Well Water

If you are buying a home with a well system and not public water you should absolutely be doing a water quality test.  It is best to test the water during the due diligence period you have as a buyer so that if anything comes up in the test results you will have time to consider your options and work out a solution if there is a problem.  Filtration systems can be expensive depending on what you need to remove.

The most common water quality issue that I encounter during the Home Inspection process is Coliform Bacteria.  Coliform is a required test for VA (Veteran Affairs) mortgage loan.  If Coliform is present in a home being bought with this type of loan it will need to be removed prior to purchase.

Coliform bacteria is referred to as an “indicator” organism.  Not all Coliform will carry diseases but they can indicate the presence of other bacteria and viruses that can cause illnesses, such as E. Coli.

If your water test comes back with Coliform present you will want to treat your well system.  This can be done by installing a whole house Chlorination System, Open Air Chlorination System or a UV filtration system.  Each home is different and a water quality and filtration professional should be consulted before investing in a system by yourself. 

If a filtration system is out of your price range another option is “Shocking” the well.  This is a process that involves putting a bleach solution down the well and flushing out the system.  There is a chance that the bacteria can return and you should test your water regularly if you do not have a filtration system in place.

If you are a home buyer and your potential home has coliform present you will want to have a professional shock the well.  Unless you plan on doing it yourself.  You do not want the current homeowners to shock the well on their own.  They may have a friend do it that doesn’t have any experience or know what to do.  They also may not even do it at all and tell you that they did.  I bring up this possibility because I have seen it before.  If you are going to have the sellers correct the issue make sure that you get receipts from a professional well company and follow up with another test to ensure the bacteria is gone.

Here is a basic guideline on shocking a well.  Keep in mind that every system is different and may need different procedures.

  • A typical solution for shocking a well requires 2 cups bleach and 10 gallons of water.
  • Dump the solution into your well.
  • Run a hose from the home to the well and run the water into the well to promote mixing of the solution. When you smell bleach coming out of the hose, shut it off.
  • Allow the well to sit for a few hours.
  • Run the exterior hoses away from the home and any plants and vegetation.
  • Run all the interior faucets and flush the toilets.
  • The flushing process can take a few hours or repeated flushing over a few day.
  • You may see brown water coming out of the faucets during this process.  This is common and is from sediment breaking up from the bleach solution.  Keep running the water and it should work itself out.
  • When you no longer smell bleach at the faucets you should be all set.  Chlorine test strips can also be used.
  • You should re-test your water about a week after shocking to ensure the bacteria is removed.

During the shocking process you should NOT use your water supply.  Here are some other things that you should NOT do during this process:

  • Drink the water
  • Shower
  • Give water to your pets
  • Water your plants
  • Do Laundry (the bleach may discolor your clothes and the rust deposits may stain your clothes)

Like any issue found during a Home Inspection, Coliform bacteria is easily fixed if handled properly.  If shocked properly the water may remain clean for a long time or it may not.  Most experts will advise that you test your well water once a year, while some say every other year.  If you have a shallow dug well you may want to test your water twice a year or more.  Especially if you live a quarter mile from a dairy farm with 100 cows.


I have also seen coliform form inside of a water softener brine tank.  The salt had not been filled and the tank had filled up with water which had a nice thick layer of growth on top of it.  A plumbing cross connection can also back flow waste water back into the system causing contamination.

There are many different ways that Coliform and other bacterias can enter your water supply and several different ways to treat it.  Obviously a high quality filtration system is the ideal solution but if that is not in the budget than hopefully a bottle of bleach is and you can clean your system.

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If your water comes from a well ANYWHERE in New Hampshire you should do a water quality test before purchasing.  Water quality is so important.  Poor water quality is a health concern and a problem for the pipes and systems of your home.  Knox Home Inspections is here to help.

We will test your water for you even if you are not buying a home, just give us a call and we will come right over.  The test only takes 1-2 days and the knowledge of what you are drinking is worth way more than the cost of the test.

What to Test for?

Total Coliform & E.coli Bacteria 

The organisms in the total coliform group are called indicator organisms. That is, if present, they indicate that there is a possibility, but not a certainty, that disease organisms may also be present in the water. When absent there is a very low probability of disease organisms being present in the water. The ability of the total coliform test to reliably predict the bacterial safety of water relative to the hundreds of possible diseases that might be present is critical since it is impossible, in a practical sense, to check separately for every disease organism directly on a monthly or quarterly basis. The presence of only Total Coliform generally does not imply an imminent health risk but does require an analysis of all water systems facilities and their operation to determine how these organisms entered the water system. Escherichia Coli (E.coli). This is a specific species (subgroup) within the coliform family. They originate only in the intestines of animals and humans. They have a relatively short life span compared to more general Total Coliform. Their presence indicates a strong likelihood that human or animal wastes are entering the water system, and have a much higher likelihood of causing illness.

