How Clean Is Mark Twain Lake by Hwy J?
Mark Twain Lake by Hwy J has fair water quality — typical of lakes with moderate nutrient enrichment. It received a water quality grade of C (Fair) based on EPA monitoring data. Water clarity (Secchi depth): 3.7 ft. Phosphorus: 33.6 µg/L. Chlorophyll-a (algae): 14.6 µg/L. Trophic State Index: 57.
Cleanliness Snapshot
| Metric | Mark Twain Lake by Hwy J | Wisconsin avg |
|---|---|---|
| Overall Grade | C | C |
| Water Clarity (Secchi) | 3.7 ft | — |
| Phosphorus | 33.6 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 14.6 µg/L | <10 = clean |
| Trophic State Index | 57 | <50 = clean |
How does Mark Twain Lake by Hwy J compare?
Mark Twain Lake by Hwy J's grade of C matches or beats the Wisconsin state average of C. It ranks #1 of 4 lakes in Ralls County by water quality score.