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Federal water data

County water report

Caroline County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Caroline County, Maryland.

Water grade

F

Water score

27.7

State rank

#22

of 24

Health violations

10

EPA SDWIS, 5-year lookback

Watershed impaired

57.9%

19 water bodies assessed

Monitoring sites

10

11,375 recent measurements

Live streamflow

24%

CHOPTANK RIVER NEAR GREENSBORO, MD

Water at a glance

Key Water Indicators for Caroline County

EPA SDWIS

Safety Grade

F

Score: 27.7 / 100

EPA SDWIS

Active Violations

10

5-year health-based lookback

EPA ATTAINS

Watershed Health

58% impaired

19 bodies assessed

USGS NWIS

Streamflow Snapshot

24% of mean

CHOPTANK RIVER NEAR GREENSBORO, MD

EPA WQP

Monitoring Sites

10

11,375 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.

27.7/100

Health violations

10

Health-based violations

Violations per 100K served

77.4

Population-normalized SDWIS rate

Editorial analysis

Understanding Caroline County’s Water

Drinking Water Quality Overview

EPA SDWIS

Caroline County's water systems carry a failing grade, scoring 27.7 out of 100. Over the past five years, EPA SDWIS records 10 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 57.9% of assessed waterways are impaired (11 of 19 water bodies) across Caroline County's watersheds. The leading impairment causes are total suspended solids (tss) and phosphorus, total. 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 2026-05-14T14:15:00.000-04:00) puts CHOPTANK RIVER at 34.7 cfs — well below its long-term average at 24% 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. Caroline County has moderate coverage with 10 active monitoring sites with 11,375 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 Caroline County

Water Verdict

Caroline County receives a poor water quality assessment with a grade of F and a score of 27.7 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.

Violation Context

Caroline County has recorded 10 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 77.4 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Drinking-water compliance in Caroline County is rated Grade F, reflecting significant health-based violations in the recent reporting period. Caroline County's drinking-water compliance score is 27.7 out of 100. The violation rate for Caroline County is 77.4 per 100,000 people served. An NSF 53 or NSF 58-certified filter is recommended for drinking and cooking water. Check the Consumer Confidence Report from your utility to identify the specific contaminants and required corrective actions — utilities are legally required to notify customers of violations. Total Suspended Solids (Tss) is the leading impairment cause in Caroline County's watershed. There are 10 active water-quality monitoring sites in Caroline County. A pipeline streamflow snapshot from the CHOPTANK RIVER gauge is also available on this page.

Regional Context

Caroline County has poorer water quality than the average county in Maryland. Its water score is 22.8 points lower than the state average, suggesting more challenges with contamination control or infrastructure than 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 Caroline County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Total Suspended Solids (Tss)

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

  • 2

    Phosphorus (excess nutrients)

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

  • 3

    Habitat Alterations

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Caroline County

EPA How's My Waterway

Interactive watershed health data for Caroline County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Caroline County

Consumer Confidence Reports (MD)

Annual water quality reports from utilities in Maryland

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

57.9%

11 of 19 assessed

Moderate concern

Top Impairment Causes

  • 1

    TOTAL SUSPENDED SOLIDS (TSS)

  • 2

    PHOSPHORUS, TOTAL

  • 3

    HABITAT ALTERATIONS

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

10

Active in the past 5 years

Measurements Recorded

11K

11,375 total readings

Most Measured

  • Physical
  • Nutrient
  • Inorganics, Major, Non-metals

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

34.7cfs

May 14, 6:15 PM UTC

vs Long-Term Average

24%

Well below typical

Primary Streamgage

CHOPTANK RIVER NEAR GREENSBORO, MD

USGS site
01491000
Drainage area
113 sq mi
Long-term mean
144 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

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Caroline County:F — Failing

High violation count or severe watershed conditions.

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 Caroline County, Maryland?
Caroline County, Maryland has a drinking-water quality grade of F with a score of 27.7/100, based on EPA SDWIS compliance data. The county has 10 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 Caroline County?
Caroline County has 10 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 Caroline County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 57.9% of Caroline County's 19 assessed water bodies are classified as impaired (11 impaired). The top reported causes are TOTAL SUSPENDED SOLIDS (TSS), PHOSPHORUS, TOTAL, HABITAT ALTERATIONS. 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 Caroline County?
EPA's Water Quality Portal records 11,375 measurements from 10 monitoring sites in Caroline County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Inorganics, Major, Non-metals. 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 Caroline County right now?
Caroline County's primary USGS streamgage on the CHOPTANK RIVER has a pipeline snapshot of 34.7 cubic feet per second — 24% of the long-term mean of 144.36 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 Caroline County water compare to the Maryland average?
Caroline County's SDWIS water quality score of 27.7/100 is lower than the Maryland state average of 50.5. The average water quality grade across Maryland is D, based on data from 24 counties with available SDWIS data.
Is tap water safe to drink in Caroline County?
Based on EPA SDWIS data, Caroline County has a water quality grade of F (27.7/100). 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 Caroline County have so many water violations?
Caroline County has 10 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 Caroline County rank for water quality in Maryland?
Caroline County ranks #22 out of 24 counties in Maryland by SDWIS water quality score (1 = best). With a score of 27.7/100, it falls in the bottom 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

Baltimore County

Maryland

F

26.7

Water score

Cecil County

Maryland

F

25.2

Water score

Talbot County

Maryland

F

32.1

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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