The Environmental Working Group (EWG) recently analyzed US EPA data that found levels of the mineral chromium-6 to be present in water samples taken from water treatment plants in several southern Ohio counties.
An interactive map designed by the EWG shows that water samples taken from water treatment plants in Fairborn, Xenia, Wilmington, and Washington Court House have different levels of chromium-6 present in the drinking water.
The EWG report lists four water samples that were taken from the Washington Court House water treatment plant. The range of detection for chromium-6 listed in the four samples is between .25 parts per billion to .39 parts per billion.
“Parts per billion” is the ratio at which contaminant concentrations are measured and is usually explained as being one drop per every billion drops of water. Or said another way, one part per billion would be measured as one microgram of contaminant for every liter of water.
The EWG reports that in January of 2014, there was a level of .33 parts per billion of chromium-6 detected in the water from the Washington Court House water treatment plant.
The US Environmental Protection Agency (EPA) mandates a maximum contaminant level of all chromium to be 100 parts per billion. Chromium-6 is one of several types of chromium that may be present in drinking water.
While there is no national standard established by the US EPA for chromium-6 levels, the state of California set its own maximum contaminant level for chromium-6 at 10 parts per billion.
The Ohio EPA does not have its own maximum contaminant level established for chromium-6. Instead it uses the US EPA standard of 100 parts per billion of all chromium contaminants, which includes chromium-6.
“Ohio EPA takes drinking water safety very seriously. If US EPA sets a national standard for chromium-6, Ohio will move quickly to adopt that standard to ensure that Ohioans are protected,” said Heidi Griesmer, spokesperson for Ohio EPA in Columbus.
Griesmer said people should not be concerned to drink their water because of the chromium-6 levels that have been detected in the water.
“The vast majority of our water systems have chromium-6 levels of less than one part per billion, and because they are so low, the general indication would be that the source may be naturally occurring from things in the soil,” said Griesmer.
She said the EWG report analyzed Ohio EPA data that was sent to the US EPA, which is working on a scientific review to determine if Ohio should establish maximum contaminant levels for chromium-6.
“If at some point US EPA comes out with a number that was lower than that [.33 ppb], we would work with our state water systems to lower that number to meet US EPA standards,” said Greismer.
Representatives from the EWG and the Washington Court House water treatment plant could not be reached for comment Wednesday.