specific general permit. Permittees who have their
coverage revoked for cause according to WAC 173-226-240 may request temporary coverage
under this permit during the time an individual permit is being developed, provided the request
is made within ninety (90) days from the time of revocation and is submitted along with a
complete individual permit application form.
G6. REPORTING A CAUSE FOR MODIFICATION
The Permittee must submit a new application, or a supplement to the previous application,
whenever a material change to the construction activity or in the quantity or type of discharge is
anticipated which is not specifically authorized by this permit. This application must be submitted
at least sixty (60) days prior to any proposed changes. Filing a request for a permit modification,
revocation and reissuance, or termination, or a notification of planned changes or anticipated
noncompliance does not relieve the Permittee of the duty to comply with the existing permit until
it is modified or reissued.
G7. COMPLIANCE WITH OTHER LAWS AND STATUTES
Nothing in this permit will be construed as excusing the Permittee from compliance with any
applicable federal, state, or local statutes, ordinances, or regulations.
G8. DUTY TO REAPPLY
The Permittee must apply for permit renewal at least 180 days prior to the specified expiration
date of this permit. The Permittee must reapply using the electronic application form (NOI)
available on Ecology’s website. Permittees unable to submit electronically (for example, those who
do not have an internet connection) must contact Ecology to request a waiver and obtain
instructions on how to obtain a paper NOI.
Department of Ecology
Water Quality Program - Construction Stormwater
PO Box 47696
Olympia, WA 98504-7696
G9. REMOVED SUBSTANCE
The Permittee must not re-suspend or reintroduce collected screenings, grit, solids, sludges, filter
backwash, or other pollutants removed in the course of treatment or control of stormwater to the
final effluent stream for discharge to state waters.
G10. DUTY TO PROVIDE INFORMATION
The Permittee must submit to Ecology, within a reasonable time, all information that Ecology may
request to determine whether cause exists for modifying, revoking and reissuing, or terminating
this permit or to determine compliance with this permit. The Permittee must also submit to
Ecology, upon request, copies of records required to be kept by this permit [40 CFR 122.41(h)].
Construction Stormwater General Permit Page 37
G11. OTHER REQUIREMENTS OF 40 CFR
All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference.
G12. ADDITIONAL MONITORING
Ecology may establish specific monitoring requirements in addition to those contained in this
permit by administrative order or permit modification.
G13. PENALTIES FOR VIOLATING PERMIT CONDITIONS
Any person who is found guilty of willfully violating the terms and conditions of this permit shall be
deemed guilty of a crime, and upon conviction thereof shall be punished by a fine of up to ten
thousand dollars ($10,000) and costs of prosecution, or by imprisonment at the discretion of the
court. Each day upon which a willful violation occurs may be deemed a separate and additional
violation.
Any person who violates the terms and conditions of a waste discharge permit shall incur, in
addition to any other penalty as provided by law, a civil penalty in the amount of up to ten
thousand dollars ($10,000) for every such violation. Each and every such violation shall be a
separate and distinct offense, and in case of a continuing violation, every day’s continuance shall be
deemed to be a separate and distinct violation.
G14. UPSET
Definition – “Upset” means an exceptional incident in which there is unintentional and temporary
noncompliance with technology-based permit effluent limitations because of factors beyond the
reasonable control of the Permittee. An upset does not include noncompliance to the extent
caused by operational error, improperly designed treatment facilities, inadequate treatment
facilities, lack of preventive maintenance, or careless or improper operation.
An upset constitutes an affirmative defense to an action brought for noncompliance with such
technology-based permit effluent limitations if the requirements of the following paragraph are met.
A Permittee who wishes to establish the affirmative defense of upset must demonstrate, through
properly signed, contemporaneous operating logs or other relevant evidence that: 1) an upset
occurred and that the Permittee can identify the cause(s) of the upset; 2) the permitted facility was
being properly operated at the time of the upset; 3) the Permittee submitted notice of the upset as
required in Special Condition S5.F, and; 4) the Permittee complied with any remedial measures
required under this permit.
In any enforcement proceeding, the Permittee seeking to establish the occurrence of an upset has
the burden of proof.
