Tests on Kentucky’s public drinking water shows the Commonwealth clearly meets even the most stringent standards in the country for chromium-6.
Kentucky’s public water systems are required by the Safe Drinking Water Act to monitor regularly for total chromium and other inorganic compounds and provide these results to the Division of Water (DOW).
Other monitoring by the Environmental Protection Agency (EPA) and by Kentucky’s public water systems under the Unregulated Contaminants Monitoring Rule in 2014 and 2015 for hexavalent chromium (chromium-6) show the levels of total chromium and chromium-6 are well below current regulatory thresholds.
The Environmental Work Group (EWG), a public health advocacy group, recently released a report highlighting the detections of chromium-6 in public drinking water across the nation and leaving the public with the impression that there were grave concerns regarding the occurrence of chromium-6 in public drinking water.
The group has been advocating for the EPA to regulate chromium-6, and wants the EPA to attach a maximum contaminant level to chromium-6. The evaluation of available monitoring data for chromium-6 in Kentucky’s public drinking water dispels the EWG’s suggestion that the occurrence of chromium-6 is a concern in Kentucky. In fact, the data shows Kentucky’s public drinking water clearly meets even the most stringent standards for chromium-6 in the nation, and generally public water systems provide exceptional quality water to Kentucky residents.
Test results on public drinking water, sent to DOW for the past 10 years, show that only 125 of 2296 samples had any detection for total chromium. The detection results ranged from a minimum detection of 0.20 µg/L (or parts per billion, ppb) to a maximum 38.00 ppb. The average detection of total chromium was 3.89 ppb.
Kentucky employs the EPA’s federal drinking water standard of 0.1 milligrams per liter (mg/L) or 100 parts per billion (ppb) for total chromium. This includes all forms of chromium, including chromium-6. So in regards to total chromium, Kentucky’s public drinking water is exceptionally good and there have been zero compliance issues identified.
Public water systems that rely on surface water test for chromium annually. Water systems that use groundwater as their source monitor for chromium every three years.
Chromium is an odorless and tasteless metallic element found naturally in rocks, plants, soil, volcanic dust and animals. Chromium-6 occurs naturally in the environment from the erosion of natural chromium deposits and can also be produced by industrial processes. There are demonstrated instances of chromium being released to the environment by leakage, poor storage or inadequate industrial waste disposal practices.
The EPA’s drinking water standard for total chromium is based on potential adverse dermatological effects, such as allergic dermatitis (skin reactions) that may occur over many years of use of the drinking water. The EPA regularly re-evaluates drinking water standards and, based on new science on chromium-6, began a rigorous and comprehensive review of the health effects of chromium-6 in 2008.
The EPA’s Unregulated Contaminants Monitoring Rule (UCMR) is a monitoring effort conducted by the EPA in conjunction with PWSs across the country to gather data to provide a basis for future regulatory actions to protect public health.
The EPA’s Third UCMR required monitoring for 30 contaminants, including chromium-6. UCMR-3 sampling at Kentucky PWSs yielded 1216 sample results, 952 of which had detections of chromium-6. The results ranged from a minimum detection of 0.03 ppb to a maximum detection of 1.5 ppb.
Neither the EPA nor Kentucky has established a maximum contaminant level for chromium-6. California has established a state public health goal for chromium-6 in drinking water of 10.0 ppb. While this standard is not an enforceable standard for Kentucky PWSs, this standard can be used for purposes of comparison. In that regard, the level of chromium-6 in Kentucky’s public drinking water is far lower than the most stringent regulatory standard for chromium-6 in the nation.