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"Lead may leach into the water from some kinds of home plumbing." United States Office of Water Environmental Protection WHS50A Agency EPA 570/19.91-400 June1991 Lead avind Coper Rule The Lead and Copper Rule was published in the Federal Register on June 7, 1991. It becomes effective on November 7, 1992. This rule requires treatment when lead and/or copper in drinking water exceeds certain levels: Lead enters drinking water mainly from the corrosion of lead -containing house- hold plumbing. Since lead.and capper contamination generally occurs after water has left the public water system, the best way for the water system operator to find out if customer water is contaminated is to test water that has come from a household faucet. This type of contamination can be prevented by controlling the corrosiveness of the water supply. If corrosion wntrol is not sufficient, lead - containing materials may have to be replaced. Water Quality Standards Maximum Contaminant Level Goals (MCLG): Water systems should try to supply water which is free of lead and has no more than 1.3 milligrams of copper per liter. This is a non -enforceable health goal. ' '' ' Action Levels: When the concentration of lead or copper reaches the MCLG Action Level action level in ten percent of the total number of required samples, the (mg1L) (mgrL) water system is required to carry out the water treatment requirements of Lead 0 0.015 the rule. These enforceable treatment requirements are described below.. Copper 1.3 1.3 Monitoring Requirements Lead/copper monitoring at high -risk homes. Water systems must complete a materials evaluation of their distribution system. and/or review other information to target homes that are at high risk of lead/copper contamination. Monitoring is to be conducted at the tap in these homes, with the number of tap -sampling sites based on the population served. One sample is required at each site. • Number of Initial Sampling Sites # at home System taps for size Pb/Cu 9 within dist. for other factors >100,000 100 50 10,001-100,000 60 10 3,301-10,000 40 3 501.3,300 20 2 101-500 10 1 5100 5 1 Additional monitoring for other factors affecting corrosion is required to optimize treatment and determine compliance with State lead/copper standards. Two types of systems must perform this monitoring under the following conditions: • Large systems serving more than 50,000 Dermas, regardless of the lead/copper levels in tap samples. • Smaller systems serving less than 50,000 persons, if the action levels are exceeded in tap samples. Two types of sampling sites are specified for this purpose: • Within the distribution system, with the number of sites based on population served (sites may be same as for coli-f- orm sampling). Two samples are required from each site. • One sample at each entry point to the distribution system. `..Pii6GcEdiicvtiortFaelSfieet5erirs