National Drinking Water Database
Combined Uranium (mg/L) in Colorado
Uranium is a radioactive element commonly found in most rocks; processed uranium ore is used for power generation and weapons manufacture. [read more]
Uranium is a radioactive heavy metal used in nuclear power plants and nuclear weapons. Uranium is a known human carcinogen. It has been observed to cause lung cancer in miners, and bone cancer and leukemia in workers and animals exposed to the substance (Hazardous Substances Data Bank (HSDB) 2003h).
In addition to nuclear applications, uranium is also used to make helicopters, airplanes, army tanks, bullets and missiles. Small amounts are used to make pottery glazes and photographic chemicals. Since uranium is often found in naturally occurring phosphorus, phosphorus fertilizers and pesticides often have uranium impurities in them (Agency for Toxic Substances and Disease Registry (ATSDR) 1999c).
A drinking water contaminant fact sheet written by EPA notes that exposure to uranium in drinking water above the maximum contaminant level (MCL) of 30 parts per billion (ppb) may damage the kidney and cause cancer (U.S. Environmental Protection Agency (USEPA) 2009b). Renal (kidney) problems are a hallmark of uranium toxicity; these effects develop early on following uranium exposure (Thun 1985).
The Most Polluted Communities in Colorado
1 water utilities reported detecting Combined Uranium (mg/L) in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Combined Uranium (mg/L) level
|Rank||System||Population Served||Positive test results of total reported tests||Average Level|
|1||City of Englewood|
|29,500||1 of 1||9.7 ppb|
Health Based Limits for Combined Uranium (mg/L)
|Maximum Contaminant Limit Goal (MCLG)||A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.||0 ppb|
|California Public Health Goals||Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.||0.5 ppb|
|Drinking Water Equivalent Level||A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.||20 ppb|
|Maximum Contaminant Limit (MCL)||The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.||30 ppb|
Violation Summary for Combined Uranium (mg/L) in Colorado
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Colorado since 2004
|Violation Type||Number of Violations|
|Over maximum contaminant level, Average||77|
|Failure to monitor regularly||15|
|Over maximum contaminant level, Single Sample||3|