In February 2000, the U.S. Court of Appeals affirmed a lower court ruling that the US Bureau ofReclamation must provide drainage service to the irrigators in the San Luis Unit whichcomprises an area of more than 700,000 acres. Reclamation recently completed a yearlongeffort to evaluate various alternatives for the treatment and disposal of about150,000 acre-ft/year of drainwater, that is 134 million gallons per day if spread outevenly throughout the year. The final preferred alternative consists of the followingcomponents:drainwater collection and reuse;biological treatment;desalination; and,disposal to evaporation ponds.The next phase of the project is a feasibility study which consists of field investigationsand preparation of detailed designs and cost estimates. The feasibility study will be usedto obtain congressional authorization and funding to implement drainage service andcomply with the court order.Water quality analyses and projections of future water quality indicate there will besubstantial challenges for desalting the drainwater. The total dissolved solidsconcentration is expected to range between 5,000 and 20,000 mg/L across the Valleyover the 50-year planning period. Recovery will be limited by hardness which exceeds2,000 mg/L as CaCO3 at some locations. The drainwater contains boron (
Product Details
Edition: Vol. - No. Published: 03/05/2003 Number of Pages: 10File Size: 1 file , 480 KB