Along with human activities, water quality is affected by a combination of natural processes. Most relate
to chemical compositions underground. However, other factors such as biological, physical, and
radiological conditions can affect water quality as well.
Water contaminants - scroll down for more information:
- Hard water
- Iron & Manganese
- Total Dissolved Solids
- Heavy Metals (naturally occuring)
- Lead & Copper from Pipes
- Fertilizers and Pesticides
- Industrial Products and Wastes
- Household Wastes
Microorganisms (Bacteria In-Depth) (E.Coli in Depth)
Bacteria, viruses, parasites and other microorganisms are sometimes found in water. Shallow wells —
those with water close to ground level — are at most risk. Runoff, or water flowing over the land
surface, may pick up pollutants from wildlife and soils. This is often the case after flooding. Some of
these organisms can cause a variety of illnesses. Symptoms include nausea and diarrhea, and can
occur shortly after drinking contaminated water. The effects could be short-term yet severe (similar to
food poisoning) or might recur frequently or develop slowly over a long time.
Hard Water (In Depth)
The most common problem associated with ground water may be hardness, generally associated with
an abundance of calcium and/or magnesium dissolved in the water. Hard water has not been shown to
cause health problems, but can be a nuisance as it may cause soap curds and/or cause deposits to
form on pipes and other plumbing fixtures. Over time this can reduce the diameter of the pipes.
Calcium and magnesium are found in ground water that has come in contact with certain rocks and
minerals, especially limestone and gypsum. When these materials are dissolved, they release calcium
and magnesium. Hard water is considered bad for your plumbing, but people with heart or circulatory
problems may want to consult their physician about drinking softened water, because the softening
process removes calcium and magnesium, and adds sodium to the water.
Iron and Manganese (In Depth)
A "rusty" or metallic taste in water is a result of iron, and sometimes manganese, in ground water. They
not only create a bad taste, but they also can stain pipes and clothing.
Iron and manganese are naturally occurring, and most ground water has some amount of dissolved iron
and manganese in it. It comes from contact with minerals that contain iron, such as pyrite.
There are several treatment methods. Installing a water softener may help if iron and manganese are
present in low quantities and the softener is designed for their removal. Aeration (the addition of oxygen
to the water), chlorination, and feeding ozone or hydrogen peroxide can aid in the precipitation of iron,
which it is removed from the water by filtration. Potassium permanganate feed with manganese
greensand filters, and some recently designed synthetic media, will remove iron and manganese, as well.
Nitrogen (In Depth)
Most nitrogen in ground water comes from the atmosphere. Some plants can "attach" nitrogen from the
atmosphere onto their roots. The nitrogen not used by the plants is then released into the soil.
Nitrogen compounds also can work their way into ground water through fertilizers, manure, and urine
from farm animals, sewage, and landfills. The most common forms in ground water are ammonia,
nitrate, and nitrite. Nitrates can be especially toxic to children under six months of age. Exposure to
ammonia also presents a health risk. It is toxic to aquatic life such as fish, and it interferes with water
There are a variety of treatment methods to correct this problem, including reverse osmosis systems
with water softeners to remove nitrates and nitrites, and oxidation to remove small amounts of ammonia.
However, treatment should be a last resort. Removing the source of contamination is the first priority.
You should also be sure to protect the area around the wellhead from contamination by animals or
Sulfur (In Depth)
Sulfur can occur in ground water in two forms: sulfides and sulfates. Sulfides are naturally occurring in
much of the United States in limestone containing organic materials; ground water affected by oil, gas,
and coal deposits; in marshes and manure pits; and in the byproduct of well-established iron biofilms.
Sulfates often come from the dissolving of minerals, such as gypsum and anhydrite.
A “rotten egg” smell coming from your water indicates the presence of hydrogen sulfide gas. Along with
creating an unpleasant odor and taste, sulfides cause corrosion to plumbing and darken water.
There are several methods for treating sulfur. Aeration, ozone, hydrogen peroxide, and chlorine (best
followed by filtration) are effective against dissolved hydrogen sulfide or gas. A reverse osmosis system,
nanofiltration system, or a negative ion-exchanger also can be effective in reducing sulfates. Filtration is
necessary in combating sulfur formation as a mineral or in biofilms.
Total Dissolved Solids
TDS, as it is commonly known, is the concentration of all dissolved minerals in water. It is the direct
measurement of the interaction between minerals and ground water.
TDS levels above 1000 mg/L will usually yield poor tasting water. Levels above 2000 mg/L are
considered undrinkable due to taste, and levels more than 10,000 mg/L are defined as undrinkable.
