Watertown Water Hardness & Quality Report (2026)
Water Hardness
3.6 grains per gallon
Source
reservoir
pH Level
7.5
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
122.4 mg/L
Est. Daily Cost
$0.16
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 Watertown, your appliances are currently losing 8% efficiency due to mineral buildup.
| Appliance | In Watertown | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 7.6 yrs | 8.5 yrs | -11% |
| Washing Machine | 11.3 yrs | 12 yrs | -6% |
| Water Heater | 13.1 yrs | 15 yrs | -13% |
Regional Water Comparison
How Watertown compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Watertown, Massachusetts | 61.5 mg/L | 7.4 ppt | 🟡 Moderately Hard | reservoir |
| Belmont, Massachusetts | 123 mg/L | 11.6 ppt | 🟠 Hard | reservoir |
| Brighton, Massachusetts | 60 mg/L | 7.3 ppt | 🟡 Moderately Hard | reservoir |
| Newton, Massachusetts | 103 mg/L | 10.3 ppt | 🟡 Moderately Hard | reservoir |
| Chestnut Hill, Massachusetts | 19.5 mg/L | 4.5 ppt | 🟢 Soft | reservoir |
National Benchmark
How Watertown compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Watertown | 61.5 mg/L | 🟡 Low |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Watertown's Water Unique?
Local geology and source profile
Watertown, Massachusetts, in Middlesex County — a major west Boston inner suburban community (Watertown is a historically significant Middlesex County town on the Charles River — one of the original Puritan settlements of Massachusetts Bay Colony (1630); Watertown is home of a significant Armenian-American community (one of the largest Armenian-American communities in the United States, with roots in the early 20th century Armenian Genocide refugee settlement), the Watertown Arsenal (the historic Civil War-era federal arsenal that has been redeveloped into the Arsenal Yards mixed-use development), and a significant biotechnology and pharmaceutical cluster), a diverse Middlesex County community with a significant Armenian-American, Brazilian-American, and professional population, and a city that made national headlines in 2013 (the Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured in Watertown after a major manhunt and shootout that locked down the community) — draws its municipal water supply via the MWRA. Water hardness in Watertown measures 61.5 mg/L — classified as moderately soft.
Watertown's moderate softness reflects the MWRA Wachusett–Quabbin supply's calcareous-poor granite watershed with effective treatment. The MWRA metropolitan Boston supply distributes Wachusett Reservoir water to the Watertown west Boston zone (primarily 19th–early 20th century dense residential and industrial mains), producing the moderately soft 61.5 mg/L.
With hardness at 61.5 mg/L, Watertown residents enjoy moderately soft water. MWRA consistently delivers water meeting all Massachusetts DEP and EPA Safe Drinking Water Act requirements.
Geology & Source: Reservoir supply from the Wachusett Reservoir (Nashua River watershed) via the Massachusetts Water Resources Authority (MWRA) — the Middlesex County west Boston inner suburban Watertown corridor (Precambrian calcareous-poor Marlboro Tonalite and Wachusett area granite — MWRA metropolitan Boston distribution to Watertown west Boston zone; effective softening); moderately soft supply at 61.5 mg/L in Middlesex County.