Stormwater Construction General Permit (CGP)

What is a Stormwater Construction General Permit (CGP)?

A Stormwater Construction General Permit (CGPs) is a subset of the National Pollutant Discharge Elimination System (NPDES) that manages the discharge of stormwater related to construction activity. Issued under the Clean Water Act (CWA), the CGP authorizes discharges of:

• • Sites that disturb one or more acres of land
  • Smaller sites that are part of larger, common plan of development

Operators covered under CGP are required to:

• • Develop and follow a Stormwater Pollution Prevention Plan (SWPPP).
  • Implement and maintain Best Management Practices (BMPs) or Stormwater Control Measures.
  • Minimize erosion, sediment discharge, and chemical pollution.
  • Meet stabilization deadlines after land disturbance activities.

Who Issues CGPs?

Stormwater CGPs are authorized either by the US Environmental Protection Agency (EPA) or state environmental agencies.

1. 1. States Authorized by EPA
      1. Most states have authorization under the Clean Water Act (CWA) to administer their own stormwater permitting programs
      2. Specific regulations thus differ state to state (e.g. The Stormwater CGP in Tennessee is known as TNR 100000)
   2. Jurisdiction Where EPA Remains the Authority
      1. States: Massachusetts, New Hampshire, New Mexico, Idaho
      2. District of Columbia (DC)
      3. US Territories (except US Virgin Islands)
      4. Tribal lands
      5. Lands of Exclusive Federal Jurisdiction (e.g. national parks, military bases, etc.)

General Steps to Apply to CGP

The steps to apply for Stormwater CGP follow:

1. 1. Determine Eligibility
      1. Project disturbs ≥1 acre of soil disturbing activities
      2. Disturb <1 acre but is part of a common plan of development
   2. Develop a SWPPP
      1. Outline site-specific erosion controls
      2. Identify pollutant sources and BMPs
      3. Include inspections, maintenance, and stabilization procedures
   3. Submit Notice of Intent (NOI)
      1. Submitted 14 days before construction
      2. Submitted within 30 days for emergency projects
   4. Many CGPs require a Professional Engineer (PE) or a Landscape Architect to prepare the following, when necessary:
      1. Design or modification of sediment basins or other sediment controls
      2. Drainage design including hydraulic, hydrologic or other engineering calculations
   5. Implement Erosion & Sediment Controls
      1. ≥5 acres disturbed: Begin stabilization immediately, complete within 14 days
      2. Inactive areas: Begin stabilization and complete within 7 days of initiation

Recent CGP Updates

The most recent EPA CGP was updated in 2022, with the following key changes:

1. 1. Expanded eligibility for projects on Lands of Exclusive Federal Jurisdiction
   2. New Definition of Lands of Exclusive Federal Jurisdiction
   3. Clarification of requirements for projects discharging to receiving waters within Lands of Exclusive Federal Jurisdiction
   4. Clarification of eligibility requirements related to endangered species

For specific details regarding the modifications, refer to the Federal Register page on Modification to 2022 NPDES CGP for Stormwater Discharges from Construction Activities.

Staying Ahead of CGP

Navigating the Construction General Permit (CGP) process can be challenging due to varying state-specific regulations and federal requirements. SEC strongly recommends that companies seek guidance from experts to accurately determine permit applicability and select the most efficient path to compliance. Our SEC team is ready to support you every step of the way, helping ensure your project stays on schedule and fully compliant with stormwater regulations!