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Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

NPDES Wastewater & Stormwater Permits

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Municipal Separate Stormwater Sewer Systems (MS4) Program Audits

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Program evaluations of Municipal Separate Stormwater Sewer Systems (MS4) are being conducted to determine permittee compliance with NPDES permit requirements and to evaluate the implementation status of EPA's stormwater regulations.

The program evaluations are also being conducted to evaluate the overall effectiveness of the MS4 program. This includes obtaining an overall picture of MS4 compliance, documenting positive elements of programs that may benefit other municipalities, identifying ways to improve the reporting aspects of MS4 programs, and developing guidance to assist inspectors in conducting future MS4 evaluations.

The program evaluation reports identify potential permit violations, program efficiencies, and positive attributes of each program. The reports do not represent a formal finding of violation.

The following audits (listed chronologically) have been conducted by Tetra Tech, Inc. in conjunction with state regulatory authorities through a U.S. EPA Region 9 contract.

EPA Region 9 Case Studies

EPA has developed a series of stormwater case studies to help Phase II municipal separate storm sewer systems (MS4s) get started on or improve their stormwater management programs. These case studies present additional information about notable program elements in the EPA Region 9 states of Arizona, California, and Hawaii. Each case study is a two- to three-page description of how a Phase I or Phase II community has implemented a specific aspect of its stormwater program. The case studies are organized by program area, but they do not necessarily represent all the activities that each community is undertaking to implement that minimum measure. Each case study description includes links to materials that further describe or were developed for the case study and the minimum control measure.

Municipal Separate Storm Sewer System (MS4) Program Evaluation Guidance

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Adobe Reader.

The MS4 Evaluation Guide is primarily for use by NPDES authorities to evaluate the quality of Phase I and Phase II MS4 programs, for permit compliance, technical assistance, and other purposes. It can be used for comprehensive program evaluations, or for certain components. It can also be used by MS4 program managers to evaluate their own programs.

Arizona MS4 Program Evaluations

Location Date of Evaluation Documents
Arizona Department of Transportation (ADOT) October 25-29, 2010

ADOT MS4 Audit Report (PDF) (43 pp, 200K)
Administrative Order on Consent -
EPA Docket No. CWA-09-2012-2004 (PDF)
(14 pp, 3.1M)

City of Mesa Aug 25-27, 2008

City of Mesa (PDF) (14 pp, 640K)
Appendix A (PDF) (3 pp, 128K)
Appendex B (PDF) (11 pp, 466K)
Appendix C (PDF) (11 pp, 127K)

Industrial Interviews - Phoenix, Tempe, Mesa, Glendale, Scottsdale Aug 25-28, 2008 Industrial and Commercial Program Interviews (PDF) (16 pp, 92K)
Appendix A (PDF) (2 pp, 53K)
Phoenix - City of Phoenix October, 2001 City of Phoenix (PDF) (12 pp, 157K)
City of Scottsdale June, 2009 City of Scottsdale (PDF) (96 pp, 4.6M)
Cover Letter (PDF) (2 pp, 56K)
Tucson Area - Pima County, Cities of Tucson and Marana May, 2006 City of Tucson (PDF) (25 pp, 191K)

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California MS4 Program Evaluations

Location Date of Evaluation Documents
Alameda - Cities of Dublin, Fremont, Hayward, Livermore, and Oakland November, 2001 Alameda County (PDF) (19 pp, 190K)
American Canyon - City of June, 2005 City of American Canyon (PDF) (8 pp, 88K)
Bakersfield (City of ) and Kern County November, 2002 City of Bakersfield-Kern County (PDF) (18 pp, 649K)
Bakersfield - City of

