Weekly tests conducted of some Harford County streams that are popular for swimming this summer found levels of harmful bacteria that are well above the federal Environmental Protection Agency's safety standard for recreation, especially after heavy rain, according to the Chesapeake Bay Foundation.
Tests to monitor pollution from runoff were conducted along streams in three counties – Harford, Howard and Frederick – by the Chesapeake Bay Foundation, in partnership with local colleges. Most of the areas tested are popular with swimmers, a foundation spokesperson said.
Six places tested in Harford were: Falling Branch at Kilgore Falls in Rocks State Park; Deer Creek at the Eden Mill Nature Center in Pylesville; Deer Creek near the Wilson Picnic Area, also in Rocks State Park; Deer Creek at Route 136 in Darlington; Deer Creek at Sandy Hook Road, in the Deer Creek Conservation Area north of Bel Air; and Swan Creek at Route 40 near Aberdeen, according to data posted on the Chesapeake Bay Foundation's website.
Tami Imbierowicz, an associate professor of biology at Harford Community College, said she has been working with students, community volunteers and her children to do the Harford tests. Faculty members at Hood College in Frederick and Howard Community College handled tests in their respective counties, according to the CBF.
More information can be found online at www.cbf.org/bacteria-testing.
"The numbers are higher than I expected, but I did expect them to be high just from what I knew," Imbierowicz said, noting that bacteria originating on land that ends up in streams originates from a number of sources, especially animal waste.
She said Deer Creek is "a beloved waterway here in Harford County," and it is heavily used for boating, swimming and fishing. Falling Branch is a major Deer Creek tributary in Harford County.
"My children are on it at least once a week in some way," she said.
The Harford County Health Department only has the authority to close public bathing beaches when there is a safety hazard, not recreational bodies of fresh water, spokesperson Bill Wiseman said.
"There are no approved bathing beaches in Harford County, and thus no authority relating to closures," he wrote in an email.
Tom Zolper, spokesperson for the CBF, said the Annapolis-based organization has conducted testing of tidal waters before, but this year is the first for testing in freshwater streams.
Zolper said the participants wanted to determine if freshwater streams – which are tributaries for the Chesapeake Bay – have the same pollution problems as the "main stem" of the bay.
"This data seems to suggest that it is, that these streams are suffering from the same pollution problems," he said.
The EPA's standard for safe swimming in fresh water is 61 colony forming units (cfu) of bacteria per 100 milliliter of water. The tests conducted in Harford County showed levels that were many times above that standard, especially after a rainstorm.
The tests have been conducted each week since June 3. Zolper said they will continue through August.
As an example, the level at Falling Branch and Kilgore Falls, which is among Harford County's most popular swimming areas, was 3,000 cfu on June 3, according to the test result which was obtained 48 hours after at least half an inch of rain fell in the area.
A June 25 test, which happened during a dry period, showed the lowest level so far, 60 cfu.
The most recent test, which was conducted on Wednesday, after had it rained overnight, showed 13,800 cfu, 226 times higher than the EPA's safety standard. That was the highest level of bacteria measured in Kilgore Falls since the testing started.
Swan Creek had the highest level of bacteria measured during Wednesday's test with 31,600 cfu, followed by Deer Creek at Eden Mill with 25,100 cfu, Deer Creek at Route 136 with 14,800 cfu, Kilgore Falls with 13,800 cfu, Deer Creek in Rocks State Park with 9,100 cfu and Deer Creek at Sandy Hook Road with 5,100 cfu, according to the data.
Swan Creek was selected for testing by the Havre de Grace Maritime Museum, which provided volunteers for testing, Imbierowicz said.
"It's the one outlier," she said. "It was a location that was selected by the Havre de Grace Maritime Museum, just to get a baseline on Swan Creek."
"No matter how you slice it, these are staggeringly high numbers in some places in Harford County after a rain storm, so that means the chances of someone swimming there and getting sick are very high, especially if they're ingesting the water," Zolper said.
Zolper noted the Maryland Department of the Environment recommends waiting 48 hours after a storm to go swimming in a freshwater body.
The testers have been evaluating the levels of enterococcus bacteria, a fecal bacterial that comes from animal and human waste. Enterococcus can also indicate whether other harmful bacteria is in the water, according to a news release from the Chesapeake Bay Foundation.
The bacteria typically comes from stormwater runoff that carries waste from livestock, pet droppings or leaking septic systems, Zolper said.
He said all streams and creeks in Harford feed the Chesapeake Bay, so any pollution that enters those smaller bodies of water eventually ends up in the bay.
"We're trying to show that the same issues that are happening here in Annapolis are happening in Bel Air, and what happens in Bel Air obviously affects what's downstream," he said. "What we're trying to demonstrate is, we're sort of all in this together; we all have the same pollution issues."