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-38- canal and lateral lining wo~ld combine many' old earthen laterals. Total salt load reductions are estimated to be 8,800' tons per year wi th about 7,700 tons. resulting from ~v lateral improvements. This unit has met the prerequisite ~ for construction. q) Virgin Valley (USDA). The area consists of about 0) 5,000 acres of irrigated lands in southern Nevada. The plan includes improvements of about B miles of off-farm oanals and laterals. Deep percolation reduotion for the planned actions is estimated to bel9,~00 acre-feet per year and salt load reductions would be 37,200 tons per year. While the Virgin Valley is independent of any Reclamation salinity oontrol project, the downstream impacts on Reclamation's Lower Virgin River Unit are to be evaluated by Reclamation and SCS colleotively. Otherwise, this unit has met the prerequisite ,for construction. The Virgin Valley,report was p~blished in March 1982. San Juan River lReclamation). San Juan River Unit investigations area includes the entire 23,000 square mile watershed from its headwaters in south-central Cqlorado to its mouth at Lake Powell. The drainage contributes approximat~ly one million tons of salt annually to the Colorado River Basin. The study area covers many thousands of square miles of natural resource lands as well as agricultural, municipal, and industrial areas which may oontribute controllable salt. Most of the natural source of salt is contributed 'by surfice runoff and ground water discharge from the Nacimiento Formation and Mancos shale. Many thousands of acres of vegetation along the streams and washes contribute to salt concentration. Irrigation projects, coal-fired powerplants, surface mining operations, oil and gas fields, and refinery operations also contribute to th~ river's salinity. Initial investigations indicate that the Hammond Project, Na\'sjo Indian Irrigation Project (NIIP), and the Hogback Irrigation Project (also a Navajo Indian project) are the principal irrigation sources of salt in the basin, with control on the Hammond Project being cost effective. Investigation will continue on these other areas. The Hogback Project contributes heavy salt loading but the mechanisms have not yet been identified. Other human caused salt contributions include abandoned gas or oil wells which have developed leaks at the wellhead, coolant discharges from powerplants, 'and wastewater from a petroleum refinery. Dirtv Devil River (Reclamation). The Dirty Devil River study area, in Emery and Wayne Counties in southern Utah, include the Muddy Creek, the Fremont River, Dirty Devil River, and the tributaries of Muddy Creek, Salt Wash, and South Salt Wash. The drainage contributes