August, 2012

City of Bakersfield (PDF) (28 pp, 460K)
City of Bakersfield Response (PDF) (7 pp, 474K)
December, 2010 City of Bakersfield (PDF) (23 pp, 200K)
Caltrans Districts 1-4 October 5–7, 13–14, and 21–22, 2009 Caltrans Districts 1-4 Final Audit, February 2010 (includes Appendix A) (PDF) (36 pp, 433K) Reponse from Caltrans (PDF) (2 pp, 353K)

Findings of Violation and Order for Compliance, EPA Docket No. CWA-09-2011-0001 (PDF) (24 pp, 1.3MB)

Caltrans - District 5 July, 2002 Caltrans - District 5 (PDF) (12 pp, 169K)
Chico - City of September, 2009 City of Chico (PDF) (25 pp, 199K)
Transmittal memo (PDF) (2 pp, 39K)
Contra Costa - Cities of Antioch, Brentwood, and Oakley March, 2005 Contra Costa County (PDF) (30 pp, 274K)
Contra Costra - Cities of Concord, Pinole, Pittsburg, Richmond, and San Pablo September, 2004 Contra Costa County (PDF) (37 pp, 386K)
Contra Costa - Cities of Hercules and Pittsburg, Walnut Creek, and Concord,  Contra Costa County, and Contra Costa Clean Water Program May, 2003 Contra Costa County (PDF) (26 pp, 192K)
Elk Grove - City of Elk Grove April, 2005 City of Elk Grove (PDF) (16 pp, 191K)
August 2012 City of Elk Grove (PDF) (64 pp, 4.0M)
City of Elk Grove Response (PDF) (313 pp, 17M)
Fresno - Cities of Fresno and Clovis, and the Fresno Metropolitan Flood Control District (District) January, 2005 Fresno (PDF) (20 pp, 186K)
Fresno - Cities of Fresno and Clovis, and the Fresno Metropolitan Flood Control District (District) February, 2010 Fresno (PDF) (18 pp, 151K)
MFCD's Response to EPA (PDF) (11 pp, 600K)
Indio - City of August, 2012 Indio (PDF) (14 pp,365K)
City of Indio Response (PDF) (2 pp, 52K)
Kern County Storm Water Management Program August, 2012 Kern County Stormwater Management Program (PDF) (27 pp, 566K)
Kern County Response (PDF) (17 pp, 1.1M)
Lake Tahoe - City of South Lake Tahoe, El Dorado County and Placer County June, 2002 Lake Tahoe (PDF) (13 pp, 154K)
Lake Tahoe - City of South Lake Tahoe, El Dorado County and Placer County July, 2009 Lake Tahoe (PDF) (24 pp, 106K)
Cover Letter memo (PDF) (2 pp, 36K)
Long Beach - City of Long Beach August, 2001 City of Long Beach (PDF) (19 pp, 262K)
Long Beach - Port of Long Beach and Los Angeles
More information
November, 2007 Ports of Long Beach & Los Angeles (PDF) (42 pp, 2.9MB)
Port of Long Beach Response (PDF) (26 pp, 2.6MB)
Los Angeles SUSMP  - LA County and Cities of Glendale, Los Angeles, and Santa Monica Standard Urban Stormwater Mitigation Measures (SUSMP) March, 2003 LA SUSMP (PDF) (63 pp, 503K)
Los Angeles Construction Program - Cities of Calabasas, Carson, Glendora, Pomona and Santa Clarita August, 2006 Los Angeles Construction Program (PDF) (31 pp, 168K)
Los Angeles - Port of Long Beach and Los Angeles
More information
November, 2007 Ports of Long Beach & Los Angeles (PDF) (42 pp, 2.9MB)
City of Los Angeles Response (PDF) (3 pp, 83K)
Modesto - City of Modesto February, 2004 City of Modesto (PDF) (11 pp, 154K)
August, 2012 City of Modesto (PDF) (10 pp, 54K)
Monterey - City of Monterey September, 2009 City of Monterey (PDF) (20 pp, 154K)
Cover memo (PDF) (2 pp, 24K)
Murrieta - City of Murieta September, 2007
January, 2008
City of Murrieta (PDF) (13 pp, 427K)
Napa - City of Napa June, 2005 City of Napa (PDF) (9 pp, 53K)
Orange County - Cities of Laguna Beach, Laguna Hills, Lake Forest, Rancho Santa Margarita May, 2005 Orange County (PDF) (34 pp, 308K)
Orange County - Orange County and Cities of Mission Viejo, San Clemente, and San Juan Capistrano June, 2003 Orange County (PDF) (31 pp, 292K)
Oxnard - City of Oxnard July, 2013 City of Oxnard(PDF) (32 pp, 1.9M)
City of Oxnard Response (PDF) (7 pp, 332K)
Petaluma - City of Petaluma June, 2005 City of Petaluma (PDF) (7 pp, 78K)
Riverside - Cities of Corona, Moreno Valley and Riverside. May, 2004 Riverside (Corona, Moreno Valley and Riverside) (PDF) (21 pp, 280K)
Riverside - County August 14-15, 2014 Riverside County (PDF) (15 pp, 373K)
Riverside County Response (PDF) (5 pp, 140K)
Sacramento - County of Sacramento

