All 16 carbon filters at West Virginia American Water’s Elk River treatment plant have been replaced, more than six months after a chemical leak contaminated drinking water for about 300,000 residents.
Tests on filtered water showed no trace amounts of the coal-cleaning chemical MCHM, company officials announced Thursday.
The company took 64 filtered water samples from the newly change filters, in addition to 26 samples from water in other phases of the water treatment process. Samples were sent to Eurofins Lancaster Laboratories, in Pennsylvania, where the lab can detect MCHM levels as low as 0.38 parts per billion.
“We committed to our customers 10 days after the spill that we would change the filter material as soon as conditions allowed to ensure customer confidence in the quality of the water that deliver 24/7 to their homes and businesses,” water company president Jeff McIntyre said in a press release. “Restoring full service and full confidence in our water was not just our job — it was our promise to our neighbors and our families in the communities we serve because this community is our home too.”
McIntyre again addressed the possibility of a filter change in late March after questions were raised at by independent scientist investigating the leak’s impacts. The company released more-detailed test results that showed low levels of MCHM between 0.42 parts per billion and 0.60 parts per billion in water that completed multiple stages of filtration and treatment. MCHM was not found in raw water entering the plant or in settled water, but testing did detect the chemical in 10 of 14 filtered samples and in six of seven finished water samples.
When those results were made public around the end of March, McIntyre said, “It is not unexpected that MCHM effectively captures in filter material may show up in trace amounts in water leaving the plant.”
McIntyre told the Gazette a week before that the plant’s filters “have not been impacted” by the chemical leak and were being changed only because of a public “perception” that they needed to be replaced.
Each filter took about four days to change and another couple days for test results to come back before a changed filter could be put back online. Pittsburgh-based Calgon Carbon replaced the filters.
The project, estimated to cost $1.1 million, began April 1, replacing filters two at a time.