Oxford Township residents were warned Monday to either boil their water or use bottled water because recent tests revealed the presence of coliform bacteria in the municipal well system.
A routine monthly water sample plus follow-up samples collected by the Oakland County Drain Commission all tested positive for total coliform bacteria, according to a written notice from the county.
“Total coliform bacteria are generally not harmful themselves,” the notice stated. “Coliforms are bacteria which are naturally present in the environment and are used as an indicator that other, potentially harmful bacteria (such as fecal coliform or E. coli) may be present. Coliforms were found in more samples than allowed (by Michigan Department of Environmental Quality guidelines) and this was a warning sign of potential problems.”
According to Tim Prince, chief engineer for the drain commission, the initial sample tested positive for total coliform bacteria on Saturday. He said that sample was obtained from the water tower in the Red Barn subdivision.
The follow-up samples, which were taken from two neighboring homes on either side of the tower Sunday, also showed the presence of coliform bacteria, which led the drain commission to rule out the possibility of error in the initial sampling and required them to notify residents, Prince said.
Prince said this is the first time this bacteria has turned up in the drain commission’s monthly testing.
Although coliform bacteria can be an indicator that harmful bacteria are present in the water, follow-up testing did NOT show the presence of any fecal coliform or E. coli, Prince said.
However, as a precautionary measure, county officials warned the township’s 1,700 municipal water customers not to consume their tap water without first boiling it for five minutes and letting it cool. Boiled water should be used for drinking, making ice, brushing teeth, washing dishes and food preparation.
Using bottled water was suggested by the county as an acceptable alternative to boiling.
To eliminate the bacteria, the county treated the township’s water supply with chlorine and flushed the chlorinated water through the system to disinfect the pipes, which may have caused some residents to receive discolored water from their taps.
Prince said the chlorination process was completed and consecutive water samples were collected on Tuesday and Wednesday.
If both samples’ test results come back clean and in compliance with MDEQ guidelines, township residents will be notified Thursday that the precautionary boil water notice has been lifted and they can return to normal water service.
If the samples still test positive for coliform bacteria, the chlorination process will continue and the precautionary boil water notice will remain in effect.
According to the notice, “Coliforms are a sign that there could be a problem with the treatment or distribution system (pipes).”
Prince said the drain commission has not determined the exact cause of the coliform bacteria, but hypothesized it could be something located somewhere in the distribution system (pipes) that never caused a problem until now or an external source such as a cross-connection to the township system.
Drain commission officials have checked to make sure tank hatches are secured and locked, searched for local water main breaks or repairs and looked for any construction involving a water main that might not have been properly cleaned prior to connection with the system, but no cause has been found.
Prince said it’s a “long process” to determine the bacteria’s origin.
Township residents with private wells and Oxford Village residents who are served by a separate municipal well system were not affected by this situation.
Superviser Bill Dunn said as soon as the drain commission informed the township about the water situation on Monday, he notified all the television stations and newspapers and local cable community access Channel 19 to alert the general public. He said he also notified the state and county health departments so they could alert area businesses and restaurants.