Iron & Manganese (Limits = 0.3 & 0.05 mg/l respectively)

Iron and manganese occur naturally in New England’s geology. They dissolve into groundwater as acidic rainfall percolates through the soil and rock. In higher concentrations, they can cause staining on laundry and water fixtures Elevated concentrations can also cause the water to have a metallic or vinyl type taste in the water Their appearance can also give an oily “crusty” sheen to the water’s surface. The non-health related iron bacteria can clog strainers, pumps, and valves.

NH Department of Environmental Services (DES) is in the process of establishing an enforceable standard of 0.3 mg/L for manganese for all NH public water systems. The effective date is currently July 1, 2022. EPA, at present, has not set health standards for either iron or manganese in drinking water, both are considered aesthetic concerns only.


The presence or absence of conventional hardness in drinking water is not known to pose a health risk to users. Hardness is normally considered an aesthetic water quality factor. The presence of some dissolved mineral material in drinking water is typically what gives the water its characteristic and pleasant “taste”. At higher concentrations however, hardness creates the following consumer problems:

  1. Produces white mineral deposits on tubs, showers, and dishes
  2. Reduces the efficiency of devices that heat water. As hardness deposits build in thickness,

    they act like insulation, reducing heat transfer.

  3. Can reduce the ability of soaps to create suds, thus reducing the efficiency of cleaning

    ability. Can cause problems with laundry.

Nitrate & Nitrite Nitrogen (Limits = 10.0 & 1.0 mg/l respectively)

Nitrate is a component in fertilizer, and both nitrate/nitrite are found in sewage and sanitary wastes from humans and animals. Nitrate/nitrite concentrations are not normally high in New England’s wells or surface waters. When elevated, the surrounding area is often heavily developed, used for agricultural purposes, or subject to heavy fertilization. Excessive levels of these nitrogen compounds in drinking water have caused serious illness and sometimes death in infants under six months of age. Symptoms include shortness of breath and blueness of the skin (methemoglobinemia).

Sodium & Chloride (Limit Chloride = 250 mg/l )

The compound known as “salt” consists of the elements sodium and chloride. Substantially higher levels of Sodium and Chloride tend to imply contamination by activities of man including road salt storage, use of road salts, and discharges from water softeners. Typical background levels of Sodium and Chloride for pristine locations in New England’s are generally less than 15 mg/L and 30 mg/L respectively.

pH (Acceptable Range = 6.5 – 8.5)

The pH of water is a measure of its acidity or alkalinity. A low pH indicates acidic water, which is therefore likely to be corrosive to household plumbing such as copper pipes. In older homes (prior to mid to late 1980’s) the plumbing may also contain Lead in the soldered joints. Corrosive water will dissolve these metals from the plumbing into the water. Dissolved Copper & Lead in drinking water can be a health concern, and can also be a maintenance concern as the water corrodes the plumbing in the home eventually causing water leaks.

Lead & Copper (Limits = 0.015 & 1.3 mg/l respectively)

Found in water with corrosive tendencies (see pH). There is an extremely low occurrence of naturally occurring lead & copper in water. It is nearly always from plumbing systems with copper lines and/or lead solder. Levels are highest after water has been stagnant in the pipes. The recommended method for testing of Lead & Copper when plumbing is a concern is to sample water after it has been sitting in the pipes for 6 – 10 hours, without running the water at all prior to filling the bottle. This is called a “first draw” and simulates a worst case test.

Radioactivity (Limit = 15 pCi/L for Gross Alpha)

New England’s bedrock contains naturally occurring radioactivity. A few examples include Radon, Radium 226, Radium 228 and Uranium. Radon is a gas (see separate description); the others are minerals. The basic test to determine the total radioactivity from all these sources is Gross Alpha.

Alkalinity: A measure of water’s acid neutralizing capacity. A low alkalinity in combination with low hardness may increase corrosive tendencies, especially in water that already has a pH below or at the low end of the acceptable range.

Arsenic (NH Limit = 0.005 mg/l EPA Limit 0.010 mg/l)

Arsenic occurs naturally in New England. In fact, arsenic was mined commercially in New England during the 1800s. Arsenic also occurs as a result of human activities. Activities that could have left arsenic residuals include apple orchard spraying and coal ash disposal. Generally it is not possible to predict if a well will have elevated arsenic. Arsenic has no smell, taste or coloration when dissolved in water, even at high concentrations. Arsenic has been classified by the U.S. Environmental Protection Agency (EPA) as a human carcinogen (cancer causing agent). Long term exposure to arsenic has been linked to cancer, cardiovascular disease, immunological disorders, diabetes and other medical issues. The NH DES has established a NH Maximum Contaminant Level (MCL) for arsenic of 0.005 mg/l, which took effect for July 1, 2021 for all NH public water systems. The federal EPA Safe Drinking Water Act MCL for arsenic is 0.010 mg/l. NH DES recommends that at least two tests be processed before concluding the well’s arsenic concentration, as well water quality can change due to many factors.

