First National Effluent Limit for Construction Runoff Proposed by U.S. EPA

A proposed rule released by the U.S. Environmental Protection Agency (EPA) Nov. 19 would establish the first national effluent (discharge) limit for stormwater runoff from construction sites.  Upon early review, it appears that AGC’s advocacy efforts and close work with EPA staff have produced a workable proposal that recognizes the importance of providing contractors with the flexibility to select best management practices (BMPs) to fit the conditions of their sites.  Much work remains, however, to ensure that the final rule does not include a strict numeric limit dictating the amount of sediment that may lawfully be discharged from construction sites across the country. The proposal would require contractors to meet EPA’s technology-based “floor” on most sites by installing and maintaining a range of erosion and sediment controls that “are generally recognized and accepted as effective” BMPs.  Construction sites disturbing 10 or more acres of land at a time would also need to install sediment basins to treat their stormwater discharges.  In addition, a strict numeric limit on the allowable level of turbidity would apply to sites of 30 acres or more that are located in rainy areas where the soil has high clay content. AGC is analyzing EPA’s proposal with an eye to the underlying data on the costs and benefits of the rule and will keep chapters and members informed of its actions.  The construction and development (C&D) effluent limitation guideline (ELG) proposal and other information are online here. EPA will accept public comment for 90 days after the proposal appeared in the Federal Register on Nov. 28.  The C&D ELG options being considered by EPA are as follows: Option 1 is a non-numeric ELG, based on the use of “effective” erosion and sediment control practices to minimize and control the discharge of pollutants in stormwater and other wastewater from construction sites. Sites disturbing 10 or more acres also would be required to install sediment basins to treat their stormwater discharges. Option 2 is a numeric discharge limit for turbidity of 13 NTU (nephelometric turbidity units) – in addition to the Option 1 requirements – that would require site operators to monitor stormwater running off certain larger construction sites to demonstrate compliance.  Specifically, sites of 30 acres or more that are located in areas of the country with high rainfall and soils with high clay content would have to use advanced treatment systems (i.e., ATS – chemical treatment and filtration of stormwater discharges) to meet a numeric limit for turbidity.  Option 3 applies the numeric discharge limit for turbidity – in addition to the Option 1 requirements – to all sites with common drainage points serving 10 or more disturbed acres at one time.  This option would not take soil type or rainfall intensity into account.  In the coming months, AGC will focus its regulatory review work on bolstering support for EPA’s proposed Option 1 while – at the same time – demonstrating that EPA has significantly underestimated the cost and impact of Options 2 and 3 on the industry.  AGC plans to ask EPA to extend the public comment period.    To learn more about why EPA is promulgating a C&D ELG and AGC’s close involvement in the Agency’s effort, see the latest features in AGC’s Environmental Observer newsletter online at http://newsletters.agc.org/environment/.  For questions, please contact Leah Pilconis at pilconisl@agc.org.