Issuance Date: August 1, 2012 

Effective Date: August 1, 2013 

Expiration Date: July 31, 2018 

Modification Date: January 16, 2015 

Phase I Municipal Stor1nwater Per~nit 

National Pollutant Discharge Elimination System and 

State Waste Discharge General Permit 

for discharges from 

Large and Medium Municipal Separate Storm Sewer Systems 

State of Washington 

Department of Ecology 

Olympia, Washington 98504-7600 

In compliance with the provisions of 

The State of Washington Water Pollution Control Law 

Chapter 90.48 Revised Code of Washington 

and 

The Federal Water Pollution Control Act 

(The Clean Water Act) 

Title 33 United States Code, Section 1251 et seq. 

Until this permit expires, is modified, or revoked, Permittees that have properly obtained 

coverage under this permit are authorized to discharge to waters of the state in accordance with 

the special and general conditions which follow. 

W a r Quality Program Manager 

Department of Ecology · 
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TABLE OF CONTENTS

SPECIAL AND GENERAL CONDITIONS

SPECIAL CONDITIONS............................................................................................................... 5

S1. PERMIT COVERAGE AND PERMITTEES ..................................................................... 5

S2. AUTHORIZED DISCHARGES.......................................................................................... 6

S3. RESPONSIBILITIES OF PERMITTEES ........................................................................... 7

S4. COMPLIANCE WITH STANDARDS ............................................................................... 9

S5. STORMWATER MANAGEMENT PROGRAM............................................................. 12

S5.C.1 Legal Authority............................................................................................................. 12

S5.C.2 MS4 Mapping and Documentation............................................................................... 13

S5.C.3 Coordination.................................................................................................................. 15

S5.C.4 Public Involvement and Participation........................................................................... 16

S5.C.5 Controlling Runoff from New Development, Redevelopment and Construction Sites 16

S5.C.6 Structural Stormwater Controls .................................................................................... 25

S5.C.7 Source Control Program for Existing Development..................................................... 26

S5.C.8 Illicit Connections and Illicit Discharges Detection and Elimination........................... 29

S5.C.9 Operations and Maintenance Program.......................................................................... 33

S5.C.10 Education and Outreach Program ............................................................................... 38

S6. STORMWATER MANAGEMENT PROGRAM FOR SECONDARY PERMITTEES . 39

S6.E Stormwater Management for the Ports of Seattle and Tacoma........................................ 48

S7. COMPLIANCE WITH TOTAL MAXIMUM DAILY LOAD REQUIREMENTS......... 55

S8. MONITORING AND ASSESSMENT.............................................................................. 56

S9. REPORTING REQUIREMENTS ..................................................................................... 61

GENERAL CONDITIONS .......................................................................................................... 64

G1. DISCHARGE VIOLATIONS ........................................................................................... 64

G2. PROPER OPERATION AND MAINTENANCE............................................................. 64

G3. NOTIFICATION OF DISCHARGE INCLUDING SPILLS ............................................ 64

G4. BYPASS PROHIBITED.................................................................................................... 64

G5. RIGHT OF ENTRY........................................................................................................... 65

G6. DUTY TO MITIGATE...................................................................................................... 65

G7. PROPERTY RIGHTS........................................................................................................ 65

G8. COMPLIANCE WITH OTHER LAWS AND STATUTES............................................. 65
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G9. MONITORING.................................................................................................................. 65

G10. REMOVED SUBSTANCES.......................................................................................... 67

G11. SEVERABILITY ........................................................................................................... 67

G12. REVOCATION OF COVERAGE................................................................................. 67

G13. TRANSFER OF COVERAGE....................................................................................... 67

G14. GENERAL PERMIT MODIFICATION AND REVOCATION................................... 68

G15. REPORTING A CAUSE FOR MODIFICATION OR REVOCATION....................... 68

G16. APPEALS....................................................................................................................... 68

G17. PENALTIES................................................................................................................... 69

G18. DUTY TO REAPPLY.................................................................................................... 69

G19. CERTIFICATION AND SIGNATURE ........................................................................ 69

G20. NON-COMPLIANCE NOTIFICATION....................................................................... 70

G21. UPSETS ......................................................................................................................... 70

DEFINITIONS AND ACRONYMS ............................................................................................ 71

APPENDICES

APPENDIX 1. Minimum Technical Requirements for New Development and Redevelopment

APPENDIX 2. TMDL Requirements

APPENDIX 3. Annual Report Questions for the Port of Seattle and the Port of Tacoma 

APPENDIX 4. Annual Report Questions for Secondary Permittees 

APPENDIX 5. Notice of Intent 

APPENDIX 6. Street Waste Disposal

APPENDIX 7. Determining Construction Site Sediment Damage Potential

APPENDIX 8. Businesses and Activities that are Potential Sources of Pollutants

APPENDIX 9. Stormwater Discharge Monitoring

APPENDIX 10. Equivalent Programs for Runoff Controls for New and Redevelopment and 

Construction Sites

APPENDIX 11. Structural Stormwater Controls Project List

APPENDIX 12. Annual Report Questions for Phase I Cities and Counties
S1.B.1 S1.E.1

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SPECIAL CONDITIONS

S1. PERMIT COVERAGE AND PERMITTEES

A. Geographic Area of Permit Coverage

This permit covers discharges from Large and Medium Municipal Separate Storm 

Sewer Systems (MS4s) as established at Title 40 CFR 122.26, except for the 

Washington State Department of Transportation’s MS4s. 

For Secondary Permittees required to obtain coverage under this permit, the minimum 

geographic area of coverage includes the portion of the MS4 which is located within 

the unincorporated areas of Clark, King, Snohomish, and Pierce Counties and the 

incorporated areas of the cities of Seattle and Tacoma. The Washington State 

Department of Ecology (Ecology) may establish additional geographic areas of 

coverage specific to an individual Secondary permittee. 

B. The following cities and counties have submitted a Duty to Reapply-Notice of Intent 

(NOI) for coverage to Ecology prior to August 19, 2011, and have coverage as 

Permittees, beginning on the effective date of the permit:

1. The City of Tacoma and the City of Seattle.

2. Clark, King, Pierce, and Snohomish Counties.

C. The following entities have submitted a Duty to Reapply-Notice of Intent (NOI) for 

coverage to Ecology prior to August 19, 2011, and have coverage as Secondary 

Permittees, beginning on the effective date of the permit:

1. Port of Seattle, excluding Seattle-Tacoma International Airport.

2. Port of Tacoma.

3. The University of Washington, Seattle; Seattle School District #1; Metropolitan 

Park District of Tacoma; Washington State Military Department; Tacoma 

Community College; Washington State Department of Corrections: Larch 

Corrections Center, and Washington Corrections Center for Women.

D. Unless otherwise noted, the term “Permittee” includes city, county, or town 

Permittee, port Permittee, Co-Permittee, Secondary Permittee, and New Secondary 

Permittee. 

E. Coverage for New Secondary Permittees

1. Entities meeting the requirements in S1.E.1.a-b, below, are required to apply for 

and obtain coverage under this Permit. Upon application and coverage the 
S1.E.1 S2.A.2

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following entities will have coverage under this Permit as New Secondary 

Permittees. 

a. Active drainage, diking, flood control, or diking and drainage districts located 

in the Cities or unincorporated portions of the Counties listed in S1.B. above, 

which own or operate MS4s serving non-agricultural land uses; and were not 

covered by the permit prior to August 1, 2013.

b. Other owners or operators of MS4s located in the Cities or unincorporated 

portions of the Counties listed in S1.B above; and were not covered by the 

permit prior to August 1, 2013.

2. Application Requirements:

a. Submit a Notice of Intent (NOI) for Coverage under National Pollutant 

Discharge Elimination System (NPDES) Municipal Stormwater General 

Permit provided in Appendix 5 and provide public notice of the application 

for coverage in accordance with WAC 173-226-130. The NOI shall constitute 

the application for coverage. Ecology will notify applicants in writing of their 

status concerning coverage under this permit within 90 days of Ecology's 

receipt of a complete NOI.

b. Each Permittee applying as Co-Permittee shall submit a NOI provided in 

Appendix 5. The NOI shall clearly identify the areas of the MS4 for which 

the Co-Permittee is responsible. 

F. All MS4s owned or operated by Permittees named in S1.B. and located in another 

city or county area requiring coverage under this permit or either the Western 

Washington Phase II Municipal Stormwater Permit or the Eastern Washington 

Phase II Municipal Stormwater Permit are also covered under this permit.

S2. AUTHORIZED DISCHARGES

A. This permit authorizes the discharge of stormwater to surface waters and to ground 

waters of the state from MS4s owned or operated by each Permittee covered under 

this permit in the geographic area covered by this permit pursuant to S1.A. subject to 

the following limitations:

1. Discharges to ground waters of the state through facilities regulated under the 

Underground Injection Control (UIC) program, chapter 173-218 WAC, are not 

authorized under this permit.

2. Discharges to ground waters not subject to regulation under the federal Clean 

Water Act are authorized in this permit only under state authorities, Chapter 90.48 

RCW, the Water Pollution Control Act.
S2.B.1 S3.A.3

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B. This permit authorizes discharges of non-stormwater flows to surface waters and 

ground waters of the state from MS4s owned or operated by each Permittee covered 

under this permit, in the geographic area covered pursuant to S1.A, only under one or 

more of the following conditions:

1. The discharge is authorized by a separate National Pollutant Discharge 

Elimination System (NPDES) or State Waste Discharge permit. 

2. The discharge is from emergency fire fighting activities.

3. The discharge is from another illicit or non-stormwater discharge that is managed 

by the Permittee as provided in Special Condition S5.C.8., S6.D.3., or S6.E.3.

These discharges are also subject to the limitations in S2.A.1. and S2.A.2. above. 

C. This permit does not relieve entities that cause illicit discharges, including spills of oil 

or hazardous substances, from responsibilities and liabilities under state and federal 

laws and regulations pertaining to those discharges.

D. Discharges from MS4s constructed after the effective date of this permit shall receive 

all applicable state and local permits and use authorizations, including compliance 

with chapter 43.21C RCW (the State Environmental Policy Act).

E. This permit does not authorize discharges of stormwater to waters within Indian 

Country or to waters subject to water quality standards of Indian Tribes, including 

portions of the Puyallup River and other waters on trust or restricted lands within the 

1873 Survey Area of the Puyallup Tribe of Indians Reservation, except where 

authority has been specifically delegated to Ecology by the U.S. Environmental 

Protection Agency. The exclusion of such discharges from this permit does not waive 

any rights the State may have with respect to the regulation of the discharges.

S3. RESPONSIBILITIES OF PERMITTEES 

A. Each Permittee, Co-Permittee and Secondary Permittee is responsible for compliance 

with the terms of this Permit for the MS4s that they own or operate.

1. Each Permittee, as listed in S1.B., is required to comply with all conditions of this 

permit, except for S6. Stormwater Management Program for Secondary 

Permittees.

2. The Port of Tacoma and the Port of Seattle, are required to comply with all 

conditions of this permit except for S5. Stormwater Management Program and 

S6.D. Stormwater Management Program for Secondary Permittees.

3. All Secondary Permittees, except for the Port of Tacoma and the Port of Seattle, 

are required to comply with all conditions of this permit except for S5. 

Stormwater Management Program, S6.E. Stormwater Management Program for 
S3.A.3 S3.B.2

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the Port of Seattle and Port of Tacoma, and S8. Monitoring and Assessment 

conditions B., C., and D.

B. Permittees may rely on another entity to satisfy one or more of the requirements of 

this permit. Permittees that are relying on another entity to satisfy one or more or their 

permit obligations remain responsible for permit compliance if the other entity fails to 

implement the permit conditions. Where permit responsibilities are shared they shall 

be documented as follows:

1. Permittees and Co-Permittees that are continuing coverage under this permit shall 

submit a statement that describes the permit requirements that will be 

implemented by other entities. The statement must be signed by all participating 

entities. There is no deadline for submitting such a statement, provided that this 

does not alter implementation deadlines. Permittees and Co-Permittees may 

amend their statement during the term of the permit to establish, terminate, or 

amend their shared responsibilities statement, and submit the amended statements 

to Ecology.

2. Secondary Permittees shall submit an NOI that describes which requirements they 

will implement and identify the entities that will implement the other permit 

requirements in the area served by the Secondary Permittee’s MS4. A statement 

confirming the shared responsibilities, signed by all participating entities, shall 

accompany the NOI. Secondary Permittees may amend their NOI, during the term 

of the permit, to establish, terminate, or amend shared responsibility 

arrangements, provided this does not alter implementation deadlines.

C. Unless otherwise noted, all appendices to this permit are incorporated by this 

reference as if set forth fully within this permit.
S4.F.1 S4.F.2

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S4. COMPLIANCE WITH STANDARDS

A. In accordance with RCW 90.48.520, the discharge of toxicants to waters of the State 

of Washington which would violate any water quality standard, including toxicant 

standards, sediment criteria, and dilution zone criteria is prohibited. The required 

response to such discharges is defined in section S4.F, below.

B. This permit does not authorize a discharge which would be a violation of Washington 

State Surface Water Quality Standards (chapter 173-201A WAC), Ground Water 

Quality Standards (chapter 173-200 WAC), Sediment Management Standards 

(chapter 173-204 WAC), or human health-based criteria in the national Toxics Rule 

(Federal Register, Vol. 57, NO. 246, Dec. 22, 1992, pages 60848-60923). The 

required response to such discharges is defined in section S4.F, below.

C. The Permittee shall reduce the discharge of pollutants to the maximum extent 

practicable (MEP).

D. The Permittee shall use all known, available, and reasonable methods of prevention, 

control and treatment (AKART) to prevent and control pollution of waters of the 

State of Washington.

E. In order to meet the goals of the Clean Water Act, and comply with S4.A, S4.B, S4.C, 

and S4.D, each Permittee shall comply with all of the applicable requirements of this 

permit as defined in S3. Responsibilities of Permittees.

F. A Permittee remains in compliance with S4 despite any discharges prohibited by 

S4.A or S4.B, when the Permittee undertakes the following response toward longterm water quality improvement:

1. A Permittee shall notify Ecology in writing within 30 days of becoming aware, 

based on credible site-specific information that a discharge from the MS4 owned 

or operated by the Permittee is causing or contributing to a known or likely 

violation of Water Quality Standards in the receiving water. Written notification 

provided under this subsection shall, at a minimum, identify the source of the sitespecific information, describe the nature and extent of the known or likely 

violation in the receiving water, and explain the reasons why the MS4 discharge is 

believed to be causing or contributing to the problem. For ongoing or continuing 

violations, a single written notification to Ecology will fulfill this requirement.

2. In the event that Ecology determines, based on a notification provided under 

S4.F.1, or through any other means, that a discharge from a MS4 owned or 

operated by the Permittee is causing or contributing to a violation of Water 

Quality Standards in a receiving water, Ecology will notify the Permittee in 

writing that an adaptive management response outlined in S4.F.3 below is 

required unless:
S4.F.3 S4.F.3

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a. Ecology also determines that the violation of Water Quality Standards is 

already being addressed by a Total Maximum Daily Load (TMDL) or other 

enforceable water quality cleanup plan; or

b. Ecology concludes the MS4 contribution to the violation will be eliminated 

through implementation of other permit requirements.

3. Adaptive Management Response

a. Within 60 days of receiving a notification under S4.F.2, or by an alternative 

date established by Ecology, the Permittee shall review its Stormwater 

Management Program and submit a report to Ecology. The report shall 

include:

i. A description of the operational and/or structural Best Management 

Practices (BMPs) that are currently being implemented to prevent or 

reduce any pollutants that are causing or contributing to the violation of 

Water Quality Standards, including a qualitative assessment of the 

effectiveness of each BMP.

ii. A description of potential additional operational and/or structural BMPs 

that will or may be implemented in order to apply AKART on a sitespecific basis to prevent or reduce any pollutants that are causing or 

contributing to the violation of Water Quality Standards. 

iii. A description of the potential monitoring or other assessment and 

evaluation efforts that will or may be implemented to monitor, assess, or 

evaluate the effectiveness of the additional BMPs.

iv. A schedule for implementing the additional BMPs including, as 

appropriate: funding, training, purchasing, construction, monitoring, and 

other assessment and evaluation components of implementation.

b. Ecology will, in writing, acknowledge receipt of the report within a 

reasonable time and notify the Permittee when it expects to complete its 

review of the report. Ecology will either approve the additional BMPs and 

implementation schedule or require the Permittee to modify the report as 

needed to meet AKART on a site-specific basis. If modifications are required, 

Ecology will specify a reasonable time frame in which the Permittee shall 

submit and Ecology will review the revised report.

c. The Permittee shall implement the additional BMPs, pursuant to the schedule 

approved by Ecology, beginning immediately upon receipt of written 

notification of approval.
S4.G.1 S5.A.1

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d. The Permittee shall include with each subsequent annual report a summary of 

the status of implementation, and the results of any monitoring, assessment or 

evaluation efforts conducted during the reporting period. If, based on the 

information provided under this subsection, Ecology determines that 

modification of the BMPs or implementation schedule is necessary to meet 

AKART on a site-specific basis, the Permittee shall make such modifications 

as Ecology directs. In the event there are ongoing violations of water quality 

standards despite the implementation of the BMP approach of this section, the 

Permittee may be subject to compliance schedules to eliminate the violation 

under WAC 173-201A-510(4) and WAC 173-226-180 or other enforcement 

orders as Ecology deems appropriate during the term of this permit.

e. A TMDL or other enforceable water quality cleanup plan that has been 

approved and is being implemented to address the MS4’s contribution to the 

Water Quality Standards violation supersedes and terminates the S4.F.3 

implementation plan.

f. Provided the Permittee is implementing the approved adaptive management 

response under this section, the Permittee remains in compliance with 

Condition S4., despite any on-going violations of Water Quality Standards 

identified under S4.A or B above.

g. The adaptive management process provided under Section S.4.F is not 

intended to create a shield for the Permittee from any liability it may face 

under 42 U.S.C. 9601 et seq. or RCW 70.105D.

