Javed Iqbal | 2/10/2010 11:46:39 PM
This paper offers information on water-quality analyses performed by W.A. Callegari Environmental Center Water Quality Laboratory. The information will help determine the purity of your water for drinking, habitation or agricultural use. Manmade or natural processes continuously add chemical and biological contaminants to water. These contaminants can impair the water quality for public health, cause damage to growing plants or cause diseases. These contaminants can either be removed or rendered harmless once they are identified. Regulatory agencies are concerned with setting up appropriate standards to protect public health while farmers are interested in the effects of irrigation waters on the chemical, physical and osmotic properties of soils, particularly as they influence crop production. Similarly, aquaculturists are interested in the quality of water influencing the growth and production of their stock. Certain contaminants produce adverse effects only when consumed regularly over a long period and must be monitored regularly to avoid or minimize the adverse effects. Chronic effects are usually produced with such longer exposure.
Setting Standards -- Maximum Contaminant Levels (MCLs)Standards set under authority of the Safe Drinking Water Act (SDWA) are called Maximum Contaminant Levels (MCLs). An MCL is the highest amount of a specific contaminant allowed in the water delivered to any customer of a public water system. An MCL may be expressed in milligrams per liter (mg/l), which is the same for the purposes of water quality analysis as parts per million (ppm). The MCLs also can be expressed as micrograms/liter (µg/l) which is equivalent to parts per billion (ppb). One thousand micrograms per liter (1,000 µg/l) is equivalent to one milligram per liter (1 mg/l). MCLs have been set by the U.S. EPA and the Louisiana Department of Environmental Quality to provide a margin of safety to protect the public health.
What do the maximum contaminant level numbers mean?
Antimony MCL 6 µg/LAntimony occurs naturally in soils, groundwater and surface waters and is often used in the flame-retardant industry. It also is used in ceramics, glass, batteries, fireworks and explosives. It may get into drinking water through natural weathering of rock, industrial production, municipal waste disposal or manufacturing processes. This element has been shown to decrease longevity and altered blood levels of cholesterol and glucose in laboratory animals such as rats exposed to high levels during their lifetimes. EPA has set the drinking-water standard for antimony at 0.006 ppm to protect against the risk of these adverse health effects. Drinking water which meets the EPA standard is associated with little to none of this risk and should be considered safe with respect to antimony.
Arsenic MCL 50 µg/LAreas with elevated levels of arsenic in geologic materials are found throughout the United States. Most of the arsenic produced is a byproduct of the smelting of copper, lead and zinc ores. Arsenic has been found in both groundwater and surface waters from both natural processes and industrial activities, including smelting operations, use of arsenical pesticides and industrial waste disposal. Arsenic compounds have been shown to produce acute and chronic toxic effects which include systemic irreversible damage. The trivalent (+3) compounds are the most toxic and tend to accumulate in the body. Chronic animal studies have shown body weight changes, decreased blood hemoglobin, liver damage and kidney damage. Arsenic has been classified in EPA’s Group A (human carcinogen) based upon evidence of human carcinogenicity through inhalation and ingestion exposure. Arsenic is regulated because of its potential adverse health effects and its widespread occurrence.
Barium MCL 2,000 µg/LBarium is a naturally occurring metal found in many types of rock, such as limestones and sandstones and soils in the eastern United States. Certain geologic formations in California, Arkansas, Missouri and Illinois are known to contain barium levels about 1,000 times higher than those found in other portions of the United States. Areas associated with deposits of coal, petroleum, natural gas, oil shale, black shale and peat also may contain high levels of barium. Principal areas where high levels of barium have been found in drinking water include parts of Iowa, Illinois, Kentucky and Georgia. Acute exposure to barium in animals and humans results in a variety of cardiac, gastrointestinal and neuromuscular effects. Barium has been classified in EPA’s Group D (not classifiable) based upon inadequate data from animal studies. Barium exposure has been associated with hypertension and cardiotoxicity in animals. For this reason and because of the widespread occurrence of barium in drinking water, it is regulated.
Beryllium MCL 4 µg/LBeryllium occurs naturally in soils, ground water and surface waters and is often used in electrical equipment and electrical components. It generally gets into water from runoff from mining operations, discharge from processing plants and improper waste disposal. Beryllium compounds have been associated with damage to the bones and lungs and induction of cancer in laboratory animals such as rats and mice when the animals are exposed at high levels over their lifetimes. There is limited evidence to suggest that beryllium may pose a cancer risk via drinking water exposure. Therefore, EPA based the health assessment on noncancer effects with an extra uncertainty factor to account for possible carcinogenicity. Chemicals that cause cancer in laboratory animals also may increase the risk of cancer in humans who are exposed over long periods of time. EPA has set the drinking water standard for beryllium at 0.004 ppm to protect against the risk of these adverse health effects. Drinking water which meets the EPA standard is associated with little to none of this risk and should be considered safe with respect to beryllium.
