Radionuclides are radioactive isotopes that can occur naturally or result from manmade sources. Natural radiation comes from cosmic rays, naturally-occurring radioactive elements in the earth’s crust, and radioactive decay products. Since these radionuclides are present in soil and rock, they can also be found in groundwater and surface water. Typical radionuclides found in drinking water sources are isotopes of radium, uranium, and radon, among others. Fission products from manmade nuclear reactions are also of concern today, particularly radioactive cesium and iodine.
Water Research Foundation's Radionuclides info
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An aldehyde is a compound that contains a carbon-oxygen bond. CFPUA tests for various kinds of aldehydes twice per year, and the tests measure the levels of chemicals such as: Acetaldehyde, Butanal, Formaldehyde, Hexanal, Pentanal and Proponal. This includes testing for: Acetaldehyde, Butanal, Formaldehyde, Hexanal, Pentanal and Proponal.
Asbestos is a mineral fiber that occurs in rock and soil. Because of its fiber strength and heat resistance asbestos has been used in a variety of building construction materials for insulation and as a fire retardant. Asbestos has also been used in a wide range of manufactured goods, mostly in building materials (roofing shingles, ceiling and floor tiles, paper products, and asbestos cement products), friction products (automobile clutch, brake, and transmission parts), heat-resistant fabrics, packaging, gaskets, and coatings.
EPA Asbestos info
Bromate is a chemical that is formed when ozone used to disinfect drinking water reacts with naturally occurring bromide found in source water. EPA has established the Stage 1 Disinfectants/Disinfection Byproducts Rule to regulate bromate at annual average of 10 parts per billion in drinking water. This standard will become effective for large public water systems by December 2001 and for small surface water and all ground public water systems in December 2003.
EPA Bromide/Bromate info
Aqueous chemical reactions and the handling of chemicals used in drinking water treatment is the dominant source of environmental exposure to chlorate. Outside of exposure from drinking water treatment processes, the industrial uses of chlorate can lead to unsafe levels persisting in the environment. Chlorine dioxide, chlorite, and chlorate can occur in foods as they are used in flour processing, as decolorizing agents, as bleaching agents, and as an indirect additive from paper packaging.
American Water Works Association Chlorate/Chlorite info
Coal ash, also referred to as coal combustion residuals or CCRs, is produced primarily from the burning of coal in coal-fired power plants. Coal ash contains contaminants like mercury, cadmium and arsenic. Without proper management, these contaminants can pollute waterways, ground water, drinking water, and the air. To address the risks from improper disposal and discharge of coal ash, EPA has established national rules for coal ash disposal and is strengthening existing controls on water discharges.
EPA Coal Ash info
Disinfection byproducts are formed when disinfectants used in a water treatment react with bromide and/or natural organic matter (i.e., decaying vegetation) present in the source water. Different disinfectants produce different types or amounts of disinfection byproducts. Disinfection byproducts for which regulations have been established have been identified in drinking water, including trihalomethanes, haloacetic acids, bromate, and chlorite.
EPA DBP info
Pharmaceuticals and Personal Care Products (PPCPs) refer to products used by individuals for personal health/well-being or for cosmetic purposes. Endocrine Disrupting Chemicals (EDCs) are chemicals/compounds that have or are suspected of having an adverse effect on the body’s endocrine system. Examples include prescription and over the counter drugs, veterinary drugs, fragrances, lotions, cosmetics, detergents, plasticizers, pesticides and flame retardants.
There are a number of routes by which PPCP and EDCs can find their way into surface water and ground water supplies. Elimination from the body, flushing or disposal in landfills of unused or expired drugs, or in the case of personal care products, rinsing down the drain while showering or bathing are common pathways to the environment. In the case of agricultural focused products or veterinary drugs, runoff offers another pathway to surface water or groundwater reserves.
