In This Article
Water Testing
Water Standards
Water Quality Red Flags
Natural Sources Of Pollution
Human Sources Of Pollution
Hard Water, Acidity, And Turbidity
See also Water Treatment           View all WATER WELL articles

Once your well is completed, disinfected, and flushed, you will want to test the water quality whether or not it is required by local code. Annual testing is also a good idea as water quality can change over time, or even seasonally.

Sample drinking water test results

Sample water test results. Click to enlarge.

Many local health departments provide an inexpensive testing service for drinking water. The typical test looks for nitrates, coliform bacteria, and pH, as well as additional substances depending on common problems in your area. The report will show the levels found as well as the recommended allowable limits for each material tested (see sample Water Test Report). You can screen for other pollutants for an added cost, but this can be substantial depending on the pollutant being measured, raising the cost of testing from $10 to 20 to hundreds of dollars. EPA’s list of “Reasons to Test You Water” can alert you to conditions that might warrant additional testing. Most common problems, if identified through testing, can be addressed with water treatment systems, discussed below. However, in severe cases the well may need to be abandoned and decommissioned, and a new well or alternate water source will be needed.

Generally, the deeper the well, and the farther away from sources of pollutions, the greater the chance of finding pure groundwater, although deep well water often contains dissolved minerals. While the EPA establishes legal standards for public water supplies  water supplies and requires frequent testing of public water supplies, these laws do not cover the 15% of Americans who rely on private wells. In most cases it is up to you to make sure the water your family is drinking remains safe and wholesome. Start your investigation by checking with your local health department, which should be aware of any specific water quality issues that might affect your region and building site. They can also help you interpret water test results and make recommendations for water treatment.


Wells can be contaminated by a number of sources, both natural and man-made. Some pollutants, such as coliform bacteria, will sicken you immediately, while other contaminants such as radon or heavy metals may not sicken you for decades, if ever. Some have obvious signs you can see, taste, or smell, but that may be the extent of their harm. Others are invisible and tasteless, but may be far more dangerous (see EPA Quick Reference List of Noticeable Problems, below).

Source: US EPA Drinking Water from Household Wells EPA 816-K-02-003 January 2002Where Do Ground Water Pollutants Come From?
Understanding and spotting possible pollution sources is important. It’s the first step to safeguard drinking water for you and your family. Some threats come from nature. Naturally occurring contaminants such as minerals can present a health risk. Other potential sources come from past or present human activity — things that we do,  make, and use — such as mining, farming and using chemicals. Some of these activities may result in the pollution of the water we drink.Several sources of pollution are easy to spot by sight, taste, or smell. (See “Quick Reference List below.), however many serious problems can only be found by testing your water. Knowing the possible threats in your area will help you decide on the kind of tests you need.Quick Reference List of Noticeable Problems
• Scale or scum from calcium or magnesium salts in water
• Unclear/turbid water from dirt, clay salts, silt or rust in water
• Green stains on sinks or faucets caused by high acidity
• Brown-red stains on sinks, dishwasher, or clothes in wash points to
dissolved iron in water
• Cloudy water that clears upon standing may have air bubbles from poorly
working pump or problem with filters.Tastes
• Salty or brackish taste from high sodium content in water
• Alkali/soapy taste from dissolved alkaline minerals in water
• Metallic taste from acidity or high iron content in water
• Chemical taste from industrial chemicals or pesticidesSmell
• A rotten egg odor can be from dissolved hydrogen sulfide gas or certain
bacteria in your water. If the smell only comes with hot water it is likely
from a part in your hot water heater.
• A detergent odor and water that foams when drawn could be seepage
from septic tanks into your ground water well.
• A gasoline or oil smell indicates fuel oil or gasoline likely seeping from a
tank into the water supply
• Methane gas or musty/earthy smell from decaying organic matter in water
• Chlorine smell from excessive chlorination.Note: Many serious problems (bacteria, heavy metals, nitrates, radon, and many chemicals) can only be found by laboratory testing of water.
EPA 816-K-02-003 January 2002

“Natural” doesn’t necessarily mean healthy when it refers to such things as radon gas or heavy metals. Common sources of water pollution that may occur naturally include:

A naturally occurring gas in the soil or water caused by the breakdown of uranium. The gas can leak into the home through cracks in the foundation, but also be released from water during showering and similar activities. Only very high levels in water are considered a health risk.
Microorganisms. Runoff from rainfall and other surface water can pick up bacteria, viruses, and other microbes from soils and wildlife, especially after flooding. These can cause short-term or chronic gastrointestinal problems. This is mainly a concern with shallow wells, which are prone to intrusion from surface water.
Nitrates and nitrites. High nitrate levels are usually associated with contamination from septic systems or animal wastes, but can also occur naturally in the soil. At high levels, nitrates and nitrites can be very harmful to infants, causing so-called “blue baby syndrome,” a potentially fatal condition linked to using mixing powdered baby formula with nitrate contaminated water.
Minerals. These are common in well water. Some are a serious nuisance and, under some conditions, a health issue.

