Public water data for Brooklyn, NY reveals a split picture — tap water quality varies meaningfully by service area and the city's grade reflects that variability.

Data: EPA SDWIS Last verified: 2026-06-03

Water Quality Map: Brooklyn, NY

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Overview

We track water quality and home safety data for 51 ZIP codes in Brooklyn, New York (population ~2,646,164), covering 6 community water systems serving approximately 8,271,875 people region-wide.

51 of 51 ZIP codes (100%) have recorded EPA violations. 969 health-based violations documented.

Home Safety Score

Average Home Safety Score for Brooklyn: C (60/100)

The score combines three factors:

Factor	What It Measures
Water Quality	EPA violations and compliance history
Lead Levels	90th percentile lead concentration vs EPA action level
Radon Risk	EPA radon zone classification

Water Sources

Brooklyn water systems draw from: Groundwater.

Lead & Copper

• Average lead level (90th percentile): 0.0061 mg/L (EPA action level: 0.015 mg/L)
• 0 ZIP codes exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 3 (Low Risk)

• Zone 1 (High): 0 ZIP codes
• Zone 2 (Moderate): 0 ZIP codes
• Zone 3 (Low): 51 ZIP codes

Top Contaminants

Areas with Most Violations

All ZIP Codes in Brooklyn

• 11201 [C] — 35 violations ⚠
• 11202 [C] — 35 violations ⚠
• 11203 [C] — 35 violations ⚠
• 11204 [C] — 35 violations ⚠
• 11205 [C] — 35 violations ⚠
• 11206 [C] — 35 violations ⚠
• 11207 [C] — 35 violations ⚠
• 11208 [C] — 35 violations ⚠
• 11209 [C] — 35 violations ⚠
• 11210 [C] — 35 violations ⚠
• 11211 [C] — 35 violations ⚠
• 11212 [C] — 35 violations ⚠
• 11213 [C] — 35 violations ⚠
• 11214 [C] — 35 violations ⚠
• 11215 [C] — 35 violations ⚠
• 11216 [C] — 35 violations ⚠
• 11217 [C] — 35 violations ⚠
• 11218 [C] — 35 violations ⚠
• 11219 [C] — 35 violations ⚠
• 11220 [C] — 35 violations ⚠
• 11221 [C] — 35 violations ⚠
• 11222 [C] — 35 violations ⚠
• 11223 [C] — 35 violations ⚠
• 11224 [D] — 35 violations ⚠
• 11225 [C] — 35 violations ⚠
• 11226 [C] — 35 violations ⚠
• 11228 [C] — 35 violations ⚠
• 11229 [D] — 35 violations ⚠
• 11230 [C] — 35 violations ⚠
• 11231 [D] — 35 violations ⚠
• 11232 [C] — 35 violations ⚠
• 11233 [C] — 35 violations ⚠
• 11234 [D] — 35 violations ⚠
• 11235 [D] — 35 violations ⚠
• 11236 [D] — 35 violations ⚠
• 11237 [C] — 35 violations ⚠
• 11238 [C] — 35 violations ⚠
• 11239 [C] — 35 violations ⚠
• 11240 [C] — 35 violations ⚠
• 11241 [C] — 35 violations ⚠
• 11242 [C] — 35 violations ⚠
• 11243 [C] — 35 violations ⚠
• 11244 [C] — 35 violations ⚠
• 11245 [C] — 35 violations ⚠
• 11247 [C] — 35 violations ⚠
• 11248 [C] — 35 violations ⚠
• 11249 [C] — 35 violations ⚠
• 11251 [C] — 35 violations ⚠
• 11252 [C] — 35 violations ⚠
• 11254 [C] — 35 violations ⚠
• 11256 [C] — 35 violations ⚠

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Radon: EPA Map of Radon Zones

Updated daily.

Housing Age Profile

Plumbing risk in older housing is defined by two eras: the pre-1970 period when lead pipes were commonly used for service lines, and the 1970-to-1986 period when lead solder remained standard in copper plumbing until the federal ban. Brooklyn's median build year of 1926 lands in a range where both eras are heavily represented in the housing stock. That creates an elevated aggregate environment for plumbing-related lead exposure — one that city-level water quality averages don't capture, because the risk sits inside individual properties rather than in the distribution system.

1926

Median Year Built

84%

Pre-1986 (Lead Paint Risk)

66%

Pre-1970 (Lead Pipes Risk)

Pre-1970 (66%) 1970–1986 (18%) Post-1986 (16%)

Over half of homes in Brooklyn 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.

How Remediation Costs Compare in Brooklyn

Given current Brooklyn valuations, the remediation-to-property-value ratio is low — most homeowners are looking at a proportionally modest share that fits within routine financial planning.

Median Home Value

$1.0M

Est. Remediation

$2,994

Remediation as % of home value 0.3%

Remediation costs in Brooklyn are relatively low compared to home values. The $1,920–$4,804 estimated range is a small fraction of median property value. Home values are 180% above the New York average.

Brooklyn: Lead Risk & Vulnerable Populations

84%

Homes Built Before 1986

0.0061

mg/L Avg Lead (Limit: 0.015)

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.

In recent monitoring under the Lead and Copper Rule, citywide samples for Brooklyn have approached or crossed the regulatory action level on multiple occasions. Combined with 84% of stock dating from the pre-rule era, the picture supports baseline single-tap reads as a standard household-level step.

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

Brooklyn: Flood History & Water Damage Risk

The National Flood Insurance Program builds its dataset one claim at a time — each filed claim represents a property where flood damage was severe enough to trigger an insurance payout. For Brooklyn, that dataset has accumulated 6278 such events across the program's multi-decade history. 73% of ZIP codes here carry official FEMA flood zone designations, reflecting federal assessments of where flood risk is concentrated. Together, those data points describe a community with a documented, substantial flood exposure — the kind that shapes not just property risk but also the periodic reliability of water supply infrastructure. When flood events reach that scale, treatment systems face peak-load contamination stress, private wells become vulnerable to surface water intrusion, and the distribution network can experience backflow conditions that allow untreated water to re-enter the system.

6,278

Total FEMA Flood Claims

$34,819

Avg Claim Payout

73%

ZIPs in FEMA Flood Zones

~314

Est. Claims/Year

Brooklyn has a significant flood history with 6,278 FEMA flood insurance claims on record, averaging $34,819 per claim. With 73% of ZIP codes in FEMA-designated flood zones, flood risk is a major concern for homeowners and water quality.

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. Flood damage can add significantly to the estimated <strong>$2,994</strong> remediation cost per household.

Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.

Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.