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Program for Regulated Phase II MS4s

A Regulated Phase II MS4 is any MS4 not already covered by the Phase I Program as a medium or large MS4. The MS4s is automatically designated if any parts or the entire MS4 is located in an urbanized area boundaries as defined by the U.S. Bureau of the Census (based on the latest decennial census). An urbanized area (UA) is a central place (or places) and the adjacent densely surrounding territory that together has a minimum residential population of 50,000 and a minimum average density of 1,000 people/square mile.

Regulated MS4s that are located outside of the UA may also have potential for being designated by the NPDES Permitting Authority (DEP). For more information on Phase II MS4 designation, see Rule 62-624.800, F.A.C.

Operators of a regulated MS4 are required to:

  • Reduce the discharge of pollutants to the "maximum extent practicable" (MEP)
  • Protect water quality
  • Satisfy the water quality requirement of the Clean Water Act

Phase II MS4 Permit Requirements

A generic permit is a general permit issued by DEP under the authority of Section 403.0885, Florida Statutes (F.S.) , which is the provision authorizing the state to implement the NPDES program. The Generic Permit for Stormwater Discharge from Phase II MS4s (DEP Document 62-621.300 (7)(a)).

Develop, implement and enforce a stormwater management program (SWMP) that includes the six minimum control measures

  1. Public Education and Outreach
  2. Public Participation/Involvement
  3. Illicit Discharge Detection and Elimination
  4. Construction Site Stormwater Runoff Control
  5. Post-Construction Stormwater Management in New Development and Redevelopment
  6. Pollution Prevention/Good Housekeeping for Municipal Operations

Annual reports will be required using the measurable goals for each minimum control measure as benchmarks for evaluating program effectiveness. During the first term of coverage, regulated Phase II MS4s must submit annual reports as specified in the Generic Permit for Stormwater Discharge from Phase II MS4s. Reports are due within six months of the anniversary of the date of permit coverage. In subsequent terms, the permittee must submit reports in years two and four, unless otherwise requested by DEP. Reports are required to be submitted using DEP Form 62-621.300(7)(d).

Obtaining Permit Coverage Under the Generic Permit

  1. Obtain copy of the Generic Permit for Stormwater Discharge from Phase II Municipal Separate Storm Sewer Systems, (DEP Document 62-621.300 (7)(a))
  2. Complete a Phase II MS4 Generic Permit NOI (DEP Form 62-621.300(7)(b)) and SWMP
  3. Submit NOI with applicable fees as required by Rule 62.4.050, F.A.C. to the NPDES Stormwater Program
  4. Re-apply for coverage 180 days prior to expiration of permit coverage in accordance with the generic permit

Frequently Asked Questions (FAQs): Provides answers to the most commonly posed questions to DEP regarding the NPDES stormwater Phase II MS4 program.

NPDES Stormwater Program
Florida Department of Environmental Protection

2600 Blair Stone Road, MS 3585
Tallahassee, FL 32399-2400
Phone: 866-336-6312 (toll-free)

Last Modified:
March 30, 2021 - 1:10pm

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