Total Coliform Bacteria – Coliform bacteria occur naturally in the environment. The Maximum Contaminant level (MCL) for coliform bacteria is (0) zero total coliform colonies per 100 milliliters of water. If a water test indicates the presence of coliform bacteria, do not use the water for drinking or cooking. The next step is to identify and eliminate the pathway of contamination. This is usually done through chlorination.
Nitrate/Nitrite – The MCL for Nitrate is 10 milligrams per liter (mg/L) and the MCL for Nitrite is 1 mg/L. Nitrite is indicative of recent pollution and is usually accompanied by highly elevated fecal coliform bacteria counts. Nitrate is indicative of older pollution and is the result of organic nitrogen (fertilizers) or nitrite being weathered as it passes through the soil into the aquifer.
pH – An indicator of the acid or alkaline condition of water, the pH scale ranges from 0-14; 7 being neutral. The lower the pH is less than 7, the more acidic the water. The higher the pH is greater than 7, the more alkaline or basic the water. The Secondary MCL for pH is 6.4 – 10.0 Standard Units (SU). Acidic water tends to be corrosive while more alkaline water tends to affect the taste of the water.
Odor – The odor value should be less than (2) two and the Secondary MCL is (3) three. Odor is a parameter that may cause cosmetic or aesthetic effects such as discoloration or bad taste.
Sodium and Chloride – Sodium and Chloride are very common in nature and in the human diet. A guidance level for sodium is set at 100 mg/L. The MCL of 250 mg/L for chloride is intended to keep water from having a corrosive effect on plumbing. Higher levels of sodium and chloride can affect taste.
Hardness – The hardness level of water is determined by the amount of various salts and dissolved minerals in the water. While there is no MCL for hardness, DPH guidelines recommend softening when harness levels exceed 150 mg/L.
Apparent Color – Color values should be less than 15 SU. Color is a parameter that may cause cosmetic or aesthetic effects such as discoloration or bad taste.
Sulfate – Sulfates are part of naturally occurring minerals contained within soil and rock formations. The Secondary MCL for sulfate in drinking water is 250 mg/L. High sulfate concentrations in water can result in a “rotten egg” odor.
Turbidity – A measure of cloudiness, turbidity is used to indicate water quality and filtration effectiveness. Higher turbidity levels are often associated with higher levels of microorganisms in the water. There is no MCL for turbidity but it is recommended the turbidity level be less than (5) five Standard Units (SU).
Iron and Manganese – Iron and manganese are naturally occurring elements commonly found in groundwater and wells. While not considered a health hazard, the Secondary MCL for iron is 0.3 mg/L and for manganese it is 0.05 mg/L. Iron and manganese can result in staining of laundry and plumbing components, as well as offensive taste and appearance.