Merrillville Water Hardness & Quality Report (2026)
Water Hardness
10.2 grains per gallon
Source
river
pH Level
8
neutral = 7.0
Lead
0.004 mg/L
✓ Below action level
TDS
335 mg/L
Est. Daily Cost
$0.47
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 Merrillville, your appliances are currently losing 23% efficiency due to mineral buildup.
| Appliance | In Merrillville | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 3.8 yrs | 8.5 yrs | -55% |
| Washing Machine | 7.1 yrs | 12 yrs | -41% |
| Water Heater | 8.6 yrs | 15 yrs | -43% |
Regional Water Comparison
How Merrillville compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Merrillville, Indiana | 175 mg/L | 5.3 ppt | 🟠 Hard | river |
| Crown Point, Indiana | 245 mg/L | 7.9 ppt | 🔴 Very Hard | river |
| Hobart, Indiana | 210.5 mg/L | 6.6 ppt | 🔴 Very Hard | river |
| Griffith, Indiana | 180 mg/L | 5.5 ppt | 🔴 Very Hard | river |
| Gary, Indiana | 156.5 mg/L | 4.7 ppt | 🟠 Hard | river |
National Benchmark
How Merrillville compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Merrillville | 175 mg/L | 🟠 Moderate |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Merrillville's Water Unique?
Local geology and source profile
Merrillville, Indiana, in Lake County — the largest unincorporated community in Indiana (Merrillville is one of the largest unincorporated communities in the United States — a major commercial hub in northwest Indiana that has resisted incorporation while becoming the primary retail and commercial center of Lake County), home of the Southlake Mall (one of the major shopping destinations in northwest Indiana — the primary regional mall for the Lake County–Gary–Crown Point corridor), adjacent to Gary and part of the Calumet region (the historically significant northwest Indiana industrial zone along Lake Michigan), a diverse Lake County community with a significant African-American and Hispanic-American population, and a major commercial node in the Chicago south suburban metro area — draws its municipal water supply from the Calumet Aquifer via Indiana American Water. Water hardness in Merrillville measures 175 mg/L — classified as hard.
Merrillville's hard supply reflects the northwest Indiana Lake County Calumet Aquifer's highly calcareous glacial geology. The Calumet Aquifer at Merrillville–Lake County draws from: the Wisconsin Age Lake Border Moraines calcareous outwash (highly calcareous glacial sand and gravel — calcareous-moderate till from the Superior and Erie Lobes); and the Silurian–Devonian calcareous dolomite of the Lake Michigan basin (the northwest Indiana Niagaran and Devonian dolomite bedrock). Indiana American Water treatment produces the hard 175 mg/L.
At 175 mg/L, Merrillville residents face regular hard water challenges. Monthly descaling with citric acid solution is recommended. Indiana American Water consistently delivers water meeting all Indiana DEM and EPA Safe Drinking Water Act requirements.
Geology & Source: Groundwater from the Calumet Aquifer (Valparaiso Moraine outwash) via the Indiana American Water Company (Merrillville) — the Lake County northwest Indiana Chicago south suburban corridor (Wisconsin Age calcareous Lake Border Moraines outwash and Silurian–Devonian calcareous dolomite beneath the Lake County drift; Merrillville supply with moderate treatment); hard supply at 175 mg/L in Lake County.