United States: New Requirements For Storm Water Permits For Construction Sites

In 1972, Congress revised the Clean Water Act (CWA), to prohibit the discharge of any pollutant into navigable (surface) waters of the United States from any point source unless the discharge is authorized by a National Pollutant Discharge Elimination System (NPDES) permit. Initially, NPDES focused on industrial processes and municipal sewage treatment pollution discharge. Gradually, it became apparent that other point sources, such as construction sites, were a major contributor to water pollution. In 1987, Congress further amended the CWA to expand requirements for NPDES permits on construction sites, among other things.

This revision was implemented in two phases. Phase I required all large construction activities (disturbing greater than five acres) to obtain a NPDES permit by 1992. Phase II, issued in 1999, required NPDES permits for small construction activities (disturbing greater than one acre and less than five acres) beginning on March 10, 2003. "Disturbing" generally means grading, excavating or other clearing.

In all but six states (Alaska, Arizona, Idaho, Massachusetts, New Hampshire, and New Mexico), the EPA has authorized states to issue their own NPDES. For these six states not authorized by EPA, NPDES permits are obtained from EPA. Since requirements can differ between states, it is important to consult the state permitting authority in which the construction site is located, for requirements specific to that state. (e.g. for construction sites in Utah, consult the Utah Division of Water Quality).

The following three items are required for a Phase I permit, and Phase II state requirements will be similar:

• Submission of a Notice of Intent (NOI) that includes general information and a certification that the activity will not impact endangered or threatened species. (Most states do not require the certification).
• Development and implementation of a storm water pollution prevention plan (SWPPP) that includes the appropriate best management practices (BMPs) to minimize the discharge of pollutants from the site. BMPs may include sediment basins and/or sediment traps, silt fences, vegetative buffer strips, or equivalent sediment controls.
• Submission of a Notice of Termination (NOT) after final stabilization of the site has been achieved as defined in the permit or when another operator has assumed control of the site.

The "operator" must submit the NOI, etc. The term "operator" generally refers to either those who have the construction plans and specifications, and the ability to modify those plans and specifications; or those assigned with the day-to-day operational control of activities that ensure compliance with a SWPPP. Permits must be obtained by all parties who claim "operational control". General conditions to construction contracts should assign responsibility for obtaining permits. Permits must be obtained for each different construction site.

Activities disturbing less than one acre are small construction activity only if they are part of a larger common plan disturbing between one and five acres. If less than one acre, the NPDES authority may determine that storm water pollution is not a risk and not require a permit.

Waivers may be obtained from the NPDES permitting authority, provided that the site is a small construction activity and the operators certify to either one of two conditions:

• Low predicted rainfall potential (activity occurs during a negligible rainfall period, where the erosivity factor is less than 5 during the period).
• A determination that storm water controls are not needed, based on total maximum daily load data or an equivalent analysis that determines no control is needed