Glade Run Lake has a large amount of algae covering a great portion of the water.Holly Mead/Special to the Eagle

Holly Mead

Be careful whenever you see algae floating in local lakes — while most algae is harmless, others can make you very sick.

Algae can form in standing bodies of water during warmer weather. Although it can make boating or swimming more difficult, most algae growths are generally benign.

However, some are considered harmful algal blooms, mainly those caused by cyanobacteria thriving in bodies of water with excessive nutrients. These cyanobacteria release toxins into the water that can harm multiple forms of life, from fish to humans who swim in or drink it.

Ingesting or coming into contact with water affected by harmful algal blooms could lead to rashes, eye infection, diarrhea or other stomach illnesses.

At least three bodies of water in Butler County are prime targets for algae blooms during the summer months, both harmful and relatively harmless. These are Lake Arthur at Moraine State Park, Glade Run Lake in Middlesex Township, and Oneida Valley Reservoir in Oakland Township.

According to Dustin Drew, park manager at both Moraine and McConnells Mill state parks, there have been “some small localized blooms” of algae at different locations around Lake Arthur this summer.

“There have been no impacts to the swimming areas at this time,” Drew said.

“Algae blooms are natural, but can become excessive when days are long, the water is warm, and there are excess nutrients in the lake,“ said Roy Weitzel, a board member of the Glade Run Lake Conservancy. ”Any excessive algae can harm the lake, primarily by choking out other plant species, or by reducing oxygen in the water as it dies and is decomposed by bacteria.”

Every summer, Glade Run Lake is visited by a specific type of algae: filamentous, or “hair” algae. This type of algae is considered mostly harmless.

“Filamentous algae is not harmful, per se, though it can be inconvenient to humans,” Weitzel said. “It can lead to deoxygenation in the lake if there is too much dying and being broken down, particularly when coupled with high water temperatures.”

Pennsylvania American Water presently maintains two reservoirs in Butler County — Oneida Valley Reservoir and Thorn Run Reservoir, both in Oakland Township.

According to Pennsylvania American spokesperson Brent Robinson, both bodies of water have had issues with algae growth in the past. However, the issues have subsided since Pennsylvania American installed “SolarBees” — a series of floating water treatment machines which are powered by the sun — in 2020.

“The SolarBees we installed are a non-chemical way of preventing the growth of algae in the reservoirs by introducing movement to the water column,” Robinson said. “We also sample water throughout the summer months for taste and odor compounds which are indicators of algal activity.”

Even then, Robinson says that the algae blooms at these reservoirs were purely aesthetic and did not pose a health risk.

“Not all algal blooms are HABs or have cyanotoxins associated with them,” Robinson said. “Often times, taste and odor compounds are an aesthetic issue and do not pose a health risk.”

As for the algae in Glade Run Lake, Weitzel says that there has been no real effort to remove it, as most methods would cause new problems.

“There are chemical tools to control and kill it, but the effects are indiscriminate. That is, they would kill the natural, beneficial plants also,” Weitzel said. “Some folks have used carp and other herbivorous fish to help control algae, but the introduction of non-native aquatic organisms can be otherwise troublesome.”

The Pennsylvania Department of Environmental Protection currently maintains a dashboard of harmful algal bloom water sampling data dating back to 2018. Although not all algal blooms in water are harmful, Weitzel suggests that people don’t take the chance if they believe that they are looking at a harmful algal bloom.

“If people suspect there may be a harmful algal bloom present in a water body, they should stay out of the water, keep dogs out also, and report it to the Pennsylvania DEP,” Weitzel said.

The ponds at Succop Nature Park in Penn Township are covered in a thick layer of algae. Holly Mead/Special to the Eagle

Holly Mead