Laserfiche WebLink
<br />_ _ r <br />,. ','" \J <br />..;,--,0 <br /> <br />OPERATION AND MAINTENANCE <br /> <br />39 <br /> <br />use of activated silica and alum, and with ferric sulfate as a <br />substitute for alum, are being continued. <br />Laboratory investigations have been continued to find the most <br />satisfactory means for conditioning the water to prevent scaling <br />and minimize corrosion. A program of adding sodium hexameta- <br />phosphate to the finished water delivered into the Orange County <br />feeder was initiated in October 1951. Within the next fiscal year, <br />the line will be examined and carrying capacity tests will be con- <br />ducted to determine the efficacy of this treatment in removing <br />previously deposited scale and in reducing the deposition of new <br />scale, Work was continued to establish the best methods for treat- <br />ing the feedwater for the new low pressure steam boiler which was <br />jnstalled during the year. A treatment procedure was worked out <br />and will be put into practice when the boiler is ready for service. <br />Preliminary laboratory studies were initiated to devise a <br />method for dissolving the salt completely from the residue left in <br />the salt storage basins when these are taken out of service for <br />cleaning. The results of these tests may be useful if a unit of this <br />type is subsequently designed for plant use. <br />A small pilot unit for investigation of continuous ion exchange <br />softening was designed, and construction of the unit was more <br />than 50 per cent completed by the end of the fiscal year, <br /> <br />'I <br /> <br />Radiological sill-dies <br />lnvestigations to safeguard the quality of Colorado River water <br />in the event of radioactive contamination, either as a result of <br />atomic bombing, or radiological warfare, 01' peacetime disposal of <br />---radioactive w.~stes, were continued, To facilitate detection or suer-- <br />contaminants, it is necessary to determine accurately the ex- <br />tremely low level of radioactivity naturally present in waters prior <br />to possible contamination. The normal alpha and beta-gamma <br />activity in water samples collected regularly from Lake Mead, <br />along the Colorado River aqueduct, and at the softening and filtra- <br />tion plant, is being measured by means of special instruments, con- <br />sisting of Geiger-Muller and proportional counters, designed for <br />this purpose. Water treatment methods which can be adapted to <br />remove effectively harmful radioactive substances from District <br />water are being studied. Radiological surveys of the Lake Mead <br />area and other areas adjacent to the Colorado River watershed <br />were made before and after the atomic weapons testing program <br />in Nevada, in cooperation with the California State Office of Civil <br />