Southwest District Health sent packets of information to 78 property owners after six private wells in the area of Powerline Road and Locust Lane tested positive for E. coli, said Laurie Boston, public information officer for the health department. No illnesses related to the problem have been reported so far.

The health department was made aware of the contamination by a property owner who had their well tested and found it had E. coli, Boston said. No obvious reasons pointed to contamination, like irrigation water flooding the well or sudden spring run-off, so a health official started checking with the neighbors.

Eleven wells were tested, and six came back positive for E. coli. The health department then informed the public of the issue on Tuesday and sent packets to all property owners living within 1,000 feet of the contaminated wells. For two days, the health department’s temporary call center, set up for the problem, received more than 100 phone calls, Boston said. The call center has now closed as calls decreased, so those with questions remaining about E. coli should call the Southwest District Health environmental division, Monday through Friday, at 208-455-5400.

WHAT CAUSED THE CONTAMINATION, AND WHAT WILL THEY DO ABOUT IT?

Boston said Southwest District Health is unsure at the moment what caused the E. coli to get in people’s drinking water in south Nampa. An investigation is underway, and the Idaho Department of Environmental Quality is assisting.

Until the health department knows what the source of the contamination is, health officials will not know how to get rid of the E. coli. The area is a mixture of residential and agricultural. The contamination could be animal or human at this point.

“I just don’t think they know enough yet to be able to answer that,” Boston said Thursday in response to an Idaho Press-Tribune question about the E. coli decontamination.

It’s not just about knowing what the source of the contamination is, either. The health department is looking into groundwater flows in the area to learn more about how it spread. One possible factor is the porous lava rock in the ground, which might not filter the E. coli as well as other kinds of rock.

“We just don’t know exactly what the source is, but we do know for sure that the lava rock is a definite factor,” Boston said.

WHAT IS E. COLI?

E. coli, which stands for Escherichia coli, is a bacteria that normally is found in the intestines of humans and animals, according to the Centers for Disease Control and Prevention. So, contamination happens when bits of feces, often almost invisible, are consumed.

While an E. coli contamination is cause for concern because some strains can cause illness like diarrhea, most E. coli are important to having a healthy human intestinal tract, the CDC’s website states.

It is estimated 26,000 people get infected with toxic E. coli every year — typically by consuming drinks that have not been pasteurized, eating raw or undercooked food or food touched by people who didn’t wash their hands after going to the bathroom, through swallowing water in a lake or swimming pool or touching animals.

Finding drinking water contaminated by E. coli doesn’t happen very often, Boston said.

“It’s not unique. It does happen, but it’s also not common,” the public information officer said.

THE TESTING

The packets sent around this past week recommend the property owners get their wells tested. The $10 fee to have the health department transport the water to the laboratory in Boise will be waived. They will still have to pay the testing fees, which in this case could be around $25.

Test results could start coming back early next week, Boston said.

Boston warned that boiling water for drinking is not recommended in this case, as there is a possibility of the water being contaminated with arsenic, nitrate or uranium — which the test will also check for — because of their common occurrence in local soils. The evaporation from boiling could actually increase the concentration of certain contaminants in the water.

Testing private well water is voluntary, explained Idaho Department of Environmental Quality Deputy Director Jess Byrne. While the DEQ regulates public drinking water systems, there are no state or federal guidelines requiring private property owners to test their wells.

All the state or health department can do is make recommendations, Boston explained.

However, as part of the investigation, certain private property owners may be contacted in the next several weeks to see if they would let the DEQ test their well or surface water at no charge, Boston said.