G. Ecology may modify or revoke and reissue this General Permit in accordance with 

G14 General Permit Modification and Revocation if Ecology becomes aware of 

additional control measures, management practices or other actions beyond what is 

required in this permit, that are necessary to:

1. Reduce the discharge of pollutants to the MEP;

2. Comply with the state AKART requirements; or

3. Control the discharge of toxicants to waters of the State of Washington.
S5.A.1 S5.C.1

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S5. STORMWATER MANAGEMENT PROGRAM

A. Each Permittee listed in S1.B. shall implement a Stormwater Management Program 

(SWMP) during the term of this permit. A SWMP is a set of actions and activities 

comprising the components listed in S5, and additional actions necessary, to meet the 

requirements of applicable TMDLs pursuant to S7 Compliance with TMDL 

Requirements, and S8 Monitoring and Assessment.

1. Each Permittee shall prepare written documentation of their SWMP, called the 

SWMP Plan. The SWMP Plan shall be organized according to the program 

components in S5.C, or a format approved by Ecology, and shall be updated at 

least annually for submittal with the Permittee’s annual report to Ecology (S9 

Reporting Requirements). The SWMP Plan shall be written to inform the public 

of the planned SWMP activities for the upcoming calendar year, and shall include 

a description of:

a. Planned activities for each of the program components included in S5.C. 

b. Any additional planned actions to meet the requirements of applicable 

TMDLs pursuant to S7 Compliance with TMDL Requirements. 

c. Any additional planned actions to meet the requirements of S8 Monitoring 

and Assessment. 

2. Each Permittee shall track the cost or estimated cost of development and 

implementation of each component of the SWMP. This information shall be 

provided to Ecology upon request. 

3. Each Permittee shall track the number of inspections, official enforcement actions 

and types of public education activities as required by the respective program 

component. This information shall be included in the annual report.

B. The SWMP shall be designed to reduce the discharge of pollutants from MS4s to the 

MEP, meet state AKART requirements, and protect water quality. 

Permittees are to continue implementation of existing stormwater management 

programs until they begin implementation of the updated stormwater management 

program in accordance with the terms of this permit, including implementation 

schedules. 

C. The SWMP shall include the components listed below. The requirements of the 

SWMP shall apply to MS4s, and areas served by MS4s owned or operated by the 

Permittee. To the extent allowable under state and federal law, all SWMP 

components are mandatory. 

1. Legal Authority
S5.C.2 S5.C.2

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a. Each Permittee shall be able to demonstrate that they can operate pursuant to 

legal authority which authorizes or enables the Permittee to control discharges 

to and from MS4s owned or operated by the Permittee.

b. This legal authority, which may be a combination of statute, ordinance, 

permit, contracts, orders, interagency agreements, or similar means, shall 

authorize or enable the Permittee, at a minimum, to:

i. Control through ordinance, order, or similar means, the contribution of 

pollutants to MS4s owned or operated by the Permittee from stormwater 

discharges associated with industrial activity, and control the quality of 

stormwater discharged from sites of industrial activity;

ii. Prohibit through ordinance, order, or similar means, illicit discharges to

the MS4 owned or operated by the Permittee;

iii. Control through ordinance, order, or similar means, the discharge of spills 

and disposal of materials other than stormwater into the MS4s owned or 

operated by the Permittee;

iv. Control through interagency agreements among co-applicants, the 

contribution of pollutants from one portion of the MS4 to another portion 

of the MS4;

v. Require compliance with conditions in ordinances, permits, contracts, or 

orders; and,

vi. Within the limitations of state law, carry out all inspection, surveillance, 

and monitoring procedures necessary to determine compliance and noncompliance with permit conditions, including the prohibition on illicit 

discharges to the MS4 and compliance with local ordinances.

2. Municipal Separate Storm Sewer System Mapping and Documentation

The SWMP shall include an ongoing program for mapping and documenting the 

MS4. 

Minimum performance measures:

a. Ongoing Mapping: Each Permittee shall maintain mapping data for the 

features listed below. 

i. Known MS4 outfalls and discharge points. 

ii. Receiving waters, other than ground water. 
S5.C.2 S5.C.2

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iii. Stormwater treatment and flow control BMPs/facilities owned or 

operated by the Permittee. 

iv. Geographic areas served by the Permittee’s MS4 that do not discharge 

stormwater to surface water.

v. Tributary conveyances to all known outfalls and discharge points with a 

24-inch nominal diameter or larger, or an equivalent cross-sectional area

for non-pipe systems. For Counties, this requirement applies to 

urban/higher density rural sub-basins. For Cities, this requirement applies 

throughout the City. The following attributes shall be mapped:

(1) Tributary conveyance type, material, and size where known

(2) Associated drainage areas

(3) Land uses 

vi. Connections between the MS4 owned or operated by the Permittee and 

other municipalities or other public entities.

vii. All connections to the MS4 authorized or allowed by the Permittee after 

February 16, 2007.

viii. Existing, known connections over 8 inches in nominal diameter to 

tributary conveyances mapped in accordance with S5.C.2.a.v. For 

Counties, this requirement applies to the area of the county within 

urban/higher density rural sub-basins mapped under the previous permit. 

For Cities, this requirement applies throughout the City.

b. New Mapping: Each Permittee shall complete the following mapping no later 

than December 31, 2017.

i. Counties shall map tributary conveyances, as described in S5.C.2.a.v., for 

any urban/higher density rural sub-basins not mapped under the previous 

permit.

ii. Counties shall map existing, known connections greater than 8 inches in 

nominal diameter to tributary conveyances mapped in accordance with 

S5.C.2.b.i.

iii. Each Permittee shall map existing, known connections equal to 8 inches 

in nominal diameter to tributary conveyances mapped in accordance with 

S.5.C.2.

iv. Each Permittee shall map connections between stormwater treatment and 

flow control BMPs/facilities and tributary conveyances mapped in 
S5.C.3 S5.C.3

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accordance with S5.C.2. The Permittee shall map all associated 

emergency overflows.

c. To the extent consistent with national security laws and directives, each 

Permittee shall make available to Ecology, upon request, available maps 

depicting the information required in S5.C.2.a and b., above. The required 

format for mapping is electronic with fully described mapping standards. An 

example description is available on Ecology’s website. 

d. Upon request, and to the extent appropriate, Permittees shall provide mapping 

information to federally recognized Indian Tribes, municipalities, and other 

Permittees. This permit does not preclude Permittees from recovering 

reasonable costs associated with fulfilling mapping information requests by 

federally recognized Indian Tribes, municipalities, and other Permittees.

3. Coordination

The SWMP shall include coordination mechanisms among departments within 

each jurisdiction to eliminate barriers to compliance with the terms of this permit. 

The SWMP shall also include coordination mechanisms among entities covered 

under a municipal stormwater NPDES permit to encourage coordinated 

stormwater-related policies, programs and projects within a watershed.

Minimum performance measures:

a. Implement intra-governmental (internal) coordination agreement(s) or 

Executive Directive(s) to facilitate compliance with the terms of this permit. 

Permittees shall include a written description of internal coordination 

mechanisms in the Annual Report, due no later than March 31, 2015.

b. Implement; and within 2 years following the addition of a new Secondary 

Permittee, establish and implement:

i. Coordination mechanisms clarifying roles and responsibilities for the 

control of pollutants between physically interconnected MS4s of the 

Permittee and any other Permittee covered by a municipal stormwater 

permit.

ii. Coordinating stormwater management activities for shared waterbodies, 

among Permittees and Secondary Permittees, as necessary to avoid 

conflicting plans, policies, and regulations.

Permittees shall document their efforts to establish the required coordination 

mechanisms. Failure to effectively coordinate is not a permit violation 
S5.C.4 S5.C.5

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provided other entities, whose actions the Permittee has no or limited control 

over, refuse to cooperate. 

4. Public Involvement and Participation

Permittees shall provide ongoing opportunities for public involvement and 

participation in the Permittee’s SWMP and implementation priorities.

Minimum performance measures:

a. Permittees shall create opportunities for the public to participate in the 

decision-making processes involving the development, implementation and 

update of the Permittee’s SWMP. 

b. Each Permittee shall post on their website their SWMP Plan, and the annual 

report required under S9.A. no later than May 31 each year. All other 

submittals shall be available to the public upon request.

5. Controlling Runoff from New Development, Redevelopment, and Construction 

Sites 

The SWMP shall include a program to prevent and control the impacts of runoff 

from new development, redevelopment, and construction activities. Refer to 

Appendix 10 for a list of approved manuals and ordinances. The program shall 

apply to private and public development, including roads. 

Minimum performance measures:

a. Site and subdivision scale requirements:

i. The Minimum Requirements, thresholds, and definitions in Appendix 1, 

or Minimum Requirements, thresholds, and definitions determined by 

Ecology to be equivalent to Appendix 1, for new development, 

redevelopment, and construction sites shall be included in ordinances or 

other enforceable documents adopted by the local government. 

Adjustment and variance criteria equivalent to those in Appendix 1 shall 

be included. More stringent requirements may be used, and/or certain 

requirements may be tailored to local circumstances through the use of 

Ecology approved basin plans or other similar water quality and quantity 

planning efforts. Such local requirements and thresholds shall provide 

equal or similar protection of receiving waters and equal or similar levels 

of pollutant control as compared to Appendix 1. 

ii. The local requirements shall include the following requirements, 

limitations, and criteria that, when used to implement the minimum 

requirements in Appendix 1, will protect water quality, reduce the 
S5.C.5 S5.C.5

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discharge of pollutants to the MEP, and satisfy the State requirement 

under chapter 90.48 RCW to apply AKART prior to discharge:

(1) Site planning requirements

(2) BMP selection criteria

(3) BMP design criteria

(4) BMP infeasibility criteria

(5) LID competing needs criteria

(6) BMP limitations 

Permittees shall document how the criteria and requirements will protect 

water quality, reduce the discharge of pollutants to the maximum extent 

practicable, and satisfy the state AKART requirements. 

Permittees who choose to use the requirements, limitations, and criteria in 

the Stormwater Management Manual for Western Washington

(SWMMWW), or an equivalent manual approved by Ecology, may cite 

this choice as their sole documentation to meet this requirement.

iii. No later than June 30, 2015, each Permittee shall adopt and make 

effective a local program that meets the requirements in S5.C.5.a.i.

through ii., above. The local program adopted to meet the requirements 

of S5.C.5.a.i. through ii. shall apply to all applications1 submitted after 

June 30, 2015 and shall apply to applications submitted no later than 

June 30, 2015, which have not started construction2 by June 30, 2020. 

Ecology review and approval of the local manual and ordinances is 

required. Manuals and ordinances approved under this section are listed 

in Appendix 10, Part 2. Permittees shall provide detailed, written 

justification of any of the requirements which differ from those contained 

in Appendix 1 of this permit. 

The Permittee shall submit draft enforceable requirements, technical 

standards and manual to Ecology no later than July 1, 2014. Ecology will 

review and provide written response to the Permittee. If Ecology takes 

longer than 90 days to provide a written response, the required deadline 

for adoption and effective date will be automatically extended by the 

 1 In this context, “application” means, at a minimum, a complete project description, site plan, and, if applicable, 

SEPA checklist. Permittees may establish additional elements of a complete application.

2 In this context, “started construction” means, at a minimum, the site work associated with and directly related to 

the approved project has begun. For example: grading the project site to final grade or utility installation. Simply 

clearing the project site does not constitute the start of construction. Permittees may establish additional 

requirements related to the start of construction.
S5.C.5 S5.C.5

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number of calendar days that Ecology exceeds a 90 day period for written 

response.

In the case of circumstances beyond the Permittee’s control, such as 

litigation or administrative appeals that may result in noncompliance with 

the requirements of this section, the Permittee shall promptly notify 

Ecology and submit a written request for an extension. 

iv. The program shall include the legal authority to inspect private 

stormwater facilities and enforce maintenance standards for all new 

development and redevelopment approved under the provisions of this 

section.

v. The program shall include a process of permits, site plan review, 

inspections, and enforcement capability to meet the following standards 

for both private and public projects, using qualified personnel:

(1) Review all stormwater site plans submitted to the Permittee for 

proposed development involving land disturbing activity that meet 

the thresholds in S5.C.5.a.i., above.

(2) Inspect prior to clearing and construction, all permitted 

development sites that meet the thresholds in S5.C.5.a.i., and that 

have a high potential for sediment transport as determined through 

plan review based on definitions and requirements in Appendix 7. 

As an alternative to evaluating each site according to Appendix 7, 

Permittees may choose to inspect all construction sites that meet 

the minimum thresholds in S5.C.5.a.i.

(3) Inspect all permitted development sites involving land disturbing 

activity that meet the thresholds in S5.C.5.a.i., above, during 

construction to verify proper installation and maintenance of 

required erosion and sediment controls. Enforce as necessary based 

on the inspection. 

(4) Inspect all permitted development sites that meet the thresholds in 

S5.C.5.a.i., upon completion of construction and prior to final 

approval or occupancy to ensure proper installation of permanent 

stormwater facilities. Verify that a maintenance plan is completed 

and responsibility for maintenance is assigned for stormwater 

treatment and flow control BMPs/facilities. Enforce as necessary 

based on the inspection.

(5) Compliance with the inspection requirements in (2), (3) and (4) 

above shall be determined by the presence of an established 

inspection program designed to inspect all sites involving land 

disturbing activity that meet the thresholds in S5.C.5.a.i. 

Compliance during this permit term shall be determined by 
S5.C.5 S5.C.5

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achieving at least 80% of scheduled inspections. The inspections 

may be combined with other inspections provided they are 

performed using qualified personnel.

(6) The program shall include a procedure for keeping records of 

inspections and enforcement actions by staff, including inspection 

reports, warning letters, notices of violations, and other 

enforcement records. Records of maintenance inspections and 

maintenance activities shall be maintained. 

(7) The program shall include an enforcement strategy to respond to 

issues of non-compliance.

vi. The Permittee shall make available, as applicable, the "Notice of Intent 

for Construction Activity" and copies of the "Notice of Intent for 

Industrial Activity" to representatives of proposed new development and 

redevelopment. Permittees will continue to enforce local ordinances 

controlling runoff from sites that are covered by other stormwater permits 

issued by Ecology.

vii. Each permittee shall ensure that all staff whose primary job duties are 

implementing the program to Control Stormwater Runoff from New 

Development, Redevelopment, and Construction Sites, including 

permitting, plan review, construction site inspections, and enforcement, 

are trained to conduct these activities. As determined necessary by the 

Permittee, follow-up training shall be provided to address changes in 

procedures, techniques or staffing. Permittees shall document and 

maintain records of the training provided and the staff trained.

b. Low impact development code-related requirements:

i. No later than June 30, 2015, or by an alternative date if established in 

accordance with S5.C.5.a.iii., Permittees shall review, revise, and make 

effective their local development-related codes, rules, standards, or other 

enforceable documents to incorporate and require Low Impact 

Development (LID) Principles and LID Best Management Practices 

(BMPs). 

The intent of the revisions shall be to make LID the preferred and 

commonly-used approach to site development. The revisions shall be 

designed to minimize impervious surfaces, native vegetation loss, and 

stormwater runoff in all types of development situations. Permittees shall 

conduct a similar review and revision process, and consider the range of 

issues, outlined in the following document: Integrating LID into Local

Codes: A Guidebook for Local Governments (Puget Sound Partnership, 

2012).
S5.C.5 S5.C.5

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ii. Each Permittee shall submit a summary of the results of the review and 

revision process in S5.C.5.b.i. with the Annual Report due on March 31, 

2016. This summary shall include, at a minimum, a list of the participants 

(job title, brief job description, department represented), the codes, rules, 

standards, and other enforceable documents reviewed, and the revisions 

made to those documents which incorporate and require LID Principles 

and LID BMPs. The summary shall include existing requirements for LID 

Principles and LID BMPs in development-related codes. The summary of 

revisions shall be organized as follows:

(1) Measures to minimize impervious surfaces.

(2) Measures to minimize loss of native vegetation.

(3) Other measures to minimize stormwater runoff.

c. Watershed-scale stormwater planning requirements:

The objective of watershed-scale stormwater planning is to identify a 

stormwater management strategy or strategies that would result in hydrologic

and water quality conditions that fully support “existing uses,” and 

“designated uses,” as those terms are defined in WAC 173-201A-020, 

throughout the stream system.

i. No later than October 31, 2013, each County Permittee listed below shall 

select one watershed from the following list in which to conduct 

watershed-scale stormwater planning:

• Clark County: Whipple, Salmon

• King County: Bear, May, Soos

• Pierce County: Clover 

• Snohomish County: Swamp, North

A permittee may propose an alternative watershed that meets all of the 

following criteria:

(1) Has a drainage area of at least 10 square miles.

(2) Is partially or wholly within the County Permittee’s existing MS4 

service area with discharges to the stream.

(3) Has a stream system that has been impacted by development but 

retains some anadromous fish resources.

(4) Is targeted to accept significant population growth and associated 

development, and is partially, if not fully, within the urban growth 

area established under Chapter 36.70A RCW, or a potential future 

expansion of the urban growth area.
S5.C.5 S5.C.5

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Each County Permittee3 will notify Ecology in writing of the selected or 

proposed alternative watershed no later than October 31, 2013. Any 

proposed alternative watershed is subject to Ecology’s review and 

approval. The required deadlines for submission of a scope of work and a 

final plan will be automatically extended by the number of calendar days 

that Ecology exceeds a 60 day period for written response to the 

alternative watershed proposal.

ii. Each County Permittee shall convene and lead a documented watershedscale stormwater planning process as described in sections S5.C.5.c.ii.

through S5.C.5.c.vi. below.

A City or County MS4 Permittee within a Phase I County selected basin 

must fully participate with the stormwater planning process as described 

below. Permittees may choose to participate in a coordinated Scope of 

Work and schedule with other Permittees within the selected watershed, 

or conduct their scope of work independently. 

iii. No later than August 13, 2015, each Permittee within the basin selected 

by King County must submit to Ecology documentation of their proposed 

approach to coordinate their efforts with other Permittees within the 

watershed, including:

(1) A list of the municipal stormwater permittees with whom the 

Permittee will undertake watershed-scale planning under a 

common scope of work; and description of the coordination and 

dispute resolution procedures agreed to by all of the Permittees 

operating under the common scope of work; and

(2) A description of planned coordination and dispute resolution 

procedures for providing and receiving feedback from Permittees 

operating under different scopes of work within the same 

watershed, including procedures to:

a) Review, provide comment, and revise methods and 

assumptions to meet S5.C.5.c.iv (1) through (4) below;

 3 Ecology approved a selected watershed for all four County Permittees. Clark County chose the Whipple Creek 

watershed which was one of the options listed in the permit. King County and Pierce County chose to do planning 

on subsets of watersheds listed in the permit that meet the four criteria identified for alternative watersheds. King 

County chose a portion of the Bear Creek watershed (excluding the Cottage Lake sub-watershed, Evans Creek, and 

the area downstream of the confluence with Evans Creek), and Pierce County chose the Spanaway Creek/Lake subwatershed of the Clover Creek watershed. 

