Grass Lake
Grass Lake in Ramsey County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar.
- Trend
- ↓ Declining
- Public access
- No
Next lake in Ramsey County
Why Grass 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 Grass Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
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 MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Grass Lake is a lake in Ramsey County, Minnesota. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-02-21. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Grass Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples |
Where to stay near Grass Lake
Compare lakeside cabins, hotels, and vacation rentals near Grass Lake in Ramsey County, Minnesota — 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.
Top-rated places to stay near Grass Lake
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Fishing Grass Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.204 m/yr | 6 |
| Phosphorus | ↓ Declining | +1.29 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.73 µg/L/yr | 6 |
EPA Impairment Status
Grass Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN62-0075-02 · Official waterbody report · Matched by proximity (1.36 km)
Graded lakes near Grass Lake
Grass Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Ramsey County
Frequently asked questions about Grass Lake
What is the water quality grade for Grass Lake?
- Grass Lake in Ramsey County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar.
Is Grass Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Grass Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
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Where this data comes from
7 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA7 samples · 2020
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- Turbidity, Nephelometric Method
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