Interpreting Your Water Test

interpret water test



Arsenic occurs naturally in rocks, soil, air, water, plants and animals. It can enter well water through the ground or as a run off to surface water sources. Arsenic can be further released into well water through natural activities such as erosion of rocks and forest fires, or through human actions. Approximately 90 percent of industrial arsenic in the U.S. is currently used as a wood preservative, but arsenic is also used in paints, dyes, metals, drugs, soaps and semi-conductors. High arsenic levels can also come from certain fertilizers and animal feeding operations. Industry practices such as copper smelting, mining and coal burning also contribute to arsenic in our environment.

Human exposure to arsenic can cause both short and long term health effects. Short or acute effects can occur within hours or days of exposure. Long or chronic effects occur over many years. Long term exposure to arsenic has been linked to cancer of the bladder, lungs, skin, kidneys, nasal passages, liver and prostate. Short term exposure to high doses of arsenic can cause other adverse health effects,Potential links between arsenic and cardiovascular disease, diabetes and other cancers are being studied, but the evidence to date is not conclusive.

The maximum level for arsenic in water is 0.010 milligrams per liter (mg/L).




Chlorides do not cause health problems, but high chloride levels in drinking water may be a sign of other problems. Consuming too much chloride (Cl) has a detrimental effect on metabolism. The EPA standard has been set at the level at which the average person notices an unpleasant salty taste. Chloride contamination is associated with infiltration of road salt leaching into water supplies or backwash from a water softener and/or sea water.

14 mg/L is considered normal for well water. The maximum level for chlorides in well water is 250 mg/L



Any coliform presence in drinking water is cause for action. Groundwater in a properly constructed well or spring should be free of coliform bacteria. If coliform is found in a well or spring, it generally means that surface water has somehow leaked into the water. This could happen if rain runoff or snow melt makes its way into the well or spring through cracks in ledge outcroppings, gravelly soil, or sandy soil. It could also be due to poor construction or cracks in the well or spring casing. Coliform bacteria may enter the water supply if rain or snow runoff pools around the well or spring casing, if the well or spring cover is not airtight, or if the pipe leading to the house is not properly inserted and welded or grouted into the well or spring. In addition, insects, snakes, mice or other creatures getting into the well or spring can cause contamination.

The drinking water guidelines state drinking water should not contain more than 10 total coliform bacteria per 100 mL of water.

Your test will results will either be A=Coliform bacteria is Absent or P=Coliform bacteria is Present.



Copper is an important mineral for the formation of red blood cells. However, high amounts of copper in water can cause stomach aches, vomiting, or diarrhea. Young children are more sensitive to high levels of copper than adults. Water with large amounts of copper can stain plumbing fixtures and give the water a metallic taste.

The maximum level for copper in water is 1.3 mg/L



E. Coli comes from human and animal wastes. It is a type of bacteria commonly found in the intestines of animals and humans. E. Coli is short for Escherichia Coli. During precipitation, E. Coli may be washed into creeks, rivers, streams, lakes, or groundwater. When these are used as sources of drinking water, and the water is not treated or inadequately treated, E. Coli may end up in your drinking water.

According to the U.S. Environmental Protection Agency, the presence of E. Coli in water is a strong indication of recent sewage or animal waste contamination. There are many different kinds of E. Coli, some harmful to humans and some not harmful.

Your test results will either be A=E.Coli bacteria is Absent or P=E.Coli bacteria is Present.



Fluorides in water can be detrimental or beneficial depending upon the concentration. If the water contains over 1.5 parts per million of fluorides, use of this water during the period of tooth formation causes a condition known as "endemic dental fluorosis", a dark brown stain on the teeth. It is therefore necessary to remove fluorides present in such high concentrations. Recent work has shown that low concentrations of fluoride taken during tooth formation can minimize tooth decay.

Concentrations on the order of 1 part per million are considered optimum.



The contributors to hardness are calcium and magnesium. The presence of these elements in general is not a health hazard, but hardness elements tend to plate out on water pipes and heating coils in hot water tanks, and reduce the effectiveness of detergents. Hard water causes stains, leaves residues, or causes other physical problems in water-handling equipment.

Low (Soft) 0 - 75 mg/L

Moderate 76 - 150

Hard 151 - 250

Very Hard 251 +



Iron becomes a nuisance element. It will show its presence as rust stains on water fixtures and if chlorine bleach is used in the laundry, rust spots will appear on clothes. If this happens, use non-chlorine bleach with your clothes. Common iron removal methods include ion exchange and oxidation filtration.

Average Iron level is 0.2 mg/L. The maximum acceptable level is 0.3 mg/L. Higher levels produce a bad odor and taste.



Lead is a highly toxic metal that can cause serious health problems, especially for infants, children, and pregnant women. Nervous system, kidney, and red blood cell problems may be effects of exposure to high lead levels. In young children, lead may have harmful effects on nervous system and brain development. Lead has been used in making solder, fittings and fixtures found in household plumbing.

The maximum level for lead in water is 0.015 mg/L



Manganese does not cause health problems at levels typically found in drinking water and it is an essential element for human metabolism. However, manganese can discolor water; stain clothing, sinks, toilets and bathtubs; and can cause undesirable tastes in drinking water.