Snohomish County proposed a subset of an alternative watershed, Little Bear Creek. Ecology originally approved 

the entire Little Bear Creek watershed, which meets the four qualifying criteria, but based on the 2014 ruling by the 

Pollution Control Hearings Board and comments received during the permit modification process, Ecology accepts 

the originally proposed subset of just that part of Little Bear Creek in Snohomish County.
S5.C.5 S5.C.5

Phase I Municipal Stormwater Permit - August 1, 2013

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b) Review, provide comment, and revise present- and futurecondition B-IBI scores, pollutant concentrations, temperature 

and hydrologic metrics; 

c) Share the results of the modeling performed by the Permittee 

with all other Permittees in the watershed; 

d) Adjust the Permittee’s proposed changes to developmentrelated codes, rules, standards, plans, and potential future 

structural stormwater control projects in response to feedback 

from other Permittees so that the planning objectives, as 

described in S5.C.5.c above, are projected to be achieved 

throughout the watershed.

(3) It is not a permit violation if other entities, over whose actions the 

Permittee has limited or no control, refuse to participate in the

coordination plan described in S5.C.5.c.iii.

iv. No later than April 1, 2014 for Permittees in watersheds selected by Clark 

and Pierce counties, November 4, 2015, for Permittees in the watershed

selected by King county, and March 31, 2015, for Permittees in the 

watershed selected by Snohomish county, the Permittee shall submit a 

scope of work and a schedule to Ecology for the complete watershed 

planning process. The scope of work and schedule are subject to 

Ecology’s review and approval. If Ecology takes longer than 90 days to 

provide a written response, the required deadline for submitting a final 

watershed-scale stormwater plan to Ecology will be automatically 

extended by the number of days Ecology exceeds 90 days, but no later 

than July 30, 2018.

The scope of work and schedule must apply to the geographic extent of 

the jurisdictions of the Permittees listed under S5.C.5.c.iii (1) above and, 

at a minimum, describe:

(1) An assessment of existing hydrologic, biologic, and water quality 

conditions within the selected watershed, and an assessment of the 

current status of the aquatic community. This assessment may be 

based on existing data where such data are available. Where such 

data are not available, or are not sufficient, the scope of work and 

schedule shall include the collection of such data. 

The existing conditions assessment shall, at a minimum, include 

the following: 

a) Water quality conditions as established through sampling 

during base flows and storm flows for, at a minimum, the 

following chemical parameters: dissolved copper, dissolved 
S5.C.5 S5.C.5

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zinc, temperature, and fecal coliform. Permittees shall identify 

or collect data from locations upgradient and downgradient of 

stream sections influenced by MS4 discharges. 

b) Continuous flow monitoring of the stream to provide the data 

necessary to calibrate a continuous runoff model to the selected 

watershed. Permittees shall identify or collect flow monitoring 

data from locations upgradient and downgradient of stream 

sections influenced by MS4 discharges. 

c) Macroinvertebrate data for the purpose of estimating current 

Benthic Index of Biotic Integrity (B-IBI) scores and comparing 

them with the scores predicted by the existing values of the 

hydrologic metrics in S5.C.5.c.iv.(4).

d) The status of the aquatic community, including the presence 

and distribution of salmonid uses, shall be documented using 

data from existing sources.

(2) Efforts to compile and/or generate maps of the selected watershed 

to identify the existing distribution and totals of general soil types, 

vegetative land cover, impervious land covers, MS4s and nonregulated public stormwater systems (if applicable). Maps must be 

sufficient to allow construction of a rainfall/runoff model 

representation of the watershed. Maps must also identify areas 

within the watershed appropriate for special attention in regard to 

hydrologic and water quality impacts. For example: headwater 

wetlands and critical aquifer recharge areas.

(3) How the Permittee will use the existing conditions assessment in 

S5.C.5.c.iv.(1) and the maps described in S5.C.5.c.iv.(2), to

calibrate a continuous runoff model to reflect the existing 

hydrologic, water quality, and biologic (as represented by B-IBI 

score) conditions. 

(4) How the Permittee will use the model calibrated in S5.C.5.c.iv.(3), 

to estimate hydrologic changes from the historic condition; and 

predict the future hydrologic, biologic, and water quality 

conditions at full build-out under existing or proposed 

comprehensive land use management plan(s) for the watershed. 

Future biologic conditions shall be estimated by using a correlation 

of hydrologic metrics with B-IBI scores for Puget Sound Lowland 

Streams4

, or other similar correlation if approved by Ecology. 

 4 DeGasperi, C.L., Berge, H. B., Whiting, K. R., Burkey, J. J., Cassin, J. L. and Fuerstenberg, R. R. (2009), Linking 

Hydrologic Alteration to Biological Impairment in Urbanizing Streams of the Puget Lowland, Washington, USA. 

JAWRA Journal of the American Water Resources Association, 45: 512-533. Doi: 10.1111/j.1752-

1688.2009.00306.x
S5.C.5 S5.C.5

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Future water quality conditions shall be described through 

estimation of concentrations of, at a minimum, dissolved copper, 

dissolved zinc, temperature, and fecal coliform. 

(5) How, if the estimation in S5.C.5.c.ii.(4) predicts water quality 

standards will not be met, the Permittee will use the calibrated 

watershed model to evaluate stormwater management strategies to 

meet the standards. The same hydrologic metrics and correlated BIBI scores, and water quality parameters used in S5.C.5.c.ii.(4) 

shall be used to evaluate the effectiveness of strategies. 

a) Stormwater management strategies to be evaluated for all 

jurisdictions in the watershed must include:

• Changes to development-related codes, rules, standards, 

and plans.

• Potential future structural stormwater control projects 

consistent with S5.C.6.a. 

b) Stormwater management strategies evaluated may also include: 

• Basin-specific stormwater control requirements for new 

development and redevelopment as allowed by Section 7 of 

Appendix 1.

• Strategies to encourage redevelopment and infill, and an 

assessment of options for efficient, effective runoff controls 

for redevelopment projects, such as regional facilities, in 

lieu of individual site requirements.

(6) How the permittee will create an implementation plan and 

schedule that includes: potential future actions to implement the 

identified stormwater management strategies, responsible parties, 

estimated costs, and potential funding mechanisms. 

(7) A public review and comment process, at a minimum, focused on 

the draft watershed-scale stormwater plan. The public review must 

allow for public comment from all governmental entities with 

jurisdiction within the watershed. 

v. The watershed-scale stormwater planning process, as documented in the 

scope of work and schedule, may include an evaluation of strategies to 

preserve or improve other factors that influence maintenance of the 

existing and designated uses of the stream. Examples include: channel 

restoration, in-stream culvert replacement, quality of the riparian zone, 

gravel disturbance regime, and presence and distribution of large woody 

debris.

vi. Each Permittee (or group of Permittees operating under a single scope of 

work, as described above) must submit a final watershed-scale 
S5.C.6 S5.C.6

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stormwater plan to Ecology no later than September 6, 2017, for the 

Clark, Pierce, and Snohomish county efforts, and no later than April 4, 

2018, for the King county effort. The plan must summarize results of the 

modeling and planning process, describe results of the evaluation of 

strategies under S5.C.5.c.iv.(5), and include the implementation plan and 

schedule developed pursuant to S5.C.5.c.iv.(6). 

6. Structural Stormwater Controls

Each Permittee shall implement a structural stormwater controls program to 

prevent or reduce impacts to waters of the state caused by discharges from the 

MS4. Impacts that shall be addressed include disturbances to watershed 

hydrology and stormwater pollutant discharges. 

The program shall consider impacts caused by stormwater discharges from areas 

of existing development, including runoff from highways, streets and roads 

owned or operated by the Permittee, and areas of new development, where 

impacts are anticipated as development occurs. 

Minimum performance measures:

a. The program shall address impacts that are not adequately controlled by the 

other required actions of the SWMP. 

i. The program shall consider the following projects: 

(1) New flow control facilities, including LID BMPs. 

(2) New treatment (or treatment and flow control) facilities, including 

LID BMPs.

(3) Retrofit of existing treatment and/or flow control facilities.

(4) Property acquisition for water quality and/or flow control benefits 

(not associated with future facilities).

(5) Maintenance with capital construction costs ≥ $25,000. 

ii. Permittees should consider other projects to address impacts, such as:

(1) Riparian habitat acquisition. 

(2) Restoration of forest cover and/ or riparian buffers. 

(3) Floodplain reconnection projects on water bodies that are not flow 

control exempt per Appendix 1. 

(4) Capital projects related to the MS4 which implement an Ecologyapproved basin or watershed plan.
S5.C.7 S5.C.7

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(5) Other actions to address stormwater runoff into or from the MS4 

not otherwise required in S5.C.

iii. Permittees may not use in-stream culvert replacement or channel 

restoration projects for compliance with this requirement.

iv. The Structural Stormwater Control program may also include a program 

designed to implement small scale projects that are not planned in 

advance.

b. Each Permittee’s SWMP Plan shall describe the Structural Stormwater 

Control Program including the following:

i. The Structural Stormwater Control Program goals.

ii. The planning process used to develop the Structural Stormwater Control 

Program, including: 

(1) The geographic scale of the planning process.

(2) Issues and regulations addressed.

(3) Steps in the planning process.

(4) Types of characterization information considered.

(5) Amount budgeted for implementation.

(6) The public involvement process.

(7) A description of the prioritization process, procedures and criteria 

used to select the Structural Stormwater Control projects. 

c. No later than March 31, 2014 each Permittee shall provide a list of planned, 

individual projects scheduled for implementation during this permit term. This

list must include at a minimum the information and formatting specified in 

Appendix 11. Each Permittee’s annual report shall provide an update of this 

list. 

7. Source Control Program for Existing Development

a. The Permittee shall implement a program to reduce pollutants in runoff from 

areas that discharge to MS4s owned or operated by the Permittee. The 

program shall include the following:

i. Application of operational and structural source control BMPs, and, if 

necessary, treatment BMPs/facilities to pollution generating sources 

associated with existing land uses and activities.
S5.C.7 S5.C.7

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ii. Inspections of pollutant generating sources at commercial and industrial 

properties to enforce implementation of required BMPs to control 

pollution discharging into MS4s owned or operated by the Permittee.

iii. Application and enforcement of local ordinances at sites, identified 

pursuant to S5.C.7.b.ii, including sites with discharges authorized by a 

separate NPDES permit. Permittees that are in compliance with the terms 

of this permit will not be held liable by Ecology for water quality 

standard violations or receiving water impacts caused by industries and 

other Permittees covered, or which should be covered under an NPDES 

permit issued by Ecology.

iv. Practices to reduce polluted runoff from the application of pesticides, 

herbicides, and fertilizer discharging into MS4s owned or operated by the 

Permittee.

b. Minimum performance measures:

i. Permittees shall enforce ordinance(s), or other enforceable documents, 

requiring the application of source control BMPs for pollutant generating 

sources associated with existing land uses and activities.

Permittees shall update and make effective the ordinance(s), or other 

enforceable documents, as necessary to meet the requirements of this 

section no later than February 2, 2018.

The requirements of this subsection are met by using the source control 

BMPs in Volume IV of the Stormwater Management Manual for Western 

Washington, or a functionally equivalent manual approved by Ecology. 

Operational source control BMPs shall be required for all pollutant 

generating sources. Structural source control BMPs shall be required for 

pollutant generating sources if operational source control BMPs do not 

prevent illicit discharges or violations of surface water, ground water, or 

sediment management standards because of inadequate stormwater 

controls. Implementation of source control requirements may be done 

through education and technical assistance programs, provided that 

formal enforcement authority is available to the Permittee and is used as 

determined necessary by the Permittee, in accordance with S5.C.7.b.iv., 

below.

ii. Permittees shall implement a program to identify commercial and 

industrial properties which have the potential to generate pollutants to the 

Permittee’s MS4. The program shall include a source control inventory 

which lists businesses and/or properties identified based on the presence 

of activities that are pollutant generating (refer to Appendix 8). The 
S5.C.7 S5.C.7

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source control inventory shall also include other pollutant generating 

sources, such as mobile or home-based businesses and multifamily 

properties, which are identified based on complaint response. The 

Permittee shall update the inventory at least once every 5 years. 

iii. Permittees shall implement an inspection program for sites identified 

pursuant to S5.C.7.b.ii. above. 

(1) All identified sites with a business address shall be provided, by 

mail, telephone, electronic communications, or in person, 

information about activities that may generate pollutants and the 

source control requirements applicable to those activities. This 

information may be provided all at one time or spread out over the 

permit term to allow for some tailoring and distribution of the 

information during site inspections. 

(2) The Permittee shall annually complete the number of inspections 

equal to 20% of the businesses and/or properties listed in their 

source control inventory to assure BMP effectiveness and 

compliance with source control requirements. The Permittee may 

count follow up compliance inspections at the same site toward the 

20% inspection rate. The Permittee may select which sites to 

inspect each year and is not required to inspect 100% of sites over 

a 5-year period. Sites may be prioritized for inspection based on 

their land use category, potential for pollution generation, 

proximity to receiving waters, or to address an identified pollution 

problem within a specific geographic area or sub-basin.

(3) Each Permittee shall inspect 100% of sites identified through 

legitimate complaints.

iv. Each Permittee shall implement a progressive enforcement policy to 

require sites to come into compliance with stormwater requirements 

within a reasonable time period as specified below: 

(1) If the Permittee determines, through inspections or otherwise, that 

a site has failed to adequately implement required BMPs, the 

Permittee shall take appropriate follow-up action(s) which may 

include: phone calls, reminder letters or follow-up inspections.

(2) When a Permittee determines that a facility has failed to 

adequately implement BMPs after a follow-up inspection, the 

Permittee shall take enforcement action as established through 

authority in its municipal code and ordinances, or through the 

judicial system.

(3) Each Permittee shall maintain records, including documentation of 

each site visit, inspection reports, warning letters, notices of 

violations, and other enforcement records, demonstrating an effort 
S5.C.8 S5.C.8

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to bring facilities into compliance. Each Permittee shall also 

maintain records of sites that are not inspected because the 

property owner denies entry.

(4) A Permittee may refer non-emergency violations of local 

ordinances to Ecology, provided, the Permittee also makes a 

documented effort of progressive enforcement. At a minimum, a 

Permittee’s enforcement effort shall include documentation of 

inspections and warning letters or notices of violation.

v. Permittees shall train staff who are responsible for implementing the 

source control program to conduct these activities. The ongoing training 

program shall cover the legal authority for source control, source control 

BMPs and their proper application, inspection protocols, lessons learned, 

typical cases, and enforcement procedures. Follow-up training shall be 

provided as needed to address changes in procedures, techniques, 

requirements, or staff. Permittees shall document and maintain records of 

the training provided and the staff trained.

8. Illicit Connections and Illicit Discharges Detection and Elimination

The SWMP shall include an ongoing program designed to prevent, detect, 

characterize, trace, and eliminate illicit connections and illicit discharges into the 

MS4. 

Minimum performance measures:

a. The program shall include procedures for reporting and correcting or 

removing illicit connections, spills and other illicit discharges when they are 

suspected or identified. The program shall also include procedures for 

addressing pollutants entering the MS4 from an interconnected, adjoining 

MS4. 

Illicit connections and illicit discharges shall be identified through field 

screening, inspections, complaints/reports, construction inspections, 

maintenance inspections, source control inspections, and/or monitoring 

information, as appropriate. 

b. No later than February 2, 2018, each Permittee shall evaluate, and if necessary 

update, existing ordinances or other regulatory mechanisms to effectively 

prohibit non-stormwater, illicit discharges, including spills, into the 

Permittee’s MS4. 

i. Allowable Discharges: The ordinance or other regulatory mechanism 

does not need to prohibit the following categories of non-stormwater 

discharges: 
S5.C.8 S5.C.8

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(1) Diverted stream flows 

(2) Rising ground waters

(3) Uncontaminated ground water infiltration (as defined at 40 CFR 

35.2005(b)(20))

(4) Uncontaminated pumped ground water 

(5) Foundation drains 

(6) Air conditioning condensation

(7) Irrigation water from agricultural sources that is commingled with 

urban stormwater

(8) Springs

(9) Uncontaminated water from crawl space pumps

(10) Footing drains

(11) Flows from riparian habitats and wetlands 

(12) Non-stormwater discharges authorized by another NPDES or State 

Waste Discharge permit 

(13) Discharges from emergency fire fighting activities in accordance 

with S2 Authorized Discharges

ii. Conditionally Allowable Discharges: The ordinance or other regulatory 

mechanism, may allow the following categories of non-stormwater 

discharges only if the stated conditions are met: 

(1) Discharges from potable water sources including, but not limited

to, water line flushing, hyperchlorinated water line flushing, fire 

hydrant system flushing, and pipeline hydrostatic test water. 

Planned discharges shall be de-chlorinated to a total residual 

chlorine concentration of 0.1 ppm or less, pH-adjusted if 

necessary, and volumetrically and velocity controlled to prevent 

resuspension of sediments in the MS4.

(2) Discharges from lawn watering and other irrigation runoff. These 

discharges shall be minimized through, at a minimum, public 

education activities (see S5.C.10.) and water conservation efforts.

(3) Dechlorinated swimming pool, spa, and hot tub discharges. The 

discharges shall be dechlorinated to a total residual chlorine 

concentration of 0.1 ppm or less, pH-adjusted and reoxygenated if 

necessary, and volumetrically and velocity controlled to prevent 

resuspension of sediments in the MS4. Discharges shall be 

thermally controlled to prevent an increase in temperature of the 

receiving water. Swimming pool cleaning wastewater and filter 

backwash shall not be discharged to the MS4. 
S5.C.8 S5.C.8

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(4) Street and sidewalk wash water, water used to control dust, and 

routine external building washdown that does not use detergents. 

