Ground water is a resource found under the earth’s surface. Most ground water comes from rain and melting snow soaking into the ground. Water fills the spaces between rocks and soils, making an “aquifer”. Many families rely on private, household water borehole and use ground water as their source of fresh water.

Generally, the deeper the borehole, the better the ground water. The amount of new water flowing into the area also affects ground water quality. Ground water may contain some natural impurities or contaminants, even with no human activity or pollution.

The first step to safeguard drinking water is to understand and spot possible pollution sources. Pollution sources can be divided into two groups:

  • Naturally occurring contaminants, such as naturally occurring minerals.
  • Past or present human activity. Things we do, make, and use — such as mining, farming and using of various chemicals.

Several sources of pollution are easy to spot by sight, taste, or smell. The following are (Quick Reference List.)

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.


• 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 pesticides


• 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.

Naturally Occurring Sources of Pollution


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 these 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. These 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.

source of underground water pollution


Radionuclides are radioactive elements such as uranium and radium. They may be present in underlying rock and ground water. Radon — 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.

source of underground water pollution
radionuclides iodine cesium

Nitrates and Nitrites

Although high nitrate levels are usually due to human activities, they may be found naturally in ground water. They come from the breakdown of nitrogen compounds in the soil. Flowing ground water picks them up from the soil. Drinking large amounts of nitrates and nitrites is particularly threatening to infants (for example, when mixed in formula).

source of underground water pollution
nitrate nitrite

Heavy Metals

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.

naturally occurring source of underground water pollution
heavy metals


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.

source of underground water pollution

Ground water pollution from Human Activities

Bacteria and Nitrates

These pollutants are found in human and animal wastes.  Septic tanks can cause bacterial and nitrate pollution. So can large numbers of farm animals. Both septic systems and animal manures must be carefully managed to prevent pollution. Sanitary landfills and garbage dumps are also sources. Children and some adults are at extra risk when exposed to water-born bacteria. These include the elderly and people whose immune systems are weak due to AIDS or treatments for cancer.  Fertilizers can add to nitrate problems. Nitrates cause a health threat in very young infants called “blue baby” syndrome. This condition disrupts oxygen flow in the blood.

ground water pollution from human activities
bacteria and nitrates

Concentrated Animal Feeding Operations

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 groundwater.

ground water pollution from human activities
animal feeding

Fertilizers and Pesticides

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.

ground water pollution from human activities
fertilizers and pesticides

Industrial Products and Wastes

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.

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.

ground water pollution from human activities

Household Wastes

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.

ground water pollution from human activities
household wastes

Lead & Copper

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.

Water Treatment Chemicals

Improper handling or storage of water well treatment chemicals (disinfectants, corrosion inhibitors, etc.) close to your well can cause problems.

ground water pollution from human activities
water treatment chemical

Talk to us for your upcoming water borehole construction and treatment requirement

Geodata Evaluation & Drilling LTD. offers borehole construction, maintenance and water treatment services. For your water services requirement. contact us at Phone: +234 8037055441