Stream Study Finds Bacteria in Polluted Runoff

(HARRISBURG, PA)—Testing for polluted runoff at swimming, fishing, and boating locations in southcentral Pennsylvania found levels of bacteria in the water that in some cases were more than 10 times over health standards set by the Environmental Protection Agency (EPA), especially after heavy rains.

"Runoff can carry livestock and pet waste, untreated or partially treated human waste, and other pollutants off the landscape and into our rivers and streams," said Harry Campbell, Chesapeake Bay Foundation's (CBF) Pennsylvania executive director. "We hope the takeaway from this study is that we all must do more to reduce polluted runoff and to use caution when considering going into the water within 48 hours of a heavy rain."

Fourteen water samples were collected by CBF at each of 10 locations from June to mid-August and tested for E. coli and fecal coliform bacteria by the ALS Environmental Laboratory in Middletown.

Sampling locations in Cumberland County on the Conodoguinet Creek were the North Middleton Park and West Fairview boat launches, and Willow Mill Park. On the Yellow Breeches Creek, water was collected at the Messiah College covered bridge, New Cumberland Borough Park, and South Middleton Park bridge. In Dauphin County, samples were taken at the Fort Hunter boat launch on the Susquehanna River, and on Swatara Creek at the boat launch upstream of Hanover Street Bridge, at the Boathouse Park boat launch, and the Fulling Mill Road/Clifton Bridge access point.

"E. coli and fecal coliforms are easy-to-measure indicators of bacteria that are used to test for contamination of human or animal waste," said Renee Reber, CBF staff scientist in Pennsylvania. "They are a normal part of intestinal biology. The presence of this bacteria in the water does not guarantee risk to human health, but suggests pathogens may be present which can cause gastrointestinal illness, headache, and other symptoms."

Counts are expressed as colony-forming units (cfu) and E. coli results greater than 235 cfu/100 ml indicate conditions considered by the EPA to be unsuitable for swimming at public beaches.

The spikes in E. coli pollution were evident after 24- and 48-hour rain events of more than 0.25 inches. Samples taken on Aug. 2 were within 24 hours of a heavy rain and produced the highest numbers of the survey. That day, six of the 10 sites had levels of E. coli above the acceptable limit, four of those were more than 10 times the limit.

Throughout the study, results of samples taken at the West Fairview boat launch immediately above the mouth of the Conodoguinet at the Susquehanna River, and the Fort Hunter boat Launch on the Susquehanna were within limits acceptable to the EPA and state Department of Environmental Protection (DEP) for E. coli and fecal coliform.

In tests for fecal coliform bacteria, the DEP considers the maximum acceptable geometric mean, or average of five tests in dry conditions, to be 200 cfu/100 ml. The geometric mean was over the 200 cfu/100 ml threshold for tests of water from the North Middleton Park (248), New Cumberland Borough Park (258), and South Middleton Park (616) locations.

More E. coli was found in water taken at the South Middleton Park bridge on Yellow Breeches Creek than from anywhere else. Nine of the 14 samplings for E. coli returned results above the 235 cfu/100 ml threshold set by the EPA. In six tests, the level of E. coli was more than four times that limit. Three of those were in dry conditions when rain was not likely to have been a factor.

The good news is that, except for South Middleton Park, just four tests from all other locations, during dry conditions, came back slightly over standards for E. coli.

The sources of bacteria found in all of the streams and whether it was human or animal, were not determined in the testing. Sample sites were chosen in order to gauge input by agriculture, urban and suburban, and mixed land uses.

Roughly 19,000 miles of Pennsylvania rivers and streams are polluted and the Commonwealth has a Clean Water Blueprint to reduce nitrogen, phosphorus, and sediment runoff that is damaging its waters.

The DEP has acknowledged that Pennsylvania will not meet its Blueprint goal of having 60 percent of the pollution-reduction practices necessary to restore water quality in place by 2017. The Commonwealth must accelerate efforts if it to reach its 2025 goal of having 100 percent in place.

Reducing polluted runoff in Pennsylvania is critical to restoring and protecting the Chesapeake Bay. Half of the freshwater that flows into the Bay comes from the Commonwealth. CBF staff in Maryland and Virginia also conducted similar stream studies to measure bacteria levels in those waters.

"We want to educate people about polluted runoff," Campbell added. "When we mention that E. coli and fecal coliform bacteria are in the mix, people may better understand how important it is that we reduce runoff that is harming our rivers and streams, and can affect our health."

More information and water-by-water results of CBF's polluted runoff study can be found at www.cbf.org/pa.

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