more on risks of copper pipe used in residential plumbing, notice the second bullet below
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Lead in Water. The greatest risks seem to occur when the house water supply is "highly acidic" (see Chapter 7 - Force 5) or is allowed to sit in the pipes for a long period of time. Lead in the house domestic water system comes primarily from two sources: a.. Lead water supply pipes were used in houses until the 1920's. In some areas, they were used until the 1950's (see Chapter 7 - 7.1). b.. A 50% lead based solder was used to connect copper water supply pipes until 1988. per
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copper water supply piping may allow lead to leach into water supply. Check with Poison Control to see whether such a condition is believed to represent a problem in your area (S, A).