| Contaminants (Units) | Primary | Standards | Ideal Conditions | Major Sources In Drinking Water | Potential Health Effects From Ingestion of Water |
| MCLG | MCL | ||||
| Alkalinity (ppm) | NA | NA | 150-200 | Dissolved limestone or minerals | No health effects, but high alkalinity can contribute to scale buildup in plumbing |
| Arsenic (ppb) | 0 | 50 | 0 | Erosion of natural deposits; runoff from glass & electronics production, applications of herbicides and pesticides and some wood preservatives | Skin damage; circulatory systems problems; increased risk of cancer |
| Bacteria, Coliform | 0 | 0 | 0 | Naturally present in the environment | Used as an indicator that other potentially harmful bacteria may be present |
| Bacteria, Fecal and E.Coli | 0 | 0 | 0 | Human and animal fecal waste | Used as an indicator that other potentially harmful bacteria may be present |
| Calcium (ppm) | NA | NA | <50 | Limestone deposits, gypsum and gypsiferous shale | No health effects, but calcium in water can contribute to scale buildup in plumbing |
| Chloride (ppm) | NA | NA | <10 | Septic systems, road salt, fertilizers, animal waste, landfills or other waste | No health effects, but high chloride in water can speed up corrosion in plumbing |
| Conductivity | NA | Na | Roughly 2X the hardness in unsoftened water | Natural and human-made dissolved substances in water | No health effects, but changing conductivity over time may indicate changing water quality |
| Copper (ppm) | 1.3 | 1.3 | <0.5 | Corrosion of household plumbing systems; erosion of natural deposits | "Short term exposure - Gastrointestinal distress. Long term exposure - Liver or kidney damage.People with Wilson's Disease should consult their personal doctor if the amount of copper in their water exceeds the action level " |
| Fluoride (ppm) | 4 | 4 | 2.0 (Dental Health) | Water additive that promotes strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories | Bone disease (pain and tenderness of bones); Children may get mottled teeth |
| Hardness (ppm) | NA | NA | 150 | Dissolved limestone or minerals | No health effects, but hardness in water can contribute to scale bulid up in plumbing |
| Iron (ppm) | NA | NA | <0.3 | Natural deposits and corrosion of iron pipes | While iron does not cause major health problems, it does contribute to cosmetic and aesthetic effects in drinking water |
| Lead (ppb) | 0 | 15 | 0 | Corrosion of household plumbing systems; erosion of natural deposits | Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilities. Adults: Kidney problems; high blood pressure |
| Magnesium (ppm) | NA | NA | <30 | Dissolved limestone or minerals | No health effects, but magnesium in water can contribute to scale build up in plumbing |
| Manganese (ppm) | NA | NA | <0.05 | Occurs in domestic wastewater; industrial effluents and receiving streams | While Manganese does not cause major health problems, it does contribute to cosmetic and aesthetic effects in drinking water |
| Nitrate (measured as Nitrogen) (ppm) | 10 | 10 | <1 | Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits | Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. |
| Nitrite (measured as nitrogen) (ppm) | 1 | 1 | <1 | Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits | Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. |
| pH | NA | NA | 7.5 - 8.3 | Low values are often caused by lack of carbonate minerals from limestone and minerals in the aquifer. Some contaminant sources such as landfills may lower pH | Low pH may lead to corrosion of plumbing and leaching of metals (copper, lead, iron, etc) in water supply |
| Potassium (ppm) | NA | NA | <20 | Septic systems, road salt, fertilizers, animal waste, landfills or other waste; erosion from other deposits | People afflicted with some diseases require low potassium concentrations. |
| Sodium (ppm) | NA | NA | <30 | Specific systems, road salt, fertilizers, animal waste, landfills or other waste; erosion from natural deposits | People afflicted with some diseases require low sodium concentrations. |
| Sulfates (ppm) | NA | NA | <75 | Erosion of natural deposits, mine drainage waste | While sulfates do not cause major health problems, it does contribute to cosmetic and aesthetic effects in drinking water |
| Total Dissolved Solids (ppm) | NA | NA | Soil runoff | High turbidity levels are often associated with higher levels of disease causing viruses, parasites and some bacteria | |
| Turbidity (NTU) | NA | <5 | <5 | Soil runoff | High turbidity levels are often associated with higher levels of disease causing viruses, parasites and some bacteria |
| Zinc | NA | NA | <5 | Zinc most commonly enters water from deterioration of galvanized iron and dezincification of brass; industrial waste pollution | While zinc does not cause major health problems, it does contribute to cosmetic and aesthetic effects in drinking water |
MCLG = Maximum Contaminant Level Goal = The maximum level of a contaminant in drinking water at which no known or anticipated adverse effect of people would occur, allowing for an adequate margin of safety. MCLGs are non-enforceable public health goals.
MCL = Maximum Contaminant Level = The maximum permissible level of a contaminant in water delivered to a user of a public water system. MCLs are enforceable standards. The margins of safety in MCLGs ensure that exceeding the MCL slightly does not pose significant public health risks.