  • Iron in well water can cause a metallic taste, and make drinks like coffee taste bitter. It also leaves a reddish-brown stain on plumbing fixtures and can permanently stain clothes, but is not generally a health hazard.
  • Manganese has similar effects on taste and leaves brownish-black stains on fixtures and clothing.
  • Calcium and magnesium compounds create hard water and can deposit scale inside pipes and heat exchangers.
  • Copper is a health hazard at high levels and may come from natural sources of be leached from plumbing by acidic water

Flouride. While many municipal water systems add this chemical to drinking water to reduce tooth decay, it can also be naturally occurring in some well water. At high levels it may discolor teeth, and at extremely high levels damage bone tissue.
Heavy metals. Trace amounts of arsenic, cadmium, chromium, lead, and selenium may be found in deep well water, but rarely at levels dangerous to human health.


More often than not, well water problems are related to human activities, such as septic systems, farming activities, or industrial sources. Beware of any red flags that indicate that pollutants are currently, or were in the past, stored or dumped nearby. Drilling a well near a current or past factory farm, industrial site, or junkyard, or town dump, is risky. Common pollutants and their sources include the following:

Nitrates and Nitrites. While these may be from natural sources, in most cases they come from the breakdown of sewage or farm animal waste. They are often used as a marker, providing an early warning of contamination from nearby septic systems or other sources of coliform bacteria. At high levels, they can cause health problems of their own, and pose a special threat to infants. If heavily contaminated water is used in baby formula, it can cause “blue baby” syndrome, a potentially fatal condition.

Bacteria. Coliform bacteria is common in soil, and is generally found at low levels in lakes and ponds. Some types of coliform can cause cramps, diarrhea, and other intestinal problems. Fecal coliform, or E. coli, comes from the intestinal tracts of people and animals, and can cause giardiasis and other serious illnesses. Any level of coliform bacteria in drinking water is unacceptable, and triggers further testing for fecal coliform. Common sources are nearby septic systems that are malfunctioning and animal manure, especially from large “factory farms.” A densely settled area with too many septic systems too close together can also contaminate the surrounding aquifer.

Household chemicals.
Septic systems are designed to process sewage and food wastes, not toxic chemicals. If cleaning solvents, paint thinner, liquid fuels, or motor oil are poured down the drain into the septic system, they are likely to end up, at some level, in the groundwater. Also chemicals used to treat well water, such as disinfectants and algicides can cause problems if handled or stored improperly near the well. Talk to your town’s waste management facility or health department about safe disposal of chemicals.

Pesticides and Fertilizers
used on farms, golf courses, and suburban lawns can end up in the aquifer, along with termiticide widely used around foundations in southern and central states. Many fertilizers break down into nitrates, which may filter into groundwater. The amount of usage, soil conditions, and patterns of rainfall and drainage all affect how much of these chemicals end up in rivers, lakes, and groundwater. The long-term health effects of low-level exposure are not well understood.

Underground storage tanks.
All gas stations, many farms, and some homes store liquid petroleum products in underground tanks, which pose a significant threat to groundwater. Nearly one in four of these tanks may leak either through the tank walls or piping, according to an EPA estimate. A small fuel leak can quickly ruin a home’s or farm’s water supply as petroleum products can move rapidly into groundwater and require an expensive (and not always effective) cleanup in addition to a new well or alternate water supply. Telltale signs may include petroleum smells and tastes in water, but low levels of pollution may go unnoticed. Tanks over 15 years old are most vulnerable and old farm sites are a concern since many farm tanks are exempt from EPA rules for chemical and petroleum storage. Wells should be at least 100 feet from petroleum storage tanks, either underground or above ground.

Modern landfills are built with heavy liners below and impermeable caps above to prevent contamination of ground water by toxic liquids and leached chemicals. Some older landfills have been sealed and decommissioned in an attempt to prevent any further contamination. In any event, drilling a well near a landfill or dump, especially an older one, is risky. Check with town health officials, who are probably aware of which areas are vulnerable to contamination.

