Chocolate Milk to Weak Tea: NC State Professor Can Discuss New EPA Regulation on Construction Runoff

Dr. Rich McLaughlin, professor of soil science and an expert in water quality protection at North Carolina State University, 919/515-7306 or rich_mclaughlin@ncsu.edu, is available to speak with reporters about a new Environmental Protection Agency (EPA) regulation on construction site runoff.

The new regulation – which goes into effect Feb. 1 for some states and will be fully phased in nationwide over the next four years – places limits on the amount of turbidity, or cloudiness, in runoff from construction sites. It also requires construction sites to monitor the runoff to ensure compliance. The rule takes effect in North Carolina in August 2011.

The regulation calls for the use of passive treatment systems (PTS) to reach turbidity limits. The rule frequently refers to research conducted by McLaughlin and others that shows the efficacy of protecting streams and lakes from construction runoff by using PTS. This includes natural fiber check dams – which slow the flow of water in ditches – treated with environmentally safe chemicals which cause sediment to clump together and settle out quickly. The combination costs about as much or less than current practices and is much more effective at limiting turbidity from roads and construction sites. The EPA cited this approach as being much more cost effective than the original proposed rule, which required construction site runoff  to be pumped through portable treatment plants.

McLaughlin conducts workshops on the use and applications of PTS, and EPA officials have been among the attendees.

McLaughlin says: “Construction site runoff looks like chocolate milk after passing through conventional practices, and this can be toxic to fish and other aquatic life. Sediment and turbidity are the biggest problems for our streams and lakes, so we’ve been developing more advanced methods which are relatively simple and inexpensive but which make the runoff look like weak tea instead of chocolate milk. We are happy that EPA has recognized this approach for reducing construction site impacts on water quality.”

– kulikowski –