August, 2012

Sacramento County (PDF) (110 pp, 14MB)
Sacramento County Response (PDF) (30 pp, 1.4M)
Sacramento - County of Sacramento and the Cities of Folsom, Galt, and Sacramento March, 2002 Sacramento County (PDF) (25 pp, 309K)
Salinas - City of Salinas July, 2003 City of Salinas (PDF) (17 pp, 188K)
San Bernardino - Cities of Fontana and Redlands and San Bernardino County October, 2004 City of Fontana (PDF) (12 pp, 160K)
City of Redlands (PDF) (13 pp, 165K)
San Bernardino County (PDF) (14 pp, 170K)
San Diego - Cities of Carlsbad, Chula Vista, and El Cajon. Review of Jurisdictional Urban Runoff Management Programs (JURMPs) May, 2002 San Diego (PDF) (21 pp, 209K)
San Diego - Cities of Encinitas, Lemon Grove, Poway, and Santee April, 2004 San Diego 5 (PDF) (20 pp, 204K)
San Diego - Cities of Escondido, National City, Oceancide February, 2003 San Diego 3 (PDF) (23 pp, 237K)
San Diego - Cities of Imperial Beach, La Mesa, San Marcos, and Vista October, 2003 San Diego 4 (PDF) (31 pp, 338K)
San Diego - City of San Diego, County of San Diego October, 2002 San Diego City (PDF) (17 pp, 195K)
San Diego County (PDF) (15 pp, 177K)
San Diego SUSMP - Cities of San Diego, Carlsbad, Lemon Grove, Chula Vista, Oceanside, National City, Poway, El Cajon, Escondido and San Diego County.  Review of Jurisdictional Urban Runoff Management Programs (JURMPs) March, 2005 SUSMP Report (PDF) (53 pp, 399K)
San Diego - Cities of Solana Beach, Coronado, and Del Mar and Port of San Diego November, 2004 San Diego 6 (PDF) (20 pp, 241K)
San Mateo - County of San Mateo and Cities of South San Francisco, Foster City, Pacifica, Redwood City, and San Mateo August, 2002 San Mateo (PDF) (25 pp, 169K)
Santa Clara - Cities of Milpitas, Palo Alto, Santa Clara, and Santa Clara County April, 2005 Santa Clara (PDF) (23 pp, 171K)
Santa Clara - City of San Jose and County of Santa Clara December, 2003 Santa Clara - SanJose (PDF) (19 pp, 270K)
Monitoring evaluation report (PDF) (11 pp, 55K)
Santa Clara - City of San Jose and County of Santa Clara December, 2003 Santa Clara - SanJose (PDF) (19 pp, 270K)
Monitoring evaluation report (PDF) (11 pp, 55K)
Santa Paula - City of Santa Paula July, 2013 City of Santa Paula (PDF) (26 pp, 882K)
City of Santa Paula Response (PDF) (4 pp, 471K)
Simi Valley - City of Simi Valley July, 2013 City of Simi Valley (PDF) (36 pp, 1.1M)
City of Simi Valley Response (PDF) (12 pp, 596K)
Stockton - City of Stockton and San Joaquin County December, 2002 Stockton-San Joaquin (PDF) (16 pp, 182K)
Stockton - Port of Stockton July, 2008 Port of Stockton Audit (PDF) (88 pp, 16MB, scanned)
Port of Stockton AOC (PDF)
(28 pp, 1.2MB, scanned)
Temecula September, 2007
January, 2008
City of Temecula (PDF) (37 pp, 3.5MB, scanned)
Thousand Oaks - City of Thousand Oaks July, 2013 City of Thousand Oaks (PDF) (32 pp, 1.2M)
City of Thousand Oaks Reponse (PDF) (20 pp, 704K)
Ventura County Flood Control District and the Cities of Ojai, Oxnard, Santa Paula, and Simi Valley October, 2001 Ventura (PDF) (18 pp, 143K)
Ventura County Watershed Protection District July, 2013 Ventura County VCWPD (PDF) (22 pp, 667K)
Ventura County VCWPD Response (PDF) (14 pp, 770K)
Ventura SQUIMP - Cities of Fillmore, Moorpark, Port Hueneme, Ojai, Oxnard, Santa Paula, Simi Valley, the County of Ventura, and the Ventura County Watershed Protection District.  Storm Water Quality Storm Water Quality Urban Impact Mitigation Plan (SQUIMP) requirements August, 2004 Ventura (PDF) (26 pp, 1.3 MB)