Cadmium MCL 5 µg/LCadmium is found in very low concentrations in most rocks, as well as in coal and petroleum and often in combination with zinc. Geologic deposits of cadmium can serve as sources in groundwater and surface water, especially when in contact with soft, acidic waters. Cadmium uses include electroplating, nickel-cadmium batteries, paint and pigments, and plastic stabilizers. It is introduced into the environment from mining and smelting operations and industrial operations, including electroplating, reprocessing cadmium scrap and incineration of cadmium-containing plastics. The remaining cadmium emissions are from fossil fuel use, fertilizer application and sewage sludge disposal. Cadmium may enter drinking water as a result of corrosion of galvanized pipe. Landfill leachates are also an important source of cadmium in the environment. Acute and chronic exposure to cadmium in animals and humans results in kidney dysfunction, hypertension, anemia and liver damage. The kidney is considered to be the critical target organ in humans chronically exposed to cadmium by ingestion. Cadmium has been classified in EPA’s Group B1 (probable human carcinogen) based upon evidence of carcinogenicity in humans through inhalation exposure. However, since cadmium has not been shown to be carcinogenic through ingestion exposure, the compound is regulated based upon chronic toxicity data. Because of cadmium’s potential adverse health effects and widespread occurrence in raw waters, it is regulated.
Chromium MCL 100 µg/LChromium is a naturally occurring metal that in drinking water forms compounds with valences of +3 and +6, with the trivalent state being the more common. Although chromium is not currently mined in the United States, wastes from old mining operations may enter surface and groundwater through runoff and leaching. Chromate wastes from plating operations may also be a source of water contamination. Fossil-fuel combustion, waste incineration, cement plant emissions, chrome plating and other metallurgical and chemical operations may result in releases of chromium to the atmosphere. Chromium III and chromium VI have greatly differing toxicity characteristics. Chromium III is a nutritionally essential element. Chromium VI is much more toxic than Chromium III and has been shown to produce liver and kidney damage, internal hemorrhage and respiratory disorders. Also, subchronic and chronic exposure to Chromium VI in the form of chromic acid can cause dermatitis and ulceration of the skin. Chromium has been classified in EPA’s Group A (human carcinogen) based upon positive inhalation data for Chromium VI in humans and animals. However, since chromium has not been shown to be carcinogenic through ingestion exposure, the compound is regulated based upon chronic toxicity data. Chromium exposure at high levels has been shown to result in chronic toxic effects in animals and humans by ingestion; thus it is regulated.
Copper 1,500 µg/L (Action Level)Copper, a reddish-brown metal, is often used to plumb residential and commercial structures that are connected to water distribution systems. Copper contaminating drinking water as a corrosion byproduct occurs as the result of the corrosion of copper pipes that remain in contact with water for a prolonged period. Copper is an essential nutrient, but at high doses it has been shown to cause stomach and intestinal distress, liver and kidney damage and anemia. Persons with Wilson’s disease may be at higher risk of health effects due to copper contamination resulting from the corrosion of plumbing materials. Public water systems serving more than 50,000 people or fewer that have copper concentrations below 1,300 parts per billion in more than 90 percent of tap water samples (the EPA action level) are not required to install or improve their treatment. Any water system that exceeds the action level must also monitor its source water to determine whether treatment to remove copper in source water is needed.
Lead 15 µg/L (Action Level)Materials that contain lead have frequently been used in the construction of water-supply distribution systems and plumbing systems in private homes and other buildings. The most commonly found materials include service lines, pipes, brass and bronze fixtures, and solders and fluxes. Lead in these materials can contaminate drinking water as a result of the corrosion that takes place when water comes into contact with those materials. Lead can cause a variety of adverse health effects in humans. At relatively low levels of exposure, these effects may include interference in red blood cell chemistry, delays in normal physical and mental development in babies and young children, slight deficits in the attention span, hearing and learning abilities of children and slight increases in blood pressure of some adults. EPA’s national primary drinking water regulation requires all public water systems to optimize corrosion control to minimize lead contamination resulting from the corrosion of plumbing materials. Public water systems serving 50,000 people or fewer that have lead concentrations below 15 parts per billion (ppb) in more than 90 percent of tap water samples (the EPA action level) have optimized their corrosion control treatment. Any water system that exceeds the action level must also monitor its source water to determine whether treatment to remove lead in source water is needed. Any water system that continues to exceed the action level after installation of corrosion control and/or source water treatment must eventually replace all lead service lines contributing in excess of 15 ppb of lead to drinking water. Any water system that exceeds the action level also must undertake a public education program to inform consumers of ways they can reduce their exposure to potentially high levels of lead in drinking water.