The Permittee shall reduce these discharges through, at a 

minimum, public education activities (see S5.C.10.) and/or water 

conservation efforts. To avoid washing pollutants into the MS4, 

Permittees shall minimize the amount of street wash and dust 

control water used. 

(5) Other non-stormwater discharges shall be in compliance with the 

requirements of a pollution prevention plan reviewed by the 

Permittee which addresses control of such discharges.

iii. The Permittee shall further address any category of discharges in 

S5.C.8.b.i or ii above if the discharges are identified as significant sources 

of pollutants to waters of the State.

c. Each Permittee shall implement an ongoing program designed to detect and 

identify non-stormwater discharges and illicit connections into the Permittee’s 

MS4. The program shall include the following components:

i. Procedures for conducting investigations of the Permittees MS4, 

including field screening and methods for identifying potential sources. 

These procedures may also include source control inspections. 

The permittee shall implement a field screening methodology appropriate 

to the characteristics of the MS4 and water quality concerns. Screening 

for illicit connections may be conducted using the Illicit Discharge 

Detection and Elimination: A Guidance Manual for Program 

Development and Technical Assessments, Center for Watershed 

Protection, October 2004; or another method of comparable or improved 

effectiveness. The Permittee shall document the field screening 

methodology in the relevant Annual Report.

(1) Each Permittee shall implement an ongoing field screening 

program of, on average, 12% of the Permittee’s known conveyance 

systems each calendar year. 

(2) Each City shall field screen all the conveyance systems within the 

Permittee’s incorporated area at least once between February 2007 

and July 31, 2018.

(3) Each County shall field screen all the conveyance systems within 

the Permittee’s urban/higher density rural sub-basins at least once 

between February 2007 and July 31, 2018.

ii. A publicly-listed and publicized hotline or other telephone number for 

public reporting of spills and other illicit discharges. 
S5.C.8 S5.C.8

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iii. An ongoing training program for all municipal field staff, who, as part of 

their normal job responsibilities might come into contact with or 

otherwise observe an illicit discharge or illicit connection to the MS4, on 

the identification of an illicit discharge and/or connection, and on the 

proper procedures for reporting and responding to the illicit discharge 

and/or connection. Follow-up training shall be provided as needed to 

address changes in procedures, techniques, requirements, or staffing. 

Permittees shall document and maintain records of the trainings provided 

and the staff trained. 

d. Each Permittee shall implement an ongoing program designed to address 

illicit discharges, including spills and illicit connections, into the Permittee’s 

MS4. The program shall include: 

i. Procedures for characterizing the nature of, and potential public or 

environmental threat posed by, any illicit discharges found by or reported 

to the Permittee. Procedures shall address the evaluation of whether the 

discharge must be immediately contained and steps to be taken for 

containment of the discharge.

ii. Procedures for tracing the source of an illicit discharge; including visual 

inspections, and when necessary, opening manholes, using mobile 

cameras, collecting and analyzing water samples, and/or other detailed 

inspection procedures.

iii. Procedures for eliminating the discharge; including notification of 

appropriate authorities; notification of the property owner; technical 

assistance; follow-up inspections; and escalating enforcement and legal 

actions if the discharge is not eliminated.

iv. Compliance with the provisions in S5.C.8.d.i, ii, and iii, above, shall be 

achieved by meeting the following timelines: 

(1) Immediately respond to all illicit discharges, including spills, 

which are determined to constitute a threat to human health, 

welfare, or the environment consistent with General Condition G3.

(2) Investigate (or refer to the appropriate agency with authority to act) 

within 7 days, on average, any complaints, reports or monitoring 

information that indicates a potential illicit discharge.

(3) Initiate an investigation within 21 days of any report or discovery 

of a suspected illicit connection to determine the source of the 

connection, the nature and volume of discharge through the 

connection, and the party responsible for the connection. 

(4) Upon confirmation of an illicit connection, use enforcement 

authority in a documented effort to eliminate the illicit connection 
S5.C.9 S5.C.9

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within 6 months. All known illicit connections to the MS4 shall be 

eliminated.

e. Permittees shall train staff who are responsible for identification, 

investigation, termination, cleanup, and reporting of illicit discharges, 

including spills and illicit connections, to conduct these activities. Follow-up 

training shall be provided as needed to address changes in procedures, 

techniques, requirements, or staff. Permittees shall document and maintain 

records of the training provided and the staff trained.

f. Each Permittee shall either participate in a regional emergency response 

program, or develop and implement procedures to investigate and respond to 

spills and improper disposal into the MS4 owned or operated by the Permittee.

g. Recordkeeping: Each Permittee shall track and maintain records of the 

activities conducted to meet the requirements of this section.

9. Operation and Maintenance Program 

Each Permittee shall implement a program to regulate maintenance activities and 

to conduct maintenance activities by the Permittee to prevent or reduce 

stormwater impacts.

Minimum performance measures:

a. Maintenance Standards. Each Permittee shall implement maintenance 

standards that are as protective, or more protective, of facility function than 

those specified in Chapter 4 of Volume V of the Stormwater Management 

Manual for Western Washington. For facilities which do not have 

maintenance standards, the Permittee shall develop a maintenance standard. 

No later than June 30, 2015 each Permittee shall update their maintenance 

standards as necessary to meet the requirements in this section.

i. The purpose of the maintenance standard is to determine if maintenance 

is required. The maintenance standard is not a measure of the facility’s 

required condition at all times between inspections. Exceeding the 

maintenance standard between inspections and/or maintenance is not a 

permit violation. 

ii. Unless there are circumstances beyond the Permittee’s control, when an 

inspection identifies an exceedance of the maintenance standard, 

maintenance shall be performed: 

(1) Within 1 year for typical maintenance of facilities, except catch 

basins. 

(2) Within 6 months for catch basins.
S5.C.9 S5.C.9

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(3) Within 2 years for maintenance that requires capital construction 

of less than $25,000. 

Circumstances beyond the Permittee’s control include denial or delay of 

access by property owners, denial or delay of necessary permit approvals, 

and unexpected reallocations of maintenance staff to perform emergency 

work. For each exceedance of the required timeframe, the Permittee shall 

document the circumstances and how they were beyond the Permittee’s 

control.

b. Maintenance of stormwater facilities regulated by the Permittee: 

i. Each Permittee shall evaluate and, if necessary, update existing 

ordinances or other enforceable documents requiring maintenance of all 

permanent stormwater treatment and flow control BMPs/facilities 

regulated by the Permittee (including catch basins that are part of the 

facilities regulated by the Permittee), in accordance with maintenance 

standards established under S5.C.9.a., above. 

ii. Each Permittee shall implement an on-going inspection program to 

annually inspect all stormwater treatment and flow control 

BMPs/facilities regulated by the Permittee to enforce compliance with 

adopted maintenance standards as needed based on inspection. The

inspection program is limited to facilities to which the Permittee can 

legally gain access, provided the Permittee shall seek access to all 

stormwater treatment and flow control BMPs/facilities regulated by the 

permittee.

Permittees may reduce the inspection frequency based on maintenance 

records of double the length of time of the proposed inspection frequency. 

In the absence of maintenance records, the Permittee may substitute 

written statements to document a specific less frequent inspection 

schedule. Written statements shall be based on actual inspection and 

maintenance experience and shall be certified in accordance with G19 

Certification and Signature.

iii. Each Permittee shall manage maintenance activities to inspect all 

permanent stormwater treatment and flow control BMPs/facilities, and 

catch basins, in new residential developments every six months, until 

90% of the lots are constructed (or when construction has stopped and the 

site is fully stabilized), to identify maintenance needs and enforce 

compliance with maintenance standards as needed.

iv. Compliance with the inspection requirements of S5.C.9.b.ii and iii, above, 

shall be determined by the presence of an established inspection program 

designed to inspect all sites, and achieving inspection of 80% of all sites.
S5.C.9 S5.C.9

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v. The Permittee shall require cleaning of catch basins regulated by the 

Permittee if they are found to be out of compliance with established 

maintenance standards in the course of inspections conducted at facilities 

under the requirements of S5.C.7. Source Control Program for Existing 

Development, and S5.C.8. Illicit Connections and Illicit Discharges 

Detection and Elimination, or if the catch basins are part of the 

stormwater facilities inspected under the requirements of S5.C.9. 

Operation and Maintenance Program.

c. Maintenance of stormwater facilities owned or operated by the Permittee

i. Each Permittee shall implement a program to annually inspect all 

permanent stormwater treatment and flow control BMPs/facilities owned 

or operated by the Permittee. Permittees shall implement appropriate 

maintenance action(s) in accordance with adopted maintenance standards. 

Permittees may reduce the inspection frequency based on maintenance 

records of double the length of time of the proposed inspection frequency. 

In the absence of maintenance records, the Permittee may substitute 

written statements to document a specific less frequent inspection 

schedule. Written statements shall be based on actual inspection and 

maintenance experience and shall be certified in accordance with G19 

Certification and Signature.

ii. Each Permittee shall implement a program to conduct spot checks of 

potentially damaged permanent stormwater treatment and flow control 

BMPs/facilities after major storm events (24 hour storm event with a 10 

year or greater recurrence interval). If spot checks indicate widespread 

damage/maintenance needs, inspect all stormwater treatment and flow 

control BMPs/facilities that may be affected. Conduct repairs or take 

appropriate maintenance action in accordance with maintenance standards 

established under S5.C.9.a, above, based on the results of the inspections.

iii. Compliance with the inspection requirements of S5.C.9.c.i., and ii. above, 

shall be determined by the presence of an established inspection program 

designed to inspect all sites and achieving at least 95% of required 

inspections.

d. Maintenance of Catch Basins Owned or Operated by the Permittee

i. Each Permittee shall annually inspect catch basins and inlets owned or 

operated by the Permittee, or implement alternatives below. 

Alternatives to the standard approach of inspecting catch basins annually: 

Permittees may apply the following alternatives to all or portions of their 

system.
S5.C.9 S5.C.9

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(1) The annual catch basin inspection schedule may be changed as 

appropriate to meet the maintenance standards based on 

maintenance records of double the length of time of the proposed 

inspection frequency. In the absence of maintenance records for 

catch basins, the Permittee may substitute written statements to 

document a specific, less frequent inspection schedule. Written 

statements shall be based on actual inspection and maintenance 

experience and shall be certified in accordance with G19 

Certification and Signature.

(2) Annual inspections may be conducted on a “circuit basis” whereby 

25% of catch basins and inlets within each circuit are inspected to 

identify maintenance needs. Include an inspection of the catch 

basin immediately upstream of any system outfall or discharge 

point, if applicable. Clean all catch basins within a given circuit for

which the inspection indicates cleaning is needed to comply with 

maintenance standards established under S5.C.9.a, above. 

(3) The Permittee may clean all pipes, ditches, catch basins, and inlets 

within a circuit once during the permit term. Circuits selected for 

this alternative must drain to a single point.

ii. The disposal of decant water shall be in accordance with the requirements 

in Appendix 6 – Street Waste Disposal.

iii. Compliance with the inspection requirements of S5.C.9.d.i. above, shall 

be determined by the presence of an established inspection program 

designed to inspect all catch basins and achieving at least 95% of required 

inspections.

e. Each Permittee shall implement practices, policies, and procedures to reduce 

stormwater impacts associated with runoff from all lands owned or maintained 

by the Permittee, and road maintenance activities under the functional control 

of the Permittee. Lands owned or maintained by the Permittee include, but are 

not limited to: parking lots, streets, roads, highways, buildings, parks, open 

space, road right-of-way, maintenance yards, and stormwater treatment and 

flow control BMPs/facilities.

The following activities shall be addressed:

i. Pipe cleaning

ii. Cleaning of culverts that convey stormwater in ditch systems

iii. Ditch maintenance

iv. Street cleaning
S5.C.9 S5.C.9

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v. Road repair and resurfacing, including pavement grinding

vi. Snow and ice control

vii. Utility installation

viii. Maintaining roadside areas, including vegetation management

ix. Dust control

x. Pavement striping maintenance

xi. Application of fertilizers, pesticides, and herbicides according to the 

instructions for their use, including reducing nutrients and pesticides 

using alternatives that minimize environmental impacts

xii. Sediment and erosion control

xiii. Landscape maintenance and vegetation disposal

xiv. Trash and pet waste management

xv. Building exterior cleaning and maintenance

f. Implement an ongoing training program for employees of the Permittee who 

have primary construction, operations or maintenance job functions may 

impact stormwater quality. The training program shall address the importance 

of protecting water quality, operation and maintenance standards, inspection 

procedures, selecting appropriate BMPs, ways to perform their job activities 

to prevent or minimize impacts to water quality, and procedures for reporting 

water quality concerns. Follow-up training shall be provided as needed to 

address changes in procedures, techniques, requirements, or staffing. 

Permittees shall document and maintain records of the training provided and 

the staff trained. 

g. Implement a Stormwater Pollution Prevention Plan (SWPPP) for all heavy 

equipment maintenance or storage yards, and material storage facilities owned 

or operated by the Permittee in areas subject to this permit that are not 

required to have coverage under the General NPDES Permit for Stormwater 

Discharges Associated with Industrial Activities or another NPDES permit 

that authorizes stormwater discharges associated with the activity. A schedule 

for implementation of structural BMPs shall be included in the SWPPP. 

Generic SWPPPs that can be applied at multiple sites may be used to comply 

with this requirement. The SWPPP shall include periodic visual observation 

of discharges from the facility to evaluate the effectiveness of BMPs. 
S5.C.10 S5.C.10

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h. Maintain records of inspections and maintenance or repair activities 

conducted by the Permittee.

10. Education and Outreach Program

The SWMP shall include an education and outreach program designed to reduce 

or eliminate behaviors and practices that cause or contribute to adverse 

stormwater impacts and encourage the public to participate in stewardship 

activities. The education program may be developed and implemented locally or 

regionally.

Minimum performance measures:

a. Each Permittee shall implement or participate in an education and outreach 

program that uses a variety of methods to target the audiences and topics 

listed below. The outreach program shall be designed to educate each target 

audience about the stormwater problem and provide specific actions they can 

follow to minimize the problem. 

i. To build general awareness, Permittees shall target the following 

audiences and subject areas: 

(1) General Public (including school age children), and businesses 

(including home-based and mobile business):

• General impacts of stormwater on surface waters.

• Impacts from impervious surfaces. 

• Impacts of illicit discharges and how to report them.

• LID principles and LID BMPs.

• Opportunities to become involved in stewardship activities.

(2) Engineers, contractors, developers, and land use planners:

• Technical standards for stormwater site and erosion control 

plans. 

• LID principles and LID BMPs.

• Stormwater treatment and flow control BMPs/facilities.

ii. To effect behavior change, Permittees shall target the following audiences 

and BMPs:

(1) General public (which may include school age children) and 

businesses (including home based and mobile businesses):

• Use and storage of automotive chemicals, hazardous cleaning 

supplies, carwash soaps, and other hazardous materials. 

• Equipment maintenance.

• Prevention of illicit discharges.
S6.A.1 S6.A.2

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Modified January 16, 2015

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(2) Residents, landscapers and property managers/owners:

• Yard care techniques protective of water quality. 

• Use and storage of pesticides and fertilizers and other 

household chemicals.

• Carpet cleaning and auto repair and maintenance.

• Vehicle, equipment, and home/building maintenance.

• Pet waste management and disposal.

• LID principles and LID BMPs. 

• Stormwater facility maintenance. 

• Dumpster and trash compactor maintenance.

b. Each permittee shall create stewardship opportunities and/or partner with 

existing organizations to encourage residents to participate in activities such 

as stream teams, storm drain marking, volunteer monitoring, riparian plantings 

and education activities.

c. Each Permittee shall measure the understanding and adoption of the targeted 

behaviors for at least one targeted audience in at least one subject area. No 

later than February 2, 2016, Permittees shall use the resulting measurements 

to direct education and outreach resources most effectively as well as to 

evaluate changes in adoption of the targeted behaviors. Permittees may meet 

this requirement individually or as a member of a regional group.

S6. STORMWATER MANAGEMENT PROGRAM FOR SECONDARY 

PERMITTEES

A. This section applies to all Secondary Permittees and all New Secondary Permittees 

whether coverage under this Permit is obtained individually, or as a Co-Permittee 

with a city, town, county, and/or another Secondary Permittee. 

New Secondary Permittees subject to this Permit shall fully meet the requirements of 

this section as modified in footnotes in S6.D below, or as established as a condition of 

coverage by Ecology. 

1. To the extent allowable under state, federal and local law, all components are 

mandatory for each Secondary Permittee covered under this permit, whether 

covered as an individual Permittee or as a Co-Permittee.

2. Each Secondary Permittee shall develop and implement a stormwater 

management program (SWMP). A SWMP is a set of actions and activities 

comprising the components listed in S6 and any additional actions necessary to 

meet the requirements of applicable TMDLs pursuant to S7 Compliance with 

TMDL Requirements, and S8 Monitoring and Assessment. The SWMP shall be 

designed to reduce the discharge of pollutants from MS4s to the maximum extent 

practicable (MEP) and protect water quality. 
S6.A.3 S6.A.6

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3. Unless an alternate implementation schedule is established by Ecology as a 

condition of permit coverage, the SWMP shall be developed and implemented in 

accordance with the schedules contained in this section and shall be fully 

developed and implemented no later than four and one-half years from initial 

permit coverage date. Secondary Permittees that are already implementing some 

or all of the required SWMP components shall continue implementation of those 

components.

4. Secondary Permittees may implement parts of their SWMP in accordance with 

the schedule for cities, towns and counties in S5, provided they have signed a 

memorandum of understanding or other agreement to jointly implement the 

activity or activities with one or more jurisdictions listed in S1.B, and submitted a 

copy of the agreement to Ecology. 

5. Each Secondary Permittees shall prepare written documentation of the SWMP, 

called the SWMP Plan. The SWMP Plan shall include a description of program 

activities for the upcoming calendar year. 

6. Conditions S6.A, S6.B, and S6.C are applicable to all Secondary Permittees 

covered under this permit. In addition:

a. S6.D is applicable to all Secondary Permittees except the Port of Seattle and 

the Port of Tacoma.

b. S6.E is applicable only to the Port of Seattle and the Port of Tacoma.
S6.D.1 S6.D.1

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B. Coordination

Secondary Permittees shall coordinate stormwater-related policies, programs and 

projects within a watershed and interconnected MS4s. Where relevant and 

appropriate, the SWMP shall coordinate among departments of the Secondary 

Permittee to ensure compliance with the terms of this permit.

