Compton Water Hardness & Quality Report (2026)
Water Hardness
5.8 grains per gallon
Source
mixed
pH Level
7.7
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
244.9 mg/L
Est. Daily Cost
$0.26
energy & soap waste
Source: USGS Water Quality Portal · 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 Compton, your appliances are currently losing 13% efficiency due to mineral buildup.
| Appliance | In Compton | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6.3 yrs | 8.5 yrs | -26% |
| Washing Machine | 10 yrs | 12 yrs | -17% |
| Water Heater | 11.7 yrs | 15 yrs | -22% |
Regional Water Comparison
How Compton compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Compton, California | 98.5 mg/L | 4.7 ppt | 🟡 Moderately Hard | mixed |
| East Rancho Dominguez, California | 136.5 mg/L | 5.8 ppt | 🟠 Hard | mixed |
| Lynwood, California | 56.5 mg/L | 3.5 ppt | 🟢 Soft | mixed |
| Willowbrook, California | 164.5 mg/L | 6.7 ppt | 🟠 Hard | mixed |
| South Gate, California | 47 mg/L | 3.2 ppt | 🟢 Soft | mixed |
National Benchmark
How Compton compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Compton | 98.5 mg/L | 🟡 Low |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Compton home
Shop water softeners on Amazon.com →
What Makes Compton's Water Unique?
Local geology and source profile
Compton, California, in south Los Angeles County, receives its municipal water supply through the City of Compton Water Department, sourcing from the Central Basin groundwater pumped from the Los Angeles Coastal Plain alluvial aquifer in Los Angeles County (under Central Basin Watermaster management), and imported treated water from the Metropolitan Water District of Southern California (MWD). The Central Basin alluvial aquifer in the Compton area is recharged primarily by the San Gabriel River spreading grounds and the Los Angeles River system. Water hardness measures 98.5 mg/L — classified as moderately soft.
Compton's moderately soft supply reflects the Central Basin groundwater character in the south Los Angeles coastal plain zone. The Central Basin in the Compton area is recharged by the San Gabriel River — carrying soft snowmelt from the San Gabriel Mountains (Precambrian anorthosite, Mesozoic granodiorite, and Triassic Pelona Schist — all calcium-poor crystalline rock) via the spreading grounds at Whittier Narrows and Long Beach spreading basins. The MWD import fraction adds a blend of Colorado River and SWP water. The south LA coastal plain zone shows slightly higher hardness than the western San Gabriel Valley but remains in the moderately soft range due to the San Gabriel River recharge dominance.
With hardness at 98.5 mg/L, Compton residents experience light to moderate scale accumulation. Faucet aerators and showerheads develop deposits slowly — bi-monthly cleaning with citric acid solution is sufficient. Dishwashers produce clean glassware. City of Compton Water Department consistently delivers water meeting all California SWRCB and EPA Safe Drinking Water Act requirements.
Geology & Source: Mixed supply from the Central Basin groundwater and Metropolitan Water District (MWD) imports via the City of Compton Water Department — the Central Basin Los Angeles Coastal Plain alluvial aquifer recharged by San Gabriel River from San Gabriel Mountains granodiorite; the south-central LA coastal zone shows moderately soft supply at 98.5 mg/L in south Los Angeles County.