There are several contaminants that occur regularly in tap water and pose major health concerns to the community. In most of our cities, water undergoes a complex and often elaborated process of treatment likely including filtration and disinfection designed to protect public health however sometimes our municipal water infrastructure can fail, with tragic results such as the 1993 waterborne disease outbreak, when more than 400,000 citizens in Milwaukee, Wisconsin, were made ill by a parasite in their tap water called cryptosporidium. More recently in 1999, more than a 1000 people in upstate New York were stricken by E. coli.
Communities are strongly encouraged to learn more about their drinking water, and to support local efforts to protect and conserve the supply of safe drinking water, as well as, to upgrade the community system.
To protect public health, the Environmental Protection Agency (EPA) has established Maximum Contaminant Levels (MCL) for all pollutants. The MCL is the maximum allowable level of a contaminant that federal or state regulations allow in public water system and water suppliers must comply with.
Water suppliers most notify costumers about any violations above the MCL, as soon as practical but not later than 30 days after the system learns about the violation. Contact your water utility and ask them for the “annual consumer confidents report,” sometimes called “water quality report. They are required by the EPA to provide the report by July 1 of each year.
Follow there is a list of most common contaminants found in your water tap (microbiological, inorganic, organic, radioactive, disinfection byproducts), potential health effects, MCLs, and best available technologies (BATs) proven to be effective to treat water (EPA) and reduce health risk.
Microbiological Contaminants:
1. Cryptosporidium: Protozoan from human and animal fecal waste known to be a parasite in humans and animals which causes gastrointestinal illness (diarrhea, vomiting, cramps). - Surveys shown that Crypto is found in 80% of US surface water. – Crypto is resistant to chlorine and chloromine treatment, only finely tuned filtration (earth/sand) or state of the art disinfection such as ozone , ultraviolet light (UV), or membrane technology will kill Crypto once it is in the water. - The MCL established for Crypto is Zero (0 mg/L).
2. Total Coliform Bacteria: Bacteria present in feces which is not a health threat in itself, it is used to indicate whether other potential harmful virus, protozoa, or bacteria such as E. coli may be present in the water system. - Exposure to disease carrying pathogens may result in diarrhea, cramps, nausea, headaches, and fatigue. - The EPA found that even at low levels of coliform there have been many waterborne disease outbreaks reported and adopted the Total Coliform Rule (TCR) which sets the MCL at Zero (0 mg/L). – Disinfection (chlorine/chloromine), filtration, flush or upgrade pipes, and source protection to prevent contamination are effective treatment methods.
3. Turbidity: the measure of the cloudiness of water, often the result of mud or organic matter. – Turbidity is associated with disease-causing microorganism such as viruses, parasites, and some bacteria. – These organisms may cause nausea, cramps, and diarrhea. – Soil runoff is a source of contamination. - For systems that use conventional or direct filtration treatment, at not time can turbidity go higher than 1 NTU (unit of measurement) and samples for turbidity must be less than or equal to 0.3 NTU in at least 95 percent of the samples in any month. Systems that use filtration other than the conventional or direct filtration must follow state limits, which must include turbidity at no time exceeding 5 NTU.
4. Other microbiological contaminants regulated by the EPA and known to cause health problems are: Giardia lamblia, heterotrophic, and legionella.
Inorganic Chemicals:
1. Arsenic: comes from mining, industrial processes (paper, smelting, burning fuels), pesticides, and natural leaching or erosion from rocks. – It is known to cause cancer of the bladder, skin, and lungs. - MCL of 0.10 mg/L or 10 ug/L - Best Available Technologies (BATs) are: ion exchange, activated alumina, reverse osmosis, coagulation/filtration, lime softening (pH exceeding 10.5), electrodialysis reversal, and oxidation/filtration or iron removal (Fe:As greater than 20:1).
2. Chromium: natural occurring metal used in industrial processes (making steel, paint, rubber, wood preservatives) and from erosion of natural deposits.- Health effects range from skin irritation to kidney, liver, and nerve tissue damage. –The MCL is set to 0.1 mg/L – Effective treatment methods are: coagulation/filtration, ion exchange, reverse osmosis, lime softening.
3. Lead: is a heavy metal that usually enters the water system from the corrosion of pipes, and plumbing. – Lead is referred as the number one health threat for children in the U.S. (delay physical and mental development in children, kidney problems and high blood pressure in adults) –The EPA requires treatment to reduce pipe corrosion, this approach involves adjusting the PH upward to make water less acidic by adding chemicals such as lime or adding zinc orthophosphate which creates a film on the pipe walls that protect it from corrosion – The MCL 0.015 mg/L
4. Nitrates: are the product of fertilizers and human or animal waste. - Children could become seriously ill and develop blue baby syndrome which prevents their blood from holding oxygen. – The MCL is set a 10 mg/L. – Effective treatment methods are: ion exchange, reverse osmosis, electrodialysis.
