A tap that smells like gasoline, paint thinner, or another chemical is unsettling, and it deserves a careful response. Stop drinking, cooking with, or making ice from that water until you know what is causing the smell. Open a window if the odor is strong, and keep children and pets away from the sink while you check. This guide is meant to help a St. Louis homeowner sort out the likely sources and decide who to call, not to tell you what the water contains.
Start With the Pattern
Before you test anything, notice how the smell behaves. Write down the answers to a few simple questions.
- Does the smell appear at every tap, or only one?
- Is it stronger on hot water, cold water, or both?
- Did it start suddenly, or has it been there for a while?
- Did anyone recently work on the plumbing, the water heater, or a fixture?
- Is anything stored nearby, such as fuel cans, paint, cleaners, or a garage that opens into the house?
A smell at one faucet that appeared after a repair points toward that fixture or its supply line. A smell at every tap that started on a particular day may point toward the water supply itself. A smell that is strongest in the basement or garage, and weak at the taps, may come from a spill or stored product rather than the water.
Check the Air Before Blaming the Water
Chemical odors often travel through a house. Walk through the garage, basement, and utility room and sniff near the floor drains, the water heater, and any area where products are stored. If the smell is clearly stronger in the air than at the sink, look for an open container, a leaking can, or a spill that has soaked into the floor. Clean up anything you find, using the product's own safety guidance, and keep the area ventilated.
If the smell is in the air and not in the water, running the tap will not change it. Test the water only after you have ruled out nearby sources.
Avoid Testing by Smelling or Heating
Do not put your nose directly over a running tap or a glass of water to judge the odor. Do not heat a sample to make the smell easier to detect. Heating can release more of the compounds into the air. If you need to describe the smell to someone else, fill a clean glass partway, cover it, let it sit for a short time, then uncover it briefly from a distance and note what you notice.
Get a Lab Test
A home kit will not reliably identify fuel or solvent compounds, and a smell alone does not tell you what is present or at what level. A certified laboratory can test for volatile organic compounds, which is the group that includes many fuel and solvent chemicals. Ask the lab which test panel fits your situation, and explain that you noticed a chemical odor so they can choose the right method.
Collect the sample the way the lab instructs. Use the container they provide, label it with the date and the tap you used, and deliver it promptly. If you can, take a sample from the cold tap that is closest to where water enters the house, and a second sample from a tap that shows the smell most strongly. Comparing the two can help show whether the problem is in the street supply or inside your plumbing.
Contact the Water Provider
Call your water provider in St. Louis as soon as you notice a chemical odor that is new or unexplained. Describe the smell, when it started, which taps it affects, and whether neighbors have reported anything similar. The provider can check its own system, look at recent work or incidents in your area, and tell you whether it has tested the supply. Ask them to note your report so there is a record.
Also look up the most recent water quality report for your area. It shows what the provider tests for and the results it has published. It does not replace a test of your own tap, but it gives you a baseline for comparison.
When to Treat It as an Emergency
Some situations need immediate action rather than a slow investigation. Call emergency services if you notice a strong fuel smell with headache, dizziness, or nausea in anyone in the home, if you see an oily sheen on the water, if the smell appeared suddenly and is getting stronger, or if neighbors on the same line report the same odor. Leave the house first, then call. Do not use electrical switches or open flames near a strong fuel odor.
What to Do Next
- Stop using the water for drinking, cooking, and ice until the cause is known.
- Check the garage, basement, and storage areas for spills or open containers.
- Note the pattern of when and where the smell appears.
- Arrange a certified laboratory test using the sample method the lab gives you.
- Report the odor to your St. Louis water provider and keep a record of the call.
A clear pattern, a quick check of the air, and a proper lab test will usually tell you more than any guess about the smell. Take each step in order, and bring in the right people as soon as the situation looks more serious than a simple plumbing problem.