The maximum level for manganese in water is 0.05



Nitrate in elevated levels is linked with two known health problems. Methemoglobinemia or "blue baby syndrome" is caused by an oxygen deficiency in the blood. This causes bluish skin tone in infants. In adults, nitrates can form chemicals called nitrosamines that have been linked to cancer. These may pose long-term health risks. Elevated nitrate levels in well water may also indicate other problems such as contamination from sources such as septic systems or fertilizers.

The maximum level for nitrate in water is 10.0 mg/L. However, when levels exceed 5 mg/L, the source of nitrate should be investigated.



Nitrites are a salt or ester anion of nitrous acid, which can be naturally or artificially occurring in ground water. Nitrites come from fertilizers through run-off water, sewage, and mineral deposits. Nitrite is used in food production for the curing of meat products due to it inhibiting the growth of bacteria. Unfortunately it can also stimulate the grown of bacteria when introduced in high levels into a body of water.

The federal standard for nitrate in drinking water is 10 milligrams per liter (10 mg/L) nitrate-N, or 45 mg/L nitrate-NO3...when the oxygen is measured as well as the nitrogen. Unless otherwise specified, nitrate levels usually refer only to the amount of nitrogen present, and the usual standard, therefore, is 10 mg/l.



PH is a measure of acidity. Acidic water, along with low hardness (soft water), tends to be corrosive to your water pipes, potentially dissolving lead and copper. Basic water itself is not a problem, but may have a bitter taste. Alkalinity, which is a separate measurement, is your water's capacity against drastic pH changes.


The scale is 0 - 14

0 to 5 is acidic (not desirable)

5.5 to 8.0 is average

8.5 to 14 is basic (or alkaline)



The EPA has been trying to set guidelines for maximum levels of radon in water for municipal water systems for more than a decade. In 1999 the EPA proposed a double standard that set a level of 300 pCi/l for sates that had no radon in air program and 4000 pCi/l for states that have an active radon in air program. There are presently no recommended action levels from the EPA.

Massachusetts and New Hampshire have set their own recommended action levels...

Massachusetts - allows radon in water up to 10,000 pCi/L

New Hampshire - allows radon in water up to 2,000 pCi/L

If your well water exceeds these State levels, then an Aeration treatment is imminent in order to lower the levels of radon in your well water.



Sodium is a necessary dietary element and occurs naturally in all water, but more so in areas where there is sea water, salt from septic systems and road de-icing salt may elevate levels in wells and indicate other water problems. Sodium has no set health hazard level, but those individuals on a low sodium diet should take into account the amount of sodium in their drinking water when determining overall sodium intake. High levels of sodium in drinking water may cause an unpleasant taste. For people with sodium restricted diets it may cause health problems by contributing to high blood pressure.

32 mg/L is considered average. Levels above 50 mg/L may affect performance. 250 mg/L is the maximum level for sodium in all drinking water.



Turbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. They may also cause plugged piping or fouled water treatment equipment.

Turbidity levels should be less than 5 NTU's (turbidity units) for clear, acceptable water.



No (VOCs) should be detected in well water, PERIOD. The presence of VOCs may be indicative of a well contaminated by petroleum products, industrial solvents or chemical byproducts. The presence of these compounds is potentially a health risk which can cause long-term adverse health effects.

VOCs are emitted as gases from certain solids or liquids. They are a group of commonly used chemicals (numbered in the thousands) that evaporate, or volatilize, when exposed to air. Since they dissolve many other substances, VOC's are widely used as cleaning and liquefying agents in fuels, degreasers, solvents, polishes, cosmetics, drugs, and dry cleaning solutions. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors.

VOC's are found at airports and service stations; machine, printing and paint shops; electronics and chemical plants; dry cleaning establishments; pesticides, building materials, furnishings and in household products. Paints, varnishes, and wax all contain organic solvents, as do many cleaning, disinfecting, cosmetic, degreasing, and hobby products.

When VOC's are spilled or dumped, a portion will evaporate, but some usually soaks into the ground. In soil, the VOC's can be carried deeper with percolating rainwater or melting snow. If they reach the water table, they can persist for years because the cool, dark, low-bacteria environment does not promote decomposition. If the VOC's in the groundwater migrate to nearby wells, they can end up in your drinking water.

VOC contamination in your well water is a very serious heath concern.



Share:  Add to Facebook Tweet This Add to Delicious Submit to Digg Stumble This

Here is what my clients have to say about my home inspection services:

Press F5 (on your keyboard) for additional testimonials


Hi Dave,

I just wanted to write and thank you very much for doing our inspection today. You really took an awful lot of extra time to explain things to us. It was a huge help and by far my favorite part of this whole home-buying process. In addition to drawing our attention to the major projects that need to be undertaken right away or in the near future, I was glad that you were also so thorough as to point out smaller things and provide suggestions for fixes that we'd be able to do ourselves. Thanks again for all your effort. I'm finding your "Know Your Home" book a great source of information along with your report. I'll no doubt have some questions for you at some point and really appreciate your willingness to answer them. Have a great rest of your weekend!

Take care,



   massachusetts state seal     Certified Professional Home Inspector     certified master inspector seal     indoor air certification

massachusetts seal     guarantee    

Last updated on  Nov 15, 2019