State regulators plan to loosen runoff rules at construction sites

Critics say new rules could run afoul of Clean Water Act

An apartment building under construction on McEwen Drive in Franklin, Tennessee. (Photo: Tennessee Lookout staff)

A state plan to roll back long-standing regulations for construction site runoff is drawing opposition from environmental groups that fear Tennessee creeks and streams will suffer.

Stormwater discharge from construction sites - rainwater that sweeps soil or other particles off-site - can flow into nearby waterways, often creating silt deposits that affect aquatic life and water quality.

Historically, silt has been one of the primary pollutants in Tennessee's waterways, a paper explaining the proposed new rules from the Tennessee Department of Environment and Conservation, or TDEC, said. Just one millimeter of soil spread over a one-acre site can weigh 5 tons, and "even a minor uncontrolled construction activity can cause major impairment in surface water" through runoff, the paper said.

Nevertheless, TDEC is proposing significant changes in state environmental oversight of builders, developers, property owners, contractors and subcontractors in controlling runoff.