County water report

Somerset County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Somerset County, New Jersey.

Water grade

Water score

59.3

State rank

#12

of 21

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

194

26,987 recent measurements

Live streamflow

14%

Raritan River below Calco Dam at Bound Brook NJ

Water at a glance

Key Water Indicators for Somerset County

EPA SDWIS

Safety Grade

Score: 59.3 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

14% of mean

Raritan River below Calco Dam at Bound Brook NJ

EPA WQP

Monitoring Sites

194

26,987 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

59.3/100

Health violations

Health-based violations

Violations per 100K served

6.9

Population-normalized SDWIS rate

Data center water stress

Somerset County has 15 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #62 nationally by combining its water score with mapped data center density.

DCWSI

71.7

0-100 index

Facility count

90.3 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+9.3

Compared with US county median

Named operators

CyrusOneDigital RealtyPSE&G

Mapped facilities

365 Bridgewater NJ
Bridgewater
OSM
BNY Mellon Somerset
Facility details limited
OSM
CyrusOne Somerset
CyrusOne
OSM
FIDESSA
SOMERSET
EPA ECHO
Goldman Sachs
Bridgewater Township
OSM
OpenStreetMap data center 460182337
Digital Realty
OSM

9 more mapped facilities included in the county score.

See the Somerset County data-center report Review methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Somerset County.

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayHigh Impact

Your facility would use 55.3% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

55.3% of county industrial baseline0.65 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Somerset County’s Water

Drinking Water Quality Overview

EPA SDWIS

Somerset County's drinking water earned a C grade, scoring 59.3 out of 100. Over the past five years, EPA SDWIS records 4 health-based violations — a pattern that public water utilities are required to disclose and correct.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T14:15:00.000-04:00) puts Raritan River below Calco Dam at 169.0 cfs — well below its long-term average at 14% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Somerset County has extensive coverage with 194 active monitoring sites with 26,987 recent measurements on record. Predominant monitoring categories include physical and nutrient. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Somerset County

Water Verdict

Somerset County receives a fair water quality assessment with a grade of C and a score of 59.3 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring.

Violation Context

Somerset County has recorded 4 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 6.9 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges.

Consumer Guidance

Tap water in Somerset County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Somerset County's drinking-water compliance score is 59.3 out of 100. The violation rate for Somerset County is 6.9 per 100,000 people served. Residents who are immunocompromised, pregnant, or have young children may benefit from using an NSF 53-certified filter. Contacting your local utility for the current Consumer Confidence Report will confirm which specific violations were recorded and whether they have been resolved. With 194 active water-quality monitoring sites in Somerset County, data coverage is strong. A pipeline streamflow snapshot from the Raritan River below Calco Dam gauge is also available on this page.

Regional Context

Somerset County has water quality close to the average county in New Jersey. Its water score is within 3.6 points of the state average, meaning its overall water system performance is broadly representative of New Jersey as a whole.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Somerset County's water environment

Official EPA Resources for Somerset County

EPA How's My Waterway

Interactive watershed health data for Somerset County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Somerset County

Consumer Confidence Reports (NJ)

Annual water quality reports from utilities in New Jersey

Past 5 years

Water Quality Monitoring

Monitoring Sites

194

Active in the past 5 years

Measurements Recorded

27K

26,987 total readings

Most Measured

Physical
Nutrient
PFAS,Perfluorinated Alkyl Substance

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

169cfs

May 14, 6:15 PM UTC

vs Long-Term Average

14%

Well below typical

Primary Streamgage

Raritan River below Calco Dam at Bound Brook NJ

USGS site: 01403060
Drainage area: 785 sq mi
Long-term mean: 1,210 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

Household size

3 people · ~225 gal/day

Filter type

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Somerset County:D — Poor

Elevated violations or significant watershed impairment.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in Somerset County, New Jersey?

Somerset County, New Jersey has a drinking-water quality grade of C with a score of 59.3/100, based on EPA SDWIS compliance data. The county has 4 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.

Are there any water violations in Somerset County?

Somerset County has 4 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.

How much water-quality monitoring happens in Somerset County?

EPA's Water Quality Portal records 26,987 measurements from 194 monitoring sites in Somerset County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, PFAS,Perfluorinated Alkyl Substance. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.

What's happening with rivers in Somerset County right now?

Somerset County's primary USGS streamgage on the Raritan River below Calco Dam has a pipeline snapshot of 169 cubic feet per second — 14% of the long-term mean of 1,210.06 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.

How does Somerset County water compare to the New Jersey average?

Somerset County's SDWIS water quality score of 59.3/100 is higher than the New Jersey state average of 55.7. The average water quality grade across New Jersey is D, based on data from 21 counties with available SDWIS data.

Is tap water safe to drink in Somerset County?

Based on EPA SDWIS data, Somerset County has a water quality grade of C (59.3/100). This indicates moderate compliance. Some violations have been recorded but overall standards are maintained. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).

Does Somerset County have clean drinking water?

Somerset County has 4 health-based drinking water violations according to EPA records. With a water quality score of 59.3/100 and grade C, the county's drinking water has had some compliance issues but continues to be monitored. Note: drinking-water compliance speaks to the public water system, not necessarily to the watershed itself — check the Watershed Health zone for ATTAINS §303(d) data.

How does Somerset County rank for water quality in New Jersey?

Somerset County ranks #12 out of 21 counties in New Jersey by SDWIS water quality score (1 = best). With a score of 59.3/100, it falls in the middle third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Atlantic County

New Jersey

59.9

Water score

Burlington County

New Jersey

60.6

Water score

Camden County

New Jersey

57.5

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated May 14, 2026Reviewed by Evan Brooks, Data Editor

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