Several papers were presented which discussed the San Diego water reuse project. The system will apparently meet the criteria discussed earlier by the California Department of Health Services. Experimental work involving preparation for water reuse in San Diego were discussed by several presenters. The removal of MS-2 microphage varied from 2.1 logs in the microfiltration unit to 6 logs in the ozone treatment unit. Fouling status significantly effects MS-2 removal by microfiltration.
Clean membranes perform poorly.
Ultrafiltration provided 6 log removals of MS-2 after a compromised membrane was replaced. Combined chlorine on tertiary effluent was not particularly effective. A curve in the literature shows 0.8 log removal with CT of 700. Free chlorine CT of 55 produced a 6 log removal of MS-2. The MS-2 coliphage is a virus which is slightly smaller in size than the poliovirus and is cultured by determining the effect on coliform colonies.