PHILADELPHIA — The U.S. Environmental Protection Agency has announced it has sent orders to 79 municipalities in south central Pennsylvania requiring improvements to their Municipal Separate Storm Sewer System (MS4) programs.

The orders require the cited municipalities to correct problems with their respective MS4 programs and come into compliance with their Clean Water Act permits. MS4s are publicly owned drainage systems, including storm drains, pipes, and ditches, designed to collect and convey stormwater runoff in urbanized areas.

“These actions are critical since improperly managed stormwater can wash harmful pollutants into local streams and rivers,” said Shawn M. Garvin, regional administrator for EPA’s mid-Atlantic region. “EPA is committed to gaining compliance with these municipalities for the health of local waterways in Pennsylvania and the Chesapeake Bay.”

Urbanized areas contain large portions of impervious surfaces such as roads, rooftops and parking lots that channel stormwater directly into local streams, rivers, and other water bodies. Improperly managed stormwater runoff from urbanized areas can damage streams, cause significant erosion, and carry excessive nutrients, sediment, toxic metals, volatile organic compounds, and other pollutants downstream.

EPA will provide compliance information to municipalities receiving these orders, and will host a one-day conference on May 5 in Harrisburg, Pa., to discuss the MS4 requirements of the Clean Water Act.

For a list of municipalities receiving the orders, or more information about MS4s, please visit www.epa.gov, or http://cfpub.epa.gov/npdes/stormwater/munic.cfm, respectively.