NJDEP has established standards for various water quality parameters called secondary parameters. There are three secondary water quality constituents included in the PWTA program: pH, manganese, and iron. Secondary standards or recommended upper limits (RUL) were established for contaminants that may cause problems with taste and odor, cause discoloration of skin, or teeth, and contaminants that corrode, stain plumbing fixtures or clothes during washing.
The pH is a numerical expression indicating the degree of acidity or alkalinity of water. The pH is measured on a scale of 0 to 14. Water with a pH of zero is the most acidic, 14 is the most alkaline, and 7 is neutral. The secondary standard, or RUL, for pH was set for both aesthetic reasons and for control of corrosion. The pH for drinking water should be between an optimum range of 6.5 and 8.5. If the pH is too low (less than 6.5) water may have a bitter metallic taste, and there may be corrosion of pipes and fixtures. If the pH is too high (greater than 8.5) the water may have a slippery feel, taste like soda, and deposits can form on plumbing fixtures. In general, ground water in southern New Jersey is acidic (lower than pH 7.0), and ground water in northern New Jersey is
basic (higher than pH 7.0).
Iron is a naturally occurring inorganic constituent of ground water.
standard, or RUL, for iron is 0.3 mg/l. If the concentration of iron is above the standard, the water may have a rusty color, a metallic taste, cause reddish or orange staining and a sediment deposit in the holding tank and in the plumbing fixtures.
Manganese is a naturally occurring inorganic constituent of ground water. The RUL for manganese is 0.05 mg/l. If the concentration of manganese is above the RUL, the water may appear black to brown colored, black stains may occur on plumbing fixtures, and the water may have a bitter metallic taste.
Figure 9 provides a summary of the percent of wells with results that exceeded any of the secondary standards (pH, iron, manganese) between September 2002 and April
pH - Of the 51,028 wells sampled between September 2002 and April 2007
(45%) exceeded the secondary standard (optimum range of 6.5 to 8.5) for pH. Out of the wells tested 22,373 wells (44%) of the wells had a pH below 6.5 and only 326 wells (0.6%) had a pH above 8.5. Typically the pH of ground water in New Jersey ranges from 4 to 9.
Iron - Of the 51,028 wells sampled between September 2002 and April 2007, 14,751 or 29% of the wells exceeded the secondary standard for iron. Iron concentrations ranged from ND to 19,735 µg/l.