Clear water can still carry lead. Lead does not show up as color, cloud, or taste, so a tap that looks fine tells you nothing about it. The useful question is whether your house or the pipe feeding it could be a source at all. You can answer that with records and a short list of checks before you pay for anything.

Start with the age of the house and the service line

Look at when the home was built and whether plumbing was replaced or added later. Older construction is more likely to include lead materials. The service line, the pipe that runs from the street main to your house, is the part most often overlooked. Your water utility keeps records of service line materials and can tell you what it has for your address. Ask for the material on the utility side and on your side, and ask whether the record is confirmed or estimated. An estimated record is a reason to test, not a reason to relax.

Check the fixtures and the old solder

Solder joints on older copper pipe, and some brass faucets, valves, and fittings, can release lead into water. Repairs made decades ago often left the same kind of joints. You cannot see lead in solder from outside the wall, so treat the age of any plumbing work as the clue. If you are renovating, write down the materials used in the new work too, so the next owner or the next test has a record to work from.

Know what a lead test should measure

Use a laboratory certified for drinking water testing, and ask for the result as a number with its units. Ask for two samples. One should be a first-draw sample, taken from water that has sat in the pipes for several hours, since that shows what the plumbing is adding. The other should be taken after the tap has run for a few minutes, which shows the water coming in. Ask the lab for its sampling instructions and follow them exactly, because a result is only useful if the sample was collected the same way the lab expects.

Decide what a result means for you

If a test finds lead, talk with your doctor or your local health department about who in the home should be checked, especially young children and pregnant people, who are most affected. Then plan the fix. Replacing the lead pipe or fixtures is the lasting answer. While that is planned, a point-of-use filter can reduce exposure at the tap you use for drinking and cooking. For a filter, choose a product certified specifically for lead reduction, and confirm that claim on the product's own certification listing. Ask the maker how long the cartridge lasts for lead, because the cartridge runs out on capacity, not on a calendar date alone.

For general background on the water supplied across the county, the St. Charles County report card gives a broad picture. It does not replace a test of your own plumbing, which is the only way to learn what your tap delivers.