pH
Technically, pH is the expression of the intensity of the acid or base conditions of a solution. It is measured by the negative logarithm of the hydrogen ion concentration and is affected by carbon dioxide, carbonates, hydroxides, and other minerals in the water. Low pH means the water is acidic; high pH is associated with caustic alkalinity (basic). The pH of water is important in the treatment process, as it affects the reaction efficiency of chemicals used in the treatment process with water and influences corrosion of plumbing fixtures. The pH is adjusted by adding lime to the water. The pH of treated Charleston Water System water is around 8.3 SUs.

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Alkalinity
Alkalinity is the measure of water's capacity to neutralize a strong acid, or buffering capacity. Alkalinity is caused by alkaline salts, or carbonates and bicarbonates of calcium, sodium, and magnesium which are common in most water sources. Water that is high in alkalinity can have an unpleasant taste. As with pH, monitoring and adjustment of the alkalinity of water during the treatment process is essential for optimum reaction efficiency between chemicals used in the treatment process.

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Hardness
Hardness in water is determined primarily by the level of calcium and/or magnesium minerals present in water. High levels of these minerals results in "hard" water (because it's "hard" to produce a soap lather); low amounts produce "soft" water. "Hard" water can cause pipe scaling. Surface waters tend not to have a high concentration of minerals, and therefore tend to be relatively soft. Charleston Water System's water could be classified as moderately soft.

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Turbidity
Turbidity refers to the "cloudiness" of water, or the amount of very small suspended particles (silt, clay, algae, or other organisms) present in the water. Turbidity is measured using Nephelometric Turbidity Units (NTU), which is a measurement of the amount of light allowed to pass through a sample. Charleston Water System's uses both continuous on-line monitors and laboratory benchtop turbidimeters to precisely measure turbidity levels.

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Color
The color of water is caused by naturally occurring compounds from decaying vegetation and organic matter that enters source water through runoff, falling vegetation, etc. While discoloration is rarely a health concern, it is an aesthetic concern. Color is measured in platinum-cobalt units (PCUs). Charleston Water System's lab is equipped with state-of-the-art spectrophotometers to obtain exact color level measurements.

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