Lake Forest Water Hardness & Quality Report (2026)
Water Hardness
15.1 grains per gallon
Source
river
pH Level
8.5
neutral = 7.0
Lead
0.008 mg/L
✓ Below action level
TDS
656.3 mg/L
Est. Daily Cost
$0.69
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 Lake Forest, your appliances are currently losing 35% efficiency due to mineral buildup.
| Appliance | In Lake Forest | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 1.5 yrs | 8.5 yrs | -82% |
| Washing Machine | 4 yrs | 12 yrs | -67% |
| Water Heater | 5.2 yrs | 15 yrs | -65% |
Regional Water Comparison
How Lake Forest compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Lake Forest, Illinois | 259 mg/L | 9 ppt | 🔴 Very Hard | river |
| North Chicago, Illinois | 237 mg/L | 8.3 ppt | 🔴 Very Hard | river |
| Highland Park, Illinois | 219.5 mg/L | 7.7 ppt | 🔴 Very Hard | river |
| Deerfield, Illinois | 144 mg/L | 5.1 ppt | 🟠 Hard | river |
| Waukegan, Illinois | 163 mg/L | 5.8 ppt | 🟠 Hard | river |
National Benchmark
How Lake Forest compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Lake Forest | 259 mg/L | 🔴 High |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Lake Forest's Water Unique?
Local geology and source profile
Lake Forest, Illinois, in Lake County — a Lake County affluent North Shore community on Lake Michigan north of Chicago, one of the Gold Coast's signature residential suburbs with the Chicago Botanic Garden nearby and the home of Lake Forest College — receives its municipal water from the City of Lake Forest Water Division, drawing from Lake Michigan at the Lake Forest intake and water treatment plant.
The hard 259 mg/L hardness and high TDS of 656.3 mg/L reflect Lake Michigan's carbonate character — significantly harder than Lake Superior (very soft, Shield-dominated) but consistent with the southern Lake Michigan zone. Lake Michigan receives drainage from the Silurian Niagara Dolomite belt (the platform underlying much of the lower Michigan Peninsula and the Wisconsin-Illinois lake plain), calcareous Pleistocene glacial till from the Great Lakes basin, and the Milwaukee-Racine-Kenosha urban-industrial contribution from the western Lake Michigan shore. Lake Forest at the far north end of the Chicago North Shore uses the same Lake Michigan intake as Chicago, producing the hard, high-TDS water characteristic of the North Shore Lake Michigan supply.
At 259 mg/L, Lake Forest's water is hard — scale builds rapidly in appliances and plumbing. A water softener is recommended. Dishes spot heavily, and bathroom fixtures develop calcium deposits quickly. The PFAS level of 9.0 ppt warrants a certified reverse osmosis drinking water filter — the Great Lakes Naval Training Station (North Chicago, Lake County — a major US Navy AFFF user in the Lake Michigan watershed), the Waukegan industrial-chemical corridor (Lake County), and the Chicago North Shore Lake Michigan PFAS complex contribute to Lake Forest's elevated readings.
Geology & Source: Lake Forest in Lake County draws from the City of Lake Forest Water Division on Lake Michigan — Lake Michigan receives the Great Lakes basin drainage from the Laurentian Shield (Precambrian Canadian Shield crystalline) and the Great Lakes Lowland (Silurian Niagara Dolomite) — Lake Michigan Great Lakes carbonate-dolomite drainage produces hard water at 259 mg/L with high TDS 656 mg/L in this Lake County Illinois city.