The U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Resiliency and Finance Center, in collaboration with the...
Every day, we hear customers ask, “How do I know if my water is safe?” Unfortunately, there is no straightforward answer, as each situation’s response varies from case to case. The simplest and most proactive answer is to have water tested on a regular basis.
The next step is determining what parameters to test and how frequently. For a municipal water system, the U.S. EPA dictates which analyses should be tested and how often. The EPA bases many of its requirements on the Safe Drinking Water Act. These tests are mandatory routine assessments on a wide range of analytes, from microbiological to physical and chemical. For private well owners who are solely responsible for monitoring their own water quality, it would be very expensive and often unnecessary to test to the same standards as municipal supplies.
A basic water quality assessment for any residential well user should include at least a bacterial screen for total Coliform. This test is important above all else in determining the overall microbiological quality of the water. Positive results for Coliform bacteria signify exposure to contaminants such as surface runoff, animal waste, septic system sewage or other decaying organic matter. Most labs will then further evaluate the positive total Coliform result to determine if E. coli is also present.
Other parameters to evaluate are total nitrates and nitrites. Both occur naturally in the environment; however, the majority of nitrates and nitrites in drinking water result from fertilizer, sewage and feedlot influences. High nitrates and nitrites are of greatest impact to infants; these contaminants can cause methemoglobinemia (blue baby syndrome), which affects the ability of the blood to carry oxygen to parts of the body. These pollutants are odorless and tasteless; therefore, a preemptive evaluation can be essential to protecting the health of children before a problem could otherwise be detected.
A pH test is a fundamental factor in evaluating overall water activity. Water with a pH less than 6.5 is generally considered acidic, while a pH above 8.5 indicates basic or alkaline water. Acidic water can damage plumbing and leach undesirable contaminants such as lead and copper into the supply. Alkaline water will impart a bitter taste and make it difficult to get soaps and detergents to lather. Treatment processes and efficiency can be greatly affected by pH. That is why measurement of pH is an essential tool to any treatment professional.
Total dissolved solids (TDS) is the measurement for the combined content of all soluble inorganic and organic substances in water. The most general chemical constituents are calcium, phosphates, nitrates, sodium, potassium and chloride. These can come from any number of sources such as nutrient runoff, general storm water runoff, leaching of soil or bedrock contamination, and point source water pollution discharge from industrial or sewage treatment plants. TDS is not usually considered a primary pollutant, but is rather used as an indication of water’s aesthetic characteristics and as a collective indicator of the presence of a broad array of chemical contaminants and mineral content.
Many customers are also concerned about pesticides, herbicides and PCBs, which may be of particular concern if the water supply is located near a landfill, golf course, farm land, or land that had been used for farming in the past. Volatile organic chemicals may also come from similar sources of contamination.
Those are the basics. Of course, particular circumstances can have additional geographical impacts that need to be considered. Some regions have known high levels of arsenic, which may be naturally occurring from the rock surrounding the water supply. In such an instance, arsenic should be tested for on a regular basis. The same goes for radon, another naturally occurring contaminant. Iron bacteria and sulfur-reducing bacteria can both cause concerns because of their byproducts. These byproducts can include biofilms, slimes, sulfates and particle precipitation, which can eventually lead to extensive system renovation.
Other events, both naturally occurring and as the result of human activities, should always be taken into account. If flooding occurs around a well, the drinking water could become contaminated. Tainted water can enter through a well cap or vent, carrying bacteria, viruses and chemical contaminants. Shallow wells and older constructed wells with poor hydrogeology can be particularly vulnerable to impact from floodwaters. Any well supply located near the banks of a river into which industrial effluent is introduced can become contaminated. Industrial runoff can range from metals to complex styrene and benzene molecules. Additionally, well supplies near gas stations can become tainted with gasoline byproducts such as toluene and MTBE. These toxic chemicals can cause acute problems for young children and adults with compromised immune systems, and chronic problems for any person exposed for long periods.
Test results are what help a treatment professional determine what steps need to be taken to remediate a given problem. By identifying specific contaminants, you can help select water treatment systems for your customers that are capable of treating those specified compounds. It is important to educate your customers about proper testing. And remember, all treatment equipment requires regular maintenance. Test results can help verify when repairs or routine filter changes are necessary.
So, is the water safe to drink? Obviously, that’s very hard to determine without proper testing.