Superfund - A commonly used name for the federal Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).
Surface water - Water that flows on the surface in streams.
Terminal storage - A facility for storage of water near the end of a pipeline or canal. A facility to be used in times of water shortage in the CAP system (due, for example, to damage to the canal), that would supply water during a period of system repair or while wells are being reactivated.
Trichloroethylene (TCE) - A compound used most often for degreasing metal parts during manufacturing. Found as a pollutant in some Tucson-area groundwater, suspected of causing certain serious diseases.
Trihalomethanes (THMs) - Disinfection byproducts arising from the combination of chlorine with organic matter in the water.
Tertiary treatment - Post-secondary treatment of water designed to improve the quality of the water to the point where it can be put to a particular beneficial use.
Total dissolved solids (TDS) - A measure of the minerals dissolved in water. Up to 500 ppm is considered satisfactory and above that level increasingly unsuitable for domestic use. Tucson-area groundwater generally has TDS levels between 200 and 600 ppm; CAP water has TDS of about 700 ppm.
Transmissibility - The flow capacity of an aquifer measured in volume per unit time per unit width. Equal to the product of permeability times the saturated thickness of the aquifer.
Transmission line - A pipeline for transporting water.
Treated wastewater - The treated water that comes from a sewage treatment plant.
Treatment plant - A facility using various physical and chemical processes for treating water or wastewater. Treatment can include disinfection, filtration, adjusting the pH, adding corrosion inhibitors, and improving taste and odor.
Turbidity - The reduction of transparency in water due to the presence of suspended particles, or a cloudy appearance in the water. Increased turbidity raises the risk of water-borne pathogens growing and reproducing. Turbid water is therefore more difficult to disinfect.
Underground storage facility (USF) - A facility for artificial recharge of water supplies into an aquifer.
Underground Water Storage, Savings, and Replenishment Program (UWS) - A program administered by the ADWR to encourage the storage and/or use of renewable supplies. Rules governing permitting and operation of Underground Storage Facilities and Groundwater Savings Facilities are described under this program.
Vadose zone - The unsaturated zone lying between the earth’s surface and groundwater table.
Volatile organic compounds (VOCs) - Solvents used as degreasers or cleaning agents. They evaporate easily producing odors typical of gasoline, kerosene, lighter fluid or dry cleaning fluid. Some may be cancer-causing.
Water main - A large pipeline which transports water to smaller distribution lines which take water to homes and businesses.
Water table - The upper boundary of a free groundwater body, at atmospheric pressure.
Wellfield - A group of wells in a particular geographic area, usually operated by one entity.
Wetlands - An area that always has water at or near the surface. A natural wetland receives its water from a groundwater source and is also called a “cienega”. A constructed, or artificial, wetland usually receives its water from some wastewater source, either agricultural, industrial or municipal.

ACRONYMS