G15. PROPERTY RIGHTS
This permit does not convey any property rights of any sort, or any exclusive privilege.
G16. DUTY TO COMPLY
The Permittee must comply with all conditions of this permit. Any permit noncompliance
constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit
termination, revocation and reissuance, or modification; or denial of a permit renewal application.
Construction Stormwater General Permit Page 38
G17. TOXIC POLLUTANTS
The Permittee must comply with effluent standards or prohibitions established under Section
307(a) of the Clean Water Act for toxic pollutants within the time provided in the regulations that
establish those standards or prohibitions, even if this permit has not yet been modified to
incorporate the requirement.
G18. PENALTIES FOR TAMPERING
The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders
inaccurate any monitoring device or method required to be maintained under this permit shall, upon
conviction, be punished by a fine of not more than $10,000 per violation, or by imprisonment for not
more than two years per violation, or by both. If a conviction of a person is for a violation committed
after a first conviction of such person under this condition, punishment shall be a fine of not more
than $20,000 per day of violation, or imprisonment of not more than four (4) years, or both.
G19. REPORTING PLANNED CHANGES
The Permittee must, as soon as possible, give notice to Ecology of planned physical alterations,
modifications or additions to the permitted construction activity. The Permittee should be aware
that, depending on the nature and size of the changes to the original permit, a new public notice
and other permit process requirements may be required. Changes in activities that require
reporting to Ecology include those that will result in:
A. The permitted facility being determined to be a new source pursuant to 40 CFR 122.29(b).
B. A significant change in the nature or an increase in quantity of pollutants discharged,
including but not limited to: a 20% or greater increase in acreage disturbed by construction
activity.
C. A change in or addition of surface water(s) receiving stormwater or non-stormwater from
the construction activity.
D. A change in the construction plans and/or activity that affects the Permittee’s monitoring
requirements in Special Condition S4.
Following such notice, permit coverage may be modified, or revoked and reissued pursuant to 40
CFR 122.62(a) to specify and limit any pollutants not previously limited. Until such modification is
effective, any new or increased discharge in excess of permit limits or not specifically authorized by
this permit constitutes a violation.
G20. REPORTING OTHER INFORMATION
Where the Permittee becomes aware that it failed to submit any relevant facts in a permit
application, or submitted incorrect information in a permit application or in any report to Ecology,
it must promptly submit such facts or information.
G21. REPORTING ANTICIPATED NON-COMPLIANCE
The Permittee must give advance notice to Ecology by submission of a new application or
supplement thereto at least forty-five (45) days prior to commencement of such discharges, of any
facility expansions, production increases, or other planned changes, such as process modifications,
in the permitted facility or activity which may result in noncompliance with permit limits or
conditions. Any maintenance of facilities, which might necessitate unavoidable interruption of
Construction Stormwater General Permit Page 39
operation and degradation of effluent quality, must be scheduled during non-critical water quality
periods and carried out in a manner approved by Ecology.
G22. REQUESTS TO BE EXCLUDED FROM COVERAGE UNDER THE PERMIT
Any discharger authorized by this permit may request to be excluded from coverage under the
general permit by applying for an individual permit. The discharger must submit to the Director an
application as described in WAC 173-220-040 or WAC 173-216-070, whichever is applicable, with
reasons supporting the request. These reasons will fully document how an individual permit will
apply to the applicant in a way that the general permit cannot. Ecology may make specific requests
for information to support the request. The Director will either issue an individual permit or deny
the request with a statement explaining the reason for the denial. When an individual permit is
issued to a discharger otherwise subject to the construction stormwater general permit, the
applicability of the construction stormwater general permit to that Permittee is automatically
terminated on the effective date of the individual permit.
G23. APPEALS
A. The terms and conditions of this general permit, as they apply to the appropriate class of
dischargers, are subject to appeal by any person within 30 days of issuance of this general
permit, in accordance with Chapter 43.21B RCW, and Chapter 173-226 WAC.
B. The terms and conditions of this general permit, as they apply to an individual discharger,
are appealable in accordance with Chapter 43.21B RCW within 30 days of the effective date
of coverage of that discharger. Consideration of an appeal of general permit coverage of an
individual discharger is limited to the general permit’s applicability or nonapplicability to
that individual discharger.
