Document X735kzZb87DNVZK8E9XyXEVYd

E. I. DU Pont de Nemours & Company WILMINGTON, DELAWARE 19898 EMPLOYEE RELATIONS (DEPARTMENT 10:' US 'TOT 10: amt- February 4, 1985 L. T. FREELAND POLYMER PRODUCTS DEPARTMENT BEAUMONT ASBESTOS CEMENT (AC1 PIPE FOR WATER LINES This confirms our recent telephone conversation in which I indicated that the Safety and Occupational Health Division recommends that no new AC pipe be installed for potable water. Some pertinent information which we recognize in making this recommendation is Municipal water systems already contain a lot of AC pipe. A 1981 American City and County water main pipe survey reported that the proportion of AC pipe in place was 13.9 percent in 1980. It was estimated that 40 percent of pipe installed in 1980 was AC. The American Water Works Association standard permits the use of AC pipe except for water which is highly corrosive toward AC. Corrosivity is measured by a "aqgressivity index" which is a function of pH, total alkalinity and calcium hardness. However, some studies have indicated tfyat the AI is not appropriate for predicting fiber release from AC pipe because other factors, e.q., iron, silica, manqanese and zinc may contribute some protection against corrosion. Deteriorated AC pipe has been found in some municipal water mains. In at least one case, a scraping procedure used to clean the pipe interior DUP 0908885 SC-DP-08050