The Kansas Department of Health and Environment (KDHE) lifted an E. coli advisory for the swimming beach at Eureka Lake last Friday, June 5 after follow- up testing showed bacteria levels had returned to safe recreational standards.
The advisory had been issued after elevated levels of E. coli bacteria were detected in the water at the popular swimming area north of Eureka. Additional water testing conducted by KDHE found that bacteria concentrations had dropped below advisory thresholds, allowing the agency to remove the warning.
Officials emphasized that the E. coli advisory was separate from any harmful algal bloom advisories that may affect Kansas lakes.
The advisory was originally announced on Friday, May 29, after testing identified elevated bacteria levels that could pose health risks to swimmers. Certain strains of E. coli can cause illnesses including diarrhea, urinary tract infections, pneumonia, sepsis and other serious health conditions. Young children, older adults, individuals with weakened immune systems and pets are considered particularly vulnerable.
With the advisory now lifted, the Eureka Lake swimming beach is once again considered safe for recreational use.
Residents and visitors are encouraged to continue monitoring KDHE lake advisories for the latest information on water quality conditions throughout the state.
Understanding E. coli in Lakes and Creeks When E. coli levels test high in lakes or creeks, many people assume the water will remain unsafe for an extended period. In reality, most contamination events caused by stormwater runoff, wildlife waste, or other temporary sources begin to decline within 24 to 48 hours after the source of contamination is reduced or eliminated.
Sunlight plays a major role in this process, as ultraviolet (UV) rays naturally kill bacteria near the water’s surface. Dilution, settling and competition from naturally occurring microorganisms also help reduce E. coli concentrations over time. However, recovery times can vary depending on weather conditions, water temperature, water flow, and whether contamination sources continue to enter the lake or creek.
Unlike swimming pools, lakes cannot be treated with chemicals such as chlorine to eliminate E. coli. Large-scale chemical treatment would harm fish, aquatic plants, and other organisms that make up the ecosystem.
The most effective way to address E. coli is by eliminating contamination at its source. Manage Wildlife: Do not feed geese, ducks, or gulls, as their droppings are a major contributor to bacteria.
Control Runoff: Create vegetative buffer zones around the lake to filter out animal waste and nutrients before they enter the water.
Inspect Septic Systems: Ensure that nearby residential septic systems are functioning correctly and pumped every 3 years. Pick Up Pet Waste: Always pick up after dogs and properly dispose of pet waste.
Best Practices for Open Water Swimming Avoid heavy rains: Do not swim or engage in water sports for 24 to 48 hours after a significant rain event, as runoff frequently spikes bacteria levels. Look out for algae: E. coli advisories are entirely separate from Harmful Algal Bloom (HAB) warnings. Even if bacteria levels are safe, avoid the water if you see blue-green scum, foam, or paint-like streaks. Check local postings: Before heading out to local lakes, check active water quality and health advisories on the KDHE website or watch local news and city postings.