C. Legal Authority 

To the extent allowable under state law and federal law, each Secondary Permittee 

shall be able to demonstrate that it can operate pursuant to legal authority which 

authorizes or enables the Secondary Permittee to control discharges to and from 

MS4s owned or operated by the Secondary Permittee.

This legal authority may be a combination of statutes, ordinances, permits, contracts, 

orders, interagency agreements, or similar instruments.

D. Stormwater Management Program for Secondary Permittees 

The SWMP for Secondary Permittees shall include the following components:

1. Public Education and Outreach

Each Secondary Permittee shall implement the following stormwater education 

strategies:

a. Storm drain inlets owned or operated by the Secondary Permittee that are 

located in maintenance yards, in parking lots, along sidewalks, and at 

pedestrian access points shall be clearly labeled with the message similar to 

“Dump no waste – Drains to water body.” 5

As identified during visual inspection and regular maintenance of storm drain 

inlets per the requirements of S6.D.3.d and S6.D.6.a.i below, or as otherwise 

reported to the Secondary Permittee, any inlet having a label that is no longer 

clearly visible and/or easily readable shall be re-labeled within 90 days. 

b. Each year, beginning no later than three years from the initial date of permit 

coverage, public ports, colleges, and universities shall distribute educational 

information to tenants and residents on the impact of stormwater discharges 

on receiving waters, and steps that can be taken to reduce pollutants in 

stormwater runoff. Distribution may be by hard copy or electronic means. 

Appropriate topics may include: 

 5 New Secondary Permittees shall label all inlets as described in S6.D.1.a no later than four years from the initial 

date of permit coverage.
S6.D.2 S6.D.3

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i. How stormwater runoff affects local waterbodies. 

ii. Proper use and application of pesticides and fertilizers. 

iii. Benefits of using well-adapted vegetation.

iv. Alternative equipment washing practices, including cars and trucks that 

minimize pollutants in stormwater. 

v. Benefits of proper vehicle maintenance and alternative transportation 

choices; proper handling and disposal of vehicle wastes, including the 

location of hazardous waste collection facilities in the area. 

vi. Hazards associated with illicit connections, and illicit discharges.

vii. Benefits of litter control and proper disposal of pet waste.

2. Public Involvement and Participation

Each year, no later than May 31, each Secondary Permittee shall:

a. Make the annual report available on the Permittee’s website. 

b. Make available on the Permittee’s website the latest updated version of the 

SWMP Plan. 

c. A Secondary Permittee that does not maintain a website may submit their 

updated SWMP Plan in electronic format to Ecology for posting on Ecology’s 

website. 

3. Illicit Discharge Detection and Elimination

Each Secondary Permittee shall:

a. From the initial date of permit coverage, comply with all relevant ordinances, 

rules, and regulations of the local jurisdiction(s) in which the Secondary 

Permittee is located that govern non-stormwater discharges.

b. Implement appropriate policies prohibiting illicit discharges6 and an 

enforcement plan to ensure compliance with illicit discharge policies.7 These 

policies shall address, at a minimum: illicit connections; non-stormwater 

 6 New Secondary Permittees shall develop and implement appropriate policies prohibiting illicit discharges, and 

identify possible enforcement mechanisms as described in S6.D.3.b no later than one year from initial date of permit 

coverage.

7 New Secondary Permittees shall develop and implement an enforcement plan as described in S6.D.3.b no later 

than 18 months from the initial date of permit coverage.
S6.D.3 S6.D.3

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discharges, including spills of hazardous materials; and improper disposal of 

pet waste and litter. 

i. Allowable discharges: The policies do not need to prohibit the following 

categories of non-stormwater discharges:

(1) Diverted stream flows 

(2) Rising ground waters

(3) Uncontaminated ground water infiltration (as defined at 40 CFR 

35.2005(b)(20))

(4) Uncontaminated pumped ground water

(5) Foundation drains

(6) Air conditioning condensation

(7) Irrigation water from agricultural sources that is commingled with 

urban stormwater

(8) Springs

(9) Uncontaminated water from crawl space pumps

(10) Footing drains

(11) Flows from riparian habitats and wetlands

(12) Discharges from emergency fire fighting activities in accordance 

with S2 Authorized Discharges

(13) Non-stormwater discharges authorized by another NPDES or State 

Waste Discharge permit 

ii. Conditionally allowable discharges: The policies may allow the following 

categories of non-stormwater discharges only if the stated conditions are 

met and such discharges are allowed by local codes: 

(1) Discharges from potable water sources, including but not limited to 

water line flushing, hyperchlorinated water line flushing, fire 

hydrant system flushing, and pipeline hydrostatic test water. 

Planned discharges shall be de-chlorinated to a total residual 

chlorine concentration of 0.1 ppm or less, pH-adjusted if 

necessary, and volumetrically and velocity controlled to prevent 

resuspension of sediments in the MS4.

(2) Discharges from lawn watering and other irrigation runoff. These 

discharges shall be minimized through, at a minimum, public 

education activities and water conservation efforts conducted by 

the Secondary Permittee and/or the local jurisdiction. 
S6.D.3 S6.D.3

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(3) Dechlorinated swimming pool, spa, and hot tub discharges. The 

discharges shall be dechlorinated to a total residual chlorine 

concentration of 0.1 ppm or less, pH-adjusted and reoxygenated if 

necessary, and volumetrically and velocity controlled to prevent 

resuspension of sediments in the MS4. Discharges shall be 

thermally controlled to prevent an increase in temperature of the 

receiving water. Swimming pool cleaning wastewater and filter 

backwash shall not be discharged to the MS4. 

(4) Street and sidewalk wash water, water used to control dust, and 

routine external building washdown that does not use detergents. 

The Secondary Permittee shall reduce these discharges through, at 

a minimum, public education activities and/or water conservation 

efforts conducted by the Secondary Permittee and/or the local 

jurisdiction. To avoid washing pollutants into the MS4, the 

Secondary Permittee shall minimize the amount of street wash and 

dust control water used. 

(5) Other non-stormwater discharges shall be in compliance with the 

requirements of a pollution prevention plan reviewed by the 

Permittee which addresses control of such discharges.

iii. The Secondary Permittee shall address any category of discharges in i. or 

ii. above if the discharge is identified as a significant source of pollutants 

to waters of the State.

c. Maintain a storm sewer system map showing the locations of all known storm 

drain outfalls and discharge points, labeling the receiving waters (other than 

groundwater), and delineating the areas contributing runoff to each outfall and 

discharge point. Make the map (or completed portions of the map) available 

on request to Ecology and to the extent appropriate to other Permittees. The 

preferred format for mapping is an electronic format with fully described 

mapping standards. An example description is provided on Ecology’s 

website.8

d. Conduct field inspections and visually inspect for illicit discharges at all 

known MS4outfalls and discharge points. Visually inspect at least one third 

(on average) of all known outfalls and discharge points each year beginning 

no later than two years from the initial date of permit coverage. Implement 

procedures to identify and remove illicit discharges. Keep records of 

inspections and follow-up activities.

 8 New Secondary Permittees shall meet the requirements of S6.D.3.c no later than four and one-half years from the 

initial date of permit coverage.
S6.D.4 S6.D.5

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e. Implement a spill response plan that includes coordination with a qualified 

spill responder.9

f. No later than two years from initial date of permit coverage, provide staff 

training or coordinate with existing training efforts to educate staff on proper 

BMPs for preventing illicit discharges, including spills. Train all Permittee 

staff who, as part of their normal job responsibilities, have a role in preventing 

such illicit discharges. 

4. Construction Site Stormwater Runoff Control

From the initial date of permit coverage, each Secondary Permittee shall:

a. Comply with all relevant ordinances, rules, and regulations of the local 

jurisdiction(s) in which the Secondary Permittee is located that govern 

construction phase stormwater pollution prevention measures.

b. Ensure that all construction projects under the functional control of the 

Secondary Permittee which require a construction stormwater permit obtain 

coverage under the NPDES General Permit for Stormwater Discharges 

Associated with Construction Activities, or an individual NPDES permit prior 

to discharging construction related stormwater. 

c. Coordinate with the local jurisdiction regarding projects owned or operated by 

other entities which discharge into the Secondary Permittee’s MS4, to assist 

the local jurisdiction with achieving compliance with all relevant ordinances, 

rules, and regulations of the local jurisdiction(s).

d. Provide training or coordinate with existing training efforts to educate relevant 

staff in erosion and sediment control BMPs and requirements, or hire trained 

contractors to perform the work. 

e. Coordinate as requested with Ecology or the local jurisdiction to provide 

access for inspection of construction sites or other land disturbances, which 

are under the functional control of the Secondary Permittee during land 

disturbing activities and/or the construction period.

5. Post-Construction Stormwater Management for New Development and 

Redevelopment

From the initial date of permit coverage, each Secondary Permittee shall:

 9 New Secondary Permittees shall develop and implement a spill response plan as described in S6.D.3.e no later than 

four and one-half years from the initial date of permit coverage.
S6.D.6 S6.D.6

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Modified January 16, 2015

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a. Comply with all relevant ordinances, rules, and regulations of the local 

jurisdiction(s) in which the Secondary Permittee is located that govern postconstruction stormwater pollution prevention measures.

b. Coordinate with the local jurisdiction regarding projects owned or operated by 

other entities which discharge into the Secondary Permittee’s MS4, to assist 

the local jurisdiction with achieving compliance with all relevant ordinances, 

rules, and regulations of the local jurisdiction(s).

6. Pollution Prevention and Good Housekeeping for Municipal Operations

Each Secondary Permittee shall: 

a. Implement a municipal operation and maintenance (O&M) plan to minimize 

stormwater pollution from activities conducted by the Secondary Permittee. 

The O&M Plan shall include appropriate pollution prevention and good 

housekeeping procedures for all of the following operations, activities, and/or 

types of facilities that are present within the Secondary Permittee’s boundaries 

and under the functional control of the Secondary Permittee.10

i. Stormwater collection and conveyance systems, including catch basins, 

stormwater pipes, open channels, culverts, and stormwater treatment and 

flow control BMPs/facilities. The O&M Plan shall address, at a 

minimum: scheduled inspections and maintenance activities, including 

cleaning and proper disposal of waste removed from the system. 

Secondary Permittees shall properly maintain stormwater collection and 

conveyance systems owned or operated by the Secondary Permittee and 

regularly inspect and maintain all stormwater facilities to ensure facility 

function. 

Secondary Permittees shall establish maintenance standards that are as 

protective or more protective of facility function than those specified in 

Chapter 4 Volume V of the Stormwater Management Manual for Western 

Washington. 

Secondary Permittees shall review their maintenance standards to ensure 

they are consistent with the requirements of this section.

Secondary Permittees shall conduct spot checks of potentially damaged 

permanent stormwater treatment and flow control BMPs/facilities 

following major storm events (24 hour storm event with a 10-year or 

greater recurrence interval).

 10 New Secondary Permittees shall develop and implement the operation and maintenance plan described in 

S6.D.6.a no later than three and a half years from the initial date of permit coverage.
S6.D.6 S6.D.6

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ii. Roads, highways, and parking lots. The O&M Plan shall address, but is 

not limited to: deicing, anti-icing, and snow removal practices; snow 

disposal areas; material (e.g., salt, sand, or other chemical) storage areas; 

all-season BMPs to reduce road and parking lot debris and other 

pollutants from entering the MS4. 

iii. Vehicle fleets. The O&M Plan shall address, but is not limited to: storage, 

washing, and maintenance of Secondary Permittee vehicle fleets; and 

fueling facilities. Secondary Permittees shall conduct all vehicle and 

equipment washing and maintenance in a self-contained covered building 

or in designated wash and/or maintenance areas. 

iv. External building maintenance. The O&M Plan shall address, building 

exterior cleaning and maintenance including cleaning, washing, painting; 

maintenance and management of dumpsters; other maintenance activities.

v. Parks and open space. The O&M Plan shall address, but is not limited to: 

proper application of fertilizer, pesticides, and herbicides; sediment and 

erosion control; BMPs for landscape maintenance and vegetation 

disposal; and trash and pet waste management. 

vi. Material storage facilities, and heavy equipment maintenance or storage 

yards. Secondary Permittees shall develop and implement a Stormwater 

Pollution Prevention Plan to protect water quality at each of these 

facilities owned or operated by the Secondary Permittee and not covered 

under the General NPDES Permit for Stormwater Discharges Associated 

with Industrial Activities or under another NPDES permit that authorizes 

stormwater discharges associated with the activity. 

vii. Other facilities that would reasonably be expected to discharge 

contaminated runoff. The O&M Plan shall address proper stormwater 

pollution prevention practices for each facility.

b. From the initial date of permit coverage, Secondary Permittees shall also have 

permit coverage for all facilities operated by the Secondary Permittee that are 

required to be covered under the General NPDES Permit for Stormwater 

Discharges Associated with Industrial Activities or another NPDES permit 

that authorizes discharges associated with the activity. 

c. The O&M Plan shall include sufficient documentation and records as 

necessary to demonstrate compliance with the O&M Plan requirements in 

S6.D.6.a.i. through vii. above.

d. No later than three years from the initial date of permit coverage, Secondary 

Permittees shall implement a program designed to train all employees whose 
S6.E.1 S6.E.3

Phase I Municipal Stormwater Permit - August 1, 2013

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primary construction, operations, or maintenance job functions may impact 

stormwater quality. The training shall address:

i. The importance of protecting water quality. 

ii. The requirements of this Permit. 

iii. Operation and maintenance requirements. 

iv. Inspection procedures. 

v. Ways to perform their job activities to prevent or minimize impacts to 

water quality. 

vi. Procedures for reporting water quality concerns, including potential illicit 

discharges (including spills). 

E. Stormwater Management Program for the Port of Seattle and Port of Tacoma

Permittees that are already implementing some or all of the Stormwater Management 

Program (SWMP) components in this section shall continue implementation of those 

components of their SWMP. 

The SWMP for the Port of Seattle and the Port of Tacoma of shall include the 

following components:

1. Education Program 

The SWMP shall include an education program aimed at tenants and Permittee 

employees. The goal of the education program is to reduce or eliminate behaviors 

and practices that cause or contribute to adverse stormwater impacts.

Minimum performance measure:

a. The Permittee shall make educational materials available to tenants and 

Permittee employees whose job duties could impact stormwater.

2. Public Involvement and Participation

Each Permittee shall make the latest updated version of the SWMP Plan available 

to the public. The most recent SWMP Plan and Annual Report shall be posted on 

the Permittee’s website. 

3. Illicit Discharge Detection and Elimination

The SWMP shall include a program to identify, detect, remove and prevent illicit 

connections and illicit discharges, including spills, into the MS4s owned or 

operated by the Permittee. 
S6.E.3 S6.E.3

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Minimum performance measures: 

a. Comply with all relevant ordinances, rules, and regulations of the local 

jurisdiction(s) in which the Permittee’s MS4 is located that govern nonstormwater discharges.

b. Implement appropriate policies prohibiting illicit discharges and an 

enforcement plan to ensure compliance with illicit discharge policies. These 

policies shall address, at a minimum: illicit connections; non-stormwater 

discharges, including spills of hazardous materials; and improper disposal of 

pet waste and litter. 

i. Allowable Discharges: The policies do not need to prohibit the following 

categories of non-stormwater discharges:

(1) Diverted stream flows 

(2) Rising ground waters

(3) Uncontaminated ground water infiltration (as defined at 40 CFR 

35.2005(b)(20))

(4) Uncontaminated pumped ground water

(5) Foundation drains

(6) Air conditioning condensation

(7) Irrigation water from agricultural sources that is commingled with 

urban stormwater

(8) Springs

(9) Uncontaminated water from crawl space pumps

(10) Footing drains

(11) Flows from riparian habitats and wetlands 

(12) Discharges from emergency fire fighting activities in accordance 

with S2 Authorized Discharges

(13) Non-stormwater discharges authorized by another NPDES permit 

ii. Conditionally allowable discharges: The policies may allow the following 

categories of non-stormwater discharges only if the stated conditions are 

met and such discharges are allowed by local codes: 

(1) Discharges from potable water sources, including but not limited 

to, water line flushing, hyperchlorinated water line flushing, fire 

hydrant system flushing, and pipeline hydrostatic test water. 

Planned discharges shall be de-chlorinated to a total residual 

chlorine concentration of 0.1 ppm or less, pH-adjusted if 
S6.E.3 S6.E.3

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necessary, and volumetrically and velocity controlled to prevent 

resuspension of sediments in the MS4.

(2) Discharges from lawn watering and other irrigation runoff. These 

discharges shall be minimized through, at a minimum, public 

education activities and water conservation efforts conducted by 

the Permittee and/or the local jurisdiction. 

(3) Dechlorinated swimming pool, spa, and hot tub discharges. The 

discharges shall be dechlorinated to a total residual chlorine

concentration of 0.1 ppm or less, pH-adjusted and reoxygenated if 

necessary, and volumetrically and velocity controlled to prevent 

resuspension of sediments in the MS4. Discharges shall be 

thermally controlled to prevent an increase in temperature of the 

receiving water. Swimming pool cleaning wastewater and filter 

backwash shall not be discharged to the MS4. 

(4) Street and sidewalk wash water, water used to control dust, and 

routine external building wash down that does not use detergents. 

The Ports of Seattle and Tacoma shall reduce these discharges 

through, at a minimum, public education activities and/or water 

conservation efforts conducted by the Port and/or the local 

jurisdiction. To avoid washing pollutants into the MS4, the amount 

of street wash and dust control water used shall be minimized. 

