Laserfiche WebLink
<br />l'- <br />.:.:-.) <br />(\,1 <br /> <br />'. <br /> <br />.,....f <br /> <br />(,..'~ <br /> <br />Section 4. The Salinity Problem <br /> <br />AQUATRAIN <br />April 1983 <br /> <br />(. :' <br /> <br />Title II of that Act directed the Secretary of the Interior to construct <br />four salinity control units and to expedite completion of planning on <br />Colorado River Water Quality Improvement Program salinity control units <br />to maintain and protect water quality from further degradation in the <br />U.S. and Mexico. <br /> <br />Other pertinent legislation and agreements are: <br /> <br />1944 Water Treaty With Mexico. - Established a U.S. commitment to provide <br />1.5 million acre-feet of Colorado River water annually to Mexico. <br />The 1973 Minute No. 242 to the treaty specified that the amount of <br />water received at the Northern International Boundary would have an <br />average annual salinity of no more than 115 parts per million (+/-30 ppm) <br />above the level at Imperial Dam, the last major U.S. diversion point. <br /> <br />1972 Amendment, Federal Water Pollution Control Act (P.L. 92-500). <br />Interpreted by the Environmental Protection Agency (EPA) to require <br />numeric salinity standards and a plan for their implementation. Standards <br />were subsequently set by the Colorado River Basin States (represented <br />by the Colorado River Basin Salinity Control Forum), adopted by the <br />States, and approved by EPA. Criteria call for average annual concentra- <br />tions to range between 723 mg/L at Hoover Dam and 879 mg/L at Imperial <br />Dam. Standards are to be maintained while Basin States continue to <br />develop their water entitlements. <br /> <br />1980 Investigation of Water Resource Development (P.L. 96-375). _ <br />Authorized feasibility studies for ten of the saline sources identified <br />in earlier studies. The Secretary of the Interior has charged the <br />Bureau of Reclamation with identifying and implementing cost-effective <br />salinity control strategies for the Colorado River. The AQUATRAIN <br />Project is proposed as one of those strategies. <br /> <br />Salinity Control Alternatives <br /> <br />Reclamation's Colorado River Water Quality Improvement Program focuses <br />on reducing salt loading by controlling agricultural, point, and diffuse <br />salinity sources. Agricultural source control is being done in cooperation <br />with the U.S. Department of Agriculture. Work includes efforts to control <br />water leakage from canals and to limit water percolation through saline <br />soils caused by farm operations (percolation causes the water to leach <br />salt as it moves over and through the soil). Point source control involves <br />collection and treatment or disposal of flows from localized areas such <br />as mineral springs, geysers, and abandoned oil wells. DiffUse source control <br />includes watershed management, land treatment, and collection and disposal <br />of irrigation return flows. <br /> <br />Several alternatives to dispose of saline vater are being explored, including <br />injecting the saline water into deep wells, evaporating it from lined <br />ponds, improving farm operating procedures, lining canals, and processing <br />in desalination plants. <br /> <br />14 <br />