Memo_MS4 Post Construction in Coastal Counties_20210128

MEMORANDUM DATE: January 28, 2021 TO: Coastal County NPDES MS4 Permittees DEMLR Stormwater Staff FROM: Brian Wrenn, Director CC: DEMLR Stormwater Permitting Program File
SUBJECT: Notice of Regulatory Requirements for NPDES MS4
Post-Construction Requirements in Coastal Counties
The purpose of this memorandum is to provide the following notice to National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer Systems located within the 20 Coastal Counties (Coastal County MS4s):
Coastal County MS4s that do not already review, approve, and enforce Post-
Construction permit applications within their own jurisdictions are required to
develop and implement their own Post-Construction program by July 1, 2023. This memo will not result in any changes for those Coastal County MS4s who currently implement their own compliant Post-Construction program throughout their MS4 permitted jurisdictional area. However, Coastal County MS4s who do not currently implement a Post-Construction program will need to develop the ability to do so. This will require completing the tasks summarized in Table 1. The status of these tasks shall also be included in the appropriate MS4 annual reports. Please note that DEQ implements the stormwater management requirements in much of the 20 Coastal Counties in accordance with 15A NCAC 02H .1019. However, 15A NCAC 02H .1019(1)(a) states that “this Rule shall be implemented by local governments and other entities within the 20 Coastal Counties that are required to implement a Post-Construction program as a condition of their NPDES permits.” Please note that local governments that are subject to one of the following programs shall implement those programs instead of the requirements set forth in the Coastal Counties Stormwater Management Rule (15A NCAC 02H .1019): a. Tar-Pamlico Nutrient Strategy Stormwater (15A NCAC 02B .0731) b. Neuse Nutrient Strategy Stormwater (15A NCAC 02B .0711)
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c. Water Supply Watershed Protection Program Nonpoint Source and Stormwater Pollution Control (15A NCAC 02b .0624) One alternative to implementing these stormwater management requirements is the optional Universal Stormwater Management Program1 (USMP) as defined in15A NCAC 02H .1020.

Table 1: Requirements for Coastal County MS4 Post-Construction Program
Development
Task Deadline 1. Incorporate the four tasks and deadlines below into the required MS4 Stormwater Management Plan (SWMP). April 28, 2021 2. Select the Post-Construction program(s) to implement and notify DEMLR of selection (see below). December 31, 2021 3. Establish local ordinance(s) or equivalent authority to review, approve, and enforce the selected Post-Construction program. July 1, 2022 4. Staff the Post-Construction program and/or execute appropriate implementation contracts, agreements, etc. July 1, 2022 5. Fully self-implement a compliant Post-Construction program. July 1, 2023 Notes 1 MS4s electing to implement the optional USMP must have local ordinances/authorities to implement that program. Note that the USMP rule states that “Local governments located within one of the 20 Coastal Counties may elect to have the Division administer and implement the USMP, either in whole or in part, within their jurisdiction following their adoption of the program.” However, DEMLR is unable to provide the option for state implementation of a local ordinance because G.S. 150B-2(8a) prevents state agencies from implementing as rule any policy, guideline or other interpretative statement that has not been adopted in accordance with the NC Administrative Procedures Act. In other words, the state of North Carolina does not have the legal authority to administer, implement or enforce local ordinances/authorities; nor does it hold the legal authority to implement an optional program on behalf of any entity. Therefore, Coastal County MS4s electing to use the USMP are required to fully implement that program by July 1, 2023 per Table 1.