CITY REPORT NJ

Denville, NJ: 1 Violation — 36/100 (2026)

1 ZIP code · 3 water systems · Updated 2026-06-03

Unlike better-scoring cities in NJ, Denville records health-based violations across a meaningful portion of its service areas — the overall safety grade is well below average.

How Denville Compares

Denville36/100
New Jersey avg58/100
National avg67/100

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

1
ZIP Codes
3
Water Systems
1
ZIPs with Violations
F · 36
Avg Safety Score
Zone 1
Radon Risk (High)
$552K
Median Home Value
$3,600
Est. Remediation (0.7% of home value)

Denville Water: The Quick Version

  • Your city's water systems recorded 1 violation in the past 5 years.
  • Average lead level: 0.0127 mg/L.
  • Homes built before 1986: 72% — older plumbing may contain lead solder.
  • Estimated remediation: $3,600 per household.
  • CDC health risk index: 9.89.

Water Systems Serving Denville

Across Denville, NJ, residential water comes from 3 primary utilities rather than a single consolidated provider. Each system operates independently — managing its own distribution infrastructure, rate schedules, and EPA compliance filings. Federal records track 3 water systems in the area, with these top providers accounting for the majority of residential connections.

Parsippany-troy Hills Water Department
Serves ~50,400 people · 1 violation
36
/100
Denville Twp Water Department
Serves ~15,881 people · 1 violation
36
/100
ROCKAWAY TWP WATER DEPT
Serves ~14,000 people · 1 violation
36
/100

Overview

We track water quality and home safety data for 1 ZIP code in Denville, New Jersey (population ~18,203), covering 3 community water systems serving approximately 80,281 people region-wide.

1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.

Home Safety Score

Average Home Safety Score for Denville: F (36/100)

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

Denville water systems draw from: Groundwater.

Lead & Copper

  • Average lead level (90th percentile): 0.0127 mg/L (EPA action level: 0.015 mg/L)
  • 0 ZIP codes 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
Total Organic Carbon Disinfection Byproducts 2 1

Areas with Most Violations

ZIP Code Safety Score Violations Health-Based System
07834 F 1 0 Denville Twp Water Department

All ZIP Codes in Denville

  • 07834 [F] — 1 violation

Data Sources

Updated daily.

CDC Health Data for Denville

8.3%
Asthma (US: 9.8%)
9%
Diabetes (US: 10.4%)
13%
Poor Mental Health (US: 14.8%)

Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.

Compared to National Average

Asthma 8.3% ↓
Diabetes 9% ↓
Mental Health 13% ↓

Vertical line = national average. Above national · Below national

Key Contaminants Detected in Denville

Total Organic Carbon 2 violations
Disinfection Byproducts

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

How Old Is Denville's Housing Stock?

1966
Median Build Year
72%
Built Before 1986
45%
Built Before 1970
Galvanized Steel or Copper
Likely Pipe Material

With 72% 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

The median home in Denville was built in 1966 — a figure that places most of the city's residential stock in the era when lead solder was still standard in copper plumbing. Homes built before 1986 may have lead-soldered joints; those built before 1970 face the additional possibility of lead pipes in the service line itself.

1966
Median Year Built
72%
Pre-1986 (Lead Paint Risk)
45%
Pre-1970 (Lead Pipes Risk)
Pre-1970 (45%) 1970–1986 (27%) Post-1986 (28%)

Over half of homes in Denville 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.

Denville: Remediation Cost in Perspective

For most homeowners in Denville, the estimated cost of water and safety remediation represents a proportionally modest share of what properties are worth — placing this area in the lower tier of the remediation share scale.

Median Home Value
$552,300
Est. Remediation
$3,600
Remediation as % of home value 0.7%

Remediation costs in Denville are relatively low compared to home values. The $2,400–$4,800 estimated range is a small fraction of median property value. Home values are 14% above the New Jersey average.

Protecting Children from Lead in Denville

72%
Homes Built Before 1986
0.0127
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.

Despite citywide averages serving as the standard public reference point, those aggregates cannot resolve what is happening at one specific faucet — and where 72% of Denville homes come from before the solder rule or where utility samples sit at or above the action mark, the gap between system data and faucet reality matters more than it does in lower-exposure communities. An in-home draw closes that gap, with certified filtration through retailer networks available where confirmed faucet results warrant additional measures.

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

Climate-Related Water Risk for Denville

Denville carries a substantial flood exposure profile — 879 claims filed over the program's long tracking window and 100% of ZIP codes within FEMA flood zones. For water quality, that exposure level means flooding has likely stressed local treatment and distribution infrastructure on multiple occasions, creating periodic windows of elevated contamination risk.

879
Total FEMA Flood Claims
$20,863
Avg Claim Payout
100%
ZIPs in FEMA Flood Zones
~44
Est. Claims/Year

Denville has a significant flood history with 879 FEMA flood insurance claims on record, averaging $20,863 per claim. With 100% 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>$3,600</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.

What You Can Do in Denville

  1. Test your water at home. City-level data shows averages — your tap may differ. Lead testing is especially recommended given the area's lead levels.
  2. Install a certified water filter. Filters rated for Total Organic Carbon can reduce the most common contaminant found in Denville's water.
  3. Check your home's plumbing. With 72% 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

Is the water safe to drink in Denville, NJ?
Denville has an average water safety score of 36/100 (Grade F). 1 EPA violation has been recorded. Check individual ZIP code reports for details specific to your neighborhood.
How many water violations does Denville have?
Denville water systems have a total of 1 EPA violation. Violations are tracked across 1 ZIP code.
Does Denville water have lead?
The average 90th-percentile lead level in Denville is 0.0127 mg/L. This is below the EPA action level of 0.015 mg/L. Lead levels can vary by home — testing is recommended especially in older properties.
How does Denville compare to New Jersey average?
Denville has an average water safety score of 36/100, which is below the New Jersey state average of 58/100.
How many water systems serve Denville?
Denville is served by 3 public water systems across 1 ZIP code, serving approximately 18,203 people.
How much does it cost to fix water issues in Denville?
Estimated remediation costs in Denville average $3,600 per household, ranging from $2,400 to $4,800. Costs include filtration, pipe replacement, radon mitigation, and flood protection.
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