A new statewide search is targeting ponds and lakes in Lancaster County that may contain harmful algae of the sort that famously occurred in Lake Erie last summer, restricting drinking water to Toledo, Ohio.

If your farm or backyard pond turns soupy pea green suddenly this summer, Diane Oleson, a Penn State Extension educator in York County, wants to hear from you.

 “If the pond looks really nasty, keep the kids and dogs and the livestock away from it until it clears up,” advises Oleson. “It’s about now that you start seeing these things.

“Farmers need to be aware of this if they are irrigating from a pond or they have livestock watering in these ponds.”

Penn State Extension has plenty of documented cases of dogs and cows being sickened or killed by drinking water from ponds where blue-green algae has produced toxins, she said.

Now, for the first time, there is a statewide effort to determine where, and how frequently, harmful algal blooms develop in the state.

The project is being funded by a grant from the Penn State-based Pennsylvania Water Resources Research Center.

Oleson is one of 10 Extension educators around the state recently trained to identify the toxic blooms. She is based in York and will handle samplings of ponds and lakes in eastern Pennsylvania.

Pennsylvania is home to thousands of natural and man-made ponds and lakes. When too many nutrients get into these stagnant bodies of water and the water warms, algae often blooms.

Usually, the algae is harmless. But certain types of algae in the right conditions produce toxins that can harm livestock, pets, fish and humans.

“They do not produce the toxins all the time. That’s why they’re sneaky,” says Oleson.

“We identified it in a few ponds we sampled last summer. We’re not sure how common it is,” said Bryan Swistock, a Penn State senior Extension associate who is heading the new statewide project.

Bodies of water that typically develop algae are ones that are stagnant and have lots of nutrients flowing into them. Typical sources of nutrients can be livestock defecating in the water or grass clippings or fertilizer running into the ponds.

“A pond in the middle of a pasture is a big candidate,” says Oleson. So are irrigation ponds. Lakes also can develop the blooms.

Most backyard ornamental or fish ponds are safe if the water is filtered or being circulated such as through a fountain or waterfall.

The Susquehanna and Conestoga rivers, source of drinking water for some Lancaster County communities, won’t get toxic algal blooms because they are moving, she says.

And municipalities with water-treatment plants closely monitor water for blue-green algae, she adds.

In addition to livestock and pets, waters that produce the toxins can also cause skin irritations if people swim in them, Oleson says. The spray of water that is being used for irrigation can be inhaled by people, causing damage to the liver or nerves.

Long known as blue-green algae, the source of the toxins is actually bacteria.

The best way to have a pond that has developed an algal bloom tested for toxins is to take a sample to Oleson at the York County Extension Office at 112 Pleasant Acres Road, York. She can test the sample while you wait. If she is not there, she will call or e-mail you results.

If you can’t drive over a sample of the water, send a digital photo of the pond or lake to her at djo13@psu.edu. Oleson’s phone number is 717-840-7429.  

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