Water Quality Association PPCP and EDC Fact Sheet
The mineral fluoride occurs naturally on earth and is released from rocks into the soil, water, and air. All water contains some fluoride. Usually, the fluoride level in water is not enough to prevent tooth decay; however, some groundwater and natural springs can have naturally high levels of fluoride. Community water fluoridation is the process of adjusting the amount of fluoride found in water to achieve optimal prevention of tooth decay.
Although other fluoride-containing products, such as toothpaste, mouth rinses, and dietary supplements are available and contribute to the prevention and control of tooth decay, community water fluoridation has been identified as the most cost-effective method of delivering fluoride to all, reducing tooth decay by 25% in children and adults.
CDC Flouride info
Pathogens, such as Giardia, Cryptosporidium and Legionella, are often found in water. If consumed, these pathogens can cause gastrointestinal illness (e.g., diarrhea, vomiting, cramps) and other health risks. These illnesses may be severe and sometimes fatal for people with weakened immune systems. Cryptosporidium is a significant concern in drinking water because it is resistant to chlorine and other disinfectants. The Surface Water Treatment Rules were established to protect against these pathogens. To protect public health, drinking water from lakes, rivers streams and some other sources needs to be treated. This treatment includes disinfection and, in most cases, filtration.
EPA Giardia/ Cryptosporidium info
The chemical contaminants were promulgated in phases collectively called the Phase II/V Rules or the Chemical Contaminant Rules. These rules regulate over 65 contaminants in three contaminant groups:
The rules apply to all public water systems (PWS). PWS type, size, and water source type determine which contaminants require monitoring for that system.
The Chemical Contaminants Rules provide public health protection through the reduction of chronic, or long-term, risks from:
EPA IOC info
Lead and copper enter drinking water primarily through plumbing materials. Exposure to lead and copper may cause health problems ranging from stomach distress to brain damage.
In 1991, EPA published a regulation to control lead and copper in drinking water. This regulation is known as the Lead and Copper Rule (also referred to as the LCR). The treatment technique for the rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level of 15 parts per billion or copper concentrations exceed an action level of 1.3 parts per million in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion.
Learn more about how Lead can enter water through home plumbing.
Learn more about the Lead and Copper Rule
The Long Term 2 Enhanced Surface Water Treatment Rule addresses the health effects associated with Cryptosporidium in surface water used as a drinking water supply. Surface water systems are required to conduct source water monitoring for Cryptosporidium, E. coli, and turbidity.
EPA Long Term 2 info
Nitrates are a form of nitrogen, which is found in several different forms in terrestrial and aquatic ecosystems. These forms of nitrogen include ammonia (NH3), nitrates (NO3), and nitrites (NO2). Nitrates are essential plant nutrients, but in excess amounts they can cause significant water quality problems. Sources of nitrates include wastewater treatment plants, runoff from fertilized lawns and cropland, failing on-site septic systems, runoff from animal manure storage areas, and industrial discharges that contain corrosion inhibitors.
EPA Nitrate info
Perchlorate is a naturally occurring and manufactured chemical anion that consists of one chlorine atom bonded to four oxygen atoms (ClO4-). Perchlorate is commonly used as an oxidizer in rocket propellants, munitions, fireworks, airbag initiators for vehicles, matches and signal flares. It is naturally occurring in some fertilizers.
On February 11, 2011, EPA determined that perchlorate meets the Safe Drinking Water Act criteria for regulation as a contaminant. The Agency found that perchlorate may have an adverse effect on the health of persons and is known to occur in public drinking water systems with a frequency and at levels that present a public health concern.
EPA Perchlorate info
Alkalinity is a measure of the capacity of water to neutralize acids (see pH description). Alkaline compounds in the water such as bicarbonates (baking soda is one type), carbonates, and hydroxides remove H+ ions and lower the acidity of the water (which means increased pH). Total alkalinity is measured by measuring the amount of acid (e.g., sulfuric acid) needed to bring the sample to a pH of 4.2. At this pH all the alkaline compounds in the sample are "used up." The result is reported as milligrams per liter of calcium carbonate (mg/L CaCO3).
EPA Carbon/Alkalinity info