Zip 77001 · Houston, TX · 670 water systems · EWG data 2013–2023
Houston’s tap water has 105 contaminants, 33 above health guidelines.
- Water quality score
- 1out of 10Poor
Counts contaminants above an EWG health guideline, weighted by the harm the guideline protects against. 8 and above is good; 5 and above is fair.
- Above a health guideline
- 33of 105 found
- Linked to cancer
- 19above guideline
- In the SGS test programme
- 10of 105 found
Contaminants found here that SGS measured the Sans Water Purifier against.
Water data: EWG Tap Water Database, utility test results 2013–2023. Guidelines are EWG health guidelines set by federal or state public-health authorities; legal limits differ.
What’s in the water
Worst first. Contaminants Sans has no evidence for come last unless they are above their guideline. Levels are utility averages reported to EWG.
- PFAS
Level found: 4.15 ppt
Health guideline: 0.001 ppt
4,150×Removed by RO
Level found: 12.3 ppb
Health guideline: 0.004 ppb
3,069×Tested · >97.2%
Level found: 49.6 ppb
Health guideline: 0.06 ppb
827×Removed by RO
Level found: 71.4 ppb
Health guideline: 0.15 ppb
476×Removed by RO
Level found: 45.1 ppb
Health guideline: 0.1 ppb
451×Removed by RO
Level found: 8.07 ppb
Health guideline: 0.02 ppb
403×Removed by RO
Level found: 9.5 ppb
Health guideline: 0.03 ppb
317×Removed by RO
Level found: 16.5 ppb
Health guideline: 0.06 ppb
275×Removed by RO
Level found: 3.2 ppb
Health guideline: 0.02 ppb
160×Tested · 98.6%
Level found: 15 ppb
Health guideline: 0.1 ppb
150×Removed by RO
10 of 105 contaminants
Tested: measured by SGS on the Sans Water Purifier, the lab’s own figure. Removed by RO: listed by EWG as reduced by reverse osmosis, the purifier’s filter type. Not tested: neither.
Where this report applies
Utilities serving zip 77001. Map data © OpenStreetMap contributors.
What the Sans Water Purifier is tested to reduce
SGS, an ISO/IEC 17025 laboratory, measured the purifier’s reduction of 19 contaminants (Dec 2023 to Mar 2024). These are the worst in Houston’s water that were in that programme.
- Arsenic>97.2%Maximum measured reduction
- Hexavalent chromium98.6%Maximum measured reduction
- Nitrate>99.9%Maximum measured reduction
Figures are the laboratory’s own, measured under test conditions. Your tap water differs from the challenge water.