Water Contaminants Glossary

Chloride

Description: The SMCL of 250 milligrams per liter for chloride is the level above which the taste of the water may become objectionable. In addition to adverse taste, high chloride concentrations in the water contribute to the deterioration of domestic plumbing and water heaters and municipal waterworks equipment. High chloride concentrations may also be associated with the presence of sodium in drinking water. See sodium discussion.

You Might Notice:

• Salty taste
• Corrosion of fixtures

Copper

Description: Copper in drinking water normally is not a concern, as the levels required to produce health effects in most people exceed the maximum possible concentrations. Experience indicates that copper at concentration levels exceeding 2 milligrams per liter causes blue-green staining of plumbing fixtures and an off taste. To many people, copper imparts a detectable taste at a concentration level of 1 milligram per liter. In instances where high copper concentration levels in the drinking water are observed, it is likely that other heavy metals are also present. Water containing 4 milligrams per liter copper was found to impart a green tint to dyed hair.

You Might Notice:

• Metallic tastes
• Blue/green staining
• No odors

Fluoride

Description: Fluoride are salts that a naturally form when the element fluorine combines with minerals in soils and rocks. Some fluoride compounds such as sodium fluoride and fluorosilicates, dissolve easily into ground water as it moves through rock formations. Fluoride can also enter drinking water from discharge from fertilizer or aluminum factories. Most community water systems also add fluoride to the drinking water to help promote dental health. A fluoride concentration of approximately 1 milligram per liter helps prevent dental cavities and osteoporosis. At concentrations below 0.7 milligram per liter, fluoride would likely not be of benefit. This is most commonly a problem for children up to about 10 years old. Because this is the only effect, EPA recently increased the MCL for fluoride. Crippling bone changes may occur in some people if drinking water is above 8 milligrams per liter fluoride. There is no conclusive evidence that fluoride or fluoridation causes cancer in humans.

You Might Notice:

• No odors or tastes
• Levels above 1.8 mg/L can cause tooth
• Enamel staining

Hardness

Description: A characteristic of water caused mainly by the salts of calcium and magnesium, such as bicarbonate, carbonate, sulfate, chloride and nitrate. Hardness or total hardness is generally defined as the sum of the calcium and magnesium concentrations expressed in milligrams per liter of equivalent calcium carbonate.

You Might Notice:

• Bathtub rings
• Scale formation
• White on faucets and glass
• Hot water heater/home appliances not functioning

Iron

Description: Iron occurs naturally in many groundwater supplies throughout the US. It is essential in human and animal diets, but levels above the SMCL may impart an objectionable taste or odor to water and cause red staining of porcelain fixtures and laundry. Iron-contaminated water often causes reddish-brown stains to develop on bathtubs, sinks and toilet bowls. It can also stain laundry a pink or reddish color. These stains are very difficult to remove with ordinary cleaning compounds.

You Might Notice:

• Metallic tastes
• No odors
• Visible red or brown water
• Staining

Lead

Description: Lead normally enters the drinking water supply when service pipes, (house and city) contain lead, and corrode due to acidic water, or low mineral content. The most common problem is with brass or chrome-plated brass faucets, fixtures with lead solder, plumbing pipes/connections with lead-based solder or made from lead. With plumbing, the hot water side is more prone to leach lead back into the hot water. Homes built before 1986 are more likely to have lead pipes, fixtures, and solder. Exposure to lead in water, either brief or prolonged, can seriously injure health. Prolonged exposure to relatively small quantities (more than 0.05 milligram per day) may affect health. Lead exposure occurs from air, food and water sources. All exposure is additive. Lead accumulates in the bones, resulting in elevated levels in the blood. Known effects range from subtle biochemical changes at low levels of exposure to severe neurological and toxic effects and even death at much higher levels. As with several other water contaminants, children, infants and fetuses are especially vulnerable to lead. Infants and children absorb a much greater portion of lead intake than adults and they're immature, developing bodies and central nervous systems are much more sensitive to its effects. A child's mental and physical development can be irreversibly stunted by over-exposure to lead. Health effects include reduced mental capacity (even mental retardation), interference with kidney and neurological functions and hearing loss in children. The EPA-proposed MCL should be followed whenever pregnant women, infants or children are consuming water.

You Might Notice:

• No odor, tastes, or colors

Manganese

Description: Manganese is naturally occurring in many surface and groundwater sources and in soils that may erode into these waters. However, human activities are also responsible for much of the manganese contamination in water in some areas.

You Might Notice:

• Metallic taste
• Brown to black stain on fixtures

Nitrate

Description: Nitrate has caused methemoglobinemia (infant cyanosis) or blue baby disease in infants less than 6 months old who have been given water or formula mixed with water high in nitrate. Children under one year of age and pregnant women are at risk for adverse effects.

You Might Notice:

• No odors, tastes or colors.

Nitrite

Description: This standard is closely linked to the nitrate standard because the problem really occurs when nitrate is chemically changed to nitrite in the digestive system. Nitrite is readily absorbed by blood in the digestive tract. It attaches to the hemoglobin and interferes with the blood's capacity to carry oxygen to body cells. Because nitrite does not have to be chemically changed in the body to exhibit its effect, the reaction is direct and is similar in infants, children and adults. Fortunately, nitrite is not very stable, so high concentrations are rarely found in the environment.

You Might Notice:

• No odors, tastes or colors.

pH

Description: 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 1980s) 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.

You Might Notice:

• Corrosion to pipes and fixtures

Sulfate

Description: Sulfate has no known health effects at concentrations up to about twice the standard, so it has a secondary standard. High concentrations of sulfate in drinking water have three effects:

• Water containing appreciable amounts of sulfate tends to form hard scales in boilers and heat exchangers
• Sulfate affects taste
• High sulfate can cause laxative effects for those not used to it

You Might Notice:

• Laxative effects in house guests
• Diarrhea in higher volumes

Tannins

Description: Tannins can cause yellow water and yellow staining on fabrics and fixtures. Tannins measuring 0.5 PPM or higher may cause staining and/or interference with various water treatment processes.

You Might Notice:

• A faint yellow to tea-like color
• Yellow staining on fabrics, fixtures, china and laundry
• A tangy or tart aftertaste
• A musty or earthy odor

TDS

Description: Total dissolved solids (TDS) is a measure of all dissolved inorganic material in water. TDS higher than about 1,000 milligrams per liter is objectionable because of the mineral taste and possible health effects. Additionally, water with TDS above a typical household level of 400 milligrams per liter has been found to decrease the average life of home hot water heaters approximately one year for each additional 200 milligrams per liter of TDS in the water. High TDS values may be an indication of the presence of an excessive concentration of some specific substance, not addressed by other parameters in the Safe Drinking Water Act, which could make the water aesthetically objectionable to the user.

You Might Notice:

• Staining
• Salty taste
• Hardness
• Deposits
• Colored water

Total Coliform

Description: A group of related bacteria whose presence is largely not harmful to humans. 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.

You Might Notice:

• No odors, tastes or colors.

Turbidity

Description: Turbidity is a measure of water clarity on how much the material suspended in water decreases the passage of light through the water. Suspended materials include soil particles (clay, silt, and sand), algae, plankton, microbes, and other substances. Sources of turbidity include:

• Soil erosion
• Waste discharge

You Might Notice:

• Cloudiness in water
• Suspended solids in the bottom of glasses