Tucson water mains are mostly asbestos cement and galvanized iron. By 1998-99, approximately 140 miles had been replaced. High salinity levels also can reduce crop yields and affect the growth rates of some landscape plants. Soil salinity is controlled by water quality and irrigation practices. Salt tolerance of vegetation varies greatly.
Citrus has low salt tolerance, but bermuda and rye grasses tolerate salts well.
U.S. Department of the Interior, Quality of Water - Colorado River Basin, 1997. CAP water has about 2.5 more TDS than Tucson groundwater, but most of the CAP salinity comes from salts that are benign to plants in the soil-plant environment. Dissolved gypsum and calcium carbonates, found in CAP water, are also common minerals in the semi-desert soils. Compared to groundwater, salt leaching estimates indicate that five to seven percent additional water may be needed to maintain the same salinity in soils when CAP water is used to water plants. Before Treatment Your water bill reflects the various costs of pumping and delivering water, repayment of bonds to lay pipes and build reservoirs, disinfection, reading meters and sending water bills, conservation education programs and administration.