CITY REPORT CT

Cos Cob, CT: 24 Violations - Home Safety 50/100

1 ZIP code · 1 water system · Updated

ZipCheckup grade for Cos Cob: D.

Several federal signals point to home-safety risks in this ZIP.

Cos Cob ranks below average for tap water safety in CT - health-based violations are documented across multiple service areas in recent EPA monitoring data.

How Cos Cob Compares

Cos Cob50/100
Connecticut avg63/100
National avg73/100

Data: EPA SDWIS

1
ZIP Codes
1
Water Systems
1
ZIPs with Violations
D · 50
Avg Safety Score
Zone 1
Radon Risk (High)
$1.2M
Median Home Value
$3,000
Est. Remediation (0.2% of home value)

What You Should Know About Cos Cob Water

  • Your city's water systems recorded 24 violations in the past 5 years.
  • Homes built before 1986: 77% - older plumbing may contain lead solder.
  • Estimated remediation: $3,000 per household.

Who Supplies Your Water in Cos Cob

Across most of Cos Cob, CT, residential water comes from a single utility. That provider sets rates, manages infrastructure maintenance, and files compliance reports with the EPA on behalf of the households it serves. Federal tracking data shows 1 system on record, but one carries the bulk of the service load.

Overview

We track home safety data for 1 ZIP code in Cos Cob, Connecticut (population ~7,667), covering 1 community water system serving approximately 351,756 people region-wide. The EPA snapshots used for this build directly map water systems to 1 of 1 ZIP codes.

1 of 1 ZIP code with a reported violation count in the available EPA record (100%) have recorded EPA violations. The available record reports no health-based violations for this measured scope.

Home Safety Score

Average Home Safety Score for Cos Cob: D (50/100)

Model 4.0.0 uses four measured components across three equally weighted domains. If a required domain is unavailable, no score is published:

Factor What It Measures
Water Quality EPA violations and compliance history
PFAS MCL Screen UCMR 5 testing against the covered federal MCLs
Radon Risk EPA radon zone classification
Annual AQI EPA AirData county-year median with at least 90 observed days

Water Sources

Cos Cob water systems draw from: Surface water.

Lead & Copper

  • Average lead level (90th percentile): 0.0000 mg/L (EPA action level: 0.015 mg/L)
  • 0 of 1 ZIP code with known status exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 1 (High Risk)

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

Top Contaminants

Contaminant Category Violations ZIPs Affected
Barium Inorganic 4 1
Cadmium Inorganic 4 1
Chromium Inorganic 4 1
Fluoride Inorganic 4 1
Selenium Inorganic 4 1

Areas with Most Violations

ZIP Code Safety Score Violations Health-Based System
06807 D 24 0 Aquarion-eastern Fairfield County

All ZIP Codes in Cos Cob

  • 06807 [D] - 24 violations

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Top Contaminants in Cos Cob Water

Barium 4 violations
Inorganic · EPA limit: 2 mg/L
Increased blood pressure
Cadmium 4 violations
Inorganic · EPA limit: 0.005 mg/L
Chromium 4 violations
Inorganic · EPA limit: 0.1 mg/L
Allergic dermatitis

Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.

Housing & Infrastructure in Cos Cob

1966
Median Build Year
77%
Built Before 1986
44%
Built Before 1970
Galvanized Steel or Copper
Likely Pipe Material

With 77% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.

Source: U.S. Census Bureau American Community Survey (ACS).

Housing Age Profile

Cos Cob's housing stock is predominantly older, with a median build year of 1966 that reflects decades of construction before federal plumbing standards were tightened. The 1986 ban on lead solder and the pre-1970 era of lead service lines are both relevant benchmarks here - a significant share of the residential inventory predates one or both of those cutoffs, creating an elevated baseline for plumbing-related lead risk that aggregate water quality data may not fully reflect at the household level.

1966
Median Year Built
77%
Pre-1986 (Lead Paint Risk)
44%
Pre-1970 (Lead Pipes Risk)
Pre-1970 (44%) 1970–1986 (33%) Post-1986 (23%)

Over half of homes in Cos Cob were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.