5. Perchlorates: have been detected in many Southern California communities, it is a contaminant that usually comes from rocket fuel spills or leaks at military facilities. Perchlorates harm the thyroid and may cause cancer. – Effective treatments are: ion exchange, biological filtration, tailored granular activated carbon, and membrane separation. -Perchlorate is not regulated by USEPA in drinking water, but is an unregulated chemical drinking water contaminant listed on the USEPA's Contaminant. California has regulated this contaminant to maximum action level of 18 ug/L.
6. Other inorganic contaminants regulated by the EPA and known to cause health problems are: Asbestos, barium, beryllium, cadmium, copper, cyanide, fluoride, mercury, nitrite, selenium, thallium.
Organic chemicals:
1. Most organic chemicals enter the water sources through agricultural run off, they also volatize or evaporate forming volatile organic compounds (VOCs) which are redeposit in the ground with rain. – Organic chemical compounds are the cause of kidney / liver damage, reproductive difficulties, and increase the risk of cancer. – Effective treatments proven to remove VOCs are: granulated activated carbon (GAC) and reverse osmosis (RO). – MCLs can be checked at the EPA website. – Dichloroethylene (DCEs), Trichloroethylene (TCEs), Hexachlorocyclopentadiene (HEX), MTBEs, Perchloroethylene (PCEs), Atrazine.
Radioactive contaminants:
1. These contaminants are generally resulting from the decay of radioactive minerals in underground rocks and it is sometimes a by-product of the mining or nuclear industries. – They are carcinogenic contaminants and can cause severe kidney damage. – The most effective treatment to remove the majority of radioactive contaminants (radium, photon emitters, beta & alpha particles) is reverse osmosis (RO) except for Uranium that can also be removed with lime softening and enhanced coagulation followed by filtration. –MCLs can be checked at the EPA website.
Disinfection byproducts (DBPs):
1. Total triahalomethanes (TTHMs) and haloacetic acids (HAAs) are volatile organics contaminants (VOCs) resulting when chlorine & chloromines are used to disinfect drinking water. - Some researches by EPA indicate that certain byproducts of water disinfection are linked to increases in cancer incidence, kidney and central nervous system problems, reproductive effects. – The MCL for TTHMs is 80 ug/L and for HAAs 60 ug/L.
Communities are strongly encouraged to learn more about their drinking water, and to support local efforts to protect and conserve the supply of safe drinking water, as well as, to upgrade the community system.
To protect public health, the Environmental Protection Agency (EPA) has established Maximum Contaminant Levels (MCL) for all pollutants. The MCL is the maximum allowable level of a contaminant that federal or state regulations allow in public water system and water suppliers must comply with.
Water suppliers most notify costumers about any violations above the MCL, as soon as practical but not later than 30 days after the system learns about the violation. Contact your water utility and ask them for the “annual consumer confidents report,” sometimes called “water quality report. They are required by the EPA to provide the report by July 1 of each year.
Follow there is a list of most common contaminants found in your water tap (microbiological, inorganic, organic, radioactive, disinfection byproducts), potential health effects, MCLs, and best available technologies (BATs) proven to be effective to treat water (EPA) and reduce health risk.
Microbiological Contaminants:
1. Cryptosporidium: Protozoan from human and animal fecal waste known to be a parasite in humans and animals which causes gastrointestinal illness (diarrhea, vomiting, cramps). - Surveys shown that Crypto is found in 80% of US surface water. – Crypto is resistant to chlorine and chloromine treatment, only finely tuned filtration (earth/sand) or state of the art disinfection such as ozone , ultraviolet light (UV), or membrane technology will kill Crypto once it is in the water. - The MCL established for Crypto is Zero (0 mg/L).
2. Total Coliform Bacteria: Bacteria present in feces which is not a health threat in itself, it is used to indicate whether other potential harmful virus, protozoa, or bacteria such as E. coli may be present in the water system. - Exposure to disease carrying pathogens may result in diarrhea, cramps, nausea, headaches, and fatigue. - The EPA found that even at low levels of coliform there have been many waterborne disease outbreaks reported and adopted the Total Coliform Rule (TCR) which sets the MCL at Zero (0 mg/L). – Disinfection (chlorine/chloromine), filtration, flush or upgrade pipes, and source protection to prevent contamination are effective treatment methods.
