Audit Process

DEQ audits MS4s at least once per permit term, typically right before the permit is renewed.  Per the MS4 Audit Schedule, approximately 20% of MS4s are audited each year.  In the short term, this results in 42 MS4 permits being short cycled, 25 being extended and 55 that have no change in renewal date.  Read about audits below and also find more detailed information by viewing the MS4 Audit Presentation.

Step 1:  Implement an Excellent MS4 Program

DEQ uses the MS4 Audit Report Template to conduct audits.  You are encouraged to apply this template to your MS4 program as soon as possible to determine if it meets permit requirements. You should address any deficiencies in your program as soon as possible.

If you do not have a Stormwater Management Plan (SWMP), then developing one is a top priority.  You can use the Stormwater Management Plan (SWMP) Template as you prepare a SWMP for the remainder of your permit term.  The SWMP Template Instructions and the General SWMP Guidance will also be helpful.  If you would like DEQ to provide one 30-minute courtesy review of your SWMP in advance of the audit, please contact Jeanette Powell.  

Step 2:  Provide Documentation When Requested by DEQ

DEQ staff will contact you via certified mail during your audit year with a date for your audit and a request for permit documentation. The following documentation for the current permit shall be submitted within seven (7) calendar days of request:

  1. Stormwater Management Plan (SWMP)
  2. Annual Reports not already submitted through DEQ’s online BIMS SWMPA portal
  3. MS4 Program organizational chart and MS4 program responsibilities for staff/positions
  4. MS4 map of outfalls and receiving waters
  5. Formal stormwater program implementation agreements with any other entities
  6. Post-construction ordinance reference or link
  7. Illicit Discharge Detection and Elimination Program Plan
  8. MS4 Operation and Maintenance Plan
  9. Municipal SCM Operation and Maintenance Plan

Step 3:  Wait for DEQ to Determine the Audit Type

There are two types of audits: live and remote.  DEQ will determine the type of audit based on the documentation submitted in Step 2.

A remote audit will be performed if documentation demonstrates significantly non-compliance.  In this case, DEQ will issue a Notice of Violation.  Remote audits consist of an online conference with MS4 staff, and on-site inspection(s) of any municipal industrial facilities that are potentially subject to the MS4 permit or an NPDES industrial stormwater permit.  Remote audits will typically be completed over two days. MS4s receiving remote audits will also receive interim program reviews mid-permit term under their new MS4 permits.  Program reviews are mini-audits that include technical guidance and discussion of any needed program changes to bring the MS4 into compliance by the end of the permit term.  Interim program reviews will typically be completed over one day and performed live.

A live audit will be performed if documentation demonstrates significant compliance.  Live audits consist of on-site interviews with MS4 representatives, and on-site inspection(s) of municipal industrial facilities that are subject to oversight under the MS4 permit and/or NPDES industrial stormwater permitting.  Live audits will typically be completed over one or two consecutive days, depending on the size and complexity of the MS4 Program.

Step 4:  Prepare for and Participate in the Audit

Regardless of the audit type, the permittee should:

  • Arrange for access to any electronic tools routinely utilized to implement the MS4 Program (e.g. databases, GIS, etc.). 
  • Ensure that all relevant staff, contractors, and management/leadership/officials are present for scheduled audit meetings.  
  • Answer questions posed by DEQ staff from the MS4 Audit Report Template.  Typically DEQ will select only some of the Minimum Control Measures to audit.

In addition, for live audits the permittee should:

  • Provide an appropriate meeting room that will accommodate its representatives, and 2-3 staff members from DEQ.  On-site meeting rooms must provide adequate space for all participants to maintain appropriate social distancing protocols for COVID-19. 
  • Ensure that all participants of on-site meetings wear personal protective equipment in accordance with current state requirements, guidelines and recommendations.
  • Maintain appropriate social distancing protocols for COVID-19 at all times. 

The most common deficiencies found during MS4 audits are:

  • Lack of required documentation
  • Insufficient MS4 mapping
  • Reactive rather than proactive illicit discharge programs
  • Poor housekeeping practices at municipal facilities

    Step 5:  Respond to the Audit Report & Create a New SWMP

    After an audit, the MS4 should receive an Audit Report within 60 days.  In addition, the permittee will receive a Notice of Compliance, Deficiency or Violation with specific instructions to address audit issues. 

    All permittees will be required to self-audit any program areas that were not audited by DEQ and to develop and submit a new SWMP for review and approval.  For Phase II MS4s, the new SWMP should be provided using the Stormwater Management Plan (SWMP) Template.  Be sure to consult the SWMP Template Instructions as you prepare your new SWMP.  The General SWMP Guidance will also be helpful.

    Step 6:  Submit a Permit Renewal Application

    After the DEQ concurs on your new SWMP, you will be notified to submit an MS4 Permit Renewal Application.  DEQ will prepare a draft permit that is similar to the Baseline Phase II MS4 Permit Template.  The draft permit and draft SWMP will be sent to public notice for 30 days and issued by DEQ after any public comments are addressed.