Though advisories have been issued warning of high E. coli levels in Lake Springfield, the professionals who supervise water quality at the lake don’t consider this to be much of a problem.
“It happens after every rainstorm in every body of water from runoff from soils and from bacteria,” said Tom Skelly, water division director at City Water, Light and Power. “It’s just typical of any natural body of water.”
Escherichia coli, more commonly known as E. coli, is a bacterium that is found in the intestines of humans and most animals. E. coli is commonly associated with food-borne illness, but much of the E. coli found in the body and in nature is harmless.
Besides being found within the body, E. coli is often found in the environment. It occurs naturally and is primarily examined by scientists as a natural indicator of human or animal feces in a body of water. It is not always an indicator, however, as E. coli is found in all warm-blooded animals, and is also present in some sand and soil.
After rain, considerable runoff occurs, pulling sediment and bacteria, like E. coli, into water supplies, such as Lake Springfield. However, most of this bacteria in the water dissipates in a few days.
“What we see is either, in the case of sediment, it will settle out, or, in the case of bacteria, it will photodegrade,” Skelly said.
The other danger for the lake after heavy rains, like the ones that Springfield has been having since May 26, is runoff of atrazine, a commonly used herbicide.
The most used herbicide in the world, atrazine has been banned in the European Union for its poisonous effect on amphibians and people. Nonetheless, the product is still widely used in the United States. Its use is criticized by scientists who want the EPA to reexamine the chemical’s safety.
Despite the danger that the chemical may pose, Skelly says that Lake Springfield has managed to be atrazine free.
“It’s been a success story,” Skelly said. “Over the last five or six years, we had to treat almost no atrazine in the water.”
CWLP used to spend more than $30,000 a year on treating atrazine in Lake Springfield, but after encouraging farmers to use different herbicides or stagger their uses of the chemical, CWLP was able to avoid pollution in the lake. Now the water is regularly subjected to a powdered activated carbon treatment, which is able to absorb and latch onto synthetic chemicals, such as atrazine, that enter the lake.
“I think they [CWLP] have done a lot to reduce atrazine, but it might be that fewer people are using atrazine,” said Teri Holland, environmental protection specialist for the lakes unit of the Environmental Protection Agency.
Holland said that although CWLP is not required to display their E. coli levels, the company places the results of the tests on its website and shares the information with the EPA.
“To the city’s credit, they are monitoring these levels as a city service,” Holland said.
Even with precautions for bacteria and contaminants, Lake Springfield can still have E. coli in the days immediately following a rainstorm. Skelly recommends caution to people who wish to swim on these days.
“We put the decision in people’s hands to decide if they want to swim,” Skelly said. “If it [the water] looks muddy, don’t swim. If it looks like weak tea, you’re probably OK.”
Skelly also recommends not drinking or swallowing water in the lake, or swimming if a person has open cuts or sores.
“Take these precautions, and enjoy the water safely,” Skelly said.
Contact Jackson Adams at firstname.lastname@example.org.
A chart of recent E. coli readings as well as information on sampling of microorganisms and sediment can be found at CWLP’s website, at www.cwlp.com.