Written by: Ryan Vulpis

In the state of North Carolina, many stormwater programs are required by the US EPA to maintain a Municipal Separate Storm Sewer System (MS4) Permit. This permit is designed to ensure that jurisdictions protect water quality within its jurisdiction by meeting six minimum control measures (MCM).

1. public education and outreach 2. public involvement and participation 3. illicit discharge detection and elimination 4. construction site stormwater runoff controls 5. post-construction stormwater management 6. pollution prevention and good housekeeping

In 2019, the North Carolina Department of Environmental Quality (NC DEQ) began auditing MS4 permit holders according to a 5-year audit schedule, intending to audit 20 percent of the State’s permit holders on an annual basis. NC DEQ plans to audit permittees within the state on a five-year cycle to ensure continued compliance. The three possible outcomes of an audit are a notice of compliance (NOC), notice of deficiency (NOD), or notice of violation (NOV) depending on if an infraction is found and the nature of the infraction(s) found. NODs and NOVs serve to alert the permit holders of infractions and request that the infractions be rectified immediately [1]. The EFC analyzed 29 audits completed by NC DEQ for trends in items of deficiency and non-compliance across stormwater programs. While two of the audited communities received notices of compliance, two communities received notices of deficiency and 25 communities received notices of violation.

Since this analysis was completed, NC DEQ finished 5 more audits. The results as of June 2020 are below [2]:

audit results: NOC: 3, NOD: 3, NOV: 24, Compliance decision pending: 5, total audits completed: 35


According to NC DEQ, the following infractions may lead to the issuance of a NOD or NOV:
• Illegal animal feedlot operations/discharge
• Discharge of wastewater without a permit
• Fish kills
• Late/non submittal of reporting requirements
• Improperly certified laboratory
• Limits and monitoring violations of NPDES permit
• illegal discharge of oil or hazardous substances
• Operation of a treatment works without a permit
• Failure to employ a properly certified wastewater treatment plant operator
• Violation of permit conditions other than limit or monitoring frequency
• Late registration or renewal
• Violation of stream standards
• Various violations of statutes and/or rules relating to water quality

When an MS4 permittee receives an NOV or NOD, they are required to perform a few actions.

1. Within 30 days of receiving the notice, the permittee is required to submit a response to the notice.
2. Within 120 days, the permittee is required to submit a draft Stormwater Management Plan as well as a self-audit of any sections that the DEQ did not audit themselves.
3. Pass a Council resolution about the audit’s findings (only for NOV recipients).

According to NC DEQ “the most common deficiencies have been a lack of required documentation, insufficient MS4 mapping, reactive rather than proactive illicit discharge programs, and poor housekeeping practices at municipal facilities.”

This analysis sought to find more nuanced trends in infractions by scanning through each audit and evaluating each permit holder’s performance based off ten criteria. These ten criteria serve to categorize the information in all the audits so that trends in infractions can be seen clearly. These categories represent key functions of an MS4 permit.

The criteria are as follows:
Current approved SWMP: The permittee is expected to maintain and update a Stormwater Management Plan which outlines the programs goals, operations, as well as the characteristics of the jurisdiction area. This plan is expected to be presented at the time of the audit.
Adequate Education and Outreach: The permittee is expected to measure the impact that each of its operations has on informing and educating the community. These operations range from media presences to events and activities run by the permittee.
Submitted Annual Reports: The permittee is expected to submit annual reports of their operations to the DEQ as part of the audit. These reports document the actions and accomplishments of the permittee for each year.
Performs Dry Weather Screening: The permittee is expected to perform observations of dry weather flows to determine the potential existences of illicit Stormwater discharges. Dry weather flows are water flows that do not contain running water on a year-round basis.
Adequate Employee Training: The permittee is expected to implement and document an appropriate training program for municipal staff who, as a part of their normal job responsibilities, may encounter or otherwise observe an illicit discharge or illicit connection.
Has an Updated Outfalls Map: The permittee is expected to keep and update a map of all outfalls within their jurisdiction.
Has Written Spill Response Procedures: The permittee is expected to maintain procedures for dealing with illicit spills within their jurisdiction.
Enforceable IDDE Stormwater Ordinance: The permittee is expected to maintain an Illicit Discharge Detection and Elimination (IDDE) ordinance or some other regulatory mechanism that provides the legal authority to prohibit illicit connections and discharges to the MS4.
Maintained a Written IDDE Program: The permittee is expected to maintain a written design of their IDDE program which serves as an outline of the program’s operations.
Adequate Staffing and Funding: The permittee is expected to maintain adequate funding and staffing to implement and manage the provisions of the stormwater plan and meet all the requirements of the permit.

Each of the criteria was posed in question form, for which the auditor awarded one of four answers depending on their findings: “Yes,” “No,” “Partially,” and “Not mentioned/not reviewed.” “Partially” was awarded when the auditor found that the criteria had been met but still fell short of permit guidelines. There are additional criteria used by the NC DEQ to audit MS4 programs. This list of criteria represents the most common infractions among audit reports as of May 2020. Because this is not an exhaustive list of all the items in an MS4 audit, it is possible for a community to meet these ten criteria and still be issued an NOV or NOD.

Trends in Compliance

Among the 29 audited communities audited before May 2020, more than 50 percent of communities were out of compliance in seven of the 10 criteria. The table below shows the percentage of non-compliance by category.

This chart shows the percentage yes, no, partially, and not mentioned for the different criteria

Based on the data collected from each of the 29 audited MS4s, the two most common criteria of infraction were not having an updated Stormwater Management Plan and failing to perform dry-weather screening; for each of these criterion, 72 percent of utilities were found to have not met the permit goals. Having an updated Stormwater Plan is an important part of a functioning program, as a plan outlines the specific functions and duties of the Stormwater program, as well as characteristics of the permit holder’s jurisdiction. Dry weather screening is a detection method for illicit discharges in dry flows and is therefore important for the permit goal of preventing and dealing with illicit discharges and connections.

Additionally, the criterion with the highest amount of permittees in compliance was the presence of an enforceable IDDE ordinance. 55 percent of audited MS4s were reported to have adequate IDDE legal authority within their jurisdiction, allowing them to identify illicit connections and enforce their removal.

Up Next in Stormwater

Stay tuned for a blog on the state of stormwater fees in North Carolina as of July 1, 2019.



[2] https://deq.nc.gov/about/divisions/energy-mineral-land-resources/energy-mineral-land-permits/stormwater-permits/npdes-ms4

Ryan Vulpis is a Research Assistant working on stormwater and drinking water research projects for the Environmental Finance Center. He is a junior at UNC pursuing a Political Science degree with a double minor in Environmental Studies and Medieval and Early Modern Studies. Ryan plans to apply to and attend law school after graduation, and hopes to work as an attorney one day.