Pomperaug District Department of Health Water Quality Interpretive Guide

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COLIFORM BACTERIA are not disease-producing organisms themselves, but are used as an indicator of disease-producing organisms. When coliform bacteria are present, this is a good indication that the source of the water may have been contaminated by surface water or fecal material, and may contain disease-producing organisms. Chlorination is the best method for eliminating bacteria from the water, but the source of contamination should be located and treated so the problem does not recur.

COLOR may be caused by dissolved organic material from decaying vegetation and/or certain inorganic material such as iron or manganese. While color is not objectionable from a health standpoint, its presence is aesthetically objectionable and suggests that the water needs appropriate treatment.

ODOR in water can be caused by foreign matter such as organic compounds, inorganic salts or dissolved gases. These materials may come from domestic, agricultural or natural sources.

TURBIDITY is the presence of suspended material such as clay, silt, plankton, finely divided organic material and other inorganic materials.

NITRATE NITROGEN - an elevated level may be an indication that agricultural fertilizer or waste disposal is polluting the water. An excess of nitrates in drinking water is of particular concern for infants under six months of age. (see attached sheet on Nitrates).

pH is a measure of the acid or alkaline content of water. Water with a low pH (acidic), or a very high pH (basic), is corrosive to plumbing and may cause leaching of toxic metals such as lead or copper.

CHLORIDE was established primarily as an aesthetic standard. The concentration at which the average person can detect a salty taste in water is 250 mg/L. A very high chloride level can lead to corrosiveness or water on pipes and heating equipment and is usually associated with an elevated level of sodium. Elevated sodium levels are likely to be seen with a water softener. Other possible causes are run-off from road salting or sewage contamination.

IRON - elevated levels can discolor fixtures and laundry and may impart a metallic taste to the water. Iron is frequently present in water because of the large amounts present in soil. Corrosive water will also pick up iron from pipes.

MANGANESE - elevated levels may produce a brownish black stain in laundry and on fixtures and impart an objectionable odor and taste. It is usually found along with iron in soil with a high mineral content.

HARDNESS - calcium and magnesium salts are the major cause of hardness in water supplies. Although not detrimental to health, hard water retards the cleaning action of soaps and detergents. When hard water is heated it will deposit a hard scale on heating coils and cooking utensils with a consequent waste of fuel.

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