- Total Dissolved Solids (TDS): Total of all dissolved mineral constituents. The concentration of dissolved solids may affect the taste of water. Some dissolved mineral matter is desirable, otherwise the water would have no taste. The dissolved solids concentration is often referred to as the water’s salinity. Fresh water= 0-1,000 mg/L, slightly saline= 1,000-3,000, moderately saline= 3,000-10,000, very saline= 10,000-35,000.
- Nitrate, NO₃-N: Elevated levels can cause serious blood disorders in infants. Higher amounts may indicate leached surface-level contaminants from fertilizer, agricultural runoff, or septic systems.
- Sulfate, SO₄-S: Large concentrations of sulfate have a laxative effect on some people and, in combination with other ions, give water a bitter taste. Specific forms may form hard “scale”.
- Chloride, Cl: Often an indicator of above ground contamination from road salts or human/ animal waste. Large concentrations increase the corrosive capability of water and, in combination with sodium, produce a salty taste.
- Magnesium, Mg: May contribute to water hardness. Aids in over 200 processes within the human body, but laxative effects are possible higher concentrations.
- Fluoride, F: Historically controversial. According to the US EPA, “fluoride reduces incidence of tooth decay when optimum fluoride concentrations present in water consumed by children during the period of tooth calcification. Potential health effects of long-term exposure to elevated fluoride concentrations include dental and skeletal fluorosis. Effects are greater on children.”
- pH: A means of measuring hydrogen ion concentration. pH of 7.0 indicates a neutral solution, pH values less than 7.0 indicate acidity, and a pH greater than 7.0 indicates alkalinity. Water generally becomes more corrosive with decreasing pH; however, excessively alkaline water also may be corrosive.
- Total Alkalinity, CaCO₃: A measure of the capacity of water to neutralize acid. In almost all natural waters, alkalinity results from dissolved carbon dioxide species, bicarbonate and carbonate. Typically expressed as mg/L CaCO₃.
- Carbonate, CO₃: Contributes to total alkalinity, see above.
- Bicarbonate, HCO₃:Contributes to total alkalinity, see above.
- Total Iron, Fe: Problematic for food and beverage processing. May promote certain types of bacterial growth. At high concentrations, rust-colored sediment is possible along with reddish brown staining.
- Sodium, Na: Aids the human body in maintaining internal water balance (hydration). Concentrations over the recommended limit may contribute over 10% of total salt intake, potentially endangering those with certain heart conditions, circulatory or kidney diseases, or cirrhosis of the liver.
- Potassium, K: Presence of potassium in groundwater is generally minimal, however, elevated levels have known laxative effects on humans and may indicate contamination from sewage or livestock.
- Calcium, Ca: Generally the main cation in WI groundwater, contributes to hardness. Contributes to bodily health, elevated consumption levels are generally not a concern.
- Total Hardness, CaCO₃: Calcium Carbonate – May concern the water’s interaction with soap. Hardness results in “scum” formation when soap is added. Scale buildup may occur in boilers, water heaters, and pipes. Calcium, magnesium, bicarbonate and carbonate mineral species all can contribute to hardness.
Water that has a hardness less than 61 mg/L is considered soft. 61-120 mg/L= moderately hard, 121-180 mg/L= hard, greater than 180 mg/L= very hard.
- Electrical Conductivity: The water’s ability to conduct electrical current. Magnitude depends on concentration, kind, and degree of ionization of dissolved constituents. Useful in determining the approximate concentration of dissolved solids.
- Cations / Anions: The cation to anion (positive and negatively charged ions) ratio is important because it helps to validate the water test results. When a test is accurate, the sum of milliequivalents of the positive and negative ions should be nearly equal.
*Other future possibilities include: radium, arsenic, lead, atrazine (and other pesticides). Bacterial testing is also an option. Cast your vote at the “Everything” member level.