Radon (No EPA regulated limit)
IMPORTANT NOTE: Radon levels may test significantly different when collected from a well that is not in a normal pattern of use, compared to Radon levels from the same well when in normal daily use.
Radon gas is normally found in all well water. Bedrock wells typically have much higher levels then dug or point wells. The most significant concern is the inhalation of Radon from the air. Radon typically enters air via two common pathways:

  1. Migration (up from the soil) into the house air through cracks and/or other openings in the foundation.
  2. Release of dissolved radon gas into the air from water usage in the home.

In New England’s, the migration of radon up from the soil contributes the largest percent of radon found in the average home. Radon from a groundwater type water supply source, particularly a bedrock (artesian, drilled) well, contributes the next largest percentage of radon in the home. The US EPA has set an advisory “action level” of 4 pCi/L for radon gas in indoor air. Studies show that high levels of radon gas in the air increase the risk of developing lung cancer. At present there is no federal or state regulated standard for radon in drinking water. In 2016, the NH DES and the Maine Radon Program recommended that private wells with radon concentrations at or above 10,000 pCi/L be treated to reduce radon levels. Treatment for water with concentrations between 2000 and 10,000 pCi/L (in NH), or 4000 and 10,000 (in ME), may be advisable if the air concentrations in the home exceed 4 pCi/L. The EPA has proposed a limit of 4000 pCi/L, but this has never been enacted. Massachusetts recommends 10,000 pCi/L and V ermont 4,000 pCi/L. A useful equation developed by the EPA to determine the seriousness of Radon in water is that 1 pCi/L of Radon will develop in air for every 10,000 pCi/L in water.

Fluoride (Limit = 2.0/4.0 mg/l secondary/primary)

Fluoride occurs naturally in New England’s bedrock. Fluoride has no taste, color or odor. The Centers for Disease Control (CDC) have recommended 1.0 to 1.2 milligrams per liter (mg/L) as the optimum beneficial concentration of fluoride in drinking water for dental protection. In the range of 2.0-4.0 mg/L of fluoride, staining of tooth enamel is possible. At concentrations above 4.0 mg/L, studies have shown the possibility of skeletal fluorosis as well as the staining of teeth.

Volatile Organic Compounds (VOC’s)

Volatile Organic Chemicals (VOCs) are a class of chemicals that are carbon containing and vaporize easily into air at normal air temperatures. VOCs are found in a variety of commercial, industrial, and residential products, including gasoline, solvents, cleaners, degreasers, paints, inks and dyes. Many of these compounds are also known human carcinogens. Benzene, for example, may enter groundwater from gasoline or oil spills on the ground surface. Other examples of commonly detected VOCs are trichloroethylene, used in septic system cleaners; and tetrachloroethylene, used in the dry-cleaning industry. MtBE is the abbreviation for the compound “methyl tertiary butyl ether”. This compound is a former addititive to gasoline.The NH. Department of Health and Human Services developed a health-based drinking water standard for MtBE of 13 micrograms per liter (ug/L).
Sulfide (Rotten Egg Odor) Sulfide can be formed naturally as a by-product of the decomposition of organic material possibly aided by the presence of non-hazardous sulfur reducing bacteria, or by chemical reactions of soil and bedrock minerals containing sulfur. At the concentrations typically found in drinking water, it is not hazardous to health. It is also important to note that the odor threshold for sulfide is considerably lower than the point at which our laboratory test detects it. So you may smell it before we can find it.

Conductivity: A very basic test measuring the total dissolved mineral content of water. Includes all individual minerals separately listed on this page.

Per- and Polyfluoralkyl Substances (PFAS)
(NH Limits PFOA=12 ng/L, PFOS=15 ng/L, PFNA=11 ng/L, PFHxS = 18 ng/L) PFAS are a group of various man-made compounds. These chemicals include PFOA, PFOS, and other chemicals which are used in the manufacturing of many every day products. Examples of products containing PFAS include food packaging, fire fighting foam, non-stick pans, stain resistant fabrics, microwave popcorn bags, and numerous other common household products. The two most studied compounds of the full list of PFAS chemicals are PFOS and PFOA, which have been given a combined limit of 70 ng/L by the EPA.

For any questions about water testing call anytime, for pricing click the price list below.

2019 Price List

More Water Quality Information

For more information check out the NHDES website about PFOA’s and check out Nelson Analytical’s website for more information about water quality.

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