Is my water safe? Can I drink it safely?
People often ask themselves if their water is safe, but getting an answer isn’t as simple as looking, tasting or even testing. Since water tends to dissolve or suspend most substances it comes in contact with, it can be very costly to answer this seemingly simple question. Some rural people use the old adage–If it smells and tastes like water and looks clean like water, then it’s probably okay. Although taste, odor, color, and clarity are important, they only address water’s physical aspects. The bacteriological and chemical content of water should also be tested. If your water comes from a public water source such as a municipal water system, then your concern may be minimal as public water must meet certain set criteria before it can be used for human consumption. However, if your water is a private source, such as your own well or dugout, then it is your responsibility determine whether the water you drink is truly “safe” for you and your family.
There are two common tests for well water: bacteriological and chemical. Bacteriological is used to determine if the water is safe for human consumption. This test is around $100 and results are usual available in in a week.
Bacteriological or Coliform bacteria is the most important and commonly done with each real estate transaction. If coliform bacteria are found in a water sample, steps are taken to find the source of contamination and restore safe drinking water. There are three different groups of coliform bacteria; each has a different level of risk. Total coliform, fecal coliform, and E. coli are all indicators of drinking water quality. The total coliform group is a large collection of different kinds of bacteria. The fecal coliform group is a sub-group of total coliform and has fewer kinds of bacteria. E. coli is a sub-group of fecal coliform. When a water sample is sent to a lab, it is tested for total coliform. If total coliform is present, the sample will also be tested for either fecal coliform or E. coli, depending on the lab testing method.
A comprehensive test can also be done at the same time. This test is more comprehensive, costs more and results will be available in 2-3 weeks. A general chemical analysis for the following substances:
Although the lists of tests look thorough, it doesn’t include all of the parameters that truly make up your water chemistry. A chemistry exam will help you to determine the chemistry of your water, but you really want to know if the water is potable.
What does potable mean?
The dictionary definition of potable is a liquid that is suitable for drinking. In Washington, the Drinking Water Guidelines are used by health officials to assess the suitability of drinking water.
So, determining if your water is truly safe can be looked at in different ways. To test all the parameters listed in the Drinking Water Guideline parameters can be very costlyand in most cases is unnecessary. Upon request Pacific Crest will take samples for a comprehensive test that will identify impurities and other dissolved substances that affect water for domestic purposes.
The best way to minimize testing is to know your area and your water source. Your local Health Authority may have records on the chemical characteristics of water in your area that may assist you to narrow your search. However if you are in the mountain areas local Health Authorities may not have data for your specific area. Then a comprehensive test may be warranted.
If you are concerned about certain types of chemicals and pesticides that have been used in a close proximity to your wells or dugouts, then indicate those concerns to the persons doing your water tests. This will be extremely helpful in determining what you should be testing for to ensure you have a potable water supply.
Drinking Water Quality Regulations
Amendments to the Safe Drinking Water Act, signed into law in 1986, empower the U.S. Environmental Protection Agency (EPA) to determine and set standards for potential contaminants to drinking water.
The EPA requires local agencies to enforce these standards in their jurisdictions. The Washington Department of Health and Environment (WDHE) is the regulating agency for Washington. These agencies monitor all regulated contaminants to water.
Potable water is defined by the EPA and WDHE as being water that meets these regulatory agencies’ standards. Currently, there are 83 chemical or biological constituents that must be monitored in Skagit County.
Chemical constituents are subdivided according to chemical characteristics. The classifications are inorganic (chlorine, pH, alkalinity, hardness, fluoride, nitrate/nitrite, sulfate, specific conductance, solids, and metals), and organic (trihalomethanes, volatile organic compounds, and pesticides).
Biological constituents are also monitored on a regular basis. Monitoring includes routine testing for the presence of coliform bacteria as indicator species, and turbidity as a measure of particulate matter. The absence of coliforms as a bacterial indicator means that most other known bacterial pathogens have also been removed or inactivated by disinfection. Low turbidity indicates a lesser likelihood of the presence of pathogens that are large enough to appear as particulates. The combined information from this testing provides a good measure of water potability in respect to biological pathogens.