The following steps can be taken to minimize your exposure to lead:1. Flush your plumbing to counteract the effects of “contact time.” Flushing involves allowing the cold faucet to run until a change in temperature occurs (minimum of one minute). Water drawn during flushing doesn’t have to be wasted. It can be saved for other uses such as washing dishes or clothes and watering plants.
Lead has been classified in EPA’s Group B2 (probable human carcinogen) based upon evidence of kidney tumors in rats by the oral route.
Mercury MCL 2 µg/L
Mercury exists in two basic forms -- the inorganic salt and organic mercury compounds (methyl mercury). The major use of mercury is in electrical equipment (batteries, lamps, switches and rectifiers). Mercury also may enter the environment from mining, smelting and fossil fuel combustion. Inorganic mercury is poorly absorbed through the gastro-intestinal tract. The principal target organ of inorganic mercury is the kidney. Exposure to inorganic mercury compounds at high levels results in renal effects. Because inorganic mercury is the form of mercury detected in drinking water, has widespread occurrence and may have adverse health effects, it is regulated.
Selenium MCL 50 µg/l
Selenium occurs in U.S. soils in the western states. The more alkaline soil tends to make selenium more water-soluble, and increased plant uptake and accumulation occur. Most of the commercial selenium has toxic effects at high dose levels and is nutritionally essential at low levels. Acute and chronic toxic effects have been observed in animals. In humans, few data exist on acute toxicity. In animals, selenium deficiency results in congenital white muscle disease and other diseases. Selenium has been classified in EPA’s Group D (not classifiable), based upon inadequate data in animals and humans. Selenium exposure at high levels results in chronic adverse health effects, and thus it is regulated.
Thallium MCL 2 µg/l
Thallium is found naturally in soils and is used in electronics, pharmaceuticals and the manufacture of glass and alloys. Thallium compounds have been shown to damage the kidney, liver, brain and intestines of laboratory animals when the animals are exposed at high levels over their lifetimes. EPA has set the drinking water standard for thallium at 0.002 ppm to protect against the risk of these adverse health effects. Drinking water which meets the EPA standard is associated with little to none of this risk and should be considered safe with respect to thallium.
Aluminum SMCL 0.05-0.2 mg/l
EPA believes that in some waters post-precipitation of aluminum may take place after treatment. This could cause increased turbidity and aluminum water quality slugs under certain treatment and distribution changes. EPA also agrees with the World Health Organization (WHO, 1984) that "discoloration of drinking water in distribution systems may occur when the aluminum level exceeds 0.1 mg/l in the finished water." WHO further adopts a guidance level of 0.2 mg/l in recognition of difficulty in meeting the lower level in some situations. While EPA encourages utilities to meet a level of 0.05 mg/l where possible, it still believes that varying water quality and treatment situations necessitate a flexible approach to establish the SMCL. What may be appropriate in one case may not be appropriate in another. Hence, a range for the standard is appropriate. The definition of "secondary drinking water regulation" in the SDWA provides that variations may be allowed according to "other circumstances." The state primacy agency may make a decision on the appropriate level for each utility on a case-by-case basis. Consequently, for the reasons given above, the final SMCL for aluminum will be a range of 0.05 mg/l to 0.2 mg/l, with the precise level then being determined by the state for each system.
Iron SMCL 0.3 mg/l
At 1.0 mg/l, a substantial number of people will note the bitter, astringent taste of iron. Also at this concentration, it imparts a brownish color to laundered clothing and stains plumbing fixtures with a characteristic rust color. Staining can result at levels of 0.05 mg/l, lower than those that are detectable to taste buds (0.1-1.0 mg/l). Therefore, the SMCL of 0.3 mg/l represents a reasonable compromise, as adverse aesthetic effects are minimized at this level.
Manganese SMCL 0.05 mg/l
The SMCL was set to prevent aesthetic and economic damage. Excess manganese produces a brownish color in laundered goods and impairs the taste of tea, coffee and other beverages. Concentrations may cause a dark brown or black stain on porcelain plumbing fixtures. As with iron, manganese may form a coating on distribution pipes. These may slough off, causing brown blotches on laundered clothing or black particles in the water.
Silver SMCL 0.01 mg/lSilver is a relatively rare metal. Its major commercial uses are in photography, electric/electronic components, sterling and electroplate, and alloys and solder. Environmental releases can occur during ore mining and processing, product fabrication and disposal. However, because of the great economic value of silver, recovery practices are typically used to minimize losses. The only adverse effect resulting from chronic exposure to low levels of silver in animals and humans is argyria, a blue-gray discoloration of the skin and internal organs. Argyria is markedly disfiguring and is a permanent, nonreversible effect. Argyria is the result of silver deposition in the dermis and at basement membranes of the skin and other internal organs. There is no evidence that exposure to silver results in mutagenic or carcinogenic effects. Silver has been classified in EPA’s Group D (not classifiable) based upon inadequate data in animals and humans. The current SMCL for silver is based upon 1 gram of silver resulting in argyria.
