“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.

DIY lead testing kits are available, but they often lack the accuracy and reliability of professional services. Professional testing is recommended for more accurate results, as properly certified testers can provide a thorough analysis, clear recommendations, and the necessary legal documentation if remediation is required.

While not all homes built before 1978 contain lead paint, enough do, so you’ll still want to test to be on the safe side. The federal government banned lead-based paint for homes in 1978, but your state may have banned lead before that time. Around 24% of homes built between 1960 and 1977 contained lead-based paint, while 87% of homes built before 1940 contained lead-based paint.

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.