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the recommended range of pH, which is a measure of the acidity or alkalinity of a substance. Almost 88 percent, 207, of the samples tested outside the recommended range for the saturation index, which is a measure of the corrosive potential of the water.
In addition to the scaling on pipes and damage to appliances, too much corrosion can become a health hazard if the pipes are made of lead, copper or if the soldered connections contain lead solder. Corrosive water may cause the metals to dissolve in the water, which can cause health problems if they are ingested in sufficient amounts.
Knowing the geology of Rappahannock County, Dr. Ross said, the softness of the water was a “predictable observation.” In Page County, which is also participating in the testing program, the problem the reverse - hard water. That is caused by the limestone nature of the geology, which makes the water more alkaline, and therefore harder.
Dr. Ross suggested that those homeowners whose water tested outside the limits for both pH and saturation index should consider a followup test of the water using a technique which captures the water sitting in the pipes for a long period of time. The test done for this program, called a flush sample, is designed to sample water from the source. A first draw sample would test water which has been exposed to the distribution pipes overnight, and would therefore gauge the extent that metallic contamination from the pipes is fouling the water.
One significant contaminant, nitrate, was largely missing from the samples tested, the Extension specialists noted. That would indicate the presence of contamination from fertilizers or animal wastes, and the fact that only four of the 236 samples tested positive for nitrate was welcome news, Dr. Woodard said.
The only other contaminants found in many samples, Dr. Ross said, were iron and manganese. These two metallic contaminants are classified as “nuisances” because they pose no health danger.
Iron, found in excessive amounts in 13 of the samples, produces rust red stains on sinks, causes staining in laundry, and in large amounts the sludge deposited in water heaters and pumps can cause wear.
Manganese, found in 39 of the samples, is often mistaken for iron, Dr. Ross said. It can be distinguished by the dark brown or black stains, as opposed to the rust-red stains caused by iron.
The problems caused by manganese contamination are similar to those caused by iron, he said, and the treatmervt measures to remove it
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