Positive coliform test closes one EQSD wellJoshua Sebold
At a mid-January meeting, East Quincy Service District Manager Mary Henrici told the districtís board that she had isolated the well behind the district office, well #2, from the rest of the water system because of a positive total coliform test.
Total coliform tests look for bacteria that originate in dirt or plant matter, compared to fecal coliform that originates in sewage, septage or animal waste.
Henrici said the levels of total coliform werenít above regulations; she isolated the well from the water system anyway, until further tests could be done.
The well has remained isolated while further investigations have proceeded.
The manager said the next test was positive for both total and fecal coliform, which she found interesting.
ìItís like it drew in more of whatever it was, the issue, and made it worse.î
Henrici also told the board she looked at the most recent nitrate levels for the well, which were at 32.8 milligrams per liter, compared to a maximum allowable level of 45 mg/L.
She explained, ìNitrate is an indicator of groundwater pollution.î
The manager said the number was particularly surprising to her because nitrate levels usually rise at a relatively low rate.
She indicated that a test in 2007, showed 2.0 mg/L and one in May 2009, showed 2.1 mg/L.
Henrici added that one company did tests on all six of the districtís wells and only well #2 had the problems, which made her think it wasnít a testing problem.
She said the well, which had been in place for as long as the district has existed, could be failing and the casing around the well could be collapsing.
Henrici said she discovered the well also didnít have a gate valve, which provides a fail-safe to further isolate it from the rest of the water system.
She said one would be installed, and clarified this wasnít a cause for alarm because a check valve was already in place and the well was turned off.
A check valve opens when a significant level of pressure is applied to it; to close it, the water pressure must go down.
A gate valve is considered a ìfail-safeî because itís designed to be either in an open or closed position and would be able to stop flow under a reasonable amount of water pressure even if the well couldnít be turned off.
The manager also explained regulations dictated the district test the well quarterly because of the high nitrate levels, but added that wouldnít change anything because she wanted to figure out what the problem was at a faster pace anyway.
She said other chemicals that were indicators for pollution would be tested for as well.
In a quick telephone interview Wednesday, Jan. 27, Henrici said the well had been chlorinated and received a clean bacteria test result after that.
She said the next steps would involve sending out more samples and chlorinating the well again.