C. The appeal of general permit coverage of an individual discharger does not affect any other
dischargers covered under this general permit. If the terms and conditions of this general
permit are found to be inapplicable to any individual discharger(s), the matter shall be
remanded to Ecology for consideration of issuance of an individual permit or permits.
G24. SEVERABILITY
The provisions of this permit are severable, and if any provision of this permit, or application of any
provision of this permit to any circumstance, is held invalid, the application of such provision to
other circumstances, and the remainder of this permit shall not be affected thereby.
G25. BYPASS PROHIBITED
A. Bypass Procedures
Bypass, which is the intentional diversion of waste streams from any portion of a treatment
facility, is prohibited for stormwater events below the design criteria for stormwater
management. Ecology may take enforcement action against a Permittee for bypass unless one
of the following circumstances (1, 2, 3 or 4) is applicable.
1. Bypass of stormwater is consistent with the design criteria and part of an approved
management practice in the applicable stormwater management manual.
2. Bypass for essential maintenance without the potential to cause violation of permit limits
or conditions.
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Bypass is authorized if it is for essential maintenance and does not have the potential to
cause violations of limitations or other conditions of this permit, or adversely impact
public health.
3. Bypass of stormwater is unavoidable, unanticipated, and results in noncompliance of this
permit.
This bypass is permitted only if:
a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property
damage. “Severe property damage” means substantial physical damage to property,
damage to the treatment facilities which would cause them to become inoperable,
or substantial and permanent loss of natural resources which can reasonably be
expected to occur in the absence of a bypass.
b. There are no feasible alternatives to the bypass, such as the use of auxiliary
treatment facilities, retention of untreated wastes, maintenance during normal
periods of equipment downtime (but not if adequate backup equipment should
have been installed in the exercise of reasonable engineering judgment to prevent a
bypass which occurred during normal periods of equipment downtime or
preventative maintenance), or transport of untreated wastes to another treatment
facility.
c. Ecology is properly notified of the bypass as required in Special Condition S5.F of
this permit.
4. A planned action that would cause bypass of stormwater and has the potential to result
in noncompliance of this permit during a storm event.
The Permittee must notify Ecology at least thirty (30) days before the planned date of
bypass. The notice must contain:
a. A description of the bypass and its cause
b. An analysis of all known alternatives which would eliminate, reduce, or mitigate the
need for bypassing.
c. A cost-effectiveness analysis of alternatives including comparative resource damage
assessment.
d. The minimum and maximum duration of bypass under each alternative.
e. A recommendation as to the preferred alternative for conducting the bypass.
f. The projected date of bypass initiation.
g. A statement of compliance with SEPA.
h. A request for modification of water quality standards as provided for in WAC 173-
201A-110, if an exceedance of any water quality standard is anticipated.
i. Steps taken or planned to reduce, eliminate, and prevent reoccurrence of the
bypass.
5. For probable construction bypasses, the need to bypass is to be identified as early in the
planning process as possible. The analysis required above must be considered during
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preparation of the Stormwater Pollution Prevention Plan (SWPPP) and must be included
to the extent practical. In cases where the probable need to bypass is determined early,
continued analysis is necessary up to and including the construction period in an effort to
minimize or eliminate the bypass.
Ecology will consider the following before issuing an administrative order for this type
bypass:
a. If the bypass is necessary to perform construction or maintenance-related activities
essential to meet the requirements of this permit.
b. If there are feasible alternatives to bypass, such as the use of auxiliary treatment
facilities, retention of untreated wastes, stopping production, maintenance during
normal periods of equipment down time, or transport of untreated wastes to
another treatment facility.
c. If the bypass is planned and scheduled to minimize adverse effects on the public and
the environment.
After consideration of the above and the adverse effects of the proposed bypass and any
other relevant factors, Ecology will approve, conditionally approve, or deny the request.
The public must be notified and given an opportunity to comment on bypass incidents of
significant duration, to the extent feasible. Approval of a request to bypass will be by
administrative order issued by Ecology under RCW 90.48.120.
