How does Calexico's water compare to the national average?

The USA national average is 151 mg/L. Calexico (≈ 180+ mg/L) is 189 mg/L harder than average.

Calexico Water Hardness & Quality Report (2026)

Water Hardness

very hard

180+ mg/L

Very Hard

estimated · not lab-verified

Source

reservoir

pH Level

8.3

neutral = 7.0

Lead

0.008 mg/L

✓ Below action level

TDS

592.2 mg/L

Est. Daily Cost

$0.91

energy & soap waste

Source: See methodology section below · Updated 2026

very hard180+ mg/LVery Hard · est.

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 Calexico, your appliances are currently losing 45% efficiency due to mineral buildup.

Appliance	In Calexico	Soft Water City	Efficiency Loss
Kettle	4.7 yrs	8.5 yrs	-45%
Washing Machine	6.6 yrs	12 yrs	-45%
Water Heater	8.3 yrs	15 yrs	-45%

Regional Water Comparison

How Calexico compares to its nearest neighbours

City	Hardness	Risk	Source
▶ Calexico, California	≈ 180+ mg/L	🔴 Very Hard	reservoir
El Centro, California	340 mg/L	🔴 Very Hard	reservoir
Imperial, California	≈ 180+ mg/L	🔴 Very Hard	reservoir
Brawley, California	≈ 180+ mg/L	🔴 Very Hard	reservoir
San Luis, Arizona	≈ 180+ mg/L	🔴 Very Hard	groundwater

National Benchmark

How Calexico compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Calexico	≈ 180+ mg/L	🔴 High
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Calexico's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 592.2 mg/LpH: 8.3

The City of Calexico Water Department provides drinking water to approximately 40,000 residents in Calexico, Imperial County, California, near the U.S.-Mexico border. The primary source is groundwater pumped from municipal wells in the Imperial Valley Groundwater Basin. Water is treated at the city's Water Treatment Plant, which applies filtration, disinfection, and blending before distribution through the local pipeline network serving the urban area.

The Imperial Valley subbasin lies within the Colorado River Basin watershed. Groundwater is recharged by limited local precipitation, agricultural return flows, and historical Colorado River seepage before modern diversions. The geology consists of thick Quaternary alluvial deposits of sand and gravel, underlain by Pliocene-Pleistocene sedimentary formations containing carbonate and evaporite minerals — including limestone, dolomite, and gypsum — that dissolve over time to impart a hard character typical of arid basin aquifers.

Very hard water promotes significant scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. Faucets and fixtures may develop white deposits, and soap lathering is poor, leading to dry skin and hair. Regular deliming of appliances is advised annually, and a water softener is strongly recommended to mitigate scaling and extend equipment life. pH typically ranges 7.5–8.5 due to mineral content; the utility applies chlorination, fluoridation, and blending for compliance. Naturally elevated total dissolved solids and possible nitrates from agriculture are notable characteristics of this supply.

Geology & Source: Imperial Valley Groundwater Basin — Pleistocene-Holocene alluvial sands, gravels, and silts over Tertiary sedimentary rocks with evaporites; limestone, dolomite, and gypsum dissolve to produce a hard desert basin supply

Other California Water Reports

El Centro

340 mg/L

🔴 Very Hard

Imperial

≈ 180+ mg/L

🔴 Very Hard

Brawley

≈ 180+ mg/L

🔴 Very Hard

San Luis

≈ 180+ mg/L

🔴 Very Hard

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Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Calexico's water safe to drink?

Yes. Calexico's water meets all federal safety standards. The hardness is ≈ 180+ mg/L (Very Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Calexico?

At ≈ 180+ mg/L (Very Hard), Calexico's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 45%.

How does Calexico compare to the USA average?

The USA national average is 151 mg/L. Calexico (≈ 180+ mg/L) is 189 mg/L above the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Calexico is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

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.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

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.

Measured

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.

Modelled

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.

Calculated

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.