(5) Other non-stormwater discharges shall be in compliance with the 

requirements of a pollution prevention plan reviewed by the 

Permittee which addresses control of such discharges.

iii. The Permittee shall address any category of discharges in i. or ii. above if 

the discharges are identified as significant source of pollutants to waters 

of the State.

c. The SWMP shall include an ongoing program for gathering, maintaining, and 

using adequate information to conduct planning, priority setting, and program 

evaluation activities for Permittee-owned properties. Permittees shall gather 

and maintain mapping data for the features listed below on an ongoing basis:

i. Known MS4 outfalls and discharge points, receiving waters (other than 

groundwater), and land uses for property owned by the Permittee, and all 

other properties served by MS4s known to and owned or operated by the 

Permittee. 

ii. Tributary conveyances (including size, material, and type attributes where 

known), and the associated drainage areas of MS4 outfalls and discharge 

points with a 24 inch nominal diameter or larger, or an equivalent crosssectional area for non-pipe systems. No later than December 31, 2017, 

each Permittee shall complete this requirement for all MS4 outfalls and 
S6.E.4 S6.E.4

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discharge points with a 12 inch nominal diameter or larger, or an 

equivalent cross-sectional area for non-pipe systems.

iii. Known connections greater than or equal to 8 inches in nominal diameter 

to tributary conveyances mapped in accordance with S6.E.3.c.ii. The 

mapping shall be completed no later than December 31, 2017.

iv. To the extent consistent with national security laws and directives, each 

Permittee shall make available to Ecology upon request, available maps 

depicting the information required in S6.E.3.c.i. through iii., above. The 

required format for mapping is electronic with fully described mapping 

standards. An example description is available on Ecology’s website.

v. Implement a program to document operation and maintenance records for 

stormwater treatment and flow control BMPs/facilities and catch basins. 

vi. Upon request, and to the extent consistent with national security laws and 

directives, mapping information and operation and maintenance records 

shall be provided to the City or County in which the Permittee is located.

d. Conduct field screening of at least 20% of the MS4 each year for the purpose 

of detecting illicit discharges and illicit connections. Field screening 

methodology shall be appropriate to the characteristics of the MS4 and water 

quality concerns. Implement procedures to identify and remove any illicit 

discharges and illicit connections. Keep records of inspections and follow-up

activities.

e. Implement a spill response plan that includes coordination with a qualified 

spill responder.

f. Provide ongoing staff training or coordinate with existing training efforts to 

educate staff on proper BMPs for preventing illicit discharges, including 

spills, and for identifying, reporting, and responding as appropriate. Train all 

Permittee staff who, as part of their normal job responsibilities, have a role in 

preventing such discharges. Keep records of training provided and staff 

trained. 

4. Construction Site Stormwater Runoff Control 

The SWMP shall include a program to reduce pollutants in stormwater runoff 

from construction activities under the functional control of the Permittee. 

Minimum performance measures: 

a. Comply with all relevant ordinances, rules, and regulations of the local 

jurisdiction(s) in which the Permittee is located that govern construction phase 
S6.E.5 S6.E.5

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Modified January 16, 2015

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stormwater pollution prevention measures. To the extent allowed by local 

ordinances, rules, and regulations, comply with the applicable minimum 

technical requirements for new development and redevelopment contained in 

Appendix 1. 

b. Ensure all construction projects under the functional control of the Permittee 

which require a construction stormwater permit obtain coverage under the 

NPDES General Permit for Stormwater Discharges Associated with 

Construction Activities or an individual NPDES permit prior to discharging 

construction related stormwater. 

c. Coordinate with the local jurisdiction(s) regarding projects owned or operated 

by other entities which discharge into the Permittee’s MS4, to assist the local 

jurisdiction(s) with achieving compliance with all relevant ordinances, rules, 

and regulations of the local jurisdiction(s).

d. Provide staff training or coordinate with existing training efforts to educate 

Permittee staff responsible for implementing construction stormwater erosion 

and sediment control BMPs and requirements, or hire trained contractors to 

perform the work. 

e. Coordinate as requested with Ecology or the local jurisdiction to provide 

access for inspection of construction sites or other land disturbances that are 

under the functional control of the Permittee during active land disturbing 

activities and/or the construction period.

5. Post-Construction Stormwater Management for New Development and 

Redevelopment 

The SWMP shall include a program to address post-construction stormwater 

runoff from new development and redevelopment projects. The program shall 

establish controls to prevent or minimize water quality impacts. 

Minimum performance measures: 

a. Comply with all relevant ordinances, rules, and regulations of the local 

jurisdiction(s) in which the Permittee is located that govern post-construction 

stormwater pollution prevention measures, including proper operation and 

maintenance of the MS4. To the extent allowed by local ordinances, rules, and 

regulations, comply with the applicable the minimum technical requirements 

for new development and redevelopment contained in Appendix 1.

b. Coordinate with the local jurisdiction regarding projects owned and operated 

by other entities which discharge into the Permittee’s MS4, to assist the local 

jurisdiction in achieving compliance with all relevant ordinances, rules, and 

regulations of the local jurisdiction(s). 
S6.E.6 S6.E.6

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Modified January 16, 2015

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6. Operation and Maintenance Program

The SWMP shall include an operation and maintenance program for all 

stormwater treatment and flow control BMPs/facilities, and catch basins to ensure 

that BMPs continue to function properly.

Minimum performance measures:

a. Each Permittee shall implement an operation and maintenance (O&M) manual 

for all stormwater treatment and flow control BMPs/facilities and catch basins 

that are under the functional control of the Permittee and which discharge 

stormwater to its MS4, or to an interconnected MS4. 

i. Retain a copy of the O&M manual in the appropriate Permittee 

department and routinely update following discovery or construction of 

new stormwater facilities. 

ii. The operation and maintenance manual shall establish facility-specific 

maintenance standards that are as protective, or more protective than 

those specified in Chapter 4 of Volume V of the Stormwater Management 

Manual for Western Washington. For existing stormwater facilities which 

do not have maintenance standards, the Permittee shall develop a 

maintenance standard. No later than July 1, 2016, each Permittee shall 

update maintenance standards, as necessary, to meet the requirements of 

this section. 

iii. The purpose of the maintenance standard is to determine if maintenance 

is required. The maintenance standard is not a measure of the facility’s 

required condition at all times between inspections. Exceeding the 

maintenance standards between inspections and/or maintenance is not a 

permit violation. Maintenance actions shall be performed within the time 

frames specified in S6.E.6.b.ii. 

b. The Permittee will manage maintenance activities to inspect all stormwater 

facilities listed in the O&M manual annually, and take appropriate 

maintenance action in accordance with the O&M manual. 

i. The Permittee may change the inspection frequency to less than annually, 

provided the maintenance standards are still met. Reducing the annual 

inspection frequency shall be based on maintenance records of double the 

length of time of the proposed inspection frequency. In the absence of 

maintenance records, the Permittee may substitute written statements to 

document a specific less frequent inspection schedule. Written statements 

shall be based on actual inspection and maintenance experience and shall 

be certified in accordance with G19 Certification and Signature.
S6.E.7 S6.E.7

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ii. Unless there are circumstances beyond the Permittees control, when an 

inspection identifies an exceedance of the maintenance standard, 

maintenance shall be performed: 

(1) Within 1 year for wet pool facilities and retention/detention ponds. 

(2) Within 1 year for typical maintenance of facilities, except catch 

basins. 

(3) Within 6 months for catch basins.

(4) Within 2 years for maintenance that requires capital construction 

of less than $25,000. 

Circumstances beyond the Permittee’s control include denial or delay of 

access by property owners, denial or delay of necessary permit approvals, 

and unexpected reallocations of maintenance staff to perform emergency 

work. For each exceedance of the required timeframe, the Permittee shall 

document the circumstances and how they were beyond their control.

c. The Permittee shall provide appropriate training for Permittee maintenance 

staff.

d. The Permittee will maintain records of inspections and maintenance activities.

7. Source Control in existing Developed Areas

The SWMP shall include the development and implementation of one or more 

Stormwater Pollution Prevention Plans (SWPPPs). A SWPPP is a documented 

plan to identify and implement measures to prevent and control the contamination 

of discharges of stormwater to surface or ground water. SWPPP(s) shall be 

prepared and implemented for all Permittee-owned lands, except environmental 

mitigation sites owned by the Permittee, that are not covered by a NPDES permit 

issued by Ecology that authorizes stormwater discharges. 

Minimum performance measures:

a. SWPPP(s) shall be updated as necessary to reflect changes at the facility. 

b. The SWPPP(s) shall include a facility assessment including a site plan, 

identification of pollutant sources, and description of the drainage system. 

c. The SWPPP(s) shall include a description of the source control BMPs used or 

proposed for use by the Permittee. Source control BMPs shall be selected 

from the Stormwater Management Manual for Western Washington (or an 

equivalent Manual approved by Ecology). Implementation of non-structural 

BMPs shall begin immediately after the pollution prevention plan is 
S6.E.8 S6.E.8

Phase I Municipal Stormwater Permit - August 1, 2013

Modified January 16, 2015

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developed. Where necessary, a schedule for implementation of structural 

BMPs shall be included in the SWPPP(s). 

d. The Permittee shall maintain a list of sites covered by the SWPPP(s) required 

under this permit. At least 20% of the listed sites shall be inspected annually.

e. The SWPPP(s) shall include policies and procedures to reduce pollutants 

associated with the application of pesticides, herbicides and fertilizer.

f. The SWPPP(s) shall include measures to prevent, identify and respond to 

illicit discharges, including illicit connections, spills and improper disposal. 

When the Permittee submits a notification pursuant to G3, the Permittee shall 

also notify the City or County it is located in.

g. The SWPPP(s) shall include a component related to inspection and 

maintenance of stormwater facilities and catch basins that is consistent with 

the Permittee’s O&M Program, as specified in S6.E.6 above.

8. Monitoring Program. Monitoring requirements for the Port of Seattle and Port of 

Tacoma are included in Special Condition S8.

S7. COMPLIANCE WITH TOTAL MAXIMUM DAILY LOAD REQUIREMENTS

The following requirements apply if an applicable Total Maximum Daily Load (TMDL) is 

approved for stormwater discharges from MS4s owned or operated by the Permittee. 

Applicable TMDLs are TMDLs which have been approved by EPA on or before the 

issuance date of this Permit, or prior to the date that Ecology issues coverage under this 

permit, whichever is later. 

A. For applicable TMDLs listed in Appendix 2, affected Permittees shall comply with 

the specific requirements identified in Appendix 2. Each Permittee shall keep records 

of all actions required by this Permit that are relevant to applicable TMDLs within 

their jurisdiction. The status of the TMDL implementation shall be included as part of 

the annual report submitted to Ecology. Each annual report shall include a summary 

of relevant SWMP and Appendix 2 activities conducted in the TMDL area to address 

the applicable TMDL parameter(s).

B. For applicable TMDLs not listed in Appendix 2, compliance with this permit shall 

constitute compliance with those TMDLs. 

C. For TMDLs that are approved by EPA after this permit is issued, Ecology may 

establish TMDL-related permit requirements through future permit modification if 

Ecology determines implementation of actions, monitoring or reporting necessary to 

demonstrate reasonable further progress toward achieving TMDL waste load 

allocations, and other targets, are not occurring and shall be implemented during the 

term of this permit or when this permit is reissued. Permittees are encouraged to 
S8.B.1 S8.B.1

Phase I Municipal Stormwater Permit - August 1, 2013

Modified January 16, 2015

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participate in development of TMDLs within their jurisdiction and to begin 

implementation. 

S8. MONITORING AND ASSESSMENT

A. All Permittees including Secondary Permittees shall provide, in each annual report, a 

description of any stormwater monitoring or stormwater-related studies conducted by 

the Permittee during the reporting period. If other stormwater monitoring or 

stormwater-related studies were conducted on behalf of the Permittee during the 

reporting period, or if stormwater-related investigations conducted by other entities 

were reported to the Permittee during the reporting period, a brief description of the 

type of information gathered or received shall be included in the annual report.

Permittees are not required to provide descriptions of any monitoring, studies, or 

analyses conducted as part of the Regional Stormwater Monitoring Program (RSMP) 

in annual reports. If a Permittee conducts independent monitoring in accordance with 

requirements in S8.B or S8.C below, annual reporting of such monitoring must follow 

the requirements specified in those sections. 

B. Status and trends monitoring. 

1. No later than October 15, 2013, King, Pierce, and Snohomish Counties, the Cities 

of Seattle and Tacoma, and the Ports of Seattle and Tacoma shall notify Ecology 

in writing which of the following two options for status and trends monitoring the 

Permittee chooses to carry out during this permit cycle. Either option will fully 

satisfy the Permittee’s obligations under this section (S8.B.1). Each Permittee 

shall select a single option for the duration of this permit term. 

a. Status and Trends Monitoring Option #1: Each Permittee that chooses this 

option shall pay into a collective fund to implement RSMP small streams and 

marine nearshore status and trends monitoring in Puget Sound. The first 

payment into the collective fund is due to Ecology October 15, 2013, and 

subsequent payments into the collective fund are due to Ecology annually 

beginning August 15, 2014. The payment amounts are:

Permittee First 

payment

Second and 

subsequent 

payments 

King County $ 15,000 $ 74,540

Pierce County $ 15,000 $ 92,800 

Port of Seattle $ 5,000 $ 4,151 

Port of Tacoma $ 5,000 $ 4,151 

City of Seattle $ 15,000 $149,436 

Snohomish County $ 15,000 $ 73,452 

City of Tacoma $ 15,000 $ 49,861 
S8.B.2 S8.B.2

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Or

b. Status and Trends Monitoring Option #2: Each Permittee that chooses this 

option shall conduct status and trends monitoring as follows:

i. Beginning no later than October 31, 2014 city and county Permittees shall 

conduct wadeable stream water quality, benthos, habitat, and sediment 

chemistry monitoring according to the Ecology-approved Quality 

Assurance Project Plan (QAPP) for RSMP Small Streams Status and 

Trends Monitoring at the first twelve qualified locations (as listed 

sequentially among the potential monitoring locations defined in the 

RSMP QAPP) that are located within the jurisdiction’s boundaries. 

Counties shall monitor the first four locations inside UGA boundaries and 

the first eight locations outside UGA boundaries.

ii. Beginning no later than October 1, 2015, city and county Permittees and 

the Ports of Seattle and Tacoma shall conduct sediment chemistry, 

bacteria, and mussel monitoring according to the Ecology-approved 

QAPPs for RSMP Marine Nearshore Status and Trends Monitoring at the 

first eight qualified locations each, for sediment and for mussels and 

bacteria (as listed sequentially among the potential monitoring locations 

defined in the RSMP QAPPs), that are located adjacent to the Permittee’s 

Puget Sound shoreline boundary.

iii. Data and analyses shall be reported annually in accordance with the 

Ecology-approved QAPPs.

2. Clark County shall:

a. Continue stormwater discharge monitoring at two of the three locations 

selected pursuant to S8.D in the Phase I Municipal Stormwater Permit 

February 16, 2007 – February 15, 2012 for the duration of this permit term. 

This monitoring and reporting of findings shall be conducted in accordance 

with the previously-approved QAPP until September 30, 2014. 

b. No later than February 2, 2014 submit a revised QAPP to Ecology. The 

revised QAPP shall follow the specifications and deadlines in Appendix 9. If 

Ecology does not request changes within 90 days, the QAPP is considered 

approved. The final QAPP shall be submitted to Ecology as soon as possible 

following finalization, and before September 30, 2014.

c. If the County changes a discharge monitoring location, the County shall 

document in the revised QAPP why the pre-existing stormwater monitoring 

location is not a good location for additional monitoring and why the newly 

selected location is of interest for long term stormwater discharge monitoring. 
S8.C.1 S8.C.2

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C. Stormwater management program effectiveness studies. No later than December 1, 

2013, Clark, King, Pierce, and Snohomish Counties, the Cities of Seattle and Tacoma, 

and the Ports of Seattle and Tacoma shall notify Ecology in writing which of the 

following three options for effectiveness studies the Permittee chooses to carry out 

during this permit cycle. Any one of the three options will fully satisfy the 

Permittee’s obligations under this section (S8.C). Each Permittee shall select a single 

option for the duration of this permit term. 

1. Effectiveness Studies Option #1: Each Permittee that chooses this option shall pay 

into a collective fund to implement RSMP effectiveness studies. The payments 

into the collective fund are due to Ecology annually beginning August 15, 2014. 

The payment amounts are:

Permittee

Annual 

payment 

amount

Clark County $ 86,617 

King County $124,196 

Pierce County $154,619 

Port of Seattle $ 6,916 

Port of Tacoma $ 6,916 

City of Seattle $248,986 

Snohomish County $122,383 

City of Tacoma $ 83,077 

Or

2. Effectiveness Studies Option #2: Each Permittee that chooses this option shall 

conduct stormwater discharge monitoring in accordance with Appendix 9 and the 

following:

a. Each city and county Permittee, except Clark County, shall conduct 

stormwater discharge monitoring at five locations. Permittees are encouraged 

to continue stormwater monitoring at locations monitored under S8.D of the 

Phase I Municipal Stormwater Permit February 16, 2007 – February 15, 2012. 

Any Permittee who would like to change a discharge monitoring location or 

add a new location shall document in the revised QAPP (see S8.C.2.c, below) 

why the pre-existing stormwater monitoring location is not a good location for 

additional monitoring and why the newly selected location is of interest for 

long term stormwater discharge monitoring and associated stormwater 

management program effectiveness evaluations.
S8.C.2 S8.C.2

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Clark County shall either: 

i. Select and monitor five discharge monitoring locations in addition to the 

two discharge monitoring locations monitored pursuant to S8.B.2 above.

Or 

ii. Select and monitor two discharge monitoring locations in addition to the 

two discharge monitoring locations monitored pursuant to S8.B.2 and 

conduct receiving-water monitoring in wadeable streams or lakes at 

locations downstream of each of all four stormwater discharge monitoring 

locations. 

(1) Receiving-water chemistry samples will be collected during and 

following the storm events for which the discharge monitoring is 

conducted, and for the same parameters. 

(2) Sediment samples shall be collected during the month of May or 

June. Streambed sediment samples at these receiving-water 

monitoring locations shall be collected and analyzed pursuant to 

the RSMP Small Streams Status and Trends Monitoring QAPP and 

for any additional sediment parameters listed in Appendix 9; lake 

bed sediments shall be collected from the surficial sediment layer 

and analyzed for the same parameters. 

(3) Explain in the revised QAPP (see S8.C.2.c below) why the 

receiving-water monitoring locations were selected and describe in 

detail the design of the receiving-water monitoring. 

b. Each port Permittee shall conduct stormwater discharge monitoring at two 

locations representing different pollution-generating activities or land uses. 

