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City of Tarpon Springs
Copyright © 2015 City of Tarpon Springs. All rights registered.
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Public Services

Contact Information: (727) 942-5610, 324 East Pine St, Fax (727) 943-9609

For after hour emergencies please contact the city’s Emergency Answering Service at (727) 234-4944

Chromium 6 and Drinking Water; Points of Information

City of Tarpon Springs Public Services Department

September 22, 2016

City of Tarpon Springs Water Supply experts have reviewed a recent report by the Sarasota Patch circulated widely on social media.  Tarpon Springs’ water supply data has been reviewed and officials see absolutely no cause for concern or alarm on the part of its water customers.  The report cites the Tarpon Springs water supply, along with 27 other Tampa Bay communities, as containing levels of Chromium-6 that exceed a “public health goal” set in California of 0.02 parts per billion.  California’s established maximum contaminant level for chromium-6 is actually 10 parts per billion.  Tarpon Springs meets both California’s standard for Chromium-6 and the EPA established standard set for “total chromium” of 100 parts per billion.  Chromium-6 represents a fraction of total chromium. The most recent testing of total chromium levels at the City’s new RO Water Facility produced results of 0.8 parts per billion of total chromium.  Actual chromium 6 levels are a fraction of this, with typical values of less than 0.2 parts per billion.  The City utilizes state of the art reverse osmosis treatment for the majority of the water supply.  This treatment technology is approved at both the federal and state levels for removing chromium from drinking water.  This serves to reduce overall chromium to extremely minute levels. Over 100 times less than the current limits set by the EPA. Public health and water quality are of the upmost importance to us and we will continue to monitor this issue.  Additional detail on this issue is available below. What is chromium and where does it come from? Chromium is an odorless and tasteless metallic element. Chromium is found naturally in rocks, plants, soil and volcanic dust, and animals. In fact, chromium is the 11th most common element in the earth's crust. The most common forms of chromium that occur in natural waters in the environment are: Trivalent chromium (chromium-3) Hexavalent chromium (chromium-6) Chromium-3 is an essential human dietary element. It is found in many vegetables, fruits, meats, grains, and yeast. Chromium-6 occurs naturally in the environment from the erosion of natural chromium deposits. It 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.  We are not aware of any such instances in our water supply area. What is the regulatory limit for chromium? The national primary drinking water regulation that established the total chromium limit of 100 parts per billion. Chromium-6 and chromium-3 are covered under the total chromium drinking water standard because these forms of chromium can convert back and forth in water and in the human body, depending on environmental conditions. What is being done about reviewing chromium? EPA reviewed total chromium in March 2010, where the agency noted that it had initiated a reassessment of the health risks associated with chromium exposure and that the Agency did not believe it was appropriate to revise the national primary drinking water regulation while that effort was in process. In September, 2010, EPA released a draft of the scientific human health assessment (Toxicological Review of Hexavalent Chromium) for public comment and external peer review. When this human health assessment is finalized, EPA will carefully review the conclusions and consider all relevant information to determine if the current chromium standard should be revised. If EPA decides to revise the regulation that includes chromium-6 in drinking water, what is the process the agency will follow? Prior to EPA making any decisions about revising the chromium drinking water regulation, EPA must issue its final human health assessment for chromium-6.  