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County water report

San Juan County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for San Juan County, New Mexico.

Water grade

F

Water score

24.3

State rank

#9

of 32

Health violations

96

EPA SDWIS, 5-year lookback

Watershed impaired

25.7%

70 water bodies assessed

Monitoring sites

119

67,293 recent measurements

Live streamflow

50%

SAN JUAN RIVER AT SHIPROCK, NM

Water at a glance

Key Water Indicators for San Juan County

EPA SDWIS

Safety Grade

F

Score: 24.3 / 100

EPA SDWIS

Active Violations

96

5-year health-based lookback

EPA ATTAINS

Watershed Health

26% impaired

70 bodies assessed

USGS NWIS

Streamflow Snapshot

50% of mean

SAN JUAN RIVER AT SHIPROCK, NM

EPA WQP

Monitoring Sites

119

67,293 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

24.3/100

Health violations

96

Health-based violations

Violations per 100K served

93.2

Population-normalized SDWIS rate

Editorial analysis

Understanding San Juan County’s Water

Drinking Water Quality Overview

EPA SDWIS

San Juan County's water systems carry a failing grade, scoring 24.3 out of 100. Over the past five years, EPA SDWIS records 96 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 notable 25.7% of assessed waterways carry an impairment designation (18 of 70 water bodies) across San Juan County's watersheds. The leading impairment causes are escherichia coli (e. coli) and temperature. 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 2026-05-14T13:00:00.000-06:00) puts SAN JUAN RIVER at 951.0 cfs — well below its long-term average at 50% 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. San Juan County has extensive coverage with 119 active monitoring sites with 67,293 recent measurements on record. Predominant monitoring categories include inorganics, minor, metals and physical. 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 San Juan County

Water Verdict

San Juan County, New Mexico receives a poor water quality assessment with a grade of F and a score of 24.3 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans. Separately, EPA ATTAINS assessments cover 70 water bodies in the county's watershed, with 25.7% listed as impaired under the Clean Water Act — a source-water measure that is tracked independently of tap-water compliance. At the most recent USGS reading, local streamflow was below its historical mean at 50.1% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for San Juan County, New Mexico show 96 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 93.2 violations per 100,000 people served, this rate is high and signals significant water quality management issues. This compliance record sits alongside an unusually deep monitoring archive: 67,293 water-quality results have been logged across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

San Juan County has a Grade F compliance record with 96 health-based violations — among the highest levels in the country. San Juan County's drinking-water compliance score is 24.3 out of 100. The violation rate for San Juan County is 93.2 per 100,000 people served. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the New Mexico Department of Environmental Quality or Health can expedite utility compliance action. E. coli is the leading impairment cause in San Juan County's watershed. With 119 active water-quality monitoring sites in San Juan County, data coverage is strong. A pipeline streamflow snapshot from the SAN JUAN RIVER gauge is also available on this page.

Regional Context

San Juan County has water quality close to the average county in New Mexico. Its water score is within 2.6 points of the state average, meaning its overall water system performance is broadly representative of New Mexico 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 San Juan County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    E. coli (bacteria)

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 2

    Elevated temperature

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 3

    Polychlorinated Biphenyls (Pcbs)

    Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for San Juan County

EPA How's My Waterway

Interactive watershed health data for San Juan County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for San Juan County

Consumer Confidence Reports (NM)

Annual water quality reports from utilities in New Mexico

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

25.7%

18 of 70 assessed

Some impairment

Top Impairment Causes

  • 1

    ESCHERICHIA COLI (E. COLI)

  • 2

    TEMPERATURE

  • 3

    POLYCHLORINATED BIPHENYLS (PCBS)

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

119

Active in the past 5 years

Measurements Recorded

67K

67,293 total readings

Most Measured

  • Inorganics, Minor, Metals
  • Physical
  • Organics, Other

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

951cfs

May 14, 7:00 PM UTC

vs Long-Term Average

50%

Well below typical

Primary Streamgage

SAN JUAN RIVER AT SHIPROCK, NM

USGS site
09368000
Drainage area
12,900 sq mi
Long-term mean
1,899 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.

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Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for San Juan 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 San Juan County, New Mexico?
San Juan County, New Mexico has a drinking-water quality grade of F with a score of 24.3/100, based on EPA SDWIS compliance data. The county has 96 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 San Juan County?
San Juan County has 96 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 San Juan County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 25.7% of San Juan County's 70 assessed water bodies are classified as impaired (18 impaired). The top reported causes are ESCHERICHIA COLI (E. COLI), TEMPERATURE, POLYCHLORINATED BIPHENYLS (PCBS). 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 San Juan County?
EPA's Water Quality Portal records 67,293 measurements from 119 monitoring sites in San Juan County over the past five years. The most frequently measured characteristic groups are Inorganics, Minor, Metals, Physical, Organics, Other. 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 San Juan County right now?
San Juan County's primary USGS streamgage on the SAN JUAN RIVER has a pipeline snapshot of 951 cubic feet per second — 50% of the long-term mean of 1,899.01 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 San Juan County water compare to the New Mexico average?
San Juan County's SDWIS water quality score of 24.3/100 is higher than the New Mexico state average of 21.7. The average water quality grade across New Mexico is F, based on data from 32 counties with available SDWIS data.
Is tap water safe to drink in San Juan County?
Based on EPA SDWIS data, San Juan County has a water quality grade of F (24.3/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. 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 San Juan County have so many water violations?
San Juan County has 96 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 San Juan County rank for water quality in New Mexico?
San Juan County ranks #9 out of 32 counties in New Mexico by SDWIS water quality score (1 = best). With a score of 24.3/100, 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

Luna County

New Mexico

F

23.9

Water score

Roosevelt County

New Mexico

F

24.8

Water score

Lea County

New Mexico

F

23.0

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 Reviewed by Evan Brooks, Data Editor

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