Houston Water Quality Report
Houston's 2.3 million residents receive water from one of the largest municipal water systems in the US. While the water meets federal standards, many contaminants exceed health-based guidelines set by independent researchers.
Enter your Houston-area zip code to see what's in your tap water.
About Houston's Water Supply
Water Sources
The City of Houston draws its water primarily from surface water sources. Lake Houston and Lake Livingston provide the majority of the city's supply, supplemented by Lake Conroe and groundwater wells in some areas. This surface water undergoes extensive treatment before reaching your tap.
Treatment Process
Houston's water treatment facilities use a multi-step process including coagulation, sedimentation, filtration, and disinfection. The city uses chloramines (a combination of chlorine and ammonia) rather than free chlorine for disinfection. While chloramines are effective at maintaining water quality through the distribution system, they can create different byproducts than chlorine and are harder to remove with standard filters.
Water Hardness
Houston water is considered moderately hard, typically measuring between 8-12 grains per gallon (136-205 mg/L). Hard water contains elevated levels of calcium and magnesium, which can cause scale buildup in pipes, water heaters, and appliances. Many Houston residents choose to install water softeners to address hardness issues.
Municipal Utility Districts (MUDs)
While the City of Houston serves the urban core, many suburban areas are served by Municipal Utility Districts (MUDs). These independent entities may purchase water from Houston or operate their own wells. Water quality can vary between MUDs, which is why it's important to check the report for your specific zip code.
Houston Neighborhoods
Water quality can vary by neighborhood based on the serving utility and distribution infrastructure.
Frequently Asked Questions
Where does Houston's water come from?
Houston's water primarily comes from surface water sources including Lake Houston, Lake Livingston, and Lake Conroe. The City of Houston operates multiple treatment plants including the East Water Purification Plant and Northeast Water Purification Plant.
Does Houston use chlorine or chloramines?
Houston uses chloramines (a combination of chlorine and ammonia) for disinfection. While effective at killing bacteria, chloramines can affect taste and may create disinfection byproducts. They're also harder to remove with standard carbon filters.
Is Houston water hard or soft?
Houston water is moderately hard, typically ranging from 8-12 grains per gallon depending on your specific utility. Hard water can cause scale buildup in pipes and appliances and may affect soap lathering.
What contaminants are found in Houston tap water?
Common contaminants detected in Houston water include disinfection byproducts (TTHMs and HAAs), chromium-6, chloramines, arsenic, and various minerals. While most are within EPA legal limits, many exceed stricter health guidelines.
Is Houston tap water safe for babies?
While Houston water meets federal safety standards, infants may be more sensitive to certain contaminants. Parents often choose to use filtered water for formula preparation. Consult your pediatrician for specific guidance.
Ready to Check Your Water?
Enter your zip code to see exactly what contaminants are in your tap water and how they compare to health guidelines.