“Testing” can start with your senses: Assessing your water’s appearance, taste, and smell can all be good first steps. The best way to know for sure what’s going on with your water is to use a well water testing kit, which can tell you about the specific levels of bacteria, dissolved solids, and hardness of your water with precision. Have a pro test your well water at least once per year.

Professional testing for lead paint costs about $300, ranging from about $250 to $700, depending on the square footage, accessibility, and location. However, testing for lead paint with a DIY home-testing kit costs about $25, but doesn’t guarantee accurate results. The U.S. Environmental Protection Agency (EPA) recommends using a lead test kit that complies with the Lead Renovation, Repair, and Painting (RRP) Rule, which has strict criteria for ensuring a more accurate reading.

Common home surfaces to test for lead include:

• Walls

• Windows

• Doors

• Molding and trim

• Railings

According to the EPA, there is no safe level of lead in the blood, and so the maximum contaminant level goal (MCLG) for lead in water is zero. Even at low levels, lead is harmful to human health. It can also remain in the body and build up over time with repeated exposure.

Iron sediments from rusty pipes are not likely to cause health problems. While a glass of yellow-hued water is off-putting, it is generally safe to drink yellow water in the short term. But you certainly want to address this problem. In the meantime, switching to bottled water until the yellow water issue is resolved is a good idea.