Industrial pollution.
Nearby gas stations, dry cleaners, factories, farms, and other businesses can generate large amounts of hazardous materials that, if not managed properly, can end up in the groundwater. Mining activities can also produce large quantities of chemicals and heavy metals. Make sure the building site you are considering was not used in the past as an unofficial dump for old vehicles, chemicals, or industrial waste.


These are physical characteristics of the water itself that may cause problems with taste, equipment, and, in some cases, cause serious health problems.

Hard water.
Hard water is commonly caused in well water by calcium and magnesium compounds in well water. While not generally considered a health hazard, hard water makes soap less sudsy and less effective on dishes, clothes, skin, and hair. You also might notice a white dusty coating inside a pot used to boil water. Hard water can also lead to mineral (limescale) building in plumbing and equipment, eventually clogging pipes and reducing the service life and efficiency of boilers, and water heaters, solar collectors, and other equipment such as washing machines. Galvanic corrosion is also increased. Treatments are discussed below.

Acidic water, metallic leaching, and lead poisoning.
Like water hardness, acidity is a natural condition of some well water that is a nuisance but generally not a health hazard. Water with a pH below 7.0 is considered acidic; above 7.0 it is basic or alkaline. The U.S. EPA doesn’t regulate the pH level in drinking water, but it recommends levels from 6.5 to 8.5.

Alkalinity is not a health problem, but highly alkaline water can make drinks such as coffee taste bitter, cause scale to build up in plumbing; and reduce the efficiency of electric water heaters.

Stubborn blue stains on the tub and pitting of the chrome spout are from acidic well water.

Stubborn blue stains on the tub and pitting of the chrome spout are from acidic well water.

Highly acidic water will  leach copper or iron from the inside of piping and deposit blue-green (copper) or rust-colored (iron) scale on sinks, tubs, and other plumbing fixtures. The corrosive effect can also affect metal finishes and lead to pinhole leaks in plumbing over many years as well as a bitter metallic taste.

More ominously, acidic water can leach lead from lead pipes, plumbing fixtures, and solder in copper plumbing. Solid lead pipes were commonly used in the early 1900s and can still be found in some homes from that era. Lead solder and lead components within plumbing fixtures was not effectively banned until the late 1980s (although trace amounts are still permitted). Lead is considered a serious health threat, especially to developing children. Even at low levels lead exposure in children can cause a wide range of problems with cognitive and neurological development, some permanent. Symptoms can include hyperactivity, learning disabilities, delayed growth, and hearing loss.

Turbidity. Water that is cloudy or opaque due to fine particles suspended in the water is called “turbid.” While unpleasant to drink and not permitted in public water supplies, turbid water is not necessarily a health hazard. It depends on what the suspended materials are, typically clay, silt, dissolved minerals, organic materials, and, in some cases, bacteria and other microorganisms. Deep well water is generally free of silt due to the natural straining of the sand, gravel, and rock surrounding the well. In well water, turbidity could indicate contamination from a septic system, or the presence of algae, or air bubbles and particles from a water treatment system. High turbidity in well water is a cause for concern as it may indicate the presence of hazardous micrororginisams associated with intestinal problems. Testing and treatment are required.

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  1. Will Deeper Well Improve Water Quality?

    We have an existing drilled well at 70 feet but the quality of water is a bit poor. We have consulted many local drillers and they keep on insisting that it is hard to get water passed 70 feet. Is this really hard or its just a matter of getting a really professional well driller?

    • buildingadvisor says:

      I’m not sure why you are hearing this same story from multiple local drillers, who are usually well-informed about local conditions. In many areas, wells of 100 feet or much more are quite common. Perhaps from experience, going beyond 70 ft. in your area has not generally produced better water.

      There are few guarantees in well drilling. Drilling deeper often produces better flow, but not always. I’d suggest asking the drillers for a clearer explanation of why they don’t want to drill deeper than 70 feet. If you can’t get a straight answer, speak with a local hydrologist. Many states employ a hydrologist or other water specialist as part of their department of agriculture, forestry, or environmental quality. You can also check with local universities that may have similar professionals in the their departments of agriculture, forestry, or civil engineering.

      With any luck, you can get someone to take a look at the hydrology your site for free or a modest fee. If drillers don’t want to take your money to drill deeper, they may have a good reason. If you have adequate flow, but the water quality is an issue, you might need a better sand filter at the well head. This will help with particulates. For other water problems you may need to install a whole-house water filter.



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