Muddy Waters: The EPA’s First Effort at National Monitoring Requirements and Numeric Limitations on Construction Site Stormwater Discharges

Muddy Waters: The EPA’s First Effort at National Monitoring Requirements and Numeric Limitations on Construction Site Stormwater Discharges

By Michelle V. "Missy" Wycinsky

The National Pollutant Discharge Elimination System (NPDES) is federal water permitting program that seeks to control water pollution by regulating point sources that discharge pollutants into waters of the United States. All construction sites subject to permits (construction activity that disturbs one or more acres of land) must implement erosion and sediment controls and pollution prevention measures. Virginia is one of several states authorized by the federal government to implement and administer the NPDES stormwater program through its individual state Construction General Permit (CGP).  Virginia's Department of Environmental Quality administers the federal program through the policies and procedures established in the Virginia Pollutant Discharge Elimination System (VPDES) permit regulations. 

On December 1, 2009, the U.S. Environmental Protection Agency (EPA) finalized Effluent Limitation Guidelines (ELG) for construction and development activities on NPDES-permitted construction sites.  Codified in Title 40 of the Federal Regulations, Part 450, the ELG establishes the maximum permissible limit of pollutant discharge off sites subject to the NPDES program.  This new rule set a maximum numeric turbidity discharge limitation of 280 nephelometric turbidity units (NTUs) from any point source.  Turbidity refers to water clarity and is a degree of measurement relative to the presence of suspended particulates/sediment therein. 

Although the ELG standards were effective February 1, 2010, the EPA has phased its schedule of implementation for this standard to allow states significant time to develop and establish monitoring, compliance, and reporting processes/procedures.  Further, once the ELG are implemented, each state will determine the monitoring frequency, location, analysis, and quality control protocols attendant to a permit holder's compliance with the regulations.  The EPA did not prescribe a mandate as to how the turbidity threshold and other ELG are met; instead, the EPA noted that contractors and developers can meet the requisite levels by employing low-impact development techniques (e.g. infiltration trenches, diversion berms, and settling basins with polymer additives) or by phasing the construction such that they limit the amount of land disturbed at any one time on a project below the applicable threshold.

Perhaps most significantly, though, authorized states - like Virginia - are not required to incorporate the ELG limits and obligations until their respective state CGP is renewed.  The authorized states' respective CGPs expire at different times between 2010 through 2014; Virginia's CGP is one of the last to expire - in July 2014.  As such, it is possible that none of the standards established in the ELG (detailed below) will be applicable to VPDES-permitted projects until July 2014.  Notably, however, authorized states may adopt provisions that accelerate the implementation timeframe and apply more stringent effluent standards than those promulgated by the EPA.  As such, Virginia contractors and developers should be mindful that any of the ELG standards could become applicable to their VPDES-permitted projects long before July of 2014.  The prudent developer and contractor will monitor the Commonwealth's treatment of its CGP to determine whether (or if) it is prematurely modified to incorporate the federal ELG limits.  Contractors and developers should also anticipate that meeting these new requirements for stormwater discharges will increase the time, resources, and costs associated with VPDES-permitted projects.

Under the ELG (and unless accelerated by an authorized state's more stringent regulation), by August 2011, all construction activities that disturb 20 or more acres of land at one time must not exceed an average daily turbidity discharge limit.  After February 2014, the 280 NTU effluent limit will be applied to construction activities that disturb 10 acres or more of land.  The turbidity effluent limit must be met for the two-year, 24-hour storm event (i.e. it does not apply on days with precipitation that exceeds this storm event).  The ELG also requires that contractors and developers implement the following Best Management Practices: 1) erosion and settlement controls; 2) soil stabilization; 3) prohibition of discharge from dewatering activities; 4) implementation of specific pollution prevention measures; 5) prohibition of discharge from washout activities or fuels, oils, and other pollutants used in vehicle/equipment operation; and 6) utilization of outlet structures when discharging from basins and impoundments.

Authored by attorneys, these articles are meant to bring awareness to these topics and are not intended to be used as legal advice.  For more information, contact Mike at 757-446-8626 or Bill Franczek at 757-446-8600.  Visit: www , for our library of Construction Law Tips.  Suggestions for a topic? E-mail


Michelle V. "Missy" Wycinsky is an attorney with Vandeventer Black and concentrates her law practice in civil litigation, construction, public contracts and professional liability defense.

Her litigation practice focuses on products liability, professional liability, construction defect, commercial disputes and breach of contract.

In the area of professional liability defense, Missy's practice involves the representation of architects, engineers, project owners and contractors in a variety of construction, professional liability, employment and contract disputes and related matters.