B. Duty to Mitigate
The Permittee is required to take all reasonable steps to minimize or prevent any discharge or
sludge use or disposal in violation of this permit that has a reasonable likelihood of adversely
affecting human health or the environment.
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APPENDIX A – DEFINITIONS
AKART is an acronym for “All Known, Available, and Reasonable methods of prevention, control, and
Treatment.” AKART represents the most current methodology that can be reasonably required for
preventing, controlling, or abating the pollutants and controlling pollution associated with a discharge.
Applicable TMDL means a TMDL for turbidity, fine sediment, high pH, or phosphorus, which was
completed and approved by EPA before January 1, 2021, or before the date the operator’s complete
permit application is received by Ecology, whichever is later. TMDLs completed after a complete permit
application is received by Ecology become applicable to the Permittee only if they are imposed through
an administrative order by Ecology, or through a modification of permit coverage.
Applicant means an operator seeking coverage under this permit.
Benchmark means a pollutant concentration used as a permit threshold, below which a pollutant is
considered unlikely to cause a water quality violation, and above which it may. When pollutant
concentrations exceed benchmarks, corrective action requirements take effect. Benchmark values are
not water quality standards and are not numeric effluent limitations; they are indicator values.
Best Management Practices (BMPs) means schedules of activities, prohibitions of practices,
maintenance procedures, and other physical, structural and/or managerial practices to prevent or
reduce the pollution of waters of the State. BMPs include treatment systems, operating procedures, and
practices to control stormwater associated with construction activity, spillage or leaks, sludge or waste
disposal, or drainage from raw material storage.
Buffer means an area designated by a local jurisdiction that is contiguous to and intended to protect a
sensitive area.
Bypass means the intentional diversion of waste streams from any portion of a treatment facility.
Calendar Day A period of 24 consecutive hours starting at 12:00 midnight and ending the following
12:00 midnight.
Calendar Week (same as Week) means a period of seven consecutive days starting at 12:01 a.m. (0:01
hours) on Sunday.
Certified Erosion and Sediment Control Lead (CESCL) means a person who has current certification
through an approved erosion and sediment control training program that meets the minimum training
standards established by Ecology (See BMP C160 in the SWMM).
Chemical Treatment means the addition of chemicals to stormwater and/or authorized non-stormwater
prior to filtration and discharge to surface waters.
Clean Water Act (CWA) means the Federal Water Pollution Control Act enacted by Public Law 92-500, as
amended by Public Laws 95-217, 95-576, 96-483, and 97-117; USC 1251 et seq.
Combined Sewer means a sewer which has been designed to serve as a sanitary sewer and a storm
sewer, and into which inflow is allowed by local ordinance.
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Common Plan of Development or Sale means a site where multiple separate and distinct construction
activities may be taking place at different times on different schedules and/or by different contractors,
but still under a single plan. Examples include: 1) phased projects and projects with multiple filings or
lots, even if the separate phases or filings/lots will be constructed under separate contract or by
separate owners (e.g., a development where lots are sold to separate builders); 2) a development plan
that may be phased over multiple years, but is still under a consistent plan for long-term development;
3) projects in a contiguous area that may be unrelated but still under the same contract, such as
construction of a building extension and a new parking lot at the same facility; and 4) linear projects
such as roads, pipelines, or utilities. If the project is part of a common plan of development or sale, the
disturbed area of the entire plan must be used in determining permit requirements.
Composite Sample means a mixture of grab samples collected at the same sampling point at different
times, formed either by continuous sampling or by mixing discrete samples. May be "time-composite"
(collected at constant time intervals) or "flow-proportional" (collected either as a constant sample
volume at time intervals proportional to stream flow, or collected by increasing the volume of each
aliquot as the flow increases while maintaining a constant time interval between the aliquots.
Concrete Wastewater means any water used in the production, pouring and/or clean-up of concrete or
concrete products, and any water used to cut, grind, wash, or otherwise modify concrete or concrete
products. Examples include water used for or resulting from concrete truck/mixer/pumper/tool/chute
rinsing or washing, concrete saw cutting and surfacing (sawing, coring, grinding, roughening, hydro-
demolition, bridge and road surfacing). When stormwater comingles with concrete wastewater, the
resulting water is considered concrete wastewater and must be managed to prevent discharge to waters
of the State, including groundwater.
