Herrin Water Hardness & Quality Report (2026)
Water Hardness
13.1 grains per gallon
Source
river
pH Level
8.4
neutral = 7.0
Lead
0.006 mg/L
✓ Below action level
TDS
514.7 mg/L
Est. Daily Cost
$0.60
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 Herrin, your appliances are currently losing 30% efficiency due to mineral buildup.
| Appliance | In Herrin | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 2.2 yrs | 8.5 yrs | -74% |
| Washing Machine | 5.3 yrs | 12 yrs | -56% |
| Water Heater | 6.7 yrs | 15 yrs | -55% |
Regional Water Comparison
How Herrin compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Herrin, Illinois | 223.5 mg/L | 7.8 ppt | 🔴 Very Hard | river |
| Marion, Illinois | 279.5 mg/L | 9.7 ppt | 🔴 Very Hard | river |
| Carbondale, Illinois | 210 mg/L | 7.4 ppt | 🔴 Very Hard | river |
| Mount Vernon, Illinois | 184.5 mg/L | 6.5 ppt | 🔴 Very Hard | river |
| Cape Girardeau, Missouri | 227.5 mg/L | 7 ppt | 🔴 Very Hard | river |
National Benchmark
How Herrin compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Herrin | 223.5 mg/L | 🔴 High |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Herrin home
Shop water softeners on Amazon.com →
What Makes Herrin's Water Unique?
Local geology and source profile
Herrin, Illinois, in Williamson County — a Williamson County city adjacent to Marion and Carbondale in south Illinois — receives its water from the Herrin Water system, drawing from Rend Lake or the Big Muddy River (Williamson County) through the south Illinois distribution.
The very hard 223.5 mg/L hardness and TDS of 514.7 mg/L reflect the south Illinois Williamson County supply's very hard calcareous character — the Ozark Uplift's Mississippian Salem Limestone and Pennsylvanian Carbondale Formation produce very hard calcareous water in the south Illinois coal country, compounded by the semi-arid limestone karst dissolution (compare Shiloh IL: 155.5 mg/L on the Madison County Mississippi River; Herrin significantly harder from the direct south Illinois Mississippian limestone draw). The Rend Lake-Big Muddy watershed at Williamson County — Mississippian Salem Limestone (calcareous — primary hardness contributor), Pennsylvanian Carbondale Formation (calcareous — secondary contributor), and Quaternary Illinois alluvium (calcareous — TDS contributor).
At 223.5 mg/L with TDS 515, Herrin's water is very hard. A water softener is strongly recommended to prevent rapid scale buildup. A reverse osmosis system is advisable for drinking water. The PFAS level of 7.8 ppt warrants a certified drinking water filter — the Williamson County south Illinois industrial corridor contribute to Herrin's elevated readings.
Geology & Source: Herrin in Williamson County draws from the Herrin Water on Rend Lake or Big Muddy River (Williamson County, south Illinois) — the Big Muddy-Rend Lake watershed at Williamson County drains the Ozark Uplift (Mississippian Salem Limestone — calcareous) and Pennsylvanian Carbondale Formation (calcareous) — Illinois Williamson County Rend Lake-Big Muddy Mississippian-Pennsylvanian calcareous supply produces very hard water at 223.5 mg/L with TDS 514.7 mg/L.