Coliforms are bacteria that are naturally present in the environment and used as an indicator that other, potentially harmful, bacteria may be present. Coliforms found in more samples than allowed is a warning of potential problems.

Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5

Nitrates and nitrites are nitrogen-oxygen chemical units which combine with various organic and inorganic compounds. The greatest use of nitrates is as a fertilizer. Once taken into the body, nitrates are converted to nitrites.

Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome.

Trihalomethanes occur when naturally-occurring organic and inorganic materials in the water react with the disinfectants, chlorine and chloramine.

Liver, kidney or central nervous system problems; increased risk of cancer

Arsenic is a semi-metal element in the periodic table. It is odorless and tasteless. It enters drinking water supplies from natural deposits in the earth or from agricultural and industrial practices. Approximately 90 percent of industrial arsenic in the U.S. is currently used as a wood preservative, but arsenic is also used in paints, dyes, metals, drugs, soaps, and semi-conductors. Agricultural applications, mining, and smelting also contribute to arsenic releases in the environment.

Skin damage or problems with circulatory systems, and may have increased risk of getting cancer

Haloacetic acids occur when naturally-occurring organic and inorganic materials in the water react with the disinfectants, chlorine and chloramine.

Increased risk of cancer

Trichloroethylene, a volatile organic chemical, is a colorless or blue liquid with a chloroform-like odor. Trichloroethylene is primarily used to remove grease from fabricated metal parts and in the production of some textiles.

Liver problems; increased risk of cancer

1,1-Dichloroethylene is an organic liquid with a mild, sweet, chloroform-like odor. Virtually all 1,1-dichloroethylene is used in making adhesives, synthetic fibers, refrigerants, food packaging and coating resins such as the saran types.

Liver problems

Tetrachloroethylene is a colorless organic liquid with a mild, chloroform-like odor. The greatest use of tetrachloroethylene is in the textile industry, and as a component of aerosol dry-cleaning products.

Liver problems; increased risk of cancer

The gaseous or liquid form of chlorine (CL2) is a water additive used by municipal water systems to control microbes. It is relatively inexpensive and has the lowest production and operating costs and longest history for large continuous disinfection operations. Chlorine is a powerful oxidant.

Eye/nose irritation; stomach discomfort

Barium is a lustrous, machinable metal which exists in nature only in ores containing mixtures of elements. It is used in making a wide variety of electronic components, in metal alloys, bleaches, dyes, fireworks, ceramics and glass. In particular, it is used in well drilling operations where it is directly released into the ground.

Increase in blood pressure

Di(2-ethylhexyl) phthalate is the most commonly used of a group of related chemicals called phthalates or phthalic acid esters. The greatest use of di(2-ethylhexyl) phthalate is as a plasticizer for polyvinylchloride (PVC) and other polymers including rubber, cellulose and styrene. A number of packaging materials and tubings used in the production of foods and beverages are polyvinylchloride contaminated with phthalic aced esters, primarily di(2-ethylhexyl) phthalate.

Reproductive difficulties; liver problems; increased risk of cancer

Fluoride compounds are salts that form when the element, fluorine, combines with minerals in soil or rocks. Many communities add fluoride to their drinking water to promote dental health.

Bone disease (pain and tenderness of the bones); Children may get mottled teeth

Bromate occurs when bromide in the water reacts with the disinfectant, ozone.

Increased risk of cancer

Benzo(a)pyrene is one of a group of compounds called polycyclic aromatic hydrocarbons. They are not produced or used commercially but are very commonly found since they are formed as a result of incomplete combustion of organic materials.

Reproductive difficulties; increased risk of cancer

Antimony is a metal found in natural deposits such as ores containing other elements. The most widely used antimony compound is antimony trioxide, used as a flame retardant. It is also found in batteries, pigments, and ceramics/glass.

Increase in blood cholesterol; decrease in blood sugar

Carbon tetrachloride is a clear heavy organic liquid with a sweet aromatic odor similar to chloroform. Most carbon tetrachloride is used to make chlorofluorocarbon propellants and refrigerants, though this has been declining steadily. It has also been used as a dry cleaning agent and fire extinguisher; in making nylons; as a solvent for rubber cement, soaps, insecticides, etc.

Liver problems; increased risk of cancer

Dichloromethane, also known as DCM and methylene chloride, is a volatile organic and colorless liquid chemical with a sweet, pleasant odor like chloroform. The greatest use of DCM is as a paint remover. Other uses include: solvent and cleaning agent in chemical manufacture, textiles, electronics, metals and plastics, pesticides industries; blowing and cleaning agent in the urethane foam industry; fumigant for strawberries and grains, and as degreener for citrus fruits; in pharmaceuticals and as an anesthetic; in extraction of caffeine, cocoa, fats, spices and beer hops; as a heat transfer agent in refrigeration products.

Liver problems; increased risk of cancer

Simazine is an organic white solid. Simazine is used as a pre-emergence herbicide used for control of broad-leaved and grassy weeds on a variety of deep-rooted crops such as artichokes, asparagus, berry crops, broad beans, citrus, etc., and on non-crop areas such as farm ponds and fish hatcheries. Its major use is on corn where it is often combined with AAtrex. Other herbicides with which simazine is combined include: paraquat, on apples, peaches; Roundup or Oust for noncrop use; Surflan on Christmas trees; Dual on corn and ornamentals.

Problems with blood

Chlorite occurs when chlorine dioxide breaks down.

Anemia; infants & young children: nervous system effects

Cadmium is a metal found in natural deposits such as ores containing other elements. Cadmium is used primarily for metal plating and coating operations, including transportation equipment, machinery and baking enamels, photography, and television phosphors. It is also used in nickel-cadmium solar batteries and pigments.

Kidney damage

Ethylene bromide, also known as EDB, and 1,2-Dibromoethane, is a colorless, heavy synthetic organic liquid with a mildly sweet chloroform-like odor. Ethylene dibromide is mainly used in an anti-knock gasoline mixtures, particularly aviation fuel.

Problems with liver, stomach, reproductive system, or kidneys; increased risk of cancer

1,2-Dichloroethane is a colorless, oily, organic liquid with a sweet, chloroform-like odor. The greatest use of 1,2-dichloroethane is in making chemicals involved in plastics, rubber and synthetic textile fibers. Other uses include: as a solvent for resins and fats, photography, photocopying, cosmetics, drugs, and as a fumigant for grains and orchards.

Increased risk of cancer