EWG's Tap Water Database — 2021 UPDATE



Harris County Municipal Utility District 321

Aluminum is a metal released from metal refineries and mining operations. Too much aluminum exposure can impair children's brain development.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
201449.7 ppb182ND - 863.0 ppb
201532.9 ppb173ND - 444.0 ppb
201667.3 ppb292ND - 1,920.0 ppb
201748.9 ppb271ND - 1,320.0 ppb
2018110.2 ppb174ND - 694.0 ppb
2019126.3 ppb307ND - 3,390.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 600 ppb

The EWG Health Guideline of 600 ppb for aluminum was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to the brain and nervous system.

ppb = parts per billion

All test results

Date Lab ID Result