County water report

Adams County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Adams County, Colorado.

Water grade

Water score

60.4

State rank

#14

of 64

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

33.8%

551 water bodies assessed

Monitoring sites

25,382 recent measurements

Live streamflow

41%

SOUTH PLATTE R AT 64TH AVE. COMMERCE CITY, CO.

Water at a glance

Key Water Indicators for Adams County

EPA SDWIS

Safety Grade

Score: 60.4 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

34% impaired

551 bodies assessed

USGS NWIS

Streamflow Snapshot

41% of mean

SOUTH PLATTE R AT 64TH AVE. COMMERCE CITY, CO.

EPA WQP

Monitoring Sites

25,382 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.

60.4/100

Health violations

Health-based violations

Violations per 100K served

6.2

Population-normalized SDWIS rate

Data center water stress

Adams County has 3 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #120 nationally by combining its water score with mapped data center density.

DCWSI

60.7

0-100 index

Facility count

61.1 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+10.4

Compared with US county median

Named operators

Google

Mapped facilities

Google - Thornton
Thorton · Google
OSM
LOCKHEED MARTIN - DENVER DATA CENTER
DENVER
EPA ECHO
LOCKHEED MARTIN PROPERTIES
DENVER
EPA ECHO

See the Adams County data-center report Review methodology

Data Center Water Budget Calculator

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

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayHigh Impact

Your facility would use 40.8% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

40.8% of county industrial baseline1.16 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 Adams County’s Water

Drinking Water Quality Overview

EPA SDWIS

Adams County's drinking water earned a C grade, scoring 60.4 out of 100. Over the past five years, EPA SDWIS records 44 health-based violations — a pattern that public water utilities are required to disclose and correct.

Watershed Conditions

EPA ATTAINS

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A substantial 33.8% of assessed waterways are impaired (186 of 551 water bodies) across Adams County's watersheds. The leading impairment causes are arsenic and escherichia coli (e. coli). Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T12:45:00.000-06:00) puts SOUTH PLATTE R at 85.7 cfs — well below its long-term average at 41% 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. Adams County has extensive coverage with 62 active monitoring sites with 25,382 recent measurements on record. Predominant monitoring categories include nutrient and inorganics, minor, metals. 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 Adams County

Water Verdict

Adams County receives a fair water quality assessment with a grade of C and a score of 60.4 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

Adams County has recorded 44 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 6.2 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges.

Consumer Guidance

Residents of Adams County should be aware that arsenic has been identified as a watershed impairment cause, and drinking-water compliance is at a C-grade level. Adams County's drinking-water compliance score is 60.4 out of 100. Long-term low-level arsenic exposure is a health concern; an NSF 58-certified reverse-osmosis filter is the most effective point-of-use option for arsenic removal. Reviewing your utility's Consumer Confidence Report will show whether treated water meets the EPA's 10 ppb MCL. The violation rate for Adams County is 6.2 per 100,000 people served. With 62 active water-quality monitoring sites in Adams County, data coverage is strong. A pipeline streamflow snapshot from the SOUTH PLATTE R gauge is also available on this page.

Regional Context

Adams County has better water quality than the average county in Colorado. Its water score is 21.7 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

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 Adams County's water environment

Watershed Impairment Causes (EPA ATTAINS)

1
Arsenic
Impairment cause per EPA Clean Water Act §303(d) assessment
2
E. coli (bacteria)
Impairment cause per EPA Clean Water Act §303(d) assessment
3
Cadmium
Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Adams County

EPA How's My Waterway

Interactive watershed health data for Adams County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Adams County

Consumer Confidence Reports (CO)

Annual water quality reports from utilities in Colorado

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

33.8%

186 of 551 assessed

Moderate concern

Top Impairment Causes

1
ARSENIC
2
ESCHERICHIA COLI (E. COLI)
3
CADMIUM

Source: EPA ATTAINS · Reporting cycle 2022

Impairment is determined under the Clean Water Act §303(d): a water body is impaired when it fails to meet state-defined quality standards for designated uses (drinking, recreation, aquatic life). Assessment coverage varies by state; counties without assessed water bodies are not shown.

Past 5 years

Water Quality Monitoring

Monitoring Sites

Active in the past 5 years

Measurements Recorded

25K

25,382 total readings

Most Measured

Nutrient
Inorganics, Minor, Metals
Physical

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

85.7cfs

May 14, 6:45 PM UTC

vs Long-Term Average

41%

Well below typical

Primary Streamgage

SOUTH PLATTE R AT 64TH AVE. COMMERCE CITY, CO.

USGS site: 06714215
Drainage area: 3,895 sq mi
Long-term mean: 209 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 Adams County:C — Moderate

Some violations or watershed impairment detected.

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 Adams County, Colorado?

Adams County, Colorado has a drinking-water quality grade of C with a score of 60.4/100, based on EPA SDWIS compliance data. The county has 44 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 Adams County?

Adams County has 44 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 healthy are the watersheds in Adams County?

EPA ATTAINS assessments under Clean Water Act §303(d) indicate 33.8% of Adams County's 551 assessed water bodies are classified as impaired (186 impaired). The top reported causes are ARSENIC, ESCHERICHIA COLI (E. COLI), CADMIUM. Impairment means the water body fails to meet state quality standards for at least one designated use — drinking water source, recreation, aquatic life, or fish consumption. Note: watershed impairment doesn't always translate to tap-water issues; treatment plants can remove most regulated contaminants.

How much water-quality monitoring happens in Adams County?

EPA's Water Quality Portal records 25,382 measurements from 62 monitoring sites in Adams County over the past five years. The most frequently measured characteristic groups are Nutrient, Inorganics, Minor, Metals, Physical. 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 Adams County right now?

Adams County's primary USGS streamgage on the SOUTH PLATTE R has a pipeline snapshot of 85.7 cubic feet per second — 41% of the long-term mean of 208.88 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 Adams County water compare to the Colorado average?

Adams County's SDWIS water quality score of 60.4/100 is higher than the Colorado state average of 38.7. The average water quality grade across Colorado is F, based on data from 64 counties with available SDWIS data.

Is tap water safe to drink in Adams County?

Based on EPA SDWIS data, Adams County has a water quality grade of C (60.4/100). 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).

Why does Adams County have so many water violations?

Adams County has 44 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.

How does Adams County rank for water quality in Colorado?

Adams County ranks #14 out of 64 counties in Colorado by SDWIS water quality score (1 = best). With a score of 60.4/100, it falls in the top 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

Broomfield County

Colorado

64.6

Water score

Boulder County

Colorado

56.1

Water score

Weld County

Colorado

55.2

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.

Watershed health and impaired-waterway data from the EPA ATTAINS Clean Water Act §303(d) assessments, state-reported and EPA-finalized.

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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