The U.S. Environmental Protection Agency (EPA) has recently withdrawn its proposal to the White House Office of Management and Budget (OMB) to revise the controversial numeric turbidity limit. These limits were first issued in December 2009 as part of the Final Rule entitled "Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category", which established the first enforceable numeric limit on the amount of pollutants in stormwater that may be discharged from certain construction and development sites (as described in Field Notes Vol. 18, No. 10). Immediately following the issue of this regulation, petitions were filed by the Small Business Administration and the National Association of Home Builders (NAHB) that identified calculation errors with the mandated numeric turbidity limit of 280 nephelometric turbidity units (NTUs). Subsequently, the EPA withdrew the limit to correct this calculation error and submitted a proposed rule to revise the turbidity limit to the Office of Management and Budget (OMB) in December 2010.

As stated on the EPA Website, the EPA recently withdrew this proposal to ensure that they adequately characterize the best performance achievable by the technology. Additionally, EPA has decided to seek additional treatment performance data from construction and development sites before proposing a revised numeric turbidity limit and plans to publish a Federal Register notice soliciting data in the near future. Once the review of a proposed rule revising the numeric turbidity limit is completed by OMB, the EPA will publish the proposed rule for public comment.

Look for more updates on the status of this important topic in future issues of Field Notes. If you have questions regarding this regulation or how it will impact Virginia builders and contractors, please contact Roy Van Houten or Mike Rolband.