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Environmental Protection Agency (EPA) Proposes New Water Discharge Guidelines for Construction and Development Activities

  • February 10, 2009

Background Of New Rule

The EPA has proposed a long-awaited regulation that strengthens the existing controls on discharges from construction and development (C&D) activity by establishing technology-based effluent limitations guidelines (ELG).  The regulation establishes both non-numeric limitations and, for the first time, numeric limitations for larger C&D sites.

The proposed rule was published in the Federal Register on November 28, 2008 and is available by clicking here.  The deadline to submit comments to the EPA is February 26, 2009.  The EPA intends to finalize the rule by December 2009.

According to the EPA, improper control of stormwater discharges from C&D activity is a major contributor of sediment to streams, lakes and other surface water bodies.  The EPA reports that sediment, along with other pollutants in stormwater discharges, causes turbidity, which can harm aquatic ecosystems, increase drinking water treatment costs, and impair recreational uses of impacted waters.

The EPA estimates the annual cost of this new rule to be $1.9 billion and that improvements at C&D sites made pursuant to this rule will result in an annual reduction of 27 billion pounds of discharged sediments.  The EPA expects full implementation within five years of the effective date of the final rule, which would be around December 2014.


What C&D Activity Is Regulated?

The new rule applies to all C&D activity, which is defined broadly in the proposed rule to include site selection, planning and land-disturbing tasks (e.g., clearing, excavating, grading and other site preparation work).  The new rule covers construction of residential, nonresidential, industrial, commercial and institutional buildings (under NAICS 236) and also includes utility system, highway, street and bridge construction as well as other heavy and civil engineering construction (under NAICS 237).


What Specifically Does This Rule Require?

The new rule requires developers, builders and others who conduct C&D activity to meet specific standards for stormwater discharged from construction sites and to implement certain measures to meet these standards.  The rule can be divided into three main elements.

The first two aspects of the new rule will require best management practices (BMPs) that many of our clients already implement.

First, the new rule will require C&D sites disturbing 10 or more acres to install a sediment basin to contain and settle sediment from stormwater runoff.  EPA does not dictate that a specific technology of sediment basin be used; however the rule will provide minimum standards of design and performance for all basins.1

Second, the new rule will establish a national technology-based "floor" of non-numeric effluent limitations , requiring dischargers to provide and maintain effective erosion control measures, sediment control measures and other pollution prevention practices.  To achieve this, the rule specifies particular minimum BMPs to meet the effluent limitations, such as minimizing exposed soil, diverting stormwater away from exposed soils, perimeter controls (e.g., diversion dikes, removing sediments from paved surfaces, etc), and prohibiting or minimizing the discharge of hazardous materials associated with construction activities (e.g., concrete, paint, fuels, pesticides, etc.) to stormwater.

However, the third component to the new rule will likely change current practices at C&D sites and potentially requires a builder or developer to incur significant new costs.  Under the new rule, C&D sites disturbing 30 or more acres are required to meet a numeric turbidity level of 13 nephelometric turbidity units (NTUs).  The numeric limit is intended to remove fine-grained (silts) and slowly settling (clay) or non-settleable particles contained in stormwater that cannot be effectively removed by conventional stormwater BMPs (like sediment basins or traps).

The imposition of a numeric requirement on stormwater discharged from construction sites is different from the current general stormwater NPDES permit (NCG0100000, issued October 1, 2008), which does not require analytical sampling of stormwater and does not impose a specific, numeric turbidity limit.  The current general permit focuses on whether sediment can be visually observed at the stormwater outfall.

Under the new rule, permittees would have the flexibility to select the best-fit management practices for each site to meet the 13 NTUs limit, although the EPA suggests active treatment systems, which consist of polymer-assisted clarification followed by filtration.  Indeed, it is likely that most C&D sites subject to this portion of the new rule will need to obtain one or more active treatment systems in order to meet the low limit of 13 NTUs.


Are State and Other Federal Stormwater Programs Affected by This Rule?

EPA acknowledges that many state and local governments have existing effluent limitations and standards for controlling stormwater and wastewater discharges from construction sites.  The proposed ELGs are intended to work in concert with these existing state and local programs.  Once finalized, all states will be required to adopt the new ELG standards as minimum requirements.

The new rule will apply to C&D sites through incorporation in individual and general National Pollutant Discharges Elimination System (NPDES) stormwater permits.  Compliance with the new rule will not, however, exempt a discharger from any other requirements of the Clean Water Act (CWA).  For example, if construction activity results in the "discharge of dredged or fill material" into "waters of the United States", the discharger must still obtain a permit from the Corps of Engineers under section 404 of the CWA.

Requested Public Comment on the New Rule

The EPA is soliciting public comments on the rule through February 26, 2009.  The public comment period is an invaluable tool for interested private citizens to influence the rule making process by presenting real world data and experiences to the EPA for consideration.  For example, EPA has specifically requested comment on increasing the proposed 13 NTU limit to 50 to 150 NTUs (or some other limit), so that passive treatments can be used in lieu of active treatment systems.

If you would like for us to submit comments on your behalf, please contact a member of the Environmental Practice Group at Parker Poe Adams & Bernstein LLP.  We would be happy to work with you to submit detailed and specific comments and concerns to the EPA on this rule.

1Sediment basins must withstand a two-year, 24-hour storm event or, alternatively, a water storage volume of 3,600 ft3 per acre of total watershed; must provide for sediment storage volume of at least an additional 1,000 ft3 per acre of disturbed land; length must be four times the width; must include an outlet device, such as a skimmer, designed to withdraw surface water; and must allow minimum residence time for stored water of not less than 24 hours.