Johnston Water Hardness & Quality Report (2026)
Water Hardness
0.9 grains per gallon
Source
reservoir
pH Level
7.1
neutral = 7.0
Lead
0.001 mg/L
✓ Below action level
TDS
22.6 mg/L
Est. Daily Cost
$0.04
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 Johnston, your appliances are currently losing 2% efficiency due to mineral buildup.
| Appliance | In Johnston | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 9.1 yrs | 8.5 yrs | — |
| Washing Machine | 13 yrs | 12 yrs | — |
| Water Heater | 15 yrs | 15 yrs | — |
Regional Water Comparison
How Johnston compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Johnston, Rhode Island | 15 mg/L | 3.9 ppt | 🟢 Soft | reservoir |
| North Providence, Rhode Island | 59.5 mg/L | 8.4 ppt | 🟢 Soft | reservoir |
| Cranston, Rhode Island | 73.5 mg/L | 9.8 ppt | 🟡 Moderately Hard | reservoir |
| Providence, Rhode Island | 71.5 mg/L | 9.6 ppt | 🟡 Moderately Hard | reservoir |
| Smithfield, Rhode Island | 26.5 mg/L | 5 ppt | 🟢 Soft | reservoir |
National Benchmark
How Johnston compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Johnston | 15 mg/L | 🟢 None |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Johnston home
Shop water softeners on Amazon.com →
What Makes Johnston's Water Unique?
Local geology and source profile
Johnston, Rhode Island, in Providence County — a major central Rhode Island Providence suburban community (Johnston is a significant Providence County town — a central Rhode Island suburb directly west of Providence; Johnston is known as one of the most politically active and colorful communities in Rhode Island (Rhode Island politics are famously colorful, and Johnston has had its share of controversial local political history)), home of the massive Johnston Sanitary Landfill (one of the largest active landfills in New England — and one of the most significant environmental features of the Johnston landscape), a diverse Providence County community with a primarily Italian-American, Portuguese-American, and working-class suburban population (Johnston is one of the most predominantly Italian-American communities in Rhode Island), adjacent to Providence and North Providence in the central Rhode Island corridor, home of several significant Providence Health & Services medical facilities, and a community with a strong ethnic identity — draws its municipal water supply via the Providence Water Supply Board. Water hardness in Johnston measures 15 mg/L — classified as extremely soft.
Johnston's extremely soft supply reflects the central Rhode Island Providence Water system's calcareous-poor crystalline geology. The Scituate Reservoir system drains the Precambrian Rhode Island gneiss (calcareous-poor) and Pennsylvanian Narragansett Basin (calcareous-poor). Providence Water produces the extremely soft 15 mg/L.
With hardness at 15 mg/L, Johnston residents enjoy extremely soft water. Providence Water Supply Board consistently delivers water meeting all Rhode Island DEM and EPA Safe Drinking Water Act requirements.
Geology & Source: Reservoir supply from the Scituate Reservoir (Pawtuxet River watershed) via the Providence Water Supply Board — the Providence County central Rhode Island Johnston corridor (Precambrian calcareous-poor Rhode Island gneiss and Pennsylvanian calcareous-poor Narragansett Basin coal measures — the extremely calcareous-poor central Rhode Island crystalline watershed; Providence Water excellent treatment); extremely soft supply at 15 mg/L in Providence County.