Laserfiche WebLink
<br />Public Laws 93-320 and 98-569 authorized the Secretaries of the <br />Department of the Interior and Department of Agriculture to enhance and <br />protect the quality of water available in the Colorado River fOI" use in the <br />United States aud the Repuulic of Mexico. Und~l Title I a desalting plant, <br />...... brine discharge canal, and other features wi 11 enable the Uni ted States to <br />~ deliver water to Mexico having an average salinity no greater than 115 parts <br />..,p..' per million (ppm) :: 30 ppm over the annual average salini ty of the Colorado <br />W River at Imperial Darn. <br /> <br />The Acts also authorized the Secretary of the Interior to construct five <br />salinity control units. Further, the Secretary was directed to undertake <br />research on additional methods to control salinity and to cooperate with the <br />Department of Agriculture and others. <br /> <br />In 1987, the average annual salinity level in the Colorado River at <br />Imperial Dam was 613 milligrams per Ii ter (mg/I.). Reclamation and Agricul ture <br />controls to date are removing about l..5~r 400 tonll.. of sal t annually from the <br />river system. The salinity at Imperial Dam is projected to reach an average <br />of 970 mg/L by the year 2010 without further salinity control. Peak <br />salinities are predicted to exceed 1,200 mg/L in some years. Over a million <br />tons of salt per year will need to be removed by the year 2010 to maintain <br />average salinity below tIle numeric criteria level of 879 mg/L at Imperial Dam. <br />Even at this level of salinity reduction, there will still be temporary <br />excursions above and below 879 mg/L due to the natural variations in climatic <br />conditions, hydrology, alJd water lIsage. <br /> <br /> <br />5-2 <br />