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LakeQuality

Murdock Lake

NR
Not yet rated
Eutrophic · 15 acres
Limited DataEutrophic

Murdock Lake in Polk County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 35.8 µg/L. Surface area: 15 acres.

Area
15 acres

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Why Murdock Lake has no grade

We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Murdock Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded phosphorus, but not water clarity and algae (chlorophyll-a).

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Murdock Lake is a 15-acre lake in Polk County, Wisconsin.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-22. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

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Water quality measurements for Murdock Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

No clarity data. Phosphorus level: 35.8 µg/L. Trophic State Index: 56.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus35.8 µg/LNot graded
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)56Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Murdock Lake

Compare lakeside cabins, hotels, and vacation rentals near Murdock Lake in Polk County, Wisconsin — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

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Lake Details

CharacteristicValue
Surface Area15 acres

No bathymetric survey has been published for Murdock Lake, so its depth is not documented here.

Fishing Murdock Lake

EPA Impairment Status

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

Causes of impairment

Nutrients (phosphorus, nitrogen)

Source: EPA ATTAINS assessment unit WI10005133 · Official waterbody report · Matched by proximity (2.34 km)

Graded lakes near Murdock Lake

Murdock Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Polk County

Frequently asked questions about Murdock Lake

What is the water quality grade for Murdock Lake?

Murdock Lake in Polk County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 35.8 µg/L. Surface area: 15 acres.

Is Murdock Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Murdock Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

Where this data comes from

2 measurements from 1 monitoring station, 2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX2 samples · 2026

Analytical methods

  • Phosphorus by Colorimetry
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Fish and recreation data from Wisconsin DNR Lakes