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Hawaii MS4 Program Evaluations

Location Date of Evaluation Documents
Honolulu/HDOT October, 2003 HDOT (PDF) (21 pp, 1.6 MB)
September, 2003 City and County of Honolulu (PDF) (19 pp, 1.5MB)
September, 2003 Marine Corp. Base,Kanoche Bay (PDF) (10 pp, 164K)
Honolulu/HDOT September, 2004 HDOT (PDF) (11 pp, 232K)
City and County of Honolulu (PDF) (8 pp, 171K)
Honolulu/HDOT March, 2009 HDOT Harbors Division, Audit Report (PDF) (58 pp, 4.2MB)

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Nevada MS4 Program Evaluations

Location Date of Evaluation Documents
Nevada Department of Transportation MS4 Audit August, 2011 Final Report (PDF) (261 pp, 12.8MB)
NDOT Response to Audit (PDF) (6 pp, 552K)
Las Vegas Area: Clark County, Clark County Regional Flood Control District, and Cities of Las Vegas, North Las Vegas, and Henderson September, 2005 Final Report (PDF) (207 pp, 20MB)
Final Appendices (PDF) (164 pp, 20MB)
Follow-up Letter from EPA (PDF) (5 pp, 215K)
Reno - Cities of Reno and Sparks, Washoe County and the Nevada Department of Transportation (NDOT) January, 2002 Reno (PDF) (12 pp, 293K)
City of Reno Response July 3 2002 (PDF) (12 pp, 800K)

Report Summaries

Tetra Tech's summary of work performed to assess stormwater compliance in California, as well as a discussion of lessons learned and recommendations for improvement of stormwater program.

Document Date
Assessment Report on California Industrial Stormwater Program (PDF) (41 pp, 678K) July 12, 2006
Assessment Report on California MS4 Program (PDF) (28 pp, 773K) July 12, 2006

Contact Information

Ellen Blake (blake.ellen@epa.gov)
Office of Water Compliance and Enforcement
(415) 972-3496

Note: Scanned PDF documents are not accessible for screen readers, if necessary, contact EPA for the document's content.

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