Dixon explained the reasons for the boil order from Christmas Tuesday afternoon

Dixon residents were told they would need to boil their water on the afternoon of Christmas Day, due to a drop in pressure in the system, according to a letter by Josh Lachowicz, of Ozark Testing, a division of Anderson and Associates Consulting Engineers. The city issued a boil order that began on Dec. 25 and lasted until Dec. 30.

Lachowicz reported, in his letter, that he advised the City Maintenance Supervisor to contact the Health Department and turn the wells on to "try to keep pressure up."

On Tuesday, Dec. 27, Lachowicz said he began taking samples of the water, including two extra samples from the water tower near Dixon High School. The results of the samples came back on Dec. 29 as negative for E. coli, but "coliform positive."

The Centers for Disease Control (CDC) says coliforms "are a group of bacteria found in plant material, water, and soil. Coliforms are also present in the digestive tracts and feces of humans and animals. Most of the time, these bacteria are not harmful."

A positive coliform test "means possible contamination and a risk of waterborne disease," according to the CDC and "always requires more tests for fecal coliforms or E. coli."

Lachowitcz said that he took seven more samples on Dec. 29 and received confirmation, on Dec. 30, that "all seven water samples that were taken on Dec. 29" were considered "safe E. coli and coliform absent."

The boil order was lifted at 5 p.m. on Dec. 30 and local media outlets were notified. Dixon City Clerk Jesse Fleming included copies of the test results along with the letter from Lachowicz.

For your information...

Frequently asked questions about coliforms and drinking water from the CDC:

Q: What are coliforms?

A: Coliforms are a group of bacteria found in plant material, water, and soil. Coliforms are also present in the digestive tracts and feces of humans and animals. Most of the time, these bacteria are not harmful.

Q: Why does a water system test for coliforms?

A: Water systems test for indicators such as total coliforms, fecal coliforms, or E. coli to monitor water quality. If the water system has a positive test for one of these indicators, it can mean recent contamination with soil or human feces.

Q: What does a positive coliform test result mean?

A: A positive coliform test means possible contamination and a risk of waterborne disease. A positive test for total coliforms always requires more tests for fecal coliforms or E. coli. A confirmed positive test for fecal coliforms or E. coli means you need to take action as advised by your water system.

Q: Will coliform bacteria make me sick?

A: Most coliform bacteria are a normal part of the environment. They do not cause disease but do indicate the water might be contaminated by soil or feces. Some rare types of coliforms, such as E. coli O157:H7, can cause serious illness. Although most E. coli O157:H7 outbreaks are from eating raw or undercooked food, cases from contaminated drinking water can occur, but are rare.

Q: Why test for indicator organisms?

A: A biological pathogen is any organism, such as a bacteria, virus, protozoa, or parasite, that causes a disease. Biological pathogens are commonly called “germs.” There are many different possible pathogens. It is not possible to test for every type of pathogen in every water sample, so water systems use indicators instead.

Water systems test for indicator organisms, like coliforms, to check for possible contamination by biological pathogens. Most coliforms are not harmful, but they come from the same sources as other bacteria and organisms that could make you sick.