For more information about water quality regulations, please call:
Dept. of Health Office of Drinking Water (360) 236-3100
U.S. Environmental Protection Agency, (800) 426-4791.
You can also visit the U.S. EPA Office of Ground Water and Drinking Water.
Laboratory Reports – What Do The Numbers Mean?
Most testing laboratories report quantities of chemical substances by weight in volumetric units such as milligrams per liter (mg/l). For all practical purposes, 1 ppm = 1 mg/l. The factors reported on a water analysis report are discussed below and represent the parameters that are considered in the evaluation of domestic water quality.
- Conductivity is a measure of the ability of water to pass an electrical current. In the Pacific Northwest conductivity can give indications that there may be salt in the water. Conductivity in water is affected by the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, and phosphate anions (ions that carry a negative charge) or sodium, magnesium, calcium, iron, and aluminum cations (ions that carry a positive charge). Organic compounds like oil, phenol, alcohol, and sugar do not conduct electrical current very well and therefore have a low conductivity when in water.
- The pH value is a measure of intensity of alkali or acid contained in the water. Absolutely pure water has a pH value of 7.0. In Colorado, the pH of well water normally is between 6.5 and 8.5. Water with pH lower than 5 may cause problems due to corrosion because many metals become more soluble in low-pH waters. A pH value higher than 8.5 indicates that a significant amount of sodium bicarbonate may be present in the water.
- Calcium and magnesium cause water hardness and result from limestone-type materials in underground soil layers. Separate values are of minor concern but they are combined for calculating hardness.Hardness is the soap-consuming capacity of water; that is, the more soap required to produce lather, the harder the water. Hard water also causes greasy rings on bathtubs, film on dishes or hair after washing, and poor laundry results. Problems caused by hard water in bathing or washing can be overcome by the use of synthetic detergents or packaged softening compounds. The hardness of water may be removed by a water softening unit containing exchange resins. This will result in the exchange of calcium and magnesium (Ca and Mg) by sodium so it may be a concern to people on a low-sodium diet for medical reasons. Do not use softened water for gardens, lawns or plants. Hardness is reported as calcium carbonate in milligrams per liter (mg/l).
- Sodium may indicate salt water intrusion. Sodium can be reduced or removed by expensive treatment systems, but when Ca and Mg are removed from water by passing through a water softener, sodiumreplaces it.
- Potassium is an essential nutritional element, but its concentration in most drinking water is trivial and quantities seldom reach 10 mg/l.
- Carbonates and bicarbonates are the major contributors to the “totalalkalinity” that may be determined in a routine water test. The alkalinity of a water sample is a measure of its ability to neutralize acids. Naturally occurring levels of total alkalinity up to 400 mg/l as CaCO3 are not a health hazard. Low alkalinity is associated with low pH values and may indicate potential for problems due to corrosion of metal in plumbing systems.
- Chloride concentrations in drinking water may indicate salt water intrusion. Most people will detect a salty taste in water containing more than 250 mg/l of chloride. Expensive treatment methods are needed to remove chloride from water.
- Sulfate content in excess of 250 to 500 ppm (mg/l) may give water a bitter taste and have a laxative effect on people not adapted to the water. Expensive treatment methods are necessary to remove or reduce sulfate in a private water system.
- Nitrate in excess of 45 mg/l (or in excess of 10 mg/l if reported as nitrate-nitrogen) is of health significance to pregnant women and infants under 6 months. Do not use high nitrate-water in infant formulas or other infant foods. Considerably higher nitrate content apparently is tolerated by most adults. Nitrate can be removed from private water supplies, but the equipment is expensive and not commonly used.
- Total dissolved solids, also called “total mineral content” or “total residue,” is the total amount of material remaining after evaporation of the water. Values of less than 500 ppm (mg/l) are satisfactory and up to 1,000 ppm (mg/l) can be tolerated with little effect. Fluoride is important in the development of teeth in infants and youth. The optimum fluoride content to assist in the control of tooth decay is 0.9 to 1.5 ppm (mg/l). Excessive amounts are rarely found in Colorado waters, but a concentration over 3.0 ppm (mg/l) may cause darkening of the tooth enamel and other undesirable effects.
