What is the water quality grade for Fairfield Lake?

Fairfield Lake in Wayne County, Wisconsin received a water quality grade of F (Very Poor). Water clarity: 1.3 ft visibility. Phosphorus: 114 µg/L. Surface area: 18 acres.

Is Fairfield Lake safe to swim in?

Avoid swimming, very poor water quality, potential algae toxins. Fairfield Lake has an overall water quality grade of F. Always check local health department advisories before swimming.

Fairfield Lake

Wayne County, WisconsinHypereutrophic

Fairfield Lake is a 18-acre highly nutrient-loaded hypereutrophic lake in Wayne County, IL. Water quality is graded F based on 2 sampling years through 2022. Compared to the 2 other monitored lakes in Wayne County, Fairfield Lake ranks #3 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-10-24. Grade methodology: LakeGrade methodology.

Swimming Safety

Avoid swimming, very poor water quality, potential algae toxins

Water Quality Grade: F, Very Poor

Very murky, less than 1.3 ft of visibility. Phosphorus level: 114 µg/L. Trophic State Index: 73.

Metric	Value	Grade
Water Clarity (Secchi Depth)	1.3 ft	F
Phosphorus	114 µg/L	F
Chlorophyll-a (Algae)	No data
Trophic State Index (TSI)	73	Hypereutrophic

Very high nutrients, dense algae, poor clarity

Lake Details

Characteristic	Value
Surface Area	18 acres

Location

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County Ranking

Ranked #3 of 3 lakes in Wayne County

Cleaner Lakes Within 30 Miles

Fairfield Lake holds Grade F. 3 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Wayne County

More Wisconsin Lake Rankings

Cleanest lakes in Wisconsin

Top 25 by overall water quality score

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Grade A/B + low algae filter

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Panfish-rich, public access

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Full state directory

Other Grade F Lakes in Wisconsin

Lake Charlemagne

Cook County · Clarity: 2 ft

Bode Lake North

Cook County · Clarity: 1.5 ft

Great Lakes Quarries West

Cook County · Clarity: 2.5 ft

Bull Frog Lake

Cook County · Clarity: 3 ft

Belly Deep Slough Lake

Cook County · Clarity: 0.7 ft

Sauk Lake

Cook County · Clarity: 1 ft

Hypereutrophic Lakes in Wisconsin

Bode Lake North Belly Deep Slough Lake Sauk Lake Washington Park Lagoon Lake

Reservoir Info (USACE NID)

Fairfield Lake is a man-made reservoir impounded by the Fairfield Side Channel Reservoir Dam (completed 1979), built primarily for water supply on the TRIB LITTLE WABASH R; earth-type dam, 16 ft tall and 1,850 ft long.

Surface area: 18 ac
Normal storage: 274.66 ac-ft
Max storage: 328.66 ac-ft
Drainage area: 0.03 sq mi
Hazard class: Low
Owner: CITY OF FAIRFIELD

Source: USACE National Inventory of Dams, NID ID IL50585 · Operator website · Matched by proximity (0.21 km)

EPA Impairment Status

Fairfield Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Nutrients (phosphorus, nitrogen)

Source: EPA ATTAINS assessment unit IL_RCZJ · Official waterbody report

Data Sources

Water quality data from the EPA Water Quality Portal

Impairment status from EPA ATTAINS 303(d) database

Grading methodology based on Metropolitan Council standards

Most recent sample: 2022-10-24

Monitoring stations: 1