Under the National Pollution Discharge Elimination System, Phase II (NPDES), projects that propose to disturb more than 1 acre of land require a permit for the discharge of stormwater.   The Construction General Permit 3-9020 authorizes permittees to discharge stormwater runoff from construction activities in Vermont provided the project is in compliance with the requirements of the permit.

The permit requirements for the project are dependent on the risk posed by the project.  Projects risks are evaluated by completing an Appendix A form, to determine if the project, as designed, meets the Low Risk or Moderate Risk categories.  Projects with higher risks are required to obtain an Individual Permit.

Coverage under the Operational General Permit 3-9015 is required for discharges of stormwater runoff from the construction, expansion, and redevelopment of impervious surfaces, as described in detail in the Stormwater Management Rule including the following:

• A discharge from new development equal to or greater than one (1) acre of impervious surface;
• 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, except that a permit is not required for an expansion that meets the exemption in subsection 18-304(a)(4) of this Stormwater Management Rule;
• 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 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, except that a permit is not required if the exemptions in subsections 18-304(a)(4) and (5) of this Stormwater Management Rule are met;
• A discharge from any size of impervious surface if the Secretary determines that treatment is necessary to reduce the adverse impacts of the discharge due to the size of the impervious surface, drainage pattern, hydraulic connectivity, installation or modification of drainage or conveyance structures, location of the discharge, existing stormwater treatment, or other factors identified by the Secretary; and
• A discharge from an existing impervious surface of equal to or greater than one (1) acre if the Secretary has previously issued an individual stormwater discharge permit or individual temporary pollution permit for the discharge or has previously granted coverage for the discharge under a stormwater discharge general permit.

No Operational Stormwater permit is required in Vermont for:

1. Discharges of stormwater runoff from farms subject to accepted agricultural practices adopted by the Secretary of Agriculture, Food And Markets and discharges of stormwater runoff from silvicultural activities subject to accepted management practices adopted by the Commissioner of Forests, Parks and Recreation;
2. Discharges of stormwater runoff that are already covered by a NPDES permit for a direct or indirect discharge from a wastewater treatment plant or by a permit issued pursuant to Vermont’s Underground Injection Control Rule;
3. Discharges of regulated stormwater runoff from new development, redevelopment, or expansion of impervious surfaces if the discharge did not require a stormwater discharge permit prior to the effective date of this Stormwater Management Rule, provided that:
   • A technically complete application for all local, state, and federal permits, except NPDES construction activities permits, related to either the regulation of land use or a discharge to state waters has been submitted as of the effective date of this Stormwater Management Rule, the applicant does not subsequently file an application for permit amendment that would have an adverse impact on water quality, and substantial construction (e.g. construction of roads and drainage infrastructure) of the project commences within two years of July 1, 2005;
   • All local, state, and federal permits, except NPDES construction activities permits, related to either the regulation of land use or a discharge to state waters has been obtained as of the effective date of this Stormwater Management Rule, and substantial construction (e.g. construction of roads and drainage infrastructure) of the project commences within two years of July 1, 2005;
   • No local, state, or federal permit, except NPDES construction activities permits, related to either the regulation of land use or a discharge to state waters is required, and substantial construction (e.g. construction of roads and drainage infrastructure) of the project commences within two years of July 1, 2005; or
   • The new development, redevelopment, or expansion is a linear project, and an order of necessity has been issued or right-of-way acquisition has been substantially completed as of July 1, 2004, and construction of the project commences within five years after July 1, 2004;
4. The expansion of an existing impervious surface, such that the total resulting impervious surface is equal to or greater than one (1) acre, if:
   • the increase or addition of impervious surface is less than 5,000 square feet; and
   • the expansion is made to existing impervious surfaces created prior to June 1, 2002; and
   • This exemption may be used for consecutive expansions of an existing impervious surface up to a cumulative total of 5,000 square feet. When the cumulative total expansion exceeds 5,000 square feet, the expanded impervious surface in excess of 5,000 square feet must comply with the treatment standard in subsection 18-306(a)(1) of this Stormwater Management Rule.
5. The redevelopment of an existing impervious surface if the redeveloped portion of the existing impervious surface is less than one (1) acre;
6. Discharges of regulated stormwater runoff into a water that is not a stormwater-impaired water from impervious surfaces in existence as of January 1, 1978;
7. Discharges of regulated stormwater runoff into a water that is not a stormwater-impaired water from impervious surfaces of less than one (1) acre regardless of when constructed;
8. Discharges of regulated stormwater runoff from a single family or duplex residence, including associated driveways, that are not built as part of a multi-family residential subdivision; and
9. Discharges of regulated stormwater runoff from the portion of a bridge superstructure that spans the normal water level of a receiving water and normally no water from the approaches flows to the bridge deck

Operational Stormwater permits require designer certification that the stormwater system was constructed in accordance with the design at the completion of construction.

Additionally, all Operational Stormwater permits require annual inspections.