Stormwater five

Construction stormwater

Construction is one of the eleven categories of industrial activity that were regulated at the time of the 1987 amendments to the Clean Water Act. This category deserves special attention because polluted runoff from construction sites is such a major problem in so many watersheds across the country, and because EPA has required specific NPDES permits for construction activity.

In Phase I, only construction sites five acres or larger were required to be covered by a NPDES permit. With Phase II, as of 2003, any disturbance of one acre or greater, or even a site less than one acre if it is part of a development plan that will disturb one acre or greater, is now regulated. The permitting authority can also regulate any construction site regardless of its size if there is a potential for the disturbance to contribute to a violation of a water quality standard or to significantly contribute pollutants to waters 40CFR122.26(b)(15)(ii)).

Permitting authorities

Many states already have erosion and sedimentation control programs, and the state construction stormwater permits are usually coordinated with those programs. The same entity responsible for administering the existing program, such as the county, often takes over the responsibility for granting coverage under the general construction stormwater permit. The state agency, or the EPA in states that don't have permitting authority, retains oversight authority over the general permits. The state usually retains control over any individual construction stormwater permits.

Requirements of the construction stormwater program

In most states, regulated construction activity is covered through a general permit. The site operator must file a “Notice of Intent” (NOI) with the permitting authority before disturbing any earth.

Generally, the NOI form requires information about the location of the site, controls planned and sometimes, the name of the receiving stream. Most construction stormwater permits do not require pre-construction monitoring, yet this step is critical in determining whether the controls are working during construction.

Federal requirements do not require specific pollution limits for construction sites. Instead they focus on the preparation of a stormwater pollution prevention plan for each site. Most state construction stormwater permits depend on stormwater management plans that describe the erosion and sedimentation controls that will be put in place during construction. The plan may or may not have to be submitted to the permitting authority before construction has begun, though it would be a good idea. The plan should at least be on site, and it must be available to the public.

The construction stormwater program is not only about getting a permit and preparing a stormwater management plan. The controls identified in the plan need to be implemented, the effectiveness of the controls needs to be monitored, and changes to the plan and the controls need to be made when they are not adequate to protect waters. There should be a timeline for the implementation of the controls explaining how they will change as the project progresses. Once construction is completed, the operator must submit a “Notice of Termination” (NOT). The NOT form usually requires at least a signed statement claiming that the site has been stabilized. The definition of “stabilized” may be different in every state, however. Some states, including Pennsylvania and Wisconsin, have included requirements for post-construction planning and agreements before the NOT can be submitted.

An individual permit is warranted under certain circumstances, such as when threatened or endangered species are present or when there is potential for the discharge to cause or contribute to violations of the water quality standards (69Fed.Reg.39,087,39,089(July1, 2003)).

States can impose more stringent requirements than federal rules require, including specific pollution limits. For example, Wisconsin’s construction stormwater permit requires an 80% reduction of the sediment running off a construction site (on an average annual basis) when compared to a site with no pollution controls. In Michigan, permits are required for any construction within 500 feet of a stream or a lake, regardless of the size of the disturbance. Since many state construction stormwater permit programs are based on a sedimentation and erosion control program already in place, it is important to make sure that the program at least meets the federal construction stormwater NPDES requirements. The existing program may not be sufficient.

Unfortunately, county, state and federal agencies simply do not have enough people or money to inspect every permitted site each time it rains. In fact, many states’ inspection processes are entirely complaint-driven. Citizen information about the pollution controls on and impacts of construction sites during rain storms can improve compliance with the program.

All construction sites are new sources of pollution. Whether they are covered by a general or an individual permit, it is important that the construction stormwater permit requires documentation of the current condition of the waters receiving the impact of the activity and the designated uses and the relevant criteria for those waters. If there is any existing impairment, make sure the agency (and/or the permittee) demonstrates and documents how this activity will not “cause or contribute” to it (40CFR122.4(i)).Where water quality is better than basic water quality standards would require, an antidegradation analysis is necessary (and should be documented) to protect that quality to the greatest extent possible.

Compliance

Watershed groups can now do much more than they could just a few years ago to help prevent and control polluted runoff from construction sites. Learn what permits have been issued in your watershed and what each permit requires. Keep an eye on active sites for compliance, and notify the permitting authority when problems are suspected or detected. When the construction is completed, the site should be stabilized. Ask the state whether responsibility for maintaining the longer term sedimentation and erosion controls has been documented. Not many states require that as part of the construction stormwater permit, but all municipalities covered under the Phase I or II permits must be responsible for post-construction controls within their jurisdiction.