LAWRENCE L ERMORE LABORATORY CANALbCoB.pre December 7, 1977 Dr. William W. Burr, Jr. Department of Biomedical and Environmental Research U. S. Department of Energy Washington, D. C. 20545 Dear Bill: This letter provides some additional information pertinent to the TWX I recently sent out informing you of the coliform levels in the Bikini cistern waters. During our recent Bikini trip, Charles Fraley, working for Bob Buddemeier, analyzed our groundwater samples for coliform content by the membrane filter technique. A sufficient number of blanks were run so I am confident the data is good. Two days before departing Bikini, we used the remaining sterilized containers to determine coliform in the water from 2 cisterns on Bikini Istand. We were very surprised to find concentrations in the water, at the school and building 8 cisterns, which exceeded 25 colonies/100 ml (see tables attached for all results). In addition, one of the two existing cisterns on Enyu was sampled and found to be highly contaminated as was the groundwater at the old Bikini well (HFH-7). The groundwater on Enyu shows anywhere from no contamination to a probable small number of colonies. I have attached copies of pertinent paragraphs from the Water Quality Standards regarding coliform levels in drinking water. A quick comparison of the table of data and the standards shows that the maximum acceptable microbiological levels are greatly exceeded at Bikini. I can only suggest a few possibilities to account for the contamination. The cisterns were constructed several years ago and are covered with a cement slab. There are large separations between the caps and the cisterns and alt of the cisterns have drain openings. Rats could easily enter the cistern through these openings. It is possible that one or more rats have died in the cisterns while seeking water during dry seasons. Bird, rat or pig droppings which find their way to the roofs (I may be stretching it a bit to consider pig droppings) could wash into the cisterns with the water during rain storms. Whatever the reason, contamination is evident and the Le focpete= A FHS y Ml 4, 1977-4630 RPyyi1 r Avg 1978 University of California P O.Box 808 Livermore, California 94550 O Telephone (415)447-1100 O Twx 910-386-8339 UCLLL LVMR 1012533