Document J36goNDQnoKkrrV6QepzGdBEZ

v/ i/ laay . UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION VI 1201 ELM STREET DALLAS, TEXAS 75270 * . October. 6, 1980 *' * Mr. Robert P. Van Dyke General' Manager City Water Board .1001 E.. Market St. P. 0. Box 2449 San. Antonio,. TX 78298 .... * *: Dear Mr. Van Dyke: Thank you for your letter of September 16, 1980 requesting information on the health risks associated with various pipe materials... ...... ............................... ' The Environmental Protection Agency shares your'concern. Studies ..are underway .in the following areas: ' _ * .Animal studies of health effects- of ingested asbestos; . , * Corrosive effects of various water qualities upon asbestos cement pipe and other pipe materials; * Leaching effects-of water on organic chemicals associated with various pipe materials. There is also a question of the chemicals used in pipe processing. Organic chemicals can be part of the pipe composition, or a residue . of a sealing or coating material. In addition to vinyl chloride, polynuclear aromatics, epichlorohydrin and polychlorinated biphenyls mentioned in the Region`IV response paper, tetrachloroethylene, a carcinogen, has also been detected as a contaminant in vinyl lined asbestos pipe. We agree with the opinions expressed in Region IV*s response paper, but caution that it is difficult, if not impossible, for EPA to be aware of the consequences of all processes used by the many manu facturers of pipe materials. Additionally, these manufacturing processes change, and a pipe material which was unsuitable several years ago may be the best choice today due to changes in technology. The reverse could also be the case. It is hoped that pipe manu facturers are becoming more aware of the health effect ramifica tions of their materials and processes. CAPCO JEN 0009991 EPA has not established a list of approved pipe materials, but a major section of the August 27, 1980 Amendments to the National Interim Primary Drinking Water Regulations deals with corrosion control. We are enclosing a copy of these amendments for your .information. . Although you state that your source water is non- aggressive, I suggest you review the corrosion controi section of the Amendments.- There are several indices for determining the corrosive potential of waters. Extensive studies have shown that these indices are not conclusive.indicators of corrosivity of all waters, due to complexity of the corrosion phenomenon and the differing corrosion mechanisms. Determination*of the corrosivity is extremely important in selecting the best pipe material. ... * i . * "Extensive evidence indicates that in systems having an Aggressive Index (AI) greater than 12.0, asbestos cement pipe does not dis solve and thereby release, asbestos fibers. Such material does represent the lowest health risk pipe material for non-aggressive waters according to the best information available to us at this time.';: I hope.this information is helpful to you. Should you require clarification or-more information, please contact Mr..Warren Norris, P.E., (214) 767-1762. Sincerely, Mac A. Weaver Acting Chief, Water Supply Branch (6AVIS) Enclosure CAPCO JEN 0009992