Denville Water Hardness & Quality Report (2026)
Water Hardness
8 grains per gallon
Source
reservoir
pH Level
8
neutral = 7.0
Lead
0.006 mg/L
✓ Below action level
TDS
319.3 mg/L
Est. Daily Cost
$0.37
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Denville, your appliances are currently losing 18% efficiency due to mineral buildup.
| Appliance | In Denville | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.1 yrs | 8.5 yrs | -40% |
| Washing Machine | 8.5 yrs | 12 yrs | -29% |
| Water Heater | 10.1 yrs | 15 yrs | -33% |
Regional Water Comparison
How Denville compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Denville, New Jersey | 137.5 mg/L | 10.7 ppt | 🟠 Hard | reservoir |
| Parsippany, New Jersey | 139 mg/L | 10.7 ppt | 🟠 Hard | reservoir |
| Dover, New Jersey | 142 mg/L | 10.9 ppt | 🟠 Hard | reservoir |
| Morristown, New Jersey | 81 mg/L | 7.5 ppt | 🟡 Moderately Hard | reservoir |
| Randolph, New Jersey | 115 mg/L | 9.4 ppt | 🟡 Moderately Hard | reservoir |
National Benchmark
How Denville compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Denville | 137.5 mg/L | 🟠 Moderate |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Denville home
Shop water softeners on Amazon.com →
What Makes Denville's Water Unique?
Local geology and source profile
Denville, New Jersey, in Morris County — a Morris County township adjacent to Rockaway and Boonton on the Rockaway River in northwest New Jersey — receives its municipal water from New Jersey American Water, drawing from the Boonton Reservoir (Rockaway River, Morris County) through the NJAW system.
The moderately hard 137.5 mg/L hardness and TDS of 319.3 mg/L reflect the Morris County Rockaway-Boonton Reservoir supply's mixed Highlands-Newark Basin character. The Rockaway River at Boonton Reservoir drains the New Jersey Highlands — Precambrian Reading Prong gneiss and amphibolite (mostly insoluble), Precambrian Franklin Marble (calcareous — modest hardness contributor from the Franklin-Sterling Hill area), and minor Triassic Newark Basin Brunswick Formation (calcareous redbeds). The mixed insoluble Highlands and calcareous Franklin Marble and Newark Basin contributions produce the moderately hard Morris County supply.
At 137.5 mg/L, Denville's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 10.7 ppt warrants a certified reverse osmosis drinking water filter — Picatinny Arsenal (Morris County — AFFF, one of the most PFAS-contaminated military facilities in New Jersey), the Morris County northwest NJ industrial corridor, and the New Jersey PFAS complex contribute to Denville's very elevated readings.
Geology & Source: Denville in Morris County draws from New Jersey American Water on Boonton Reservoir (Rockaway River, Morris County, northwest New Jersey) — the Rockaway River drains the New Jersey Highlands (Precambrian Reading Prong gneiss — insoluble) and minor Triassic Newark Basin calcareous — New Jersey Morris County Rockaway River Precambrian-Triassic watershed produces moderately hard water at 137.5 mg/L with TDS 319.3 mg/L in this Morris County New Jersey township.