- Iron and manganese are nuisance chemicals that cause troublesome stains and deposits on light-colored clothes and plumbing fixtures. Iron causes yellow, red or reddish-brown stains and deposits, while manganese stains and deposits are gray or black. Excessive amounts also may cause dark discoloration in some food and beverages and cause an unpleasant taste. Iron and manganese can be removed or reduced in a softener equipped with special resins or by small treatment systems involving aeration, filtration and chlorination.
- Copper and zinc will cause an undesirable taste if concentrations are above the recommended limits. A water softening system should significantly lower the levels of these elements.
- Arsenic, selenium, barium, cadmium, lead and mercury are potentially toxic elements. Fortunately, these elements rarely exceed the mandatory limits in most Colorado well water. If high concentrations are found, it is necessary to remove these elements using expensive treatment methods, such as distillation or reverse-osmosis. Lead contamination in drinking water can come from lead pipes and lead-based solder pipe joints.
- Aluminum, ammonium, phosphorus, nickel and molybdenum are additional constituents that can be determined by the laboratory. Although no limits are established for these parameters, pollution of some sort is indicated if significant concentrations are detected in a water sample.
Taste and odor problems are difficult to solve. Some inorganic compounds may impart detectable tastes without odor. Hydrogen sulfide (rotten egg smell), when present, will impart an undesirable odor and taste. Generally, undesirable tastes may be caused by any of numerous organic compounds. These may be present naturally in the water or due to sewage or other surface contamination sources. They can impart disagreeable taste and odor in minute concentrations (a few parts per billion or a few milligrams per kiloliter) and specialized chemical tests are needed to detect such small levels. Turbidity in drinking water is caused by suspended sediments from erosion and runoff discharges. The maximum contaminant level in drinking is 1 to 5 turbidity units.
Water Treatment Systems
Some water constituents can be removed or reduced by ion-exchange resins, distillation, reverse osmosis or a combination of these methods. Other treatment processes might involve aeration or chemical oxidation followed by filtration. Organics can be removed by filtration through charcoal, but this may not be an effective method for removing inorganic contaminants. Treatment methods are specific to the type of chemical problems and generally are quite costly. For additional information on water quality or treatment systems, refer to the fact sheets listed below or call the EPA Safe Drinking Water Hotline, (800) 426-4791.
Maintaining your well system
Although a properly constructed private well should require little routine maintenance, these tips will help protect your well system and keep it in good working order for years to come:
- Get an annual well maintenance check, including a bacterial test.
- Your well should be checked any time there is a change in taste, odor or appearance, or anytime a water supply system is serviced.
- Periodically check the well cap and casing to make sure they are in good working order. A damaged casing could cause your water to become contaminated.
- Maintain a clean zone of at least 50 feet between your well and any kennels or livestock operations.
- Do not treat the area around the well with pesticides or fertilizer.
- Keep the top of your well at least one foot above the ground. Slope the ground away from your well to allow proper drainage.
- Don’t pile snow, leaves, or other materials around your well.
- Always keep your well records in a safe place.
Types of wells
Water Quality Association
Soil, Water and Plant Testing Laboratory Newsletter# 513 Colorado State University, Fort Collins, Colorado.
Follett, R.H. and Soltanpour, P.N. Fact sheet .506, Irrigation water
quality criteria. Colorado State University Cooperative Extension. 1992.
Soltanpour, P.N. and Raley, W.L. Fact sheet 4.908, Evaluation of
drinking water quality for livestock. Colorado State University Cooperative
United States Environmental Protection Agency. Fact Sheet: National
Primary Drinking Water Standards and National Secondary Drinking Water
Standards. Office of Water, Washington, DC 20450. 1989.
Self, J.R. and Waskom, R.M. Fact sheet .577, Nitrates in drinking water.
Colorado State University Cooperative Extension. 1994.