Construction Activity means land disturbing operations including clearing, grading or excavation which
disturbs the surface of the land (including off-site disturbance acreage related to construction-support
activity). Such activities may include road construction, construction of residential houses, office
buildings, or industrial buildings, site preparation, soil compaction, movement and stockpiling of
topsoils, and demolition activity.
Construction Support Activity means off-site acreage that will be disturbed as a direct result of the
construction project and will discharge stormwater. For example, off-site equipment staging yards,
material storage areas, borrow areas, and parking areas.
Contaminant means any hazardous substance that does not occur naturally or occurs at greater than
natural background levels. See definition of “hazardous substance” and WAC 173-340-200.
Contaminated soil means soil which contains contaminants, pollutants, or hazardous substances that do
not occur naturally or occur at levels greater than natural background.
Contaminated groundwater means groundwater which contains contaminants, pollutants, or hazardous
substances that do not occur naturally or occur at levels greater than natural background.
Demonstrably Equivalent means that the technical basis for the selection of all stormwater BMPs is
documented within a SWPPP, including:
1. The method and reasons for choosing the stormwater BMPs selected.
2. The pollutant removal performance expected from the BMPs selected.
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3. The technical basis supporting the performance claims for the BMPs selected, including any
available data concerning field performance of the BMPs selected.
4. An assessment of how the selected BMPs will comply with state water quality standards.
5. An assessment of how the selected BMPs will satisfy both applicable federal technology-based
treatment requirements and state requirements to use all known, available, and reasonable
methods of prevention, control, and treatment (AKART).
Department means the Washington State Department of Ecology.
Detention means the temporary storage of stormwater to improve quality and/or to reduce the mass
flow rate of discharge.
Dewatering means the act of pumping groundwater or stormwater away from an active construction site.
Director means the Director of the Washington State Department of Ecology or his/her authorized
representative.
Discharger means an owner or operator of any facility or activity subject to regulation under Chapter
90.48 RCW or the Federal Clean Water Act.
Domestic Wastewater means water carrying human wastes, including kitchen, bath, and laundry wastes
from residences, buildings, industrial establishments, or other places, together with such groundwater
infiltration or surface waters as may be present.
Ecology means the Washington State Department of Ecology.
Engineered Soils means the use of soil amendments including, but not limited, to Portland cement
treated base (CTB), cement kiln dust (CKD), or fly ash to achieve certain desirable soil characteristics.
Equivalent BMPs means operational, source control, treatment, or innovative BMPs which result in
equal or better quality of stormwater discharge to surface water or to groundwater than BMPs selected
from the SWMM.
Erosion means the wearing away of the land surface by running water, wind, ice, or other geological
agents, including such processes as gravitational creep.
Erosion and Sediment Control BMPs means BMPs intended to prevent erosion and sedimentation, such as
preserving natural vegetation, seeding, mulching and matting, plastic covering, filter fences, sediment traps,
and ponds. Erosion and sediment control BMPs are synonymous with stabilization and structural BMPs.
Federal Operator is an entity that meets the definition of “Operator” in this permit and is either any
department, agency or instrumentality of the executive, legislative, and judicial branches of the Federal
government of the United States, or another entity, such as a private contractor, performing
construction activity for any such department, agency, or instrumentality.
Final Stabilization (same as fully stabilized or full stabilization) means the completion of all soil
disturbing activities at the site and the establishment of permanent vegetative cover, or equivalent
permanent stabilization measures (such as pavement, riprap, gabions, or geotextiles) which will prevent
erosion. See the applicable Stormwater Management Manual for more information on vegetative cover
expectations and equivalent permanent stabilization measures.
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Groundwater means water in a saturated zone or stratum beneath the land surface or a surface
waterbody.
Hazardous Substance means any dangerous or extremely hazardous waste as defined in RCW
70.105.010 (5) and (6), or any dangerous or extremely dangerous waste as designated by rule under
chapter 70.105 RCW; any hazardous sub-stance as defined in RCW 70.105.010(14) or any hazardous
substance as defined by rule under chapter 70.105 RCW; any substance that, on the effective date of
this section, is a hazardous substance under section 101(14) of the federal cleanup law, 42U.S.C., Sec.
