Deer Park Water Hardness & Quality Report (2026)

Deer Park, Texas, in Harris County — a major southeast Houston industrial and petrochemical community (Deer Park is directly adjacent to the Houston Ship Channel and one of the most concentrated petrochemical industrial complexes in the world — the Deer Park refinery and chemical plant complex includes one of the largest oil refineries in the United States, the Shell Deer Park Refinery, and numerous chemical manufacturing facilities), home of the San Jacinto Museum and Monument (the San Jacinto Monument in Deer Park — a 567-foot-tall column — is the tallest monumental column in the world, commemorating the Battle of San Jacinto where Texas won its independence from Mexico in 1836), a diverse Harris County community with a significant Latino-American and working-class industrial workforce population, and a historically significant southeast Houston community — draws its municipal water supply from the Trinity River (Lake Livingston) via the City of Deer Park Water Division. Water hardness in Deer Park measures 146 mg/L — classified as moderately hard.

Deer Park's moderate hardness reflects the southeast Harris County Gulf Coastal Plain Trinity River supply characteristics. The Trinity River supply at Deer Park–Harris County (same Trinity River Authority system as La Porte) undergoes City of Deer Park treatment with somewhat more effective lime softening than La Porte (190 mg/L), producing the moderate 146 mg/L.

At 146 mg/L, Deer Park residents encounter moderate scale accumulation. Monthly cleaning with citric acid solution is recommended. City of Deer Park Water Division consistently delivers water meeting all Texas TCEQ and EPA Safe Drinking Water Act requirements.