EPA will carefully review the final assessment and consider all other relevant information to determine if a new drinking water regulation for chromium-6 or a revision to the current total chromium standard is warranted. What are others doing about chromium? California’s established a maximum contaminant level (MCL) of 10 parts per billion (ppb) for chromium-6 in drinking water is the only drinking water standard for chromium-6 in the nation.  This took effect on July 1, 2014. What is known about chromium-6 health effects? The effects of chromium-6 when it is ingested have been the subject of much debate.  It is a known fact that when some forms of chromium-6 are inhaled, they can cause cancer. However, experts have disagreed on its toxicity in drinking water due in part to the possible changes to chromium-6 in the stomach when it is ingested. The following is some information and resources about past and current research on chromium-6 health effects: EPA currently regulates total chromium based on noncancerous effects of the chemical such as its ability to cause liver damage, harm the kidney, damage nerve tissues, and cause skin irritations. The National Toxicology Program (NTP) announced in 2007 the results of a study that found chromium-6 caused oral cavity and small intestine cancers in laboratory animals when administered orally. The lowest doses given to the animals in the study were ten times higher than what humans could consume from the most highly contaminated water sources identified in California. The Office of Environmental Health Hazard Assessment (OEHHA) relied on the NTP study results when they published their public health goal in 2011. ToxStrategies has released the results of its research on the toxicity of chromium-6 and its “mode of action” (how it causes cancer in the body). The research was also designed to provide information on the differences between rodents and humans with regard to internal dose and develop the models and data needed to do a state-of-the-art risk assessment using NTP’s 2007 findings. ToxStrategies’ research found that its risk assessment using new mode of action (MOA) study data supports the current MCL (100 ppb) as protective for sensitive human subpopulations. More information is available here: http://www.toxstrategies.com/publications/CRVI_MOA_study.htm. EPA is working on a toxicological review specific to orally ingested chromium-6 through its Integrated Risk Information System (IRIS). Based on the recommendations of an external peer review panel that met in 2011 to review the draft assessment, EPA will consider the results of the ToxStrategies studies before finalizing its assessment. This new draft toxicity assessment will be combined with the inhalation assessment, which is also in draft development. How does all of this relate to the City of Tarpon Springs water supply? The City utilizes state of the art reverse osmosis for treatment for the majority of the water supply (with freshwater wells and some groundwater blending making up the remainder).  This reverse osmosis treatment is a federal and state approved technology for removing chromium from drinking water.  This serves to reduce overall chromium to extremely minute levels, over 100 times less than the current limit. What recent water quality results do we have for chromium in Tarpon Springs? Tarpon Springs’ most recent sample results showed 0.8 parts per billion for Total Chromium, the currently regulated parameter. These results are all well below the EPA limit of 100 parts per billion and are also below the only state standard of 10 parts per billion for the sub component of chromium 6.  It should be noted that our actual chromium 6 levels are a fraction of this concentration, with typical values of less than 0.2 parts per billion. Sources for additional information: https://www.epa.gov/dwstandardsregulations/chromium-drinking-water http://www.acwa.com/content/chromium-6  
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City of Tarpon Springs
Copyright © 2015 City of Tarpon Springs. All rights registered

