SAN FRANCISCO’S IMPURE WATER.

SAN FRANCISCO’S IMPURE WATER.

City Engineer Oransky, of San Francisco, Cal., after having subjected the water of the city to numerous analytical tests, claims that it is impure from its very source; he has likewise claimed that the amount kept in storage is not enough to avert a famine in the case of two dry seasons running. With respect to the latter point Mr. Oransky states that the three reservoirs have a joint capacity of 25,972,000,000 gallons,or equal to a supply for the city of 1,000 days, though the actual amount of water stored is only one-third of the capacity of the reservoirs, or about enough for 330 days. He says,with respect to the quality of the water; “The board of supervisors, by a resolution dated October 19, 1900, called for information relating to possible contamination of the water supplied to this city, and the report is the result of analyses and bacteriological examinations of waters from several sources of supply and from the mains of the Spring Valley Water company’s works, in which it is distinctly stated that the water now reaching San Francisco from Alumeda creek is intercepted in a gravel bed at Sunol. It is collected in a subsurface conduit in which it flows to a concrete bedrock dam erected near Sunol across Alameda creek. It passes longitudinally through this dam from the north to the south side of the creek to a screenhouse near Niles, where it enters the pipe which takes it across the bay of San Francisco. This water is pumped at Belmont into a force-main, which is connected with the large main from Crystal Springs reservoir to the city. At the concrete dam across Alameda creek facilities are provided for admitting the creek water direct, without nitrat ion, through the gravel bed into the conduit; but this arrangement is in the nature of an emergency device, to come into service only in case unforeseen conditions or accidents to the collecting system make it necessary. The watershed area tributary to Alameda creek above the point where Up water is intercepted is in the neighborhood of 600 square miles. The lands drained are agricultural and grazing lands and are in part densely populated. Near Pleasanton, at the lower end of Livermore valley, where a number of drainage lines converge, there was originally a large area of marsh land or lagoon. Livermore, Pleasanton, and Sunol, with an aggregate population of 4,000 to 5,000, arc located on the creek or its tributaries. These towns are without drainage systems and dispose of offal and waste by hauling to any convenient dumping place—generally the nearest water course. During harvest time beet-growing and hopraising bring toget her large numbers of laborers, who camp wherever convenient, often on the creek bankB. The use of lands on the banks of the creeks and canals for sheep and cattle pasturage at certain seasons of the year subject the water there flowing to all the dangers of contamination resulting from such use of open water conduits and lands adjucent thereto. The extent of drainage area tributary to Alameda creek above the Sunol dam is so great, and the uses to which the lauds can be put are so diversified that it seems out of the question to expect that possibility of contamination of the creek’s natural flow will ever be entirely removed, (adds the report). None of the results of chemical analysis are such as would indicate probable contamination. The results show a decrease of bacteria in the water as it approaches the city.”

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