Private Well Users

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Potential Drinking Water Contaminants and Their Related Health Threats

Probably one of the most important and basic concepts to understand about the Earth’s water is that it is not pure. The composition of water is such that materials – both natural and man-made – are easily dissolved upon direct contact. The level or quality of a substance in water is the central issue with respect to determining whether the water is adequate for human consumption.

Potential drinking water contaminants include both microbiological and chemical substances. These agents can be found in nature or be the result of some past or present human activity. Microbiological substances of concern include bacteria, viruses, and protozoa. Chemical contaminants primarily include metals, minerals, and both organic and inorganic substances.

The health effects related to drinking contaminated water can either occur over the short-or the long-term, depending upon the nature of the pollutant. Short-term or acute effects are those that occur within hours or days following consumption of contaminated water. Long-term or chronic effects are those that occur after water with low doses of a contaminate has been consumed over several years or a lifetime.

Microbiological organisms in drinking water are generally associated with human and animal wastes. These organisms are naturally occurring and can be found in source waters as well as in distribution systems. Although serious disease remains a concern, the most common illnesses due to the microbiological contamination of drinking water are short-term gastrointestinal disorders. Typical symptoms include cramps and diarrhea that may be mild to very severe.

Naturally occurring chemical contaminants found in some drinking water are primarily metals (e.g., chromium, mercury, zinc) and minerals (e.g., asbestos). Some naturally occurring chemical contaminants, such as radium and radon, radioactive.

Man-made chemicals found in drinking water are primarily organics and inorganics. These substances have numerous industrial, agricultural, municipal, and residential applications. The improper discharge or use of man-made chemicals in the environment can result in their presence in drinking water.

The health effects related to consumption of chemicals in drinking water are highly chemical-specific. With a few exceptions (nitrates), these effects are chronic (long-term) in nature. Some of the important health risks resulting from high exposure to chemical contaminants include liver, kidney, and nervous system disorders, cardiovascular and hypertensive effects, anemia, and carcinogenicity.

Most Common Contaminants Found in Private Wells

Bacteria – namely coliforms – appear to be the primary contaminant found in private wells. The presence of these microbiological organisms suggests the infiltration of animal or human wastes into well water. Septic fields, due to their location, are often the source of such contamination.

In general, nitrates represent the second most common type of contaminant found in private wells. The presence of this naturally occurring chemical suggests that animal and/or human wastes or that agricultural applications of such substances as fertilizers are entering the well. Nitrates are of special concern to young children and women of childbearing age. Excessive levels of nitrates have been linked to the occurrence of “Blue Baby” syndrome.

Two other important contaminants about which private well owners should be concerned include lead and radium (gross alpha radionuclides radium 224 and 226). Lead is a poison that can accumulate in the body and cause brain, kidney, or nerve damage in addition to anemia and even death. Lead is especially dangerous to children and pregnant women. While lead exposure through various media can happen, it has been found to occur in drinking water at sufficient levels to warrant concern. Lead gets into drinking water through the corrosion of plumbing materials. Lead pipes, lead-based solder, and brass faucets use in household and distribution system plumbing are the sources of this substance in drinking water.

Radium exists naturally underground. Radium dissolves readily into groundwater in contact with sands or soils. The acidity of the water is believed to increase the amount of radioactivity that dissolves into groundwater from contact with sands and soils.

In southern, New Jersey, the Kirkwood – Cohansey aquifer has shown elevated levels of naturally occurring radioactivity. Exposure to radium over a long period of time is believed to increase one’s risk of developing certain types of cancer.

Contamination of private wells by other chemical contaminants – whether naturally occurring or man-made – remains a potential problem but generally occurs less frequently than the types of contamination described above. The degree to which any well is vulnerable to contamination depends upon a variety of factors including local geology; depth to water table; characteristics of soil, water, and climate; local land-use activities; and characteristics of home plumbing materials.

Action Steps for Private Well Owners

1) Obtain the following information from State and local health, environmental officials, or environmental professionals:

  • Listing of contaminants whose levels of occurrence are regulated in public water supplies by the Federal government and the State;
  • State or local standards for the drilling and construction of wells and information concerning the Private Well Testing Act.
  • Listing of land-use activities in the vicinity of the well and the types of contamination problems that have been known to occur in other local wells

2) Test you water for bacteria at least once per year. If any changes are noticed in the water’s test, odor, or color, conduct bacteriological tests on at least a quarterly basis. It is also recommended that well water be tested for bacteria after periods of significant rainfall or after flooding has occurred.

3) Test your water for nitrates once a year, especially if young children and women of childbearing age are consuming the water, if agricultural activities including home gardening are taking place in the area, and if animal and human wastes are suspected of entering the well. (whenever bacteria is found in a well as a result of testing, the well water should also be analyzed for nitrates.)

4) Test your primary kitchen tap at least once for the presence of lead as a “first drawn” (unflushed) sample.

5) Test for other contaminants of concern based upon information obtained from land-use and well assessment activities.

  • Assess the sanitary features of the well (i.e., depth to water, proximity to septic field, etc.) If this information is not known by the well owner, a sanitary survey or well inspection can be contracted. The state’s drinking water office or the local health department should be able to provide suggestions on how to obtain these services.
  • Asses surrounding land-use activities – industrial, agricultural, governmental, and residential. Identify potential threats to private wells from these activities. Some questions to ask oneself when assessing land-use activities include:
  1. is your well close to or downhill from your septic field;
  2. are there gas stations nearby whose underground storage tanks could be leaking;
  3. are these municipal and hazardous waste disposal and storage facilities nearby;
  4. are materials used on local road surfaces, such as de-icing sales, properly stored and applied;
  5. are pesticides and fertilizers applied in the area; and
  6. are oils, paints, pesticides, and solvents safely stored and discarded in or around the home?

6) Contact State or local (i.e., city, county, town) drinking water officials for information on water testing.

7) Contract with a NJDEP certified laboratory to conduct drinking water analysis. Laboratory tests are substance-specific or specific to a given class of contaminants. One test will not cover all contaminants of concern to any given well owner. Depending upon the sophistication of the sample and testing procedures, the laboratory will either collect the appropriate sample(s) or will provide sampling equipment and instructions to the homeowner. Prices vary for testing services based on the level of involvement and sophistication of testing preformed.

8) Concentrations of contaminants, if detected, for which testing has been conducted will be listed on the test result form. Results will be expressed in milligrams or micrograms per liter (parts per million and parts per billion, respectively). Test results should be compared to Federal and relevant State standards for the particular contaminant in question.

9) If testing reveals concentrations of contaminants above levels acceptable to human health, conduct additional tests. If repeat tests also show unacceptable levels of a given contaminant, take remedial action. In some cases, a remedy may involve disinfecting the water source, digging or drilling a new well, replumbing or repairing the distribution system, or possibly hooking into a nearby public water system. Consult the State or local drinking water office for suggestions on remedies.

10) Home treatment units represent a potential means for remediating a contamination problem. It is important to keep in mind that no single household treatment unit will remove all potential drinking water contaminants. Treatment is very specific to the substance(s) of concern.