Definition__Mean Uranium Levels for Utah__ [[br]]
1) Yearly distribution of number of community water systems (CWS) by mean uranium concentration [[br]]
2) Yearly distribution of number of people served by CWS by mean uranium concentration
__Maximum Uranium Levels for Utah__ [[br]]
3) Yearly distribution of number of CWS by maximum uranium concentration [[br]]
4) Yearly distribution of number of people served by CWS by maximum uranium concentration
Numerator1) Count of community water systems categorized by mean uranium concentration for each year reported (cut-points: <=30, >30 ug/L uranium, Not Detected)
2) Number of people served by community water systems categorized by mean uranium concentration for each year reported (cut-points: <=30, >30 ug/L uranium, Not Detected)
3) Count of community water systems categorized by maximum uranium concentration for each year reported (cut-points: <=30, >30 ug/L uranium, Not Detected)
4) Number of people served by community water systems categorized by maximum uranium concentration for each year reported (cut-points: <=30, >30 ug/L uranium, Not Detected)
DenominatorNot applicable. There are no rate measures in this indicator.
Data Interpretation IssuesA community water system is a public water system which serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents. Data reported to other sources, such as the U.S. Environmental Protection Agency (EPA), may differ slightly.
The current measures are derived for community water systems (CWS) only. Private wells may be another source of population exposure to Uranium. Transient non-community water systems, which are regulated by the EPA, may also be an important source of Uranium exposure. Measures do not account for the variability in sampling, numbers of sampling repeats, and variability within systems. Concentrations in drinking water cannot be directly converted to exposure because water consumption varies by climate, level of physical activity, and between people (EPA 2004). Due to errors in estimating populations, the measures may overestimate or underestimate the number of affected people. (Modified from the National Environmental Public Health Tracking Network [NEPHTN] Nationally Consistent Data and Measures [NCDM] uranium indicator document, verision 7)
The required monitoring frequency for Uranium is infrequent (every 3 to 6 years) and may be as intermittent as every nine years. Ground water systems may have multiple wells with different Uranium concentrations that serve different parts of the population. Compliance samples are taken at each entry point to the distribution system. In systems with separate wells serving some branches or sections of the distribution system, the system mean would tend to underestimate the Uranium concentrations of people served by wells with higher Uranium concentrations. Exposure may be higher or lower than estimated if data from multiple entry points for water with different Uranium levels are averaged to estimate levels for the CWS. (Modified from the NEPHTN NCDM uranium indicator document, verision 7)
Why Is This Important?People drink and use water every day. The majority of Americans are provided with high quality drinking water. About 90% of people in the U.S. get their water from a community water system versus a smaller water supply, such as a household well. The U.S. Environmental Protection Agency (EPA) sets regulations for treating and monitoring drinking water delivered by community water systems. Currently, there are water quality standards and monitoring requirements for over 90 contaminants. Drinking water protection programs play a critical role in ensuring high quality drinking water and protecting the public's health.
Because people drink and use water every day, contaminants in drinking water have the potential to affect many people. The number of people served by a community water system varies from as low as 25 to hundreds of thousands. Community water systems in the U.S. provide among the highest quality drinking water in the world. However, some contaminants are present at low levels and it is still possible that drinking water can become contaminated at higher levels. If a person is exposed to a high enough level of a contaminant, they may become ill.
Uranium is a silver-white metal that is extremely dense and weakly radioactive. It usually occurs as an oxide and is extracted from ores containing less than 1% natural uranium. Natural uranium is a mixture of three isotopes: 238U (greater than 99%), 235U (about 0.72%), and 234U (about 0.01%). Uranium has many commercial uses, including nuclear weapons, nuclear fuel, in some ceramics, and as an aid in electron microscopy and photography. Depleted uranium (DU) refers to uranium in which the proportions of 235U and 234U isotopes have been reduced compared with the proportion in natural uranium. Since the 1990s, DU has been used by the military in armor-piercing ammunition and as a component of protective armor for tanks. Natural and depleted uranium are primarily chemical toxicants, with radiation playing a minor role or no role at all (ATSDR, 2009). (From the National Environmental Public Health Tracking Network [NEPHTN] Nationally Consistent Data and Measures [NCDM] uranium indicator document, verision 7)
Everyone is exposed to uranium in food, air, and water as part of the natural environment (ATSDR, 2009). Variable concentrations of uranium occur naturally in drinking water sources. In some locations the natural concentrations may have increased due to mining and milling of uranium. Thus, the primary exposure sources for non-occupationally exposed persons are likely dietary and drinking water. Populations most heavily exposed to uranium are those employed in mining and milling operations, or in uranium enrichment and processing activities (ATSDR, 2009). (From the NEPHTN NCDM uranium indicator document, verision 7)