The lake at Tuscarora State Park in Rush Township has been closed to swimming at least five times this season due to poor water quality.

The latest shutdown happened Tuesday, exactly one week after a closure that lasted four days.

“The recent swimming beach closures at Tuscarora State Park have been based on laboratory analysis results for Escherichia coli (or E. coli for short) in water samples collected from the swimming beach,” according to Wesley Robinson, spokesman for the Pennsylvania Department of Conservation and Natural Resources.

Other state parks — including Beltzville near Lehighton and Locust Lake in Barnesville — also had to put temporary stops on swimming this year as park officials awaited acceptable results.

The Pennsylvania Department of Health requires that public waters — like state park lakes — are tested frequently for E. coli.

“Most state parks collect their water samples and send the samples to the Pennsylvania Department of Environmental Protection’s lab for testing,” said Neil Ruhland, spokesman for the Department of Health. “Beaches or untreated water, such as a lake at a state park, is sampled weekly for E. coli, and the beach is closed for swimming if the result is out of compliance.”

In order to reopen, resampling and testing continues until water results are in the safe, or healthy, range.

Ruhland said samples are taken from water approximately 30 inches deep and at a midpoint between the bottom and the surface.

Depending on the size of the swimming area, number of visitors, weather conditions and bacteriological history of the water, the health department might require multiple samples to test for E. coli, Ruhland noted.

According to information provided by DCNR, there are hundreds of E. coli strains.

“Most are relatively harmless, capable of causing illnesses such as traveler’s diarrhea only when consumed in exceedingly high numbers,” the agency told the Times News. “The presence of the E. coli bacteria is an indication that there may be contamination present.”

DCNR said the bacteria lives in the intestines of warm blooded animals and humans, “so it can be associated with fecal releases from any of them.”

However, soil and water are considered secondary environments in which E. coli can survive.

“So, in highly complex systems such as a lake, it can be extremely difficult to identify sources and fates of E. coli populations with certainty,” according to DCNR.

If geese frequent a beach area, for example, DCNR has plans in place.

“To address E. coli from geese excrement, the park actively chases geese out of the swimming areas daily, fires ‘bird-banger’ flares as needed, rakes the beaches and posts, and enforces no ‘feeding of wildlife’ regulations,” DCNR said.

Park visitors can help address possible sources, too, by using responsible water recreation practices.

DCNR recommends:

• Try to avoid swallowing water while swimming.

• If you feel ill, stay out of the water (especially children).

• Take your children on frequent bathroom breaks and wash hands after.

• Check diapers often and change in bathroom areas — wash hands after.

• Shower before and after swimming.

In 2023, harmful algae blooms at Tuscarora put a stop on swimming for extended amounts of time. When it happened, DCNR also cautioned against fishing, boating and kayaking in areas with scum or discoloration.

“Swimming beach closures due to algae blooms were based on the results of laboratory analysis for cyanobacteria in water samples collected from the swimming beach,” according to DCNR. “There are hundreds of species of cyanobacteria that are an expected and common part of the environment and most of the time, they are relatively harmless. When elevated levels are found, they could cause serious illness, especially through exposure by ingestion. Again, in highly complex systems such as a lake, it can be extremely difficult to identify sources and fates of algae blooms.”

The blooms have not been detected this year.

When state park swimming areas are closed, signs are posted and announcements are made online.

The state health department also noted that treated water venues, such as public swimming pools, are tested twice daily for free chlorine and pH, and weekly for total coliform bacteria.