Public Services

Contact Information: (727) 942-5610,

324 East Pine St, Fax (727) 943-9609

For after hour emergencies please contact the city’s Emergency Answering Service at (727) 234-4944

Chromium 6 and Drinking Water; Points

of Information

City of Tarpon Springs Public Services

Department

September 22, 2016

City of Tarpon Springs Water Supply experts have reviewed a recent report by the Sarasota Patch circulated widely on social media.  Tarpon Springs’ water supply data has been reviewed and officials see absolutely no cause for concern or alarm on the part of its water customers.  The report cites the Tarpon Springs water supply, along with 27 other Tampa Bay communities, as containing levels of Chromium-6 that exceed a “public health goal” set in California of 0.02 parts per billion.  California’s established maximum contaminant level for chromium-6 is actually 10 parts per billion.  Tarpon Springs meets both California’s standard for Chromium-6 and the EPA established standard set for “total chromium” of 100 parts per billion.  Chromium-6 represents a fraction of total chromium. The most recent testing of total chromium levels at the City’s new RO Water Facility produced results of 0.8 parts per billion of total chromium.  Actual chromium 6 levels are a fraction of this, with typical values of less than 0.2 parts per billion.  The City utilizes state of the art reverse osmosis treatment for the majority of the water supply.  This treatment technology is approved at both the federal and state levels for removing chromium from drinking water.  This serves to reduce overall chromium to extremely minute levels. Over 100 times less than the current limits set by the EPA. Public health and water quality are of the upmost importance to us and we will continue to monitor this issue.  Additional detail on this issue is available below. What is chromium and where does it come from? Chromium is an odorless and tasteless metallic element. Chromium is found naturally in rocks, plants, soil and volcanic dust, and animals. In fact, chromium is the 11th most common element in the earth's crust. The most common forms of chromium that occur in natural waters in the environment are: Trivalent chromium (chromium-3) Hexavalent chromium (chromium-6) Chromium-3 is an essential human dietary element. It is found in many vegetables, fruits, meats, grains, and yeast. Chromium-6 occurs naturally in the environment from the erosion of natural chromium deposits. It 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.  We are not aware of any such instances in our water supply area. What is the regulatory limit for chromium? The national primary drinking water regulation that established the total chromium limit of 100 parts per billion. Chromium-6 and chromium-3 are covered under the total chromium drinking water standard because these forms of chromium can convert back and forth in water and in the human body, depending on environmental conditions. What is being done about reviewing chromium? EPA reviewed total chromium in March 2010, where the agency noted that it had initiated a reassessment of the health risks associated with chromium exposure and that the Agency did not believe it was appropriate to revise the national primary drinking water regulation while that effort was in process. In September, 2010, EPA released a draft of the scientific human health assessment (Toxicological Review of Hexavalent Chromium) for public comment and external peer review. When this human health assessment is finalized, EPA will carefully review the conclusions and consider all relevant information to determine if the current chromium standard should be revised. If EPA decides to revise the regulation that includes chromium-6 in drinking water, what is the process the agency will follow? Prior to EPA making any decisions about revising the chromium drinking water regulation, EPA must issue its final human health assessment for chromium-6.  EPA will carefully review the final assessment and consider all other relevant information to determine if a new drinking water regulation for chromium-6 or a revision to the current total chromium standard is warranted. What are others doing about chromium? California’s established a maximum contaminant level (MCL) of 10 parts per billion (ppb) for chromium-6 in drinking water is the only drinking water standard for chromium-6 in the nation.  This took effect on July 1, 2014. What is known about chromium-6 health effects? The effects of chromium-6 when it is ingested have been the subject of much debate.  It is a known fact that when some forms of chromium-6 are inhaled, they can cause cancer. However, experts have disagreed on its toxicity in drinking water due in part to the possible changes to chromium-6 in the stomach when it is ingested. The following is some information and resources about past and current research on chromium-6 health effects: EPA currently regulates total chromium based on noncancerous effects of the chemical such as its ability to cause liver damage, harm the kidney, damage nerve tissues, and cause skin irritations. The National Toxicology Program (NTP) announced in 2007 the results of a study that found chromium-6 caused oral cavity and small intestine cancers in laboratory animals when administered orally. The lowest doses given to the animals in the study were ten times higher than what humans could consume from the most highly contaminated water sources identified in California. The Office of Environmental Health Hazard Assessment (OEHHA) relied on the NTP study results when they published their public health goal in 2011. ToxStrategies has released the results of its research on the toxicity of chromium-6 and its “mode of action” (how it causes cancer in the body). The research was also designed to provide information on the differences between rodents and humans with regard to internal dose and develop the models and data needed to do a state-of-the-art risk assessment using NTP’s 2007 findings. ToxStrategies’ research found that its risk assessment using new mode of action (MOA) study data supports the current MCL (100 ppb) as protective for sensitive human subpopulations. More information is available here: http://www.toxstrategies.com/publications/CRVI_M OA_study.htm. EPA is working on a toxicological review specific to orally ingested chromium-6 through its Integrated Risk Information System (IRIS). Based on the recommendations of an external peer review panel that met in 2011 to review the draft assessment, EPA will consider the results of the ToxStrategies studies before finalizing its assessment. This new draft toxicity assessment will be combined with the inhalation assessment, which is also in draft development. How does all of this relate to the City of Tarpon Springs water supply? The City utilizes state of the art reverse osmosis for treatment for the majority of the water supply (with freshwater wells and some groundwater blending making up the remainder).  This reverse osmosis treatment is a federal and state approved technology for removing chromium from drinking water.  This serves to reduce overall chromium to extremely minute levels, over 100 times less than the current limit. What recent water quality results do we have for chromium in Tarpon Springs? Tarpon Springs’ most recent sample results showed 0.8 parts per billion for Total Chromium, the currently regulated parameter. These results are all well below the EPA limit of 100 parts per billion and are also below the only state standard of 10 parts per billion for the sub component of chromium 6.  It should be noted that our actual chromium 6 levels are a fraction of this concentration, with typical values of less than 0.2 parts per billion. Sources for additional information: https://www.epa.gov/dwstandardsregulations/chro mium-drinking-water http://www.acwa.com/content/chromium-6  
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