Source: U.S. Census Bureau ACS B25034.

Cost Context: What Remediation Means for Cos Cob Homeowners

Setting Cos Cob remediation figures against its property market, the resulting ratio sits comfortably in the low tier - a classification that reflects the kind of household financial position where most homeowners can identify documented issues, schedule the work, and absorb the cost without it registering as a significant budget disruption.

Median Home Value
$1.2M
Est. Remediation
$3,000
Remediation as % of home value 0.2%

Remediation costs in Cos Cob are relatively low compared to home values. The $2,000–$4,100 estimated range is a small fraction of median property value. Home values are 201% above the Connecticut average.

Lead Exposure Risk for Children in Cos Cob

77%
Homes Built Before 1986

Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

77% of Cos Cob housing dates to the pre-rule era, alongside aggregate readings hovering at the federal action mark - household-level confirmation through a draw-test kit fits the local picture.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Historical NFIP Claim Context in Cos Cob

124
Total FEMA Flood Claims
$19,641
Avg Reported Sum With Payment Data
100%
A/V Share of Claim-Record ZIPs

Historical NFIP data for Cos Cob contains 124 flood insurance claims. Among claims with payment data, the average reported building, contents, and ICC component sum is $19,641. Among ZIP codes with claim records, 100% have an A- or V-family dominant rated zone recorded in those historical claims. This is not a complete current FEMA property-map inventory.

How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. The <strong>$3,000</strong> remediation estimate shown here excludes flood insurance and is not derived from NFIP claim count.

Claim count does not establish current property risk. Check the exact address in FEMA's current map and obtain a property-specific insurance quote when relevant.

Source: historical FEMA National Flood Insurance Program (NFIP) claim records. No current FEMA property-map designation is asserted.

What You Can Do in Cos Cob

  1. Test your water at home. City-level data shows averages - your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
  2. Install a certified water filter. Filters rated for Barium can reduce the most common contaminant found in Cos Cob's water.
  3. Check your home's plumbing. With 77% of homes built before 1986, lead solder is a real possibility.
  4. Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.

Frequently Asked Questions

What does the Home Safety Score mean for Cos Cob, CT?
Cos Cob has an average Home Safety Score of 50/100 (Grade D) under model 4.0.0. The score combines EPA SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the PFAS MCL screen, EPA radon zone, and annual EPA AQI, and is published only when all required domains are observed. 24 EPA violations have been recorded. Check individual ZIP code reports for component details.
How many water violations does Cos Cob have?
Cos Cob water systems have a total of 24 EPA violations. Violations are tracked across 1 ZIP code.
How does Cos Cob compare to Connecticut average?
Cos Cob has an average Home Safety Score of 50/100, which is below the Connecticut state average of 63/100 for the same model series.
How many water systems serve Cos Cob?
Cos Cob is served by 1 public water system across 1 ZIP code, serving approximately 7,667 people.
How much does it cost to fix water issues in Cos Cob?
Estimated remediation costs in Cos Cob average $3,000 per household, ranging from $2,000 to $4,100. Costs include filtration, pipe replacement, radon mitigation, and flood protection.
HomeCitiesConnecticut → Cos Cob, CT

How to cite this page

APA ZipCheckup. (2026). Cos Cob, CT: 24 Violations - Home Safety 50/100. https://zipcheckup.com/cities/ct/cos-cob/
BibTeX
@misc{zipcheckup-cities-ct-cos-cob,
  author = {{ZipCheckup}},
  title  = {{Cos Cob, CT: 24 Violations - Home Safety 50/100}},
  year   = {2026},
  url    = {https://zipcheckup.com/cities/ct/cos-cob/}
}

Page version: August 2026.

Get safety alerts for Cos Cob, Connecticut

Free updates when EPA data changes for this area. No spam.

Unsubscribe anytime. Privacy Policy.

Share This Page

X Facebook
Violations found - check filter options Free tool - no phone call required.