State official explains water testing procedures
HARTINGTON - As was announced last week, the water in Hartington is safe to drink again.
The "boil water" notice was made on November 8, and the "cease boil water" notice came on November 14 after several tests had been conducted.
Elizabeth Esseks, a Program Specialist with the Department of Health & Hyman Services Public Drinking Water Program, said the issue was discovered because of routine testing. Nebraska cities are required to collect two routine coliform samples every month. each sample tests 10 different sites in Hartington. The initial Oct. 29 test was positive for total coliform. Samples were tested the next day and came back positive. These first tests are called presence-absence tests, and simply measure if there is total coliform in the water, Esseks said.
“In a situation like this we don’t talk about a degree of contamination,” said Esseks. “It is a yes or no situation.”
A positive sample of total coliform shows there is organic matter in the water system.
This organic matter is not necessarily dangerous, but an initial positive test triggers a second test that also tests for E. Coli and other dangerous components.
During that test, samples are taken from the original test site, from upstream and from downstream. In the follow-up test on November 6, two repeat samples tested positive for total coliform and one repeat sample tested positive for total coliform and E. Coli.
The E. Coli tested positive upstream from the original positive test.
After the positive test, the boil water notice was issued to all residents through phone calls, the media and by posting notices on doors.
“The first part is to send out the boil water notice, and we also have what is called a level two assessment,” said Esseks. “That is when one of our field staff goes to the site and works with the lead water operator to find the cause.”
This meeting with the water operator Pat Guy took place on Tuesday. Results are expected soon from this follow-up.
Esseks noted that the last time the DHHS Public Drinking Water Program noticed an issue in Hartington’s drinking water was in December of 2016. There was not a notice sent out to residents because of results from the follow-up test.
“The issue I mentioned in December 2016 was the presence of total coliform only,” said Esseks. “Total coliform is not a public health threat the way E. coli is. Some strains of E. coli can make people very, very sick. Total coliform is an indicator that triggers additional sampling, so no public notice is required.”
Esseks said a public notice was not sent out after the first routine test in October because a contamination problem had not yet been confirmed.
“Public water systems are not required to notify their customers that they must boil water until the presence of E. Coli in the public water system is confirmed,” said Esseks. “This happens when there is any combination of total coliform and E. Coli in the routine and repeat samples. In this situation, the routine sample was total coliform positive, and one of the repeat samples was total coliform positive and E. coli positive. The city clerk and water operators were notified about the situation, acute coliform violation and boil water notice, within 15 minutes of when the analyst at the state lab transmitted the results of the coliform analyses to me.”
Further updates will be given once the root cause of the positive E. Coli test is known, Esseks said.