Sodium SMCL 50 mg/lSodium is the principal cation in the hydrosphere. It is derived geologically from the leaching of surface and underground deposits of salts (e.g., sodium chloride) and from the decomposition of sodium aluminum silicates and similar minerals. The sodium ion is a major constituent of natural waters. Human activities also contribute sodium to water supplies, primarily though the use of sodium chloride as a deicing agent and the use of washing products. Based on the available studies, it appears that insufficient evidence is available to conclude whether or not sodium in drinking water causes an elevation of blood pressure in the general population. It has been estimated that food accounts for approximately 90 percent of the daily intake of sodium, whereas drinking water contributes up to the remaining 10 percent. In order to afford protection to a segment of the U.S. population on a sodium-restricted diet, in 1968, the American Heart Association (AHA) recommended a level of 5 mg of sodium per 8 ounces of water or 20 mg/l. EPA is suggesting a guidance level for sodium of 20 mg/l in drinking water for the high-risk population as recommended by the AHA. When it is necessary to know the precise amount of sodium present in a water supply, a laboratory analysis should be made. When home water softeners utilizing the ion-exchange method are used, the amount of sodium will be increased. For this reason, water that has been softened should be analyzed for sodium when a precise record of individual sodium intake is needed. For healthy persons, the sodium content of water is unimportant because the intake from salt is so much greater, but for persons placed on a low-sodium diet because of heart, kidney, circulatory ailments, or complications in pregnancy, sodium in water must be considered.
ZINC SMCL 5 mg/lZinc is found in some natural waters, most frequently in areas where it is mined. It is not considered detrimental to health unless it occurs in very high concentrations. It imparts an undesirable taste to drinking water. For this reason, the SMCL of 5.0 mg/l was set.
Water testing -- Where should I get my water analyzed?
General information on water testing
There are two types of sampling locations depending on the contaminant of interest. The sampling locations are point-of-entry (POE) and the water distribution system (consumers tap in a house). The purpose of these two types of sampling locations is to differentiate between contamination derived from the source water and contamination derived from the distribution pipes.The goal of drinking water sampling should be to collect a sample under the worst conditions; therefore, checking water a day after a heavy rainfall is a good idea. If corrosive water is suspected, a sample for lead or copper should be taken first thing in the morning, without letting the water run. For other tests, wait until mid-morning after a good quantity of water has been used. Samples for bacteria (Total Coliforms) must be collected using sterile containers and under sterile conditions. In addition, keep a record of all your water test results; by observing any changes over time, you may be able to discover any problems.
The LSU AgCenter’s W. A. Callegari Environmental Center is equipped with analytical instruments and dedicated professionals to serve you in analyzing water samples for copper contamination. We are committed to furnish results on your samples within a minimum timeframe. Submit your sample(s) in person or mail to: 1300 Dean Lee Drive, Baton Rouge, LA 70820. For more information contact the lab at (225) 765-5155 or e-mail.
Definitions of Terms
Administrative Authority -- the board of health having jurisdiction.
Carcinogenic -- producing or tending to produce cancer.
Contaminant -- any physical, chemical, biological or radiological substance or matter in the water.
Distilled Water -- water that has been purified by passing through an evaporation-condensation cycle. It contains minute amounts of dissolved solids. Multiple distilling will further lower the dissolved solids.
Ion -- an electrically charged atom or group of atoms which results when one or more electrons are gained or lost, resulting in either a positive (+) or negative (-) charge. It can be made up of one element or a group of elements; for example, the calcium (Ca++) or bicarbonate (HCO3- ) ions.
Microgram/Liter (µg/l) -- a metric unit used to denote concentration of chemicals or other substances. n water, µg/l is equivalent to parts per billion (ppb) or 10-6 grams/liter.
Milligrams Per Liter (mg/l) -a unit used to denote concentration of chemicals or other substances in water. Mg/l and ppm are equivalent expressions of concentration (10-3 grams/liter).
Milliliter (ml) -- a unit of volume denoting one-thousandth of a liter; 3,784 ml equal 1 gallon.
Mutagenic -- capable of inducing a mutation, a relatively permanent change in genes (hereditary material).Parts Per Billion (ppb or µg/l) -- a unit used to denote concentration of chemicals or other substances. The unit implies one part of something in one billion parts of water or other substances; for example, one cent in $10,000,000, or 1 second in 32 years. The ppb and µg/l are equivalent expressions of concentration.
Parts Per Million (ppm or mg/l) -- a unit used to denote concentration of chemicals or other substances. The unit implies one part of something in one million parts of water or other substances; for example, one cent in $10,000 or 1 second in 12 days. The ppm and mg/l are equivalent expressions of concentration.