Lead Concerns in drinking water.
Lead is a very, very toxic heavey metal that has been found in some water supplies around the country. Most noteably, Flint Michigan. According to KXAN Radio very small elevated levels have been found around central Texas.
The source of lead contamination is older plumbing pipes that water travels through on it's journey to your faucet. Many of the older pipes beneath the streets were manufactured with metal compounds containing lead and asbestos. Sometimes high levels of both. The copper plumbing and solder joints in older homes all contain lead.
But lead has not been a problem all these years and has not contaminated our drinking water. The water treatment facilities make the water alkaline, containing permanent and temporary hardness. With this chemistry, water creates protective layer of scale on the inside walls of all the pipes. Your water never contacts the walls of the pipe, and never picks up lead.
So...what happened in Flint Michigan? They changed water sources. The new source was an acidic, corrosive water that simply dissolved all the existing scale from the pipes allowing lead to leach into the water. They could have fixed the problem quickly, but they didn't.
The Maximum Contaminant Level Goal (MCLG) for a public water supply is Zero. Reverse Osmosis units are the most effeient tool that will effectively remove lead from your drinking and cooking water.
If you have a lead concern, purchase a Reverse Osmosis unit installed at the kitchen sink for drinking and cooking only. It will have a seperate faucet and provide the purist water imaginable.