Learn about the different types of contaminants that might put your family at risk.
- negative charge
- The electrical charge on an electrode or ion in solution due to the presence of an excess of electrons.
- negative head
- A condition of negative pressure or partial vacuum.
- negative pressure
- A pressure below that of the surrounding atmospheric pressure at a specific point; a partial vacuum.
- nephelometric turbidity unit (NTU)
- An arbitrary unit of measuring the turbidity in water by the light scattering effects of fine suspended particles in light beam.
- In electrical systems, the term used to indicate neither an excess nor a lack of electrons; a condition of balance between positive and negative charges. In chemistry, the term used to indicate a balance between acids and bases; the neutral point on the pH scale is 7.0, indicating the presence of equal numbers of free hydrogen (acidic) and hydroxide (basic) ions.
- In general, the addition of either an acid or a base to a solution as required to produce a neutral solution. The use of alkaline or basic materials to neutralize the acidity of some waters is common practice in water conditioning.
- A common designation for alkaline materials such as calcite (calcium carbonate) or magnesia (magnesium oxide) used in the neutralization of acid waters.
- noncarbonated hardness
- Water hardness due to the presence of compounds such as calcium and magnesium chlorides, sulfates, or nitrates; the excess of total hardness over total alkalinity.
- normal solution
- A solution containing a gram equivalent weight of a substance in a liter of solution.