High levels of pollutants, which can kill wildlife and make people ill, caused Baltimore County officials to issue water quality advisories this summer for a pond at the Genesee Valley Learning Center in Parkton and Hammerman Beach, located on the Gunpowder River, in Chase.
Neither beach is currently under advisory but environmental scientists remain watchful.
The county issued a water advisory regarding pollutant levels at Genesee Valley on July 11. There is a childrens' summer camp at the center but Monique Lyle, a spokeswoman for the Baltimore County Department of Health, said there had been no reports of harm to campers. Hammerman Beach tested high on June 22.
Although the beaches are no longer under advisory, excess pollutants are cause for serious concern.
"There is a real need for concentrated efforts to reduce these levels," said Jenn Aiosa, senior scientist at the Chesapeake Bay Foundation.
She is particularly worried about high amounts of nitrogen and phosphorous. "Too much overstimulates algae and other naturally existing plants," Aiosa said. "They grow too quickly and block sunlight to other plant and animals."
Aiosa said that high pollutant areas risk becoming "dead zones" where plants, fish, shellfish and anything else that resides in the waterways may die off.
There can also be adverse consequences for people. Aiosa said swallowing contaminated beach water can cause stomach ache, severe diarrhea and other forms of gastrointestinal distress.
County officials urge residents to keep an eye out for discolored water, not drink stream water, avoid contact with potentially contaminated water if you have damaged or broken skin and wash hands regularly.
According to the Environmental Health Services website, Baltimore County has about 200 miles of tidal coastline in addition to publicly and privately operated recreational beaches.
Lyle, the county health department spokeswoman, said county beaches are typically sampled every two weeks according to criteria set forth by the US EPA Beach Act of 2000.
"If elevated results are reported, an advisory is issued and the operator of the beach is notified," Lyle said. "If the results are elevated due to a reported or suspected sewage overflow, the beach would be closed."
She added that high readings occur "periodically."
Federal law requires all states with high levels of pollutants to create a plan to reduce the amounts, said Tom Zolper, communications coordinator for the Chesapeake Bay Foundation. In 2009, the Maryland Department of the Environment put together a report concerning the Loch Raven Reservoir watershed, which includes Genesee Valley.
In addition, the Baltimore County Department of Environmental Protection and Sustainability has been working with community members to create a for Oregon Branch, Baisman Run and Beaverdam Run, which are housed within the Loch Raven Reservoir. The final plan will be unveiled at the this fall.
But Lyle said measures can be taken to protect county beaches.
"The areas surrounding existing beaches are checked each year to determine if there are any new issues, such as sewage system leaks or septic system failures that might negatively impact the beach water quality," Lyle said. "In addition, everyone can do their part by recognizing that what we spill on the driveway, put on our lawns or fields, or fail to pick up from our pets can end up in the waters where we live, work and play."