Temple City Water Hardness & Quality Report (2026)
Water Hardness
~120–179 mg/L
Hardestimated · not lab-verified
Source
mixed
pH Level
7.9
neutral = 7.0
Lead
0.006 mg/L
✓ Below action level
TDS
349.3 mg/L
Est. Daily Cost
$0.40
energy & soap waste
Source: See methodology section below · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Temple City, your appliances are currently losing 20% efficiency due to mineral buildup.
| Appliance | In Temple City | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6.8 yrs | 8.5 yrs | -20% |
| Washing Machine | 9.6 yrs | 12 yrs | -20% |
| Water Heater | 12 yrs | 15 yrs | -20% |
Regional Water Comparison
How Temple City compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Temple City, California | ≈ 120–179 mg/L | 5.6 ppt | 🟠 Hard | mixed |
| Rosemead, California | ≈ 180+ mg/L | 0 ppt | 🔴 Very Hard | reservoir |
| East San Gabriel, California | ≈ 180+ mg/L | 6.3 ppt | 🔴 Very Hard | mixed |
| Arcadia, California | ≈ 180+ mg/L | 29.2 ppt | 🔴 Very Hard | groundwater |
| El Monte, California | ≈ 180+ mg/L | 15.6 ppt | 🔴 Very Hard | groundwater |
National Benchmark
How Temple City compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Temple City | ≈ 120–179 mg/L | 🟠 Moderate |
| USA National Avg | 151 mg/L | 🟠 Moderate |
| Scarsdale Top Rated | 0.02 mg/L | 🟢 None |
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What Makes Temple City's Water Unique?
Local geology and source profile
Golden State Water Company provides water service to approximately 109,422 residents in Los Angeles County, California, serving Temple City and surrounding communities. The utility sources water from the San Gabriel Valley groundwater basin, supplemented by imported surface water from regional suppliers. Treatment employs standard municipal processes including coagulation, sedimentation, filtration, and chlorination to meet all applicable state and federal drinking water standards. Annual Consumer Confidence Reports are available to customers detailing water quality parameters and treatment processes for the service area.
The San Gabriel Valley sits atop a productive groundwater basin formed by alluvial deposits from the San Gabriel River and tributary streams. The subsurface geology consists primarily of Quaternary-age sand, gravel, silt, and clay interspersed with older Tertiary marine and terrestrial sediments. These formations contain naturally occurring dissolved minerals, particularly calcium and magnesium carbonates, characteristic of Southern California's semi-arid hydrogeology and contributing to the region's moderately hard water supply.
Temple City's water is classified as moderately hard, so residents may notice some scale buildup on fixtures and appliances over time, though effects are less severe than in hard-water areas. Dishwashers, water heaters, and washing machines may accumulate mineral deposits and experience reduced efficiency. A water softener is recommended for households with sensitive skin or concerns about scale buildup. Regular descaling of appliances and use of chelating agents in cleaning products can help manage mineral-related issues. The tap water meets all EPA Maximum Contaminant Level Goals (MCLGs), with zero MCL violations recorded since 2023.
Geology & Source: San Gabriel Valley groundwater basin — Quaternary alluvial clay, silt, sand, and gravel over older Tertiary sediments deposited by the San Gabriel River; calcium and magnesium carbonates yield moderately hard water
Other California Water Reports
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Frequently Asked Questions
Is Temple City's water safe to drink?
Do I need a water softener in Temple City?
How does Temple City compare to the USA average?
Data Sources & Methodology
Water quality data for Temple City is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.
Water Hardness
Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.
pH
Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.
TDS — Total Dissolved Solids
Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.
PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances
EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.
Lead
Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.
Appliance Lifespan
Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.