Permittees are encouraged to continue stormwater monitoring at locations 

monitored under S8.D of the Phase I Municipal Stormwater Permit February 16, 

2007 – February 15, 2012. Any Permittee who would like to change a 

discharge monitoring location shall describe why the pre-existing stormwater 

monitoring location is not a good location for additional monitoring. The 

Permittee shall document why the newly selected location(s) are of interest for 

long term stormwater discharge monitoring and associated stormwater 

management program effectiveness evaluations.

c. No later than February 2, 2014 each Permittee shall submit to Ecology a draft 

updated stormwater discharge monitoring QAPP for review and approval. If 

Ecology does not request changes within 90 days, the draft QAPP is 

considered approved. Final QAPPs shall be submitted to Ecology as soon as 

possible following finalization.
S8.C.3 S8.C.3

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Modified January 16, 2015

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d. Flow monitoring at new discharge monitoring locations shall begin no later 

than October 1, 2014. Stormwater discharge monitoring shall be fully 

implemented no later than October 1, 2014 at existing discharge monitoring 

locations and October 1, 2015 at new discharge monitoring locations. All 

monitoring shall be conducted in accordance with an Ecology-approved 

QAPP.

Or

3. Effectiveness Studies Option #3: Each Permittee that chooses this option shall 

both pay into a collective fund to implement RSMP effectiveness studies and 

independently conduct an effectiveness study that is not expected to be 

undertaken as part of the RSMP.

a. Payments into the collective fund are due to Ecology annually beginning 

August 15, 2014. The payment amounts are:

Permittee

Annual 

payment 

amount

Clark County $ 43,308 

King County $ 62,098 

Pierce County $ 77,310 

Port of Seattle $ 3,458 

Port of Tacoma $ 3,458 

City of Seattle $124,493 

Snohomish County $ 61,192 

City of Tacoma $ 41,538 

And

b. Conduct the independent effectiveness study in accordance with the 

requirements below: 

i. No later than February 2, 2014 submit to Ecology, for review and 

approval, a detailed proposal describing: the purpose, objectives, design, 

and methods of the independent effectiveness study; anticipated 

outcomes; expected modifications to the Permittee’s stormwater 

management program; and relevance to other Permittees. 

ii. Submit a draft QAPP to Ecology within 120 days of Ecology’s approval 

of the detailed proposal. The QAPP shall be prepared in accordance with 

Guidelines for Preparing Quality Assurance Project Plans for 

Environmental Studies, July 2004 (Ecology Publication No. 04-03-030). 
S8.C.3 S8.C.3

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The QAPP shall include reporting details including timely uploading of 

all relevant data to Ecology’s EIM database and/or the International 

Stormwater BMP Database as appropriate. If Ecology does not request 

changes within 90 days of submittal, the QAPP is considered approved.

iii. Begin full implementation of the study no later than six months following 

Ecology’s approval of the QAPP. 

iv. Describe interim results and status of the study implementation in annual 

reports throughout the duration of the study.

v. Report final results, including recommended future actions, to Ecology 

and on the Permittee’s webpage no later than six months after completion 

of the study.

D. Source identification and diagnostic monitoring. Clark, King, Pierce, and Snohomish 

Counties, the Cities of Seattle and Tacoma, and the Ports of Seattle and Tacoma shall 

pay into a collective fund to implement the RSMP Source Identification Information 

Repository (SIDIR). The payments into the collective fund are due to Ecology 

annually beginning August 15, 2014. The payment amounts are:

Permittee

Annual 

payment

amount

Clark County $ 8,033 

King County $11,518 

Pierce County $14,339 

Port of Seattle $ 641 

Port of Tacoma $ 641 

City of Seattle $23,091 

Snohomish County $11,350 

City of Tacoma $ 7,704 

S9. REPORTING REQUIREMENTS

A. No later than March 31 of each year beginning in 2015, each Permittee shall submit 

an annual report. The reporting period for the first annual report will be from January 

1, 2014 through December 31, 2014. The reporting period for all subsequent annual 

reports shall be the previous calendar year unless otherwise specified. 

Permittees must submit annual reports electronically using Ecology’s Water Quality 

Permitting Portal (WQWebPortal) available on Ecology’s website at:

http://www.ecy.wa.gov/programs/wq/permits/paris/portal.html unless otherwise 

directed by Ecology. 
S9.C.1 S9.D.6

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Permittees unable to submit electronically through Ecology’s WQWebPortal must 

contact Ecology to request a waiver and obtain instructions on how to submit an 

annual report in an alternative format.

B. Each Permittee is required to keep all records related to this permit and the SWMP 

for at least five years.

C. Each Permittee shall make all records related to this permit and the Permittee’s 

SWMP available to the public at reasonable times during business hours. The 

Permittee will provide a copy of the most recent annual report to any individual or 

entity, upon request.

1. A reasonable charge may be assessed by the Permittee for making photocopies of 

records.

2. The Permittee may require reasonable advance notice of intent to review records 

related to this permit.

D. The annual report for Permittees listed in S1.B. shall include the following:

1. A copy of the Permittee’s current SWMP Plan as required by S5.A.1.

2. Submittal of the annual report form as provided by Ecology pursuant to S9.A, 

describing the status of implementation of the requirements of this permit during 

the reporting period.

3. Attachments to the annual report form including summaries, descriptions, reports, 

and other information as required, or as applicable, to meet the requirements of 

this permit during the reporting period. Refer to Appendix 12 for annual report 

questions.

4. If applicable, notice that the MS4 is relying on another governmental entity to 

satisfy any of the obligations under the permit.

5. Certification and signature pursuant to G19.D, and notification of any changes to 

authorization pursuant to G19.C.

6. A notification of any annexations, incorporations, or jurisdictional boundary 

changes resulting in an increase or decrease in the Permittee’s geographic area of 

permit coverage during the reporting period.
S9.E.1 S9.E.5

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E. Annual Report for Secondary Permittees, including the Port of Seattle and the Port of 

Tacoma 

Each annual report shall include the following:

1. Submittal of the annual report as provided by Ecology pursuant to S9.A, 

describing the status of implementation of the requirements of this permit during 

the reporting period. 

2. Attachments to the annual report form including summaries, descriptions, reports, 

and other information as required, or as applicable, to meet the requirements of 

this permit during the reporting period. Refer to Appendix 3 for annual report 

questions for the Ports of Seattle and Tacoma, and Appendix 4 for annual report 

questions for all other Secondary Permittees.

3. If applicable, notice that the MS4 is relying on another governmental entity to 

satisfy any of the obligations under this permit.

4. Certification and signature pursuant to G19.D, and notification of any changes to 

authorization pursuant to G19.C.

5. A notification of any jurisdictional boundary changes resulting in an increase or 

decrease in the Permittee’s geographic area of permit coverage during the 

reporting period. 
G1 - DISCHARGE VIOLATIONS

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GENERAL CONDITIONS

G1. DISCHARGE VIOLATIONS

All discharges and activities authorized by this permit shall be consistent with the terms 

and conditions of this permit.

G2. PROPER OPERATION AND MAINTENANCE

The Permittee shall at all times properly operate and maintain all facilities and systems of 

collection, treatment, and control (and related appurtenances) which are installed or used 

by the Permittee for pollution control to achieve compliance with the terms and 

conditions of this permit.

G3. NOTIFICATION OF DISCHARGE INCLUDING SPILLS

If a Permittee has knowledge of a discharge, including spill(s), into or from a MS4, which 

could constitute a threat to human health, welfare, or the environment, the Permittee, 

shall:

A. Take appropriate action to correct or minimize the threat to human health, welfare 

and/or the environment.

B. Notify the Ecology regional office and other appropriate spill response authorities 

immediately but in no case later than within 24 hours of obtaining that knowledge. 

The Department of Ecology's Regional Office 24-hr. number is (425) 649-7000 for 

the Northwest Regional Office, and (360) 407-6300 for the Southwest Regional 

Office.

C. Immediately report spills or other discharges which might cause bacterial 

contamination of marine waters, such as discharges resulting from broken sewer lines 

and failing onsite septic systems, to the Ecology regional office and to the 

Department of Health, Shellfish Program. The Department of Health's Shellfish 

number is (360) 236-3330 (business hours) or (360) 789-8962 (24-hours).

D. Immediately report spills or discharges of oils or hazardous substances to the

Ecology regional office and to the Washington Emergency Management Division, 

(800) 258-5990.

G4. BYPASS PROHIBITED 

The intentional bypass of stormwater from all or any portion of a stormwater treatment 

BMP whenever the design capacity of the treatment BMP is not exceeded, is prohibited 

unless the following conditions are met:

A. Bypass is: (1) unavoidable to prevent loss of life, personal injury, or severe property 

damage; or (2) necessary to perform construction or maintenance-related activities 

essential to meet the requirements of the Clean Water Act (CWA); and
G5 - RIGHT OF ENTRY

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B. There are no feasible alternatives to bypass, such as the use of auxiliary treatment 

facilities, retention of untreated stormwater, or maintenance during normal dry 

periods.

"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. Severe property damage does not mean economic loss. 

G5. RIGHT OF ENTRY

The Permittee shall allow an authorized representative of Ecology, upon the presentation 

of credentials and such other documents as may be required by law at reasonable times:

A. To enter upon the Permittee's premises where a discharge is located or where any 

records must be kept under the terms and conditions of this permit;

B. To have access to, and copy at reasonable cost and at reasonable times, any records 

that must be kept under the terms of the permit;

C. To inspect at reasonable times any monitoring equipment or method of monitoring 

required in the permit;

D. To inspect at reasonable times any collection, treatment, pollution management, or 

discharge facilities; and

E. To sample at reasonable times any discharge of pollutants.

G6. DUTY TO MITIGATE

The Permittee shall take all reasonable steps to minimize or prevent any discharge in 

violation of this permit, which has a reasonable likelihood of adversely affecting human 

health or the environment.

G7. PROPERTY RIGHTS

This permit does not convey any property rights of any sort, or any exclusive privilege.

G8. COMPLIANCE WITH OTHER LAWS AND STATUTES 

Nothing in the permit shall be construed as excusing the Permittee from compliance with 

any other applicable federal, state, or local statutes, ordinances, or regulations.

G9. MONITORING

A. Representative Sampling: Samples and measurements taken to meet the requirements 

of this permit shall be representative of the volume and nature of the monitored 

discharge, including representative sampling of any unusual discharge or discharge 

condition, including bypasses, upsets, and maintenance-related conditions affecting 

effluent quality.
G10 - REMOVED SUBSTANCES

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B. Records Retention: The Permittee shall retain records of all monitoring information, 

including all calibration and maintenance records and all original recordings for 

continuous monitoring instrumentation, copies of all reports required by this permit, 

and records of all data used to complete the application for this permit, for a period of 

at least five years. This period of retention shall be extended during the course of any 

unresolved litigation regarding the discharge of pollutants by the Permittee or when 

requested by Ecology. On request, monitoring data and analysis must be provided to 

Ecology.

C. Recording of Results: For each measurement or sample taken, the Permittee shall 

record the following information: (1) the date, exact place and time of sampling; (2) 

the individual who performed the sampling or measurement; (3) the dates the 

analyses were performed; (4) who performed the analyses; (5) the analytical 

techniques or methods used; and (6) the results of all analyses.

D. Test Procedures: All sampling and analytical methods used to meet the monitoring 

requirements in this Permit shall conform to the Guidelines Establishing Test 

Procedures for the Analysis of Pollutants contained in 40 CFR Part 136, unless 

otherwise specified in this permit or approved in writing by Ecology.

E. Flow Measurement: Where flow measurements are required by other conditions of 

this Permit, appropriate flow measurement devices and methods consistent with 

accepted scientific practices shall be selected and used to ensure the accuracy and 

reliability of measurements of the volume of monitored discharges. The devices must 

be installed, calibrated, and maintained to ensure that the accuracy of the 

measurements are consistent with the accepted industry standard for that type of 

device. Frequency of calibration shall be in conformance with manufacturer's 

recommendations or at a minimum frequency of at least one calibration per year. 

Calibration records should be maintained for a minimum of three years.

F. Lab Accreditation: All monitoring data, except for flow, temperature, conductivity, 

pH, total residual chlorine, and other exceptions approved by Ecology, shall be 

prepared by a laboratory registered or accredited under the provisions of, 

Accreditation of Environmental Laboratories, chapter 173-50 WAC. Soils and 

hazardous waste data are exempted from this requirement pending accreditation of 

laboratories for analysis of these media by Ecology. Quick methods of field detection 

of pollutants including nutrients, surfactants, salinity, and other parameters are 

exempted from this requirement when the purpose of the sampling is identification 

and removal of a suspected illicit discharge.

G. Additional Monitoring: Ecology may establish specific monitoring requirements in 

addition to those contained in this permit by administrative order or permit 

modification.
G10 - REMOVED SUBSTANCES

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G10. REMOVED SUBSTANCES

With the exception of decant from street waste vehicles, the Permittee must not allow 

collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in 

the course of treatment or control of stormwater to be resuspended or reintroduced to the 

storm sewer system or to waters of the state. Decant from street waste vehicles resulting 

from cleaning stormwater facilities may be reintroduced only when other practical means 

are not available and only in accordance with the Street Waste Disposal Guidelines in 

Appendix 6. Solids generated from maintenance of the MS4 may be reclaimed, recycled, 

or reused when allowed by local codes and ordinances. Soils that are identified as 

contaminated pursuant to chapter 173-350 WAC shall be disposed at a qualified solid

waste disposal facility (see Appendix 6).

G11. SEVERABILITY

The provisions of this permit are severable, and if any provision of this permit, or the 

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.

G12. REVOCATION OF COVERAGE

The director may terminate coverage under this General Permit in accordance with 

Chapter 43.21B RCW and chapter 173-226 WAC. Cases where coverage may be 

terminated include, but are not limited to the following:

A. Violation of any term or condition of this general permit;

B. Obtaining coverage under this general 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. A determination that the permitted activity endangers human health or the 

environment, or contributes significantly to water quality standards violations; 

E. Failure or refusal of the Permittee to allow entry as required in RCW 90.48.090; 

F. Nonpayment of permit fees assessed pursuant to RCW 90.48.465;

Revocation of coverage under this general permit may be initiated by Ecology or 

requested by any interested person.

G13. TRANSFER OF COVERAGE 

The director may require any discharger authorized by this general permit to apply for 

and obtain an individual permit in accordance with Chapter 43.21B RCW and chapter 

173-226 WAC. 
G14 - GENERAL PERMIT MODIFICATION AND REVOCATION

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G14. GENERAL PERMIT MODIFICATION AND REVOCATION

This general permit may be modified, revoked and reissued, or terminated in accordance 

with the provisions of WAC 173-226-230. Grounds for modification, revocation and 

reissuance, or termination include, but are not limited to the following: 

A. A change occurs in the technology or practices for control or abatement of pollutants 

applicable to the category of dischargers covered under this general permit; 

B. Effluent limitation guidelines or standards are promulgated pursuant to the CWA or 

chapter 90.48 RCW, for the category of dischargers covered under this general 

permit; 

C. A water quality management plan containing requirements applicable to the category 

of dischargers covered under this general permit is approved; 

D. Information is obtained which indicates that cumulative effects on the environment 

from dischargers covered under this general permit are unacceptable; or

E. Changes made to State law reference this permit. 

G15. REPORTING A CAUSE FOR MODIFICATION OR REVOCATION

A Permittee who knows or has reason to believe that any activity has occurred or will 

occur which would constitute cause for modification or revocation and reissuance under 

Condition G12, G14, or 40 CFR 122.62 shall report such plans, or such information, to 

Ecology so that a decision can be made on whether action to modify, or revoke and 

reissue this permit will be required. Ecology may then require submission of a new or 

amended application. Submission of such application does not relieve the Permittee of 

the duty to comply with this permit until it is modified or reissued.

G16. APPEALS 

A. The terms and conditions of this general permit, as they apply to the appropriate class 

of dischargers, are subject to appeal within thirty 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, can be appealed, in accordance with chapter 43.21B RCW, within thirty 

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.
G17 - PENALTIES

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D. Modifications of this permit can be appealed in accordance with chapter 43.21B 

RCW and chapter 173-226 WAC.

G17. PENALTIES

40 CFR 122.41(a)(2) and (3), 40 CFR 122.41(j)(5), and 40 CFR 122.41(k)(2) are hereby 

incorporated into this permit by reference.

G18. DUTY TO REAPPLY

The Permittee shall apply for permit renewal at least 180 days prior to the specified 

expiration date of this permit. 

G19. CERTIFICATION AND SIGNATURE

All formal submittals to Ecology shall be signed and certified.

A. All permit applications shall be signed by either a principal executive officer or 

ranking elected official.

B. All formal submittals required by this Permit shall 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, and

2. The authorization specifies either an individual or a position having responsibility 

for the overall development and implementation of the stormwater management 

program. (A duly authorized representative may thus be either a named individual 

or any individual occupying a named position.)

C. Changes to authorization. If an authorization under General Condition G19.B.2 is no 

longer accurate because a different individual or position has responsibility for the 

overall development and implementation of the stormwater management program, a 

new authorization satisfying the requirements of General Condition G19.B.2 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 formal submittal under this permit 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 willful violations."
G20 - NON-COMPLIANCE NOTIFICATION

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G20. NON-COMPLIANCE NOTIFICATION

In the event a Permittee is unable to comply with any of the terms and conditions of this 

Permit, the Permittee must: 

A. Notify Ecology of the failure to comply with the permit terms and conditions in 

writing within 30 days of becoming aware that the non-compliance has occurred. The 

written notification to Ecology must include all of the following: 

1. A description of the non-compliance, including the reference(s).

2. Beginning and ending dates of the non-compliance, or if the Permittee has not 

corrected the non-compliance, the anticipated date of correction.

3. Steps taken or planned to reduce, eliminate, or prevent reoccurrence of the noncompliance.

B. Take appropriate action to stop or correct the condition of non-compliance. 

G21. UPSETS

Permittees shall meet the conditions of 40 CFR 122.41(n) regarding “Upsets.” The 

conditions are as follows: 

A. 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. 

B. Effect of an upset. An upset constitutes an affirmative defense to an action brought 

for noncompliance with such technology-based permit effluent limitations if the 

requirements of paragraph (C) of this condition are met. Any determination made 

during administrative review of claims that noncompliance was caused by upset, and 

before an action for noncompliance, will not constitute final administrative action 

subject to judicial review. 

