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Colonia Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

7.8

neutral = 7.0

Lead

0.005 mg/L

✓ Below action level

TDS

237.1 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · 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 Colonia, your appliances are currently losing 20% efficiency due to mineral buildup.

ApplianceIn ColoniaSoft Water CityEfficiency 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 Colonia compares to its nearest neighbours

CityHardnessPFAS (ppt)RiskSource
Colonia, New Jersey≈ 120–179 mg/L9.2 ppt🟠 Hardreservoir
Avenel, New Jersey≈ 120–179 mg/L12.8 ppt🟠 Hardreservoir
Iselin, New Jersey≈ 120–179 mg/L50.3 ppt🟠 Hardreservoir
Woodbridge, New Jersey≈ 120–179 mg/L7.3 ppt🟠 Hardreservoir
Rahway, New Jersey≈ 120–179 mg/L22.3 ppt🟠 Hardreservoir

National Benchmark

How Colonia compares to the USA average

BenchmarkHardnessAppliance Risk
Colonia≈ 120–179 mg/L🟠 Moderate
USA National Avg151 mg/L🟠 Moderate
Scarsdale Top Rated0.02 mg/L🟢 None

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What Makes Colonia's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 237.1 mg/LpH: 7.8

Colonia, in Middlesex County, New Jersey, is served by Middlesex Water Company, which provides drinking water to 233,376 people across its service area. The utility has reported zero MCL violations as of the most recent data available, indicating full compliance with all enforceable drinking water standards. Specific treatment plant names and detailed reservoir or aquifer source data for the Colonia service area were not identified in available reports; residents may consult the Middlesex Water Company's annual Consumer Confidence Report or the EPA SDWIS database for complete operational details. Third-party assessments identify 8 contaminants above EPA health-based guidelines (MCLGs).

The Colonia area lies within the Raritan River watershed in Middlesex County, where the river drains the New Jersey Highlands underlain by Precambrian Reading Prong gneiss, and the Triassic Newark Basin featuring Brunswick Formation calcareous redbeds. These carbonate-rich sedimentary and metamorphic formations dissolve minerals into the water supply, contributing calcium and magnesium ions that produce a moderately hard character with elevated TDS levels typical of the Middlesex County region.

Hard water conditions in Colonia typically produce mineral buildup on fixtures, reduced soap effectiveness, and potential scaling in water heaters and dishwashers over time. Water softening may be beneficial for households in this area to prevent scale and extend equipment lifespan. The utility maintains zero MCL violations, confirming compliance with all enforceable standards. However, 8 contaminants have been identified above EPA health-based guidelines (MCLGs) by third-party databases; a certified water filter is recommended for households concerned about these contaminants.

Geology & Source: Raritan River watershed — Precambrian Reading Prong gneiss of the New Jersey Highlands and Triassic Newark Basin Brunswick Formation calcareous redbeds; carbonate redbeds dissolve to produce moderately hard water

Other New Jersey Water Reports

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Frequently Asked Questions

Is Colonia's water safe to drink?
Yes. Colonia's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.
Do I need a water softener in Colonia?
At ≈ 120–179 mg/L (Hard), Colonia'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 20%.
How does Colonia compare to the USA average?
The USA national average is 151 mg/L. Colonia (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Colonia 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

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.

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.