Mountain Island Lake is a mesotrophic lake in Gaston County, North Carolina. Water quality is graded B based on 2 sampling years through 2022. Compared to the 4 other monitored lakes in Gaston County, Mountain Island Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, North Carolina DNR, last sampled 2022-09-13. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
No clarity data. Phosphorus level: 20 µg/L. Chlorophyll-a: 6.5 µg/L. Trophic State Index: 48.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 20 µg/L | B |
| Chlorophyll-a (Algae) | 6.5 µg/L | B |
| Trophic State Index (TSI) | 48 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Mountain Island Lake
Location
County Ranking
Ranked #1 of 5 lakes in Gaston County
Nearby Lakes in Gaston County
Explore Mountain Island Lake across LakeGrade
More North Carolina Lake Rankings
Top 25 by overall water quality score
Top 25 by Secchi water clarity
Grade A/B + low algae filter
Panfish-rich, public access
Full state directory
Other Grade B Lakes in North Carolina
Mesotrophic Lakes in North Carolina
More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-09-13
Monitoring stations: 6