Hexavalent chromium is an odorless, tasteless metallic element found naturally in rocks, plants and soil. Chromium is the 21st most common element found in the Earth’s crust.
- There are two common forms of chromium:
- Trivalent chromium is an essential human dietary element found in vegetable, meats, fruits, grains and yeast. It can be found in most multi-vitamins and is not a risk to public health.
- Hexavalent chromium can be generated from natural deposits of chromium in soils, as well as produced by industrial processes such as steel manufacturing and pulp mills.
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The Suffolk County Water has been voluntarily testing for hexavalent chromium since 2012
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SCWA tests untreated (raw) groundwater and treated water (drinking water) at various points in our distribution system.
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In 2015, tests indicate that Suffolk County Water Authority averaged 0.39 parts per billion (ppb) of hexavalent chromium system-wide.
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The Environmental Protection Agency sets national drinking water standards and established a limit for total chromium (combined trivalent chromium and hexavalent chromium) of 100 parts per billion (ppb) in 1991.
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No SCWA well has ever exceeded 100ppb for this compound. In fact, only three of approximately 600 SCWA wells exceed 10ppb, the current maximum contaminant level set by the state of California.
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The EPA does not currently have a maximum contaminate level regulation or health advisory for hexavalent chromium.
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Though scientists are in the process of determining whether hexavalent chromium poses a danger to drinking water supplies, a study by a doctor from the University of Genoa found that when ingested orally, i.e. through drinking water, the body has the ability to detoxify the compound through saliva and stomach acid and that its potential danger is further reduced in the intestine and liver.
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The same study found that for the compound to be carcinogenic would require "massive exposure" in certain occupational settings and when inhaled.
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Bottled water, regulated by the Food and Drug Administration, is held to the same EPA standard of 100ppb for total chromium. Levels can vary by brand.
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The State of California adopted a Public Health Goal (PHG) of 0.02 parts per billion for chromium-6 in July 2011. This is a state-specific goal.
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It has been estimated that a person would see a one-in-a-million additional risk of cancer if he or she was to drink two liters of water with that level of hexavalent chromium for 70 years.
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The Suffolk County Water Authority’s primary mission is to provide safe drinking water to its customers. To accomplish this goal, SCWA tests for 249 more contaminants than required by regulators.
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SCWA also maintains internal standards for drinking water that are often more rigorous than regulators require.