What is pH?
What do bluish-green stains on a home’s fixtures mean? “pH” problems? What is “pH”?
“pH,” written with a lower case “p” and a capital “H,” is the negative logarithm of the effective hydrogen-ion concentration. In simple terms, pH refers to whether the water is acidic or alkaline. The pH scale goes from 0 to 14, with a pH of 7 generally considered neutral. Water with a pH below 7 is considered acid, and water with a pH above 7 is considered alkaline. Most natural waters fall in the range of 5 to 8. Certain areas lacking limestone are notorious for having low pH (acidic water). If you see bluish-green stains on the tub or sinks of a home using copper water pipes, acidic water is corroding the metal parts of the plumbing system. If a home has brass water faucets or copper tubing whose solder contains lead, high levels of lead may be found when water stands in the pipes overnight. Running the water before drinking generally eliminates this problem. Typically, waters with a low pH are very low in hardness and are considered naturally soft.
The Environmental Protection Agency (EPA) considers pH to be a secondary contaminant, with an acceptable range of 6.5 to 8.5. This is a non-enforceable standard set primarily for aesthetic reasons rather than health-related reasons. If you drink water with a pH of 5, it will cause no health problems since a can of carbonated soda may be 10 to 100 times more acidic. The pH in your stomach may be 1000 times more acidic.
In some counties, such as Chester County, PA, private wells nearly always have pH problems. If non-corrosive, plastic piping is used in the home, low pH has no adverse effects; however, if copper tubing is used, low pH will shorten its life span. Neutralizers, which are available from water treatment companies, can adjust the pH to the desired level.
For new, household wells, the Chester County Board of Health has established standards of pH at 6.7 to 8.5, although no treatment is required if the home’s water is conveyed in approved plastic pipe.