Common Ground Water Contaminants

Primary Contaminants

Primary drinking water contaminants which are toxic above the EPA limit or may cause adverse health affects.

Secondary Contaminants

These do not pose a reasonable health risk at the levels generally found but may adversely affect aesthetic quality, but may cause staining or odor problems.

Great 30 Contaminants

This is a combination of the above two profiles.

Individual Contaminants

Any Individual contaminate is available upon request.

Click the down arrow () next to the profile name to see more information about the particular contaminant
Profile Primary
Great 30
Low level exposure is not thought to harm your health. Aluminum, however is not a necessary substance for our bodies and too much may be harmful.
EPA Limit: (0.05-0.2 mg/L)
Above the EPA limit antimony may potentially cause nausea, vomiting, and diarrhea. Antimony is a known/potential drinking water human carcinogen.
EPA Limit: (0.006 mg/L)
Arsenic can occur in water as the result of natural mineral deposits, industrial discharge, or application of insecticides. Severe poisoning can arise from the ingestion of low levels of arsenic.
EPA Limit: (0.01 mg/L)
Barium is a naturally occurring mineral. Ingesting Barium can affect the heart, blood vessels, and nerves.
EPA Limit: (2 mg/L)
Beryllium can occur in water as the result of natural mineral deposits, discharge from metal refineries and coal-burning factories, or industrial waste. Potential health effects are damage to bones and lungs and intestinal lesions.
EPA Limit: (0.004 mg/L)
The presence of Cadmium is normally the result of the corrosion of galvanized pipe. It can also occur from waste batteries and paints. Cadmium is highly toxic.
EPA Limit: (0.005 mg/L)
Chromium can occur in water as the result of natural mineral deposits and discharge from steel and pulp mills. Potential health effects are skin irritation and damage to liver and nerve tissues.
EPA Limit: (0.1 mg/L)
Cyanide is used in a number of industries and is found at low levels in air from car exhaust. Cyanide is extremely toxic to humans. Chronic (long-term) inhalation exposure of humans to cyanide results primarily in effects on the central nervous system (CNS). Other effects in humans include cardiovascular and respiratory effects, an enlarged thyroid gland, and irritation to the eyes and skin. EPA Limit: (0.2 mg/L)
Fluoride can occur naturally in water or as a product of industrial waste. The long-term effects are permanent brown staining of the teeth, destruction of tooth enamel, and brittle bones.
EPA Limit: (4 mg/L)
Lead is a serious cumulative body poison. Lead is normally the result of the corrosive action of water on pipe fittings and solder.
EPA Limit: (0.015 mg/L)
Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands
EPA Limit: (0.002 mg/L)
Nickel can occur in water as the result of natural mineral deposits and metal alloys. Nickel can effect the heart and liver.
EPA Limit: (0.1 mg/L)
Nitrates reduce the blood's ability to carry oxygen. Infants and pregnant women are highly susceptible. Nitrate contamination usually occurs from inorganic fertilizer or animal waste.
EPA Limit: (10.0 mg/L)
Selenium can occur in water as the result of natural mineral deposits, discharge from petroleum and metal refineries, and discharge from mines. Potential health risks are hair and fingernail loss, damage to kidney and liver tissue, and damage to the nervous and circulatory systems.
EPA Limit: (0.05 mg/L)
Thallium can occur in water as the result of natural mineral deposits and industrial waste. Thallium can also cause hair loss and damage to kidney, liver, and intestinal tissues.
EPA Limit: (0.002 mg/L)
Boron may be naturally occurring or as a result of cleaning compounds. Although essential for plant growth Boron in excess of 2.0 mg/L is deterious to certain plants.
EPA Limit: (1-4 mg/L)
Calcium results from passage through limestone, dolomite, gypsum, and gypsiferous shale. It is a major contributor to the build-up of scale on kitchen and bathroom fixtures.
EPA Limit: No Limit
Chloride can cause a salty or brackish taste in water. A high chloride content may deteriorate metallic pipes, as well as plants.
EPA Limit: (250 mg/L)
Cobalt in an integral part of the Vitamin B-12 complex, and therefore essential in trace amounts for humans and animal life. However, in higher concentrations cobalt is toxic to humans and aquatic animals aqnd plants. Due to lack of data no limit has been set by the EPA for drinking water.
EPA Limit: No Limit
Conductivity measures the amount of time it takes electrical current to travel through the water. It indicates the total mineral content of the water.
EPA Limit: (700)
Most Copper contamination occurs as a result of the corrosion of copper pipes and fittings. At high levels Copper can cause a bitter metallic taste, blue-green stains, or flu-like symptoms.
EPA Limit: (1.3 mg/L)
Total Hardness results from minerals that combine with soap causing an insoluble scum. Hardness causes scaling in pots and incrustation in water heaters. The amount of soap needed increases with hardness.
EPA Limit: (250 mg/L)
Iron causes rusty staining of laundry and porcelain. Also, a bitter or astringent taste can occur.
EPA Limit: (0.3 mg/L)
Naturally occurring element
EPA Limit: No Limit
Magnesium results from passage of water through soil and rock. It is also a contributor to the build-up of scale on kitchen and bathroom fixtures.
EPA Limit: No Limit
Manganese causes tenacious stains, usually black, to laundry and plumbing fixtures. High levels can accelerate biological growth and produce taste and odor problems.
EPA Limit: (0.05 mg/L)
An essential trace element, however it imparts a slightly astrigent taste above 10mg/L
EPA Limit: No Limit
The ideal pH of drinking water is 7.5. When pH is below 7.0 the water is considered acidic which can cause corrosion of pipes. When pH is above 8.0 the water is alkaline which can cause mineral deposits on pipes.
EPA Limit: (6.5-8.5)
Potassium can be used as a substitute for Sodium in water softeners.
EPA Limit: No Limit
Silver can occur in water as the result of photographic industry discharges or using silver as a batereriostat. Silver can cause skin discoloration and graying of the white part of the eye
EPA Limit: (0.1 mg/L)
Assuming the average person ingests about 5,000 mg per day. For persons on restricted sodium diets of less than 1,000 mg per day, the upper limit for total sodium concentration of water is about 66 mg/L.
EPA Limit: No Limit
OEHHA (Office of Environmental Health Hazard Assessment) recommends a notification level of 0.50 mg/L
EPA Limit: (5.0 mg/L)
Zinc is essential and beneficial to human growth. In high concentrations it gives water a strong metallic taste.
EPA Limit: (5.0 mg/L)

Some people may be more vulnerable to contaminants in drinking water than the general population. Immune-compromised Persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers.

Milligrams per liter (mg.L) is the same as Parts per million (ppm) or one part per million corresponds to a single penny in $10,000.

Standard Methods 14th edition
Environmental Protection Agency
Last updated November 18th, 2005
Pipline Publication , Oregon Health Division