9601(14); petroleum or petroleum products; and any substance or category of substances, including
solid waste decomposition products, determined by the director by rule to present a threat to human
health or the environment if released into the environment. The term hazardous substance does not
include any of the following when contained in an underground storage tank from which there is not a
release: crude oil or any fraction thereof or petroleum, if the tank is in compliance with all applicable
federal, state, and local law.
Injection Well means a well that is used for the subsurface emplacement of fluids. (See Well.)
Jurisdiction means a political unit such as a city, town or county; incorporated for local self-government.
National Pollutant Discharge Elimination System (NPDES) means the national program for issuing,
modifying, revoking and reissuing, terminating, monitoring, and enforcing permits, and imposing and
enforcing pretreatment requirements, under sections 307, 402, 318, and 405 of the Federal Clean Water
Act, for the discharge of pollutants to surface waters of the State from point sources. These permits are
referred to as NPDES permits and, in Washington State, are administered by the Washington State
Department of Ecology.
Notice of Intent (NOI) means the application for, or a request for coverage under this general permit
pursuant to WAC 173-226-200.
Notice of Termination (NOT) means a request for termination of coverage under this general permit as
specified by Special Condition S10 of this permit.
Operator means any party associated with a construction project that meets either of the following two
criteria:
• The party has operational control over construction plans and specifications, including the
ability to make modifications to those plans and specifications; or
• The party has day-to-day operational control of those activities at a project that are necessary to
ensure compliance with a SWPPP for the site or other permit conditions (e.g., they are
authorized to direct workers at a site to carry out activities required by the SWPPP or comply
with other permit conditions).
Permittee means individual or entity that receives notice of coverage under this general permit.
pH means a liquid’s measure of acidity or alkalinity. A pH of 7 is defined as neutral. Large variations
above or below this value are considered harmful to most aquatic life.
pH Monitoring Period means the time period in which the pH of stormwater runoff from a site must be
tested a minimum of once every seven days to determine if stormwater pH is between 6.5 and 8.5.
Construction Stormwater General Permit Page 46
Point Source means any discernible, confined, and discrete conveyance, including but not limited to, any
pipe, ditch, channel, tunnel, conduit, well, discrete fissure, and container from which pollutants are or
may be discharged to surface waters of the State. This term does not include return flows from irrigated
agriculture. (See the Fact Sheet for further explanation)
Pollutant means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage,
domestic sewage sludge (biosolids), munitions, chemical wastes, biological materials, radioactive
materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and
agricultural waste. This term does not include sewage from vessels within the meaning of section 312 of
the CWA, nor does it include dredged or fill material discharged in accordance with a permit issued
under section 404 of the CWA.
Pollution means contamination or other alteration of the physical, chemical, or biological properties of
waters of the State; including change in temperature, taste, color, turbidity, or odor of the waters; or
such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the State
as will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the
public health, safety or welfare; or to domestic, commercial, industrial, agricultural, recreational, or
other legitimate beneficial uses; or to livestock, wild animals, birds, fish or other aquatic life.
Process Wastewater means any non-stormwater which, during manufacturing or processing, comes into
direct contact with or results from the production or use of any raw material, intermediate product,
finished product, byproduct, or waste product. If stormwater commingles with process wastewater, the
commingled water is considered process wastewater.
Receiving Water means the waterbody at the point of discharge. If the discharge is to a storm sewer
system, either surface or subsurface, the receiving water is the waterbody to which the storm system
discharges. Systems designed primarily for other purposes such as for groundwater drainage, redirecting
stream natural flows, or for conveyance of irrigation water/return flows that coincidentally convey
stormwater are considered the receiving water.
Representative means a stormwater or wastewater sample which represents the flow and
characteristics of the discharge. Representative samples may be a grab sample, a time-proportionate
composite sample, or a flow proportionate sample. Ecology’s Construction Stormwater Monitoring
Manual provides guidance on representative sampling.
