Home Inspection

The Importance of Water Quality Testing

Water quality testing helps assure that end-users remain healthy and well-functioning, whether people drink healthily, industries operate without impediments caused by off-spec water, or natural environments thrive without pollutant contaminants. Basic qualitative observations can be made with portable test kits.

Home InspectionHome inspectors may use these kits or send samples to a lab. The lab option provides a more comprehensive range of tests. Read on Water Quality Testing Colorado to learn more.


The water quality testing process isn’t cheap, but it can be far worse if you don’t test your drinking water for contaminants. It’s recommended by the Water Quality Association (WQA), the National Ground Water Association (NGWA) and the EPA that homeowners who use private well water regularly test their water.

The costs of this type of testing may vary, depending on what tests are requested, how samples are collected and the results interpreted. In general, basic sampling can cost $35 to $400. However, the costs can quickly add up if you’re hiring an outside business to perform testing and interpret your results.

Home inspectors can help you with water quality testing during your home inspection. They can provide you with the proper sampling containers and directions, and also provide you with a list of contaminant levels that are acceptable for safe drinking water. They can also refer you to a local laboratory that can perform the necessary testing, which is typically more cost effective than ordering tests online.

Depending on your location, your municipal water supplier may already be required to publicly report their test results on a annual basis. For example, public water suppliers in larger cities are generally required to publish Consumer Confidence Reports (CCR) on their website or via mail. In addition, if you have a water treatment system in your home, it’s important to test both the treated and untreated water as part of your water quality monitoring program.

The EPA also has easy-to-use contaminant tables, which can be helpful for homeowners with private wells. The Environmental Protection Agency does not recommend DIY testing kits, but there are a few options that you can find at most grocery stores or hardware shops. Most of these kits have a limited scope and can be inaccurate due to user error. The EPA and WQA do recommend that you use a professional certified lab to perform water quality testing for your drinking water. Find one in your area through the EPA’s website. Alternatively, WIN Home Inspection can refer you to a professional EPA-recommended water testing laboratory.


Home inspectors often offer water quality testing as a part of their standard home inspection. This specialized test checks the home’s drinking water for contaminants such as lead and coliform bacteria. It also evaluates the water’s pH and other properties, such as hardness. Most home inspectors can perform this test at a local laboratory or with an at-home kit.

The most common parameters analyzed in water quality tests are physical, chemical and bacteriological. Physical parameters include turbidity, total solids, dissolved solids and suspended solids. They can also include odors and taste, as well as temperature and color. Chemical parameters analyze the concentration of mineral and organic substances. They can also measure the presence of inorganic substances, such as arsenic, mercury, lead and cadmium.

Bacteriological examinations test for the presence of faecal pollution organisms, which are indicators of intestinal pathogens. Since the intestinal tracts of humans contain countless rod-shaped bacteria known as coliform organisms, searching for them in drinking water is an effective way to determine whether or not there are harmful pathogens present.

Depending on the type of water and the state or country in which it was tested, different threshold values may apply. These values are usually expressed as a percentage of a specific substance in the sample or as a numeric value, such as micrograms per liter or parts per million (ppm). Many states require water suppliers to report their results annually to consumers. This information can be accessed on the websites of local environmental departments, as well as by searching for “water quality reports” in your region or country.

The costs of water quality testing can vary significantly. While it’s possible to conduct the tests yourself at home with prefabricated kits, most homeowners prefer to hire a professional to sample and interpret their results. The average cost for sampling and analysis of a private water supply ranges from $35 to $400. For more information about the specific costs of your area, you can contact the ELAP-accredited laboratories that serve your county. They can provide you with a written cost estimate before sampling your home’s water.


The results of water quality tests are a vital step in determining the suitability of household drinking water for use. Many different contaminants can affect household water and most of these are of little concern, but a few contaminants may pose health risks or interfere with house- hold activities. Water quality testing allows for the identification of these contaminants and enables householders to take the appropriate action. Proper interpretation of a water analysis report is critical to the success of addressing problems related to household water quality.

A sample of household water can be tested at a laboratory or with home test kits. Lab testing is more expensive than home test kits but provides more accurate results. Water analysis reports generally include results for a number of parameters including total coliform bacteria, nitrate, pH value and hardness. While other contaminants can be tested, for purposes of a household water analysis, it is most important to test for these indicators and to maintain good record keeping.

Laboratory test results may show a range of values for each of the parameters. Some values, such as nitrate or phosphate, are used to determine the level of fertilizer needed for crop production. Other values, such as turbidity or dissolved solids, are not used for crop production but do influence the quality of household water. High turbidity results in cloudy water that is aesthetically unappealing and increases the cost of water treatment. Particulate matter in the water also hides harmful microorganisms and shields them from disinfection processes.

The most common contaminant found in household water is fecal coliform bacteria or E coli. These are bacterial strains that are usually present in the intestinal tract of warm-blooded animals, including humans. A positive result indicates that the water contains disease-causing fecal bacteria and is not suitable for human consumption unless it has been boiled for five minutes or otherwise disinfected.

Some contaminants, such as heavy metals, are endocrine disruptors that can increase the risk of certain cancers and other diseases. The EPA has set Maximum Contaminant Levels (MCL) and Secondary Drinking Water Regulations (SDWR) for many of these contaminants. These are not enforceable by law but serve as guidelines for municipal water systems and householders.


All laboratory tests must be interpreted correctly. Bacteriological tests, for example, do not necessarily prove that the water is dangerous to drink; only that faecal contamination has not occurred in the sample.

Water quality testing is useful for homeowners with private wells and cisterns as it gives them the information they need to prevent contaminant buildup in plumbing, extend the lifespan of water heaters, reduce the cost of soaps and detergents and improve the quality of life for livestock. The process is also practical for rural areas where outdated municipal plumbing systems, livestock farming and mining operations and natural disasters may cause pollution in local rivers, lakes and aquifers.

Homeowners are encouraged to watch a video on Interpreting your Test Results before purchasing kits for conducting their own tests. Some kits include hand-held digital instruments that can conduct tests for turbidity, color, pH and hardness. These devices are more convenient than traditional glass or plastic test tubes and require fewer steps to collect samples, but they cannot measure the presence of some contaminants.

A more cost-effective option is to purchase a water tester kit that includes general water quality indicators, rather than specific contaminants. Turbidity and pH tests are considered general indicators; if either of these values is above or below acceptable standards, it is likely that there is a problem with the water supply.

Some contaminants can have significant negative effects on the health of humans, while others cause nuisance symptoms such as staining of plumbing and scaly deposits on appliances and a decrease in the effectiveness of soaps and detergents. If a water analysis indicates that the sample has exceeded a legal maximum allowable concentration (MAC) or acute occurrence limit (AO), a homeowner will need to take action to eliminate the contaminant or install treatment.

Other types of contaminants include iron bacteria, hydrogen sulfide and nuisance contaminants such as excessive calcium and magnesium which create hard water that can stain plumbing and clog pipes and tanks. Many of these contaminants are not considered a health risk, but they can make the water unpalatable and increase the amount of disinfectant needed to treat it.