City working on plan to ensure safe drinking water

waterEvery 10 years the City of Benson is required to develop and implement a plan that ensures residents have a reliable and safe supply of drinking water.

“We as a city firmly believe that one of the most important charges we have is to provide safe drinking water to our people,” Mayor Paul Kittelson said at the Benson City Council meeting Monday night.

To ensure that it stays safe will require the city to be vigilant in protecting its aquifers from contamination.

Benson’s drinking water supply is considered moderately vulnerable to contamination, Terry Bovee of the Minnesota Department of Health (MDH) told the city council. Bovee specializes in working with community drinking water systems.

The city’s vulnerability stems from two factors.

First, Benson has two primary aquifers out of which it draws its drinking water. One is a surficial aquifer that comes up to ground level in areas. That aquifer is susceptible pollutant that is spilled on the ground that can then seep into the soil and eventually the aquifer.

The second aquifer is a middle aquifer that is deeper down, but is susceptible to contamination seeping in from the upper aquifer. Surface water is getting into that deeper aquifer in some capacity, he said.

MDH has run tests that involve the study of isotopes in the two drinking water sources that show some water is migrating downward to the lower aquifer, Bovee said. It also runs other tests.

The vulnerability is due to the geology of the aquifers, he explained.

Often aquifers are separated by layers of rock or clay that are impenetrable surfaces. This can ensure that contamination in an upper aquifer doesn’t affect a lower one.

However, through the decades wells have been drilled through the clay or rock to reach the lower aquifer. These wells are conduits through to the lower aquifers that potentially can allow something through, Bovee said. “It is like a straw to that aquifer,” he said.

Article from the Swift County Monitor News