C. Conditions necessary for demonstration of upset. A Permittee who wishes to 

establish the affirmative defense of upset shall 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 at the time being properly operated; and 

3. The Permittee submitted notice of the upset as required in 40 CFR 

122.41(l)(6)(ii)(B) (24-hour notice of noncompliance).

4. The Permittee complied with any remedial measures required under 40 CFR 

122.41(d) (Duty to Mitigate).

D. Burden of proof. In any enforcement proceeding, the Permittee seeking to establish 

the occurrence of an upset has the burden of proof.
DEFINITIONS AND ACRONYMS

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Modified January 16, 2015

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DEFINITIONS AND ACRONYMS

This section includes definitions for terms used in the body of the permit and in all the 

appendices except Appendix 1. Terms defined in Appendix 1 are necessary to implement 

requirements related to Appendix 1.

“40 CFR” means Title 40 of the Code of Federal Regulations, which is the codification of the 

general and permanent rules published in the Federal Register by the executive departments 

and agencies of the federal government.

“AKART” means All Known, Available and Reasonable methods of prevention, control and 

Treatment. See also State Water Pollution Control Act, chapter 90.48.010 and 90.48.520 

RCW. 

“All Known, Available and Reasonable methods of prevention, control and Treatment” refers to 

the State Water Pollution Control Act, Chapter 90.48.010 and 90.48.520 RCW.

“Applicable TMDL” means a TMDL which has been approved by EPA on or before the issuance 

date of this Permit, or prior to the date that Ecology issues coverage under this Permit, 

whichever is later.

“Beneficial uses” means uses of waters of the state, which include but are not limited to: use for 

domestic, stock watering, industrial, commercial, agricultural, irrigation, mining, fish and 

wildlife maintenance and enhancement, recreation, generation of electric power and 

preservation of environmental and aesthetic values, and all other uses compatible with the 

enjoyment of the public waters of the state.

“Best Management Practices” are the schedules of activities, prohibitions of practices, 

maintenance procedures, and structural and/or managerial practices approved by Ecology 

that, when used singly or in combination, prevent or reduce the release of pollutants and 

other adverse impacts to waters of Washington State.

“B-IBI” means Benthic Index of Biotic Integrity. 

“BMP” means Best Management Practice.

“Bypass” means the diversion of stormwater from any portion of a stormwater treatment facility. 

“Circuit” means a portion of a MS4 discharging to a single point or serving a discrete area 

determined by traffic volumes, land use, topography, or the configuration of the MS4. 

“Component” or “Program component" means an element of the Stormwater Management 

Program listed in Special Condition S5 Stormwater Management Program for Permittees or 

S6 Stormwater Management Program for Secondary Permittees, or S7 Compliance with 

Total Maximum Daily Load Requirements, or S8 Monitoring and Assessment. 

“Conveyance system” means that portion of the municipal separate storm sewer system designed 

or used for conveying stormwater.

“Co-Permittee” means an owner or operator of a MS4 which is in a cooperative agreement with 

at least one other applicant for coverage under this permit. A co-permittee is an owner or 

operator of a regulated MS4 located within or in proximity to another regulated MS4. A Co-
DEFINITIONS AND ACRONYMS

Phase I Municipal Stormwater Permit - August 1, 2013

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Permittee is only responsible for permit conditions relating to the discharges from the MS4 

the Co-Permittee owns or operates. See also 40 CFR 122.26(b)(1). 

“CWA” means the federal Clean Water Act (formerly referred to as the Federal Water Pollution 

Control Act or Federal Water Pollution Control Act Amendments of 1972) Pub.L. 92-500, as 

amended Pub. L. 95-217, Pub. L. 95-576, Pub. L. (6-483 and Pub. L. 97-117, 33 U.S.C. 1251 

et seq.).

“Director” means the Director of the Washington State Department of Ecology, or an authorized 

representative.

“Discharge point” means the location where a discharge leaves the Permittee’s MS4 through the 

Permittee’s MS4 facilities/BMPs designed to infiltrate. 

“Entity” means a governmental body, or a public or private organization.

“EPA” means the U.S. Environmental Protection Agency.

“General Permit” means a permit which covers multiple dischargers of a point source category 

within a designated geographical area, in lieu of individual permits being issued to each 

discharger.

“Ground Water” means water in a saturated zone or stratum beneath the surface of the land or 

below a surface water body. Refer to chapter 173-200 WAC.

“Hazardous substance” means any liquid, solid, gas, or sludge, including any material, substance, 

product, commodity, or waste, regardless of quantity, that exhibits any of the physical, 

chemical, or biological properties described in WAC 173-303-090 or WAC 173-303-100.

“Heavy equipment maintenance or storage yard” means an uncovered area where any heavy 

equipment, such as mowing equipment, excavators, dump trucks, backhoes, or bulldozers are 

washed or maintained, or where at least five pieces of heavy equipment are stored on a long 

term basis.

“Highway” means a main public road connecting towns and cities.

“Hydraulically near” means runoff from the site discharges to the sensitive feature without 

significant natural attenuation of flows that allows for suspended solids removal. See 

Appendix 7 Determining Construction Site Sediment Damage Potential for a more detailed 

definition.

“Hyperchlorinated” means water that contains more than 10 mg/Liter chlorine.

“Illicit connection” means any infrastructure connection to the MS4 that is not intended, 

permitted, or used for collecting and conveying stormwater or non-stormwater discharges 

allowed as specified in this permit (S5.C.8, S6.D.3, and S6.E.3). Examples include sanitary 

sewer connections, floor drains, channels, pipelines, conduits, inlets, or outlets that are 

connected directly to the MS4.

“Illicit discharge” means any discharge to a MS4 that is not composed entirely of stormwater or 

of non-stormwater discharges allowed as specified in this Permit (S5.C.8, S6.D.3 and 

S6.E.3).
DEFINITIONS AND ACRONYMS

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Modified January 16, 2015

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“Impervious surface” means a non-vegetated surface area that either prevents or retards the entry 

of water into the soil mantle as under natural conditions prior to development. A nonvegetated surface area which causes water to run off the surface in greater quantities or at an 

increased rate of flow from the flow present under natural conditions prior to development. 

Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, 

driveways, parking lots or stormwater areas, concrete or asphalt paving, gravel roads, packed 

earthen materials, and oiled, macadam or other surfaces which similarly impede the natural 

infiltration of stormwater.

“Land disturbing activity” means any activity that results in a change in the existing soil cover 

(both vegetative and non-vegetative) and/or the existing soil topography. Land disturbing 

activities include, but are not limited to clearing, grading, filling and excavation. Compaction 

that is associated with stabilization of structures and road construction shall also be 

considered land disturbing activity. Vegetation maintenance practices, including landscape 

maintenance and gardening, are not considered land disturbing activity. Stormwater facility 

maintenance is not considered land disturbing activity if conducted according to established 

standards and procedures.

“LID” means Low Impact Development.

“LID BMP” means Low Impact Development Best Management Practices.

“LID Principles” means land use management strategies that emphasize conservation, use of onsite natural features, and site planning to minimize impervious surfaces, native vegetation 

loss, and stormwater runoff.

“Low Impact Development” means a stormwater and land use management strategy that strives 

to mimic pre-disturbance hydrologic processes of infiltration, filtration, storage, evaporation 

and transpiration by emphasizing conservation, use of on-site natural features, site planning, 

and distributed stormwater management practices that are integrated into a project design.

“Low Impact Development Best Management Practices” means distributed stormwater 

management practices, integrated into a project design, that emphasize pre-disturbance 

hydrologic processes of infiltration, filtration, storage, evaporation and transpiration. LID 

BMPs include, but are not limited to, bioretention, rain gardens, permeable pavements, roof 

downspout controls, dispersion, soil quality and depth, vegetated roofs, minimum excavation 

foundations, and water re-use.

“Material Storage Facilities” means an uncovered area where bulk materials (liquid, solid, 

granular, etc.) are stored in piles, barrels, tanks, bins, crates, or other means.

“Maximum Extent Practicable” refers to paragraph 402(p)(3)(B)(iii) of the federal Clean Water 

Act which reads as follows: Permits for discharges from municipal storm sewers shall require 

controls to reduce the discharge of pollutants to the maximum extent practicable, including 

management practices, control techniques, and system, design, and engineering methods, and 

other such provisions as the Administrator or the State determines appropriate for the control 

of such pollutants.

“MEP” means Maximum Extent Practicable.

“MS4” means Municipal Separate Storm Sewer System.
DEFINITIONS AND ACRONYMS

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“Municipal separate storm sewer system” means a conveyance, or system of conveyances 

(including roads with drainage systems, municipal streets, catch basins, curbs, gutters, 

ditches, manmade channels, or storm drains): 

(i) Owned or operated by a state, city, town, borough, county, parish, district, association, or 

other public body (created by or pursuant to State Law) having jurisdiction over disposal 

of wastes, stormwater, or other wastes, including special districts under State law such as 

a sewer district, flood control district or drainage district, or similar entity, or an Indian 

tribe or an authorized Indian tribal organization, or a designated and approved 

management agency under section 208 of the CWA that discharges to waters of the State. 

(ii) Designed or used for collecting or conveying stormwater. 

(iii)Which is not a combined sewer.

(iv)Which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 

122.2. 

(v) Which is defined as “large” or “medium” or “small” or otherwise designated by Ecology 

pursuant to 40 CFR 122.26.

“National Pollutant Discharge Elimination System” 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 Department of Ecology.

“Native Vegetation” means vegetation comprised of plant species, other than noxious weeds, that 

are indigenous to the coastal region of the Pacific Northwest and which reasonably could 

have been expected to naturally occur on the site. Examples include trees such as Douglas 

Fir, western hemlock, western red cedar, alder, big-leaf maple; shrubs such as willow, 

elderberry, salmonberry, and salal; and herbaceous plants such as sword fern, foam flower, 

and fireweed.

“New Development” means land disturbing activities, including Class IV-General Forest 

Practices that are conversions from timber land to other uses; structural development, 

including construction or installation of a building or other structure; creation of hard 

surfaces; and subdivision, short subdivision and binding site plans, as defined and applied in 

chapter 58.17 RCW. Projects meeting the definition of redevelopment shall not be considered 

new development. Refer to Appendix 1 for a definition of hard surfaces.

“New Secondary Permittee” means a Secondary Permittee that is covered under a Municipal 

Stormwater General Permit and was not covered by the permit prior to August 1, 2013.

“NOI” means Notice of Intent.

“Notice of Intent” means the application for, or a request for coverage under a General NPDES 

Permit pursuant to WAC 173-226-200. 

“Notice of Intent for Construction Activity” means the application form for coverage under the 

Construction Stormwater General Permit. 
DEFINITIONS AND ACRONYMS

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“Notice of Intent for Industrial Activity” means the application form for coverage under the 

General Permit for Stormwater Discharges Associated with Industrial Activities.

“NPDES” means National Pollutant Discharge Elimination System.

“O&M” means operation and maintenance.

“Outfall” means point source as defined by 40 CFR 122.2 at the point where a discharge means a 

point source as defined by 40 CFR 122.2 at the point where a discharge leaves the 

Permittee’s MS4 and enters a surface receiving waterbody or surface receiving waters. 

Outfall does not include pipes, tunnels, or other conveyances which connect segments of the 

same stream or other surface waters and are used to convey primarily surface waters (i.e., 

culverts). 

“Permittee” unless otherwise noted, includes city, town, or county Permittee, port Permittee, CoPermittee, Secondary Permittee, and New Secondary Permittee.

“Physically Interconnected” means that one MS4 is connected to another storm sewer system in 

such a way that it allows for direct discharges to the second system. For example, the roads 

with drainage systems and municipal streets of one entity are physically connected directly to 

a storm sewer system belonging to another entity.

“Project Site” means that portion of a property, properties, or right-of-ways subject to land 

disturbing activities, new hard surfaces, or replaced hard surfaces. Refer to Appendix 1 for a 

definition of hard surfaces.

“QAPP” means Quality Assurance Project Plan.

“Qualified Personnel” means someone who has had professional training in the aspects of 

stormwater management for which they are responsible and are under the functional control 

of the Permittee. Qualified Personnel may be staff members, contractors, or volunteers.

“Quality Assurance Project Plan” means a document that describes the objectives of an 

environmental study and the procedures to be followed to achieve those objectives.

“RCW” means the Revised Code of Washington State.

“Receiving waterbody” or “receiving waters” means naturally and/or reconstructed naturally 

occurring surface water bodies, such as creeks, streams, rivers, lakes, wetlands, estuaries, and 

marine waters, or ground water, to which a MS4 discharges. “Redevelopment” means, on a 

site that is already substantially developed (i.e., has 35% or more of existing hard surface 

coverage), the creation or addition of hard surfaces; the expansion of a building footprint or 

addition or replacement of a structure; structural development including construction, 

installation or expansion of a building or other structure; replacement of hard surface that is 

not part of a routine maintenance activity; and land disturbing activities. Refer to Appendix 1 

for a definition of hard surfaces.

“Regional Stormwater Monitoring Program” means for all of western Washington, a stormwaterfocused monitoring and assessment program consisting of these components: status and 

trends monitoring in small streams and marine nearshore areas, stormwater management 

program effectiveness studies, and a source identification information repository (SIDIR). 
DEFINITIONS AND ACRONYMS

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The priorities and scope for the RSMP are set by a formal stakeholder group. For this permit 

term, RSMP status and trends monitoring will be conducted in the Puget Sound basin only.

“RSMP” means Regional Stormwater Monitoring Program.

“Runoff” is water that travels across the land surface and discharges to water bodies either 

directly or through a collection and conveyance system. See also “Stormwater.”

“Secondary Permittee” is an operator of a MS4 which is not a city, town or county. Secondary 

Permittees include special purpose districts and other public entities that meet the criteria 

inS1.E.1.

“Sediment/Erosion-Sensitive Feature” means an area subject to significant degradation due to the 

effect of construction runoff, or areas requiring special protection to prevent erosion. See 

Appendix 7 Determining Construction Site Sediment Transport Potential for a more detailed 

definition.

“Shared Waterbodies” means waterbodies, including downstream segments, lakes and estuaries, 

that receive discharges from more than one Permittee. 

“SIDIR” means a Source Identification Information Repository.

“Significant contributor” means a discharge that contributes a loading of pollutants considered to 

be sufficient to cause or exacerbate the deterioration of receiving water quality or instream 

habitat conditions. 

“Source Control BMP” means a structure or operation that is intended to prevent pollutants from 

coming into contact with stormwater through physical separation of areas or careful 

management of activities that are sources of pollutants. The SWMMWW separates source 

control BMPs into two types. Structural Source Control BMPs are physical, structural, or 

mechanical devices, or facilities that are intended to prevent pollutants from entering 

stormwater. Operational BMPs are non-structural practices that prevent or reduce pollutants 

from entering stormwater. See Volume IV of the SWMMWW for details.

“Stormwater” means runoff during and following precipitation and snowmelt events, including 

surface runoff, drainage, and interflow.

“Stormwater Associated with Industrial and Construction Activity” means the discharge from 

any conveyance which is used for collecting and conveying stormwater, which is directly 

related to manufacturing, processing or raw materials storage areas at an industrial plant, or 

associated with clearing, grading and/or excavation, and is required to have an NPDES 

permit in accordance with 40 CFR 122.26.

“Stormwater facilities regulated by the Permittee” means permanent stormwater treatment and 

flow control BMPs/facilities located in the geographic area covered by the permit and which 

are not owned by the Permittee, and are known by the permittee to discharge into MS4 

owned or operated by the Permittee.

“Stormwater Management Program” means a set of actions and activities designed to reduce the 

discharge of pollutants from the MS4 to the MEP and to protect water quality, and 

comprising the components listed in S5 or S6 of this Permit and any additional actions 
DEFINITIONS AND ACRONYMS

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Modified January 16, 2015

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necessary to meet the requirements of applicable TMDLs pursuant to S7 Compliance with 

TMDL Requirements, and S8 Monitoring and Assessment.

“Stormwater Treatment and Flow Control BMPs/Facilities” means detention facilities, treatment 

BMPs/facilities, bioretention, vegetated roofs, and permeable pavements that help meet 

minimum requirement #6 (treatment), #7 (flow control), or both.

“SWMMWW” and “Stormwater Management Manual for Western Washington” mean the 

Stormwater Management Manual for Western Washington as amended in 2014.

“SWMP” means Stormwater Management Program.

“TMDL” means Total Maximum Daily Load.

“Total Maximum Daily Load” means a water cleanup plan. A TMDL is a calculation of the 

maximum amount of a pollutant that a water body can receive and still meet water quality 

standards, and an allocation of that amount to the pollutant’s sources. A TMDL is the sum of 

the allowable loads of a single pollutant from all contributing point and nonpoint sources. 

The calculation must include a margin of safety to ensure that the water body can be used for 

the purposes the state has designated. The calculation must also account for seasonable 

variation in water quality. Water quality standards are set by states, territories, and tribes. 

They identify the uses for each water body, for example, drinking water supply, contact 

recreation (swimming), and aquatic life support (fishing), and the scientific criteria to support 

that use. The Clean Water Act, section 303, establishes the water quality standards and 

TMDL programs.

“Tributary conveyance” means pipes, ditches, catch basins, and inlets owned or operated by the 

Permittee and designed or used for collecting and conveying stormwater.

“UGA” means Urban Growth Area.

“Urban Growth Area” means those areas designated by a county pursuant to RCW 36.70A.110. 

“Urban/higher density rural sub-basins” means all areas within or proposed to be within the 

UGA, or any sub-basin outside the UGA with 50% or more area comprised of lots less than 5 

acres. 

“Vehicle Maintenance or Storage Facility” means an uncovered area where any vehicles are 

regularly washed or maintained, or where at least 10 vehicles are stored.

“Water Quality Standards” means Surface Water Quality Standards, chapter 173-201A WAC, 

Ground Water Quality Standards, chapter 173-200 WAC, and Sediment Management 

Standards, chapter 173-204 WAC.

“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 includes lakes, rivers, ponds, streams, inland 

waters, underground waters, salt waters and all other surface waters and water courses within 

the jurisdiction of the State of Washington.

“Waters of the United States” refers to the definition in 40 CFR 122.2.