DECATUR, Ala. (AP) — For more than three years, 3M Co. underreported its discharge of a class of potentially toxic chemicals into the Tennessee River by a factor of 1,000, according to a letter sent by a 3M official to regulators at the Alabama Department of Environmental Management.
The revelation comes amid a litany of legal challenges against the chemical company over its production of the chemicals known as perfluorochemicals, or PFCs.
At least one lawsuit alleges the presence of two PFCs, perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA), in the drinking water of West Morgan-East Lawrence Water and Sewer Authority caused cancer and other health problems for at least 24 water system customers.
Last year, the water authority, which draws its raw water 13 miles downstream from 3M, issued a temporary no-drink warning when levels of PFOS and PFOA in its finished drinking water exceeded federal safety guidelines for lifetime exposure in drinking water.
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In an April 20 letter to ADEM, 3M Environmental Engineer Jennifer Brown wrote that, from the last quarter of 2012 though the first half of 2016, 3M inadvertently had reported its discharge monitoring reports in milligrams per liter instead of micrograms per liter, but ADEM had recorded the data as micrograms without conversion.
A milligram is equal to a thousandth of a gram as opposed to a microgram, which is equal to a millionth of a gram, resulting in ADEM recording significantly lower discharge outputs than actually occurred.
For example, in March 2013, when 3M reported a monthly average discharge for PFOS of 0.00573 micrograms per liter, it should have reported 5.73 micrograms per liter. The 0.00573 measurement would have been correct if the report were in milligrams per liter.
The letter said 3M had discovered the discrepancy as part of an internal review. The company provided updated data to ADEM for the effected periods.
In a statement Wednesday, William Brewer III, legal counsel for Minnesota-based 3M, said the error occurred because ADEM moved to a different metric when it switched to an electronic system.
However, Brown’s letter to ADEM said, even before the switch, ADEM had taken monitoring data provided by 3M in milligrams per liter and recorded it as micrograms per liter without converting it.
“When 3M recognized the issue, we advised ADEM and corrections were made to the…