Letter - The Metropolitan Water District of Southern California

Letter: From R.A. Skinner, General Manager and Chief Engineer, The Metropolitan Water District, July 13, 1964, page 6(3) In the event of interruption in the supply of water through any of the long aqueducts involved in serving the Southern California coastal plain, an auxiliary localized source would afford a longer time for restoring service through the aqueduct without hardship in the affected service area. (4) If it should develop that a suitable plant site could be acquired in a coastal area within economic distance for transport of desalted water to the Diemer Filtration Plant, such an arrangement would afford a possible basis for omitting softeners from the plant expansion, obviating an expenditure of about $15 million for the softener units, salt unloading facilities, and waste water disposal pipe line extending from the plant to the ocean. For example, if as much as 150 mgd of desalted water were made available for mingling with filtered Colorado River water of 350 ppm hardness, the resulting hardness of mingled water would be reduced to 220 ppm when the combined discharge rate is 400 mgd, equal to the ultimate designed capacity of the plant. Subsequently, when the plant influent consists in part of State project water, the hardness of the mixture of desalted water and filtered water would be further reduced. Also, the mixed effluent, being lower in total dissolved solids, would be more suitable for injection 6.Epson Perfection 4870 Photo, 400 dpi, 8 bit, 2,614,159 byte