05-10-1989 Council Agenda - Laserfiche WebLink

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EPA has claimed that their studies indicate that benefits that could result from reducing exposure to lead in public water systems go beyond the actual health factors attributable to reducing the risk of lead contaminination to the reduction in corrosion in service pipes and materials. A key point of the analysis, however, is the emphasis that the benefit EPA attributes to reduction of lead levels also assumes that EPA will reduce lead levels in tap water as well as monitor lead levels in the operation of water utilities. EPA has acknowledged that water distributed from water treatment facilities is usually not contaminated by high lead levels, but lead levels at the user tap can be much greater due to pipe and solder corrosion. Use of lead service pipes and mains is not generally a practice for most water systems, but the use of solder and related materials is more common generally, according to EPA. In fact, EPA has stated that "...lead concentrations in fully flushed water...even under corrosive conditions and with new solder, are generally below 50 ppb and usually below 20 ppb." In the same report, the agency declared that "...levels in fully flushed water (in community water supplies) and in distribution water are typically low." Further, EPA acknowledged that while corrosive waters have the highest levels of lead contamination, non - corrosive conditions can also have significant amounts of leaching of lead into the water supplies. The key factor in that phenomenon appears to the presence of new solder. After 5 years, the levels decline and "...are generally not elevated beyond 5 years... ", according to studies cited by EPA. Another problem with the data that concerns numbers of people trying to understand the nature of the threat from lead in drinking water is the relationship between water lead levels and blood lead levels. Studies used by EPA assume that there is a direct relationship; other studies have even suggested a higher probability of damage from exposure than a simple linear relationship. Since lead is not believed to have any beneficial effect on human health, elevated blood lead levels are viewed with particular concern. Even so, EPA acknowledged that there is still much uncertainty and lack of knowledge about lead health effects and agreed that other analyses of benefits of reducing lead levels in drinking water would be helpful in judging the reasonableness of the estimates developed by EPA. In the meantime, however, the costs of implementing standards mandated by regulations such as those proposed by EPA for lead, copper and pH levels in drinking water must be of concern to every responsible city official. Attachments Attached please find a sample letter and council resolution regarding the proposed EPA rules on lead and copper. Alter the sample wording to illustrate your city's particular circumstances. PAGE -15-