State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM31
Moderately hard · 61–120 PPM2
Hard · 121–180 PPM0
Very hard · 181+ PPM0
State water index
Rhode Island water hardness
Search 12 indexed communities and 33 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.
Median indexed hardness
43PPM
Soft
Indexed range 40.5–64.1 PPM
- ZIP profiles
- 33
- Cities
- 12
- Matched utilities
- 30
- Counties
- 4
Understanding Rhode Island
Why local comparisons matter here
Rhode Island's compact water landscape includes major reservoir supply, smaller surface systems, and local groundwater in coastal and inland communities.
In this index, soft is the largest category, covering 31 of 33 profiles with hardness data. The state median is 43 PPM, but the full indexed range is 40.5–64.1 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 100%
- Lead 90th percentile
- 100%
- Copper 90th percentile
- 9%
0
Low-confidence hardness profiles
0
Nearest site more than 25 miles away
Reported source water
Utility source mix
- Groundwater
- 17
- Surface water
- 13
Highest medians
Hardest indexed cities
- 1. Hopkinton64 PPM
- 2. Charlestown62 PPM
- 3. Westerly59 PPM
- 4. Newport45 PPM
- 5. Cranston44 PPM
Lowest medians
Softest indexed cities
- 1. Woonsocket41 PPM
- 2. Providence43 PPM
- 3. Pawtucket43 PPM
- 4. East Providence43 PPM
- 5. Central Falls43 PPM
City directory
Explore Rhode Island by city
Search by city or county, then sort by name, hardness, or ZIP coverage.
12 cities · 33 ZIP profiles
12 cities found
Central Falls
Providence County · 1 ZIP
43PPM
Single indexed valueNo active flag
Charlestown
Washington County · 1 ZIP
62PPM
Single indexed value1 active record
Cranston
Providence County · 5 ZIPs
44PPM
Range 43–45.1No active flag
East Providence
Providence County · 3 ZIPs
43PPM
Range 43–43.2No active flag
Hopkinton
Washington County · 1 ZIP
64PPM
Single indexed value2 active records
Newport
Newport County · 2 ZIPs
45PPM
Single indexed valueNo active flag
Pawtucket
Providence County · 2 ZIPs
43PPM
Single indexed valueNo active flag
Providence
Providence County · 11 ZIPs
43PPM
Range 42.8–44.9No active flag
Tiverton
Newport County · 1 ZIP
44PPM
Single indexed valueNo active flag
Warwick
Kent County · 4 ZIPs
44PPM
Range 43–45.1No active flag
Westerly
Washington County · 1 ZIP
59PPM
Single indexed valueNo active flag
Woonsocket
Providence County · 1 ZIP
41PPM
Single indexed valueNo active flag
County comparison
Highest indexed county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Washington County | 62 PPM | 59.1–64.1 | 3 |
| Newport County | 45 PPM | 44.1–45.1 | 3 |
| Kent County | 44 PPM | 43–45.1 | 4 |
| Providence County | 43 PPM | 40.5–45.1 | 23 |