Whether it be accidentally pouring in far too much potassium permanganate and turning people’s drinking water pink, or a failure in a treatment technique required by the Pennsylvania Department of Environmental protection, mistakes are inevitable.
This year, both the Carlisle Water Treatment Plant and the North Middleton Authority — which manages water and sewer in the township — dealt with “mistakes.”
Officials from both municipalities told The Sentinel the issues may have appeared alarming to residents at first, but in neither case was drinking water considered to be harmful or dangerous to those people drinking it.
Residents in February began emailing and calling into The Sentinel complaining about a pink tint to the water spouting from their faucets and showers in the Carlisle area.
Two events came together to cause the pink water: about two inches of rain water runoff into the Conodoguinet Creek — the source of drinking water throughout most of the greater Carlisle area — and a power outage, according to Pete Selan, director of the Carlisle Water Treatment Plant.
The runoff from heavy rains that week created a spike in the water’s turbidity. According to U.S. Geological Survey, turbidity is the measure of cloudiness in a fluid caused by large amounts of individual particles.
Potassium permanganate is an oxidant similar to chlorine, said Mark Malarich, Carlisle’s public works director. When it was being added to the water to help handle the cloudiness, a power outage occurred, impacting the machine dispensing the potassium permanganate.
“I don’t know what happened,” Selan said.
Still, while the levels of potassium permanganate were high enough to give the water a pink color, they did not affect the taste or quality, and according to Selan, the turbidity was cleared up immediately.
The pink water lasted several days.
North Middleton Township residents received a letter on June 29 this year with an ominous first paragraph: “Our water system recently violated a drinking water standard. Although the situation does not require that you take immediate action, as our customers, you have a right to know what happened, what you should do, and what we did and are doing to correct this situation.”
Lee Koch, manager of the township’s Authority, said that in November the annual running average of total organic carbon in the water supply reached above two parts per million as measured on a quarterly basis. At this point the authority should have begun testing the water each month, but it did not, and the DEP noticed.
That’s because the authority tests on a quarterly basis.
“We had to send out that notice,” he said. “I have to do it quarterly until that ratio gets back to where it needs to be, but the plant’s the same, the creek’s the same.”
Koch explained that now, on top of the quarterly monitoring conducted at the facility, monthly monitoring will take place as well.
Total organic carbon does not pose any ill health effects, Koch said, but can provide a pathway for by-products like trihalomethanes and haloacetic acids to get into the water during the disinfecting process.
“You try to explain that in a written format and that’s tough to do,” he said.