WaterVerge

Is Cosby, MO Tap Water Safe to Drink?

Graded A+. lithium was detected — within EPA limits, but worth understanding. Here's the full picture. What to do next ↓

4K residents served 1 water system PWSID: MO1024005
Overall Score
98.2 / 100
Violations
None active
Last Updated
May 2026
Source
Purchased ground water
#1 of 509 in Missouri Top 0% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
A+GRADE
Water Quality Grade
98.2/100
waterverge.com
A+ 98.2/100

Cosby, MO — Water Quality Report

Cosby's drinking water received a grade of A+ (98.2 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 3,580 residents using purchased ground water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 2 violations on record, including 0 health-based violations. All violations have been resolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Cosby's water

Cosby ranks #1 out of 509 cities in Missouri for water quality, placing it one of the best in the state.

Cosby purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

Quality Breakdown

Water quality score

See methodology →
98.2 out of 100 Grade A+
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
44.9/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
18.2/20
A
1 PFAS compound detected.
Compliance
10/10
A
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Purchased ground water.
Water Safety

Is Cosby, MO water safe to drink?

Generally Safe

Based on EPA testing data, Cosby's tap water is generally safe to drink. The water system earned a grade of A+ (98.2/100), meeting federal drinking water standards across key contaminant categories. The city's 1 water system serves approximately 3,580 residents using groundwater (wells).

None
Violations
0.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
10 events
Disaster History

Recent water quality updates for Cosby

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Cosby's water quality assessment. Grade: A+ (98.2/100).

Disaster
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING

Federal disaster declaration (FEMA DR-4435). Flood event — may have impacted local water infrastructure.

Disaster
FLOODING

Federal disaster declaration (FEMA DR-4012). Flood event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

Contaminants: Coliform (TCR).

Violation
1 drinking water violation recorded

Contaminants: Coliform (TCR).

Key contaminant findings

Based on the most recent EPA sampling data for Cosby's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 45.0000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

Cosby's water system has 2 total violations on record, including 0 health-based violations. All violations have been resolved.

MR
Most recent violations:
Oct 2010 Coliform (TCR) Resolved
Mar 1992 Coliform (TCR) Resolved

Flood & environmental risk

Andrew County has experienced 10 federally declared disasters since 1965. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.

SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA DR-4435
FLOODING
Flood FEMA DR-4012
FLOODING
Flood FEMA DR-3325

Where does Cosby's water come from?

Cosby's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 3,580 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.

What Cosby residents can do

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Cosby's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
45.0000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Lithium
Inorganic
Detected
45.0 µg/L
State screening level: 60 µg/L · 75% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

2
Total violations
0
Health-based
0
Active / unresolved
Oct 2010
Most recent violation
Compliance Record

Violations & advisories

2 Total
0 Active
0 Health-based
2 Resolved
Oct 2010 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Oct 2010
Mar 1992 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 1992
Industrial pollution

Top industrial polluters within 10 miles of Cosby

Industrial polluters nearby

Reported releases to surface water by facilities near Cosby, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
HERZOG SAVANNAH PLANT
Petroleum · HERZOG CONTRACTING CORP
SAVANNAH, MO64485
7.3 mi
PURINA ANIMAL NUTRITION LLC-ST JOSEPH
Food · LAND O LAKES INC
SAINT JOSEPH, MO64503
7.9 mi
BOEHRINGER INGELHEIM ANIMAL HEALTH--N. BELT CAMPUS
Chemicals · BOEHRINGER INGELHEIM CORP
SAINT JOSEPH, MO64506
8.5 mi
ALTEC INDUSTRIES INC
Transportation Equipment · ALTEC INDUSTRIES INC
SAINT JOSEPH, MO64507
9.3 mi
THE HILLSHIRE BRANDS ST. JOSEPH MISSOURI
Food · TYSON FOODS INC
SAINT JOSEPH, MO645079760
8.6 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Flood & disaster history

10
Declared disasters
May 2019
Most recent
Flood
Most common type

Andrew County has experienced 10 federally declared disasters since 1965. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

May 2019
SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING
Flood FEMA #4435
Aug 2011
FLOODING
Flood FEMA #4012
Jun 2011
FLOODING
Flood FEMA #3325
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3232
Jul 1993
SEVERE STORMS & FLOODING
Flood FEMA #995
Jun 1984
SEVERE STORMS & FLOODING
Flood FEMA #713

Recommended water filters

Based on contaminants detected in Cosby's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium 45.000 HI µg/L PFAS Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 0.0 ppb from 1993 (0.0 ppb) to 2025 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Purchased Groundwater
Operator
Local Government
Population Served
3,580
Water Systems
1
Water Source

Where Cosby's water comes from

Purchased Groundwater

Cosby purchases its water supply from a regional wholesale provider rather than treating raw water directly.

Water quality depends on both the wholesaler's treatment standards and the condition of Cosby's local distribution pipes and storage facilities.

Purchased water systems are common in suburban areas and smaller communities that lack the infrastructure for independent treatment.

The system is operated by local government ownership and serves approximately 3,580 people through 1 water system.

Infrastructure

Water systems serving Cosby

System Name PWSID Population Source
ANDREW COUNTY PWSD 2 MO1024005 3,580 GWP
Regional Comparison

How Cosby compares

Full Missouri rankings →

Cosby's score of 98.2/100 is above the average of 62/100 among major Missouri cities. It outscores 10 of 10 nearby cities.

Cosby (this city)
98.2
St. Louis
40.9
Columbia
61.4
Missouri avg
62
City Profile

About Cosby, MO

Wikipedia →

Cosby is a village in Monroe Township, Andrew County, Missouri, United States. The population was 114 at the 2020 census. It is part of the St. Joseph, MO–KS Metropolitan Statistical Area.

Economic Profile
$63,125
Median Income
$97,766
Median Home Value
$728/mo
Median Rent
9.4%
Unemployment
Community
27.2
Median Age
187
People / sq mi
9.1%
College Educated
83.1%
Homeownership
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Frequently asked questions

Is Cosby, MO tap water safe to drink?

Cosby's water quality earned a grade of A+ (98.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #1 out of 509 cities tested in Missouri.

What contaminants are in Cosby's water?

Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 2 violations are on record.

How is Cosby's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Cosby?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Cosby's water come from?

Cosby's water is sourced from Purchased ground water. The city has 1 water system serving approximately 3,580 residents.

Is Cosby's groundwater at risk of contamination?

Cosby uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 2 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Cosby's water compare to other cities?

Cosby ranks #1 out of 509 cities in Missouri (better than 100% of state cities) and #49 out of 15744 cities nationally (100th percentile). The grade of A+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.