waterbycounty
EPA SDWIS

Caroline County Water Quality

Caroline County, Maryland

Water Grade

F

Water Score

27.7

Violations

10

State Rank

#22

of 24 (1 = best)

EPA SDWIS Compliance

Drinking Water Quality

Water Quality Grade

F

Based on EPA compliance history and violation data

Water Score

27.7/100

Higher = better quality

Health Violations

10

Health-based violations

Violation Rate

77.4%

Systems with violations

Water Advisory: 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 1,000 residents, this rate is high and signals significant water quality management issues.

Consumer Guidance

Residents of Caroline County are advised to use filtered or bottled water for drinking and cooking until water quality improves. A reverse-osmosis or activated-carbon filter certified to remove the contaminants listed in the utility's Consumer Confidence Report is recommended. With 10 recorded health violations, staying informed about utility communications and boil-water notices is especially important. For long-term peace of mind, request your utility's latest Consumer Confidence Report and consider independent water testing if you have specific health concerns.

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.

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; "% of typical" compares the latest reading against that average.

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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 live streamflow 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 is currently reading 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 genuine real-time data, 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, 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 Logan Johnson, Founder & Data EditorUpdated Reviewed by Logan Johnson, Founder & Data Editor

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