Self-audit guidance for Phase II MS4s

Introduction

The purpose of this document is to provide municipal separate storm sewer system (MS4) staff guidance on how to conduct a self-audit of a stormwater pollution prevention program (SWPPP).

The Minnesota Pollution Control Agency (MPCA) staff conduct audits of SWPPPs to determine compliance with the MS4 General Permit and to provide technical assistance to staff in regulated MS4s. The MPCA’s intent is to audit all SWPPPs for MS4s regulated under the MS4 General Permit every seven years. Between MPCA audits, you may want to conduct a self-audit to check your progress with meeting permit requirements.

This document details each of the six Minimum Control Measures (MCMs) described in the MS4 General Permit and the activities required to be implemented and/or documented under each MCM. During the self-audit, you should review each permit requirement and note whether or not the activity is complete. In addition, documentation of the activity should be easily accessible and available for review. If specific documentation is required, it is noted with the activity’s description. Also review the MPCA’s guidance on the documentation required to be retained under the MS4 General Permit.

During the self-audit, review your SWPPP document that was submitted to the MPCA upon application for permit coverage. The SWPPP document has, for each MCM, your MS4-specific measureable goals, established best management practices (BMPs), timeframes for new BMP implementation, and the name or position title of staff responsible for BMP implementation. The BMPs, measurable goals, and timeframes indicated in the SWPPP document may be changed if you feel your SWPPP would benefit from being updated after your self-audit or annual program evaluation.

Before conducting your self-audit, gather all files, documents, and materials related to your SWPPP, including annual reports, SWPPP document, public notices, maps, written procedures, enforcement action documentation, regulatory mechanism(s), etc. Once all documents are gathered, use the tables below to guide the self-audit of your program. To mark an activity complete, you must have all supporting documentation and the activity must meet all of the requirements.

In this guidance we have included tips on enhancing your SWPPP for each MCM. These are not direct permit requirements, but methods MPCA staff have observed during audits that make local stormwater programs more effective.

We have also included general questions MPCA staff could ask during an audit. These questions are to prompt thought about your SWPPP in areas MPCA staff may focus during the audit. MPCA staff will ask general questions during the audit, but also questions specific to your SWPPP and stormwater activities. The questions noted in this document are not a final and complete list of questions that can or will be asked during an MPCA audit.

Please note that completing a self-audit, regardless of the results, does not preclude the MPCA from taking enforcement after an MPCA lead audit related to any of the activities required by the MS4 General Permit. If you have any questions relating to your SWPPP, please contact the appropriate MPCA staff, listed on the MS4 Permittee Staff Assignments webpage in the Minnesota Stormwater Manual.

In addition, please refer to the Self-audit webinar for additional information.

Overall program management

Activity description	Activity complete and available?
Staff and their stormwater responsibilities documented for those who implement components of the SWPPP.	Yes or No
A map of the MS4 system with the following: all pipes 12 inches or more in diameter including their flow direction and an ID number, all outfalls including their ID number and geographic coordinates, all structural stormwater BMPs that are part of the MS4, and all receiving waters.	Yes or No
Partnerships established to implement the SWPPP or aspects of the SWPPP, including any formal agreements.	Yes or No
Enforcement actions conducted are documented, including verbal warnings, with the following information: name of the party in noncompliance; date, location, and description of the violation, including reference to relevant Regulatory Mechanism; corrective actions required & completion schedule; date and type of enforcement used; referrals to other regulatory organizations (if any); and date violation resolved.	Yes or No
A Pond, Wetland, and Lake Inventory complete and submitted to the MPCA.	Yes or No
For MS4s that discharge to waters with a total maximum daily load (TMDL) that was approved by USEPA before the issuance of the MS4 General Permit. For each TMDL, documentation of the following: TDML project name, numeric waste load allocation (WLA) type (i.e. categorical or individual) and units, pollutant of concern, applicable flow data, interim milestones (BMPs) and dates for implementation to make progress toward meeting the WLAs, strategies for continued BMP implementation beyond the term of the MS4 General Permit, and and target dates the applicable WLA will be achieved.	Yes or No
For MS4s with an Alum or Ferric Chloride Phosphorus Treatment System. Documentation of the following: geographic coordinates of the system, the name or position titles of those responsible for the operation of the system, and annual reporting information.	Yes or No

Tips for overall program management

• Develop a process and key contacts for coordinating SWPPP activities across departments.
• Remember to perform an annual evaluation of your SWPPP and SWPPP document.
• Perform an annual evaluation of all written procedures to ensure they reflect current processes and staff.

Questions and concepts to consider

• Which staff are involved in the implementation of your SWPPP and how are activities coordinated across departments?
• If outside groups are involved in your SWPPP, what are their roles or authorities, and how do you coordinate with them?
• How is your stormwater program funded and what aspects of the SWPPP does the funding cover?