February 1, 2010

Stormwater Discharge and New Construction


By Katie Jeremiah and Chris Reive

February 2010

Compliance May Cost Contractors Nearly $1 Billion Per Year

Construction sites of one acre or more will soon be subject to new compliance standards. As of February 1, states are required to implement changes to general stormwater permits for such construction sites, and water used to wash out concrete and construction materials, including stucco, paint, and curing compounds, as well as soaps or solvents used in vehicle and equipment washing, will be subject to new regulations. These new regulations will appear in the Oregon general permit when it is renewed, which is likely by the end of this year. But, that is not the end of the story.

These new requirements are just the first phase of a new EPA rule, which will also establish the first national standard containing numeric limitations on construction site stormwater discharges. Imposing enforceable numeric standards and limitations on stormwater from construction sites will significantly expand the reach of stormwater regulation and potential enforcement.

Permit Scheme

Under the Federal Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating sources of pollution that discharge into waters of the United States. Oregon's DEQ administers this program through the NPDES Storm Water Discharge General Permit #1200-C for Construction Activities.Construction projects that disturb one or more acres of land must register under this permit or obtain an individual permit.

Historical Stormwater Monitoring Requirements

The existing method of monitoring stormwater discharges from construction sites is based on visual observations of turbidity, i.e., the cloudiness of water that results from suspended particles. This can be measured by sensitive instruments or the trained eye.

Oregon usually requires compliance through subjective monitoring via visual inspection. Numeric turbidity monitoring is typical only for projects located within EPA-listed impaired watersheds. For those sites, if a 160 NTU (Nephelometric Turbidity Units) benchmark cannot be achieved, the operator must submit a plan showing what other methods would be implemented to limit the discharge.

New Numerical Effluent Limitations

For construction sites that disturb at least 20 acres of land, Oregon's new NPDES permit will incorporate EPA's new 280 NTU turbidity limitation and monitoring requirements. The deadline for the effective date for this new numeric standard is August 2, 2011, but it could go into effect sooner, as the general permit is expected to be renewed in ordinary course by the end of this year. The new general permit will specify the type, interval, frequency, location, and duration of numeric monitoring. The standard will relate to storm events and specific pollutants that are limited in the permit. Sampling will be required to be representative of the flow and characteristics of the discharges from the site, and the use of automated samplers and turbidity meters with data loggers may be required. There are new procedures for analyzing the sample for turbidity and appropriate quality assurance and quality control procedures. In 2014, the requirements will extend to sites that disturb more than 10 acres.

Industry Impact

Although the monetary benefit from improved water quality has been estimated by EPA to total $369 million, the new requirement comes with a hefty price tag. EPA estimates that compliance with the new requirements will impact more than 82,000 construction firms — 96 percent of which are small businesses — and cost the construction industry close to $1 billion per year. The economic impact statement that accompanied the new rule warns of firm closures, lost jobs, and potential difficulty in obtaining new-home financing as a result of increased construction costs associated with compliance. Despite these economic findings, EPA is optimistic that its phased approach to the numeric effluent limitation requirements will not disrupt the construction industry. Time will tell.

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