3. Turbidity: the measure of the cloudiness of water, often the result of mud or organic matter. – Turbidity is associated with disease-causing microorganism such as viruses, parasites, and some bacteria. – These organisms may cause nausea, cramps, and diarrhea. – Soil runoff is a source of contamination. - For systems that use conventional or direct filtration treatment, at not time can turbidity go higher than 1 NTU (unit of measurement) and samples for turbidity must be less than or equal to 0.3 NTU in at least 95 percent of the samples in any month. Systems that use filtration other than the conventional or direct filtration must follow state limits, which must include turbidity at no time exceeding 5 NTU.
4. Other microbiological contaminants regulated by the EPA and known to cause health problems are: Giardia lamblia, heterotrophic, and legionella.
Inorganic Chemicals:
1. Arsenic: comes from mining, industrial processes (paper, smelting, burning fuels), pesticides, and natural leaching or erosion from rocks. – It is known to cause cancer of the bladder, skin, and lungs. - MCL of 0.10 mg/L or 10 ug/L - Best Available Technologies (BATs) are: ion exchange, activated alumina, reverse osmosis, coagulation/filtration, lime softening (pH exceeding 10.5), electrodialysis reversal, and oxidation/filtration or iron removal (Fe:As greater than 20:1).
2. Chromium: natural occurring metal used in industrial processes (making steel, paint, rubber, wood preservatives) and from erosion of natural deposits.- Health effects range from skin irritation to kidney, liver, and nerve tissue damage. –The MCL is set to 0.1 mg/L – Effective treatment methods are: coagulation/filtration, ion exchange, reverse osmosis, lime softening.
3. Lead: is a heavy metal that usually enters the water system from the corrosion of pipes, and plumbing. – Lead is referred as the number one health threat for children in the U.S. (delay physical and mental development in children, kidney problems and high blood pressure in adults) –The EPA requires treatment to reduce pipe corrosion, this approach involves adjusting the PH upward to make water less acidic by adding chemicals such as lime or adding zinc orthophosphate which creates a film on the pipe walls that protect it from corrosion – The MCL 0.015 mg/L
4. Nitrates: are the product of fertilizers and human or animal waste. - Children could become seriously ill and develop blue baby syndrome which prevents their blood from holding oxygen. – The MCL is set a 10 mg/L. – Effective treatment methods are: ion exchange, reverse osmosis, electrodialysis.
5. Perchlorates: have been detected in many Southern California communities, it is a contaminant that usually comes from rocket fuel spills or leaks at military facilities. Perchlorates harm the thyroid and may cause cancer. – Effective treatments are: ion exchange, biological filtration, tailored granular activated carbon, and membrane separation. -Perchlorate is not regulated by USEPA in drinking water, but is an unregulated chemical drinking water contaminant listed on the USEPA's Contaminant. California has regulated this contaminant to maximum action level of 18 ug/L.
6. Other inorganic contaminants regulated by the EPA and known to cause health problems are: Asbestos, barium, beryllium, cadmium, copper, cyanide, fluoride, mercury, nitrite, selenium, thallium.
Organic chemicals:
1. Most organic chemicals enter the water sources through agricultural run off, they also volatize or evaporate forming volatile organic compounds (VOCs) which are redeposit in the ground with rain. – Organic chemical compounds are the cause of kidney / liver damage, reproductive difficulties, and increase the risk of cancer. – Effective treatments proven to remove VOCs are: granulated activated carbon (GAC) and reverse osmosis (RO). – MCLs can be checked at the EPA website. – Dichloroethylene (DCEs), Trichloroethylene (TCEs), Hexachlorocyclopentadiene (HEX), MTBEs, Perchloroethylene (PCEs), Atrazine.
Radioactive contaminants:
1. These contaminants are generally resulting from the decay of radioactive minerals in underground rocks and it is sometimes a by-product of the mining or nuclear industries. – They are carcinogenic contaminants and can cause severe kidney damage. – The most effective treatment to remove the majority of radioactive contaminants (radium, photon emitters, beta & alpha particles) is reverse osmosis (RO) except for Uranium that can also be removed with lime softening and enhanced coagulation followed by filtration. –MCLs can be checked at the EPA website.
Disinfection byproducts (DBPs):
1. Total triahalomethanes (TTHMs) and haloacetic acids (HAAs) are volatile organics contaminants (VOCs) resulting when chlorine & chloromines are used to disinfect drinking water. - Some researches by EPA indicate that certain byproducts of water disinfection are linked to increases in cancer incidence, kidney and central nervous system problems, reproductive effects. – The MCL for TTHMs is 80 ug/L and for HAAs 60 ug/L.
