Source: Lead can leach into drinking water from solder used on pipes, service lines, and fixtures. Current building codes limit the lead content of solder, but older plumbing may be a significant lead source.

In older homes, exterior lead-based paint may have flaked off, been ground into the soil, and leached into shallow wells. Certain industries and commercial enterprises such as battery shops may be an off-site source of lead in drinking water.

Health Effects: Lead is an extremely toxic metal that adversely affects many of the body's organs and systems. Those most severely impacted by lead ingestion are the central nervous system, the peripheral nerves, the kidneys, and hematopoietic system. Chronic lead exposure or subchronic exposures to high concentrations of lead cause a condition known as lead encephalopathy. The signs and symptoms of this condition are frequent headaches, restlessness, irritability, muscular tremor, mental dullness, and memory loss. The damage done by high lead exposure may persist even after treatment with chelating agents and result in epilepsy, hydrocephalus, and impaired mental functions.

Because their bodies are rapidly growing, children are particularly susceptible to lead poisoning at exposure levels much lower than those causing lead encephalopathy symptoms in adults. Even very low concentrations of lead can cause subtle behavior effects resulting from the retardation in mental development and motor skills.

Maximum Contaminant Level: The highest concentration of lead allowed in drinking water is 15 parts per billion.