Responsible Corporate Officer for the purpose of signatory authority means: (i) a president, secretary,
treasurer, or vice-president of the corporation in charge of a principal business function, or any other
person who performs similar policy- or decision-making functions for the corporation, or (ii) the
manager of one or more manufacturing, production, or operating facilities, provided, the manager is
authorized to make management decisions which govern the operation of the regulated facility
including having the explicit or implicit duty of making major capital investment recommendations, and
initiating and directing other comprehensive measures to assure long term environmental compliance
with environmental laws and regulations; the manager can ensure that the necessary systems are
established or actions taken to gather complete and accurate information for permit application
requirements; and where authority to sign documents has been assigned or delegated to the manager in
accordance with corporate procedures (40 CFR 122.22).
Sanitary Sewer means a sewer which is designed to convey domestic wastewater.
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Sediment means the fragmented material that originates from the weathering and erosion of rocks or
unconsolidated deposits, and is transported by, suspended in, or deposited by water.
Sedimentation means the depositing or formation of sediment.
Sensitive Area means a waterbody, wetland, stream, aquifer recharge area, or channel migration zone.
SEPA (State Environmental Policy Act) means the Washington State Law, RCW 43.21C.020, intended to
prevent or eliminate damage to the environment.
Significant Amount means an amount of a pollutant in a discharge that is amenable to available and
reasonable methods of prevention or treatment; or an amount of a pollutant that has a reasonable
potential to cause a violation of surface or groundwater quality or sediment management standards.
Significant Concrete Work means greater than 1000 cubic yards placed or poured concrete or recycled
concrete used over the life of a project.
Significant Contributor of Pollutants means a facility determined by Ecology to be a contributor of a
significant amount(s) of a pollutant(s) to waters of the State of Washington.
Site means the land or water area where any "facility or activity" is physically located or conducted.
Source Control BMPs means physical, structural or mechanical devices or facilities that are intended to
prevent pollutants from entering stormwater. A few examples of source control BMPs are erosion
control practices, maintenance of stormwater facilities, constructing roofs over storage and working
areas, and directing wash water and similar discharges to the sanitary sewer or a dead end sump.
Stabilization means the application of appropriate BMPs to prevent the erosion of soils, such as,
temporary and permanent seeding, vegetative covers, mulching and matting, plastic covering and
sodding. See also the definition of Erosion and Sediment Control BMPs.
Storm Drain means any drain which drains directly into a storm sewer system, usually found along
roadways or in parking lots.
Storm Sewer System means a means a conveyance, or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm
drains designed or used for collecting or conveying stormwater. This does not include systems which are
part of a combined sewer or Publicly Owned Treatment Works (POTW), as defined at 40 CFR 122.2.
Stormwater means that portion of precipitation that does not naturally percolate into the ground or
evaporate, but flows via overland flow, interflow, pipes, and other features of a stormwater drainage
system into a defined surface waterbody, or a constructed infiltration facility.
Stormwater Management Manual (SWMM) or Manual means the technical Manual published by
Ecology for use by local governments that contain descriptions of and design criteria for BMPs to
prevent, control, or treat pollutants in stormwater.
Stormwater Pollution Prevention Plan (SWPPP) means a documented plan to implement measures to
identify, prevent, and control the contamination of point source discharges of stormwater.
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Surface Waters of the State includes lakes, rivers, ponds, streams, inland waters, salt waters, and all
other surface waters and water courses within the jurisdiction of the state of Washington.
Temporary Stabilization means the exposed ground surface has been covered with appropriate
materials to provide temporary stabilization of the surface from water or wind erosion. Materials
include, but are not limited to, mulch, riprap, erosion control mats or blankets and temporary cover
crops. Seeding alone is not considered stabilization. Temporary stabilization is not a substitute for the
more permanent “final stabilization.”
Total Maximum Daily Load (TMDL) means a calculation of the maximum amount of a pollutant that a
waterbody can receive and still meet state water quality standards. Percentages of the total maximum
daily load are allocated to the various pollutant sources. A TMDL is the sum of the allowable loads of a
single pollutant from all contributing point and nonpoint sources. The TMDL calculations must include a
"margin of safety" to ensure that the waterbody can be protected in case there are unforeseen events
or unknown sources of the pollutant. The calculation must also account for seasonable variation in
water quality.
