City water no longer in violation of contaminant

The City of Bonners Ferry was notified last week that it is no longer in violation for exceeding the maximum contaminant level for haloacetic acid. 

The city water system over the summer tested high for haloacetic acids, which forms from chlorine disinfection products.  Chlorine is the most common disinfectant used in water systems.

The standard for HAA5 or maximum contaminant level is 60 parts per billion and the city drinking water has tested at 59 parts per billion.

In July the contaminant  level was 61 parts per billion, 1 part per billion over the legal limit.

According to assistant city manager  David Sims, the city has changed the way it chlorinates when it back washes the filter and it has upgraded the chlorine contact chamber.  Sims said they are also doing more flushing of the lines to reduce the time the water sits in them.

“The system had a major upgrade three years ago,” said Sims.  “We chlorinate the water after we filter the water instead of before,  which reduces the amount of chlorine that is in contact with carbon compounds.”

What this means is when the water isn’t filtered, there is more bacteria in the water, and in order for the chlorine to do its job, it produces more by-product. Now the water is filtered first and then chlorinated after meaning the chlorine doesn’t have to work quite so hard therefore producing less by-product.

The Department of Environmental Quality expressed their gratitude for the city’s staff efforts to continue to work toward overall reduction in disinfection.