Low pH: Acid Water Conditions
The most common regions for acid water conditions in the United States are New England and in the Northwest in the states of Oregon, Washington, and along the Eastern Seaboard in the Carolinas, Georgia, Virginia, Delaware, southern New Jersey, Maryland and Tennessee. In Canada, the Maritime Provinces and the western part of British Columbia are noted for acid water conditions.
Acid surface water and acid well waters may be found in many areas in the United States and Canada and are usually very low in hardness as well as total dissolved solids. The chief influence on low pH values in water is the presence of carbon dioxide (CO2) and the lack of sufficient offsetting bicarbonate alkalinity. Surface water, lakes, reservoirs, and streams pick up C02 from the atmosphere. Well water can absorb C02 created by decaying vegetation. Carbon dioxide will combine with water to form carbonic acid (C03) which is classified as a weak acid.
The relative amount of carbon dioxide present in the water supply as carbonic acid the water more neutral. By taking a sample and accurately testing the pH value of the water, you can determine whether the water is acid and aggressive in nature, tending to corrode brass, copper, steel piping, and fixtures in the home, on the farm, or in the place of business. Acid water also can attack and dissolve several heavy metals – cadmium, zinc, and lead. The EPA action level for lead of 15 ppb (0.015 mg/L) in drinking water, has focused much more attention on undesirable low-pH municipal and private well water sources.