Water softeners with a reverse osmosis system are effective in lowering the TDS to satisfactory levels.
Radionuclides are radioactive elements such as uranium and radium. They may be present in
underlying rock and ground water.
Radon is a gas that is a natural product of the breakdown of uranium in the soil — can also pose a
threat. Radon is most dangerous when inhaled and contributes to lung cancer. Although soil is the
primary source, using household water containing Radon contributes to elevated indoor Radon levels.
Radon is less dangerous when consumed in water, but remains a risk to health.
Underground rocks and soils may contain arsenic, cadmium, chromium, lead, and selenium. However,
these contaminants are not often found in household wells at dangerous levels from natural sources.
Activities such as mining and construction can release large amounts of heavy metals into nearby
ground water sources. Some older fruit orchards may contain high levels of arsenic, once used as a
pesticide. At high levels, these metals pose a health risk.
Lead & Copper (In Depth)
Household plumbing materials are the most common source of lead and copper in home drinking water.
Corrosive water may cause metals in pipes or soldered joints to leach into your tap water. Your water’s
acidity or alkalinity (often measured as pH) greatly affects corrosion. Temperature and mineral content
also affect how corrosive it is. They are often used in pipes, solder, or plumbing fixtures. Lead can
cause serious damage to the brain, kidneys, nervous system, and red blood cells. The age of plumbing
materials — in particular, copper pipes soldered with lead — is also important. Even in relatively low
amounts these metals can be harmful. EPA rules under the Safe Drinking Water Act limit lead in drinking
water to 15 parts per billion. Since 1988 the Act only allows “lead free” pipe, solder, and flux in drinking
water systems. The law covers both new installations and repairs of plumbing.
Fluoride is helpful in dental health, so many water systems add small amounts to drinking water.
However, excessive consumption of naturally occurring fluoride can damage bone tissue. High levels of
fluoride occur naturally in some areas. It may discolor teeth, but this is not a health risk.
Concentrated Animal Feeding Operations (CAFOs)
The number of CAFOs, often called “factory farms,” is growing. On these farms thousands of animals
are raised in a small space. The large amounts of animal wastes/manures from these farms can
threaten water supplies. Strict and careful manure management is needed to prevent pathogen and
nutrient problems. Salts from high levels of manures can also pollute ground water.
Fertilizers and Pesticides (In Depth)
Farmers use fertilizers and pesticides to promote growth and reduce insect damage. These products
are also used on golf courses and suburban lawns and gardens. The chemicals in these products may
end up in ground water. Such pollution depends on the types and amounts of chemicals used and how
they are applied. Local environmental conditions (soil types, seasonal snow and rainfall) also affect this
pollution. Many fertilizers contain forms of nitrogen that can break down into harmful nitrates. This could
add to other sources of nitrates mentioned above. Some underground agricultural drainage systems
collect fertilizers and pesticides. This polluted water can pose problems to ground water and local
streams and rivers. In addition, chemicals used to treat buildings and homes for termites or other pests
may also pose a threat. Again, the possibility of problems depends on the amount and kind of
chemicals. The types of soil and the amount of water moving through the soil also play a role.
Industrial Products and Wastes (In Depth)
Many harmful chemicals are used widely in local business and industry. These can become drinking
water pollutants if not well managed. The most common sources of such problems are:
- Local Businesses: These include nearby factories, industrial plants, and even small businesses
such as gas stations and dry cleaners. All handle a variety of hazardous chemicals that need
careful management. Spills and improper disposal of these chemicals or of industrial wastes can
threaten ground water supplies.
- Leaking Underground Tanks & Piping: Petroleum products, chemicals, and wastes stored in
underground storage tanks and pipes may end up in the ground water. Tanks and piping leak if
they are constructed or installed improperly. Steel tanks and piping corrode with age. Tanks are
often found on farms. The possibility of leaking tanks is great on old, abandoned farm sites. Farm
tanks are exempt from the EPA rules for petroleum and chemical tanks.
- Landfills and Waste Dumps: Modern landfills are designed to contain any leaking liquids. But
floods can carry them over the barriers. Older dumpsites may have a wide variety of pollutants
that can seep into ground water.
Household Wastes (In Depth)
Improper disposal of many common products can pollute ground water. These include cleaning solvents,
used motor oil, paints, and paint thinners. Even soaps and detergents can harm drinking water. These
are often a problem from faulty septic tanks and septic leaching fields.
OVERVIEW OF WATER PROBLEMS