Transfer of Coverage (TOC) means a request for transfer of coverage under this general permit as
specified by Special Condition S2.A of this permit.
Treatment BMPs means BMPs that are intended to remove pollutants from stormwater. A few examples
of treatment BMPs are detention ponds, oil/water separators, biofiltration, and constructed wetlands.
Transparency means a measurement of water clarity in centimeters (cm), using a 60 cm transparency
tube. The transparency tube is used to estimate the relative clarity or transparency of water by noting
the depth at which a black and white Secchi disc becomes visible when water is released from a value in
the bottom of the tube. A transparency tube is sometimes referred to as a “turbidity tube.”
Turbidity means the clarity of water expressed as nephelometric turbidity units (NTUs) and measured
with a calibrated turbidimeter.
Uncontaminated means free from any contaminant. See definition of “contaminant” and WAC 173-340-200.
Upset means an exceptional incident in which there is unintentional and temporary noncompliance with
technology-based permit effluent limitations because of factors beyond the reasonable control of the
Permittee. An upset does not include noncompliance to the extent caused by operational error,
improperly designed treatment facilities, inadequate treatment facilities, lack of preventive
maintenance, or careless or improper operation.
Waste Load Allocation (WLA) means the portion of a receiving water’s loading capacity that is allocated
to one of its existing or future point sources of pollution. WLAs constitute a type of water quality based
effluent limitation (40 CFR 130.2[h]).
Water-Only Based Shaft Drilling is a shaft drilling process that uses water only and no additives are
involved in the drilling of shafts for construction of building, road, or bridge foundations.
Water Quality means the chemical, physical, and biological characteristics of water, usually with respect
to its suitability for a particular purpose.
Waters of the State includes those waters as defined as "waters of the United States" in 40 CFR Subpart
122.2 within the geographic boundaries of Washington State and "waters of the State" as defined in
Chapter 90.48 RCW, which include lakes, rivers, ponds, streams, inland waters, underground waters, salt
Construction Stormwater General Permit Page 49
waters, and all other surface waters and water courses within the jurisdiction of the state of
Washington.
Well means a bored, drilled or driven shaft, or dug hole whose depth is greater than the largest surface
dimension. (See Injection Well.)
Wheel Wash Wastewater means any water used in, or resulting from the operation of, a tire bath or
wheel wash (BMP C106: Wheel Wash), or other structure or practice that uses water to physically
remove mud and debris from vehicles leaving a construction site and prevent track-out onto roads.
When stormwater comingles with wheel wash wastewater, the resulting water is considered wheel
wash wastewater and must be managed according to Special Condition S9.D.9.
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APPENDIX B – ACRONYMS
AKART All Known, Available, and Reasonable Methods of Prevention,
Control, and Treatment
BMP Best Management Practice
CESCL Certified Erosion and Sediment Control Lead
CFR Code of Federal Regulations
CKD Cement Kiln Dust
cm Centimeters
CPD Common Plan of Development
CTB Cement-Treated Base
CWA Clean Water Act
DMR Discharge Monitoring Report
EPA Environmental Protection Agency
ERTS Environmental Report Tracking System
ESC Erosion and Sediment Control
FR Federal Register
LID Low Impact Development
NOI Notice of Intent
NOT Notice of Termination
NPDES National Pollutant Discharge Elimination System
NTU Nephelometric Turbidity Unit
RCW Revised Code of Washington
SEPA State Environmental Policy Act
SWMM Stormwater Management Manual
SWPPP Stormwater Pollution Prevention Plan
TMDL Total Maximum Daily Load
UIC Underground Injection Control
USC United States Code
USEPA United States Environmental Protection Agency
WAC Washington Administrative Code
WQ Water Quality
WWHM Western Washington Hydrology Model
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F. 303(d) List Waterbodies / TMDL Waterbodies Information
Not applicable to this project
Solera – DevCo, LLC Page 41
G. Contaminated Site Information
1. Soil Management Plan
2. Health & Safey Plan (HASP)