Skip to main content

Stormwater General Permit 3-9050

General Permit 3-9050 was issued on September 1, 2020 and went into effect on December 1, 2020.

General Permit 3-9050 is a permit for stormwater runoff from impervious surfaces.  It is an important component of the Vermont Clean Water Act of 2015 (Act 64) and is designed to assist in the implementation of clean-up efforts in Lake Champlain, Lake Memphremagog, and stormwater-impaired waters, while also protecting high quality surface waters statewide. This general permit covers all operational stormwater permitting, including new development, redevelopment, and permit renewal. 

The following project categories are eligible for permit coverage under 3-9050:

  • A discharge from new development or redevelopment equal to or greater than ½ acre, provided the project does not qualify for one of the transition exemptions in General Permit 3-9050 1.5(F) (see below for a list of exemptions);
  • A discharge from the redevelopment of an existing impervious surface if the redeveloped portion of the existing impervious surface is equal to or greater than ½ acre provided the project does not qualify for one of the transition exemptions in General Permit 3-9050 1.5(F) (see below for a list of exemptions);
  • A discharge from the expansion of an existing impervious surface, such that the total resulting impervious surface is equal to or greater than one (1) acre;
  • A discharge from a combination of expansion and redevelopment of an existing impervious surface, such that the total resulting impervious surface is equal to or greater than one (1) acre;
  • A discharge from “impervious surfaces of three or more acres,” as defined in General Permit 3-9050;
  • A discharge that has been previously authorized pursuant to an operational discharge permit

Transition Exemptions from Coverage under General Permit 3-9050 1.5(F) 

Coverage under General Permit 3-9050 or an Individual Stormwater Discharge Permit is not required for stormwater runoff from the aforementioned ½ acre permitting thresholds, provided one of the following transition exemptions applies:

1. Except for applications for permits issued pursuant to Section 22-107(b)(6) (stormwater discharge construction permits) of the Stormwater Permitting Rule (Environmental Protection Rules, Ch. 22), complete applications for all local, State, and federal permits related to the regulation of land use or a discharge to waters of the State have been submitted as of July 1, 2022, the applicant does not subsequently file an application for a permit amendment that would have an adverse impact on water quality, and substantial construction of the project commences within two years from July 1, 2022;

2. Except for permits issued pursuant to Section 22-107(b)(6) (stormwater discharge construction permits) of the Stormwater Permitting Rule (Environmental Protection Rules, Ch. 22), all local, State, and federal permits related to the regulation of land use or a discharge to waters of the State have been obtained as of July 1, 2022, and substantial construction of the project commences within two years from July 1, 2022; 

 3. Except for permits issued pursuant to Section 22-107(b)(6) (stormwater discharge construction permits) of the Stormwater Permitting Rule (Environmental Protection Rules, Ch. 22), no local, State, or federal permits related to the regulation of land use or a discharge to waters of the State are required, and substantial construction of the project commences within two years from July 1, 2022; or,

 4. The construction, redevelopment, or expansion is a public transportation project, and as of July 1, 2022, the Agency of Transportation or the municipality principally responsible for the project has initiated right-of-way valuation activities or determined that right-of-way acquisition is not necessary, and substantial construction of the project commences within five years from July 1, 2022.

"Three-Acre General Permit"

Additionally, this General Permit serves as the “Three-Acre General Permit” as required under the Vermont Clean Water Act. 

In response to public comment, the Agency has provided "three-acre sites" additional time to prepare and submit the required permit applications.

Initial permit applications were accepted on a staggered schedule, starting 12 months from the effective date of the General Permit and extending through early 2023. Additionally, previously permitted “three-acre sites” were able to apply for permit coverage prior to expiration of their existing permits starting with the effective date of the General Permit. However, initial permit applications are no longer being accepted as all submittal due dates have passed. Full permit applications are now required, which must include an Engineering Feasibility Analysis to determine a "best-fit" stormwater system that uses modern stormwater treatment practices to filter, store, or soak up runoff. Once the stormwater system plan is approved, landowners will have up to five years to install the new stormwater systems. 

The Agency has notified property owners affected by the requirements for "three-acre sites" directly and have provided information on the application process.  This notification has affected roughly 700 projects, including 8,000 landowners.  Property owners in the Lake Champlain, Lake Memphremagog, and stormwater-impaired watersheds have been notified.  Properties outside those watersheds will be notified at a later date.  The Agency has also provided affected property owners a process for requesting reconsideration of a "three-acre site" designation.

The Agency received dozens of comments on the Draft General Permit.  In response to these comments, the Agency prepared a Response to Comments. See link below.  

Application Materials, Instructions and helpful information

Application Instructions, Forms and Worksheets

List of Stormwater Engineering Firms

When to Apply for 3 Acre Coverage

Stormwater Impact Fee Guidance and Payment Instructions

Isolated Impervious Surface Guidance for Existing Stormwater Retrofit Sites

Final Documents

General Permit 
Response to Comments