Long Lake
Peterborough, OntarioView mapDirections
Ontario MECP publishes the water-quality measurements for Long Lake. Here is what has been measured.
Long Lake in Peterborough, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 5.2 m visibility. Phosphorus: 5.6 µg/L.
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Long Lake is a lake in Peterborough County, Ontario.
Source: Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring) — not the EPA Water Quality Portal, last sampled 2025-08-14. Grade methodology: LakeQuality methodology.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water16.9 ft of visibility
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Long Lake is safe to swim in today is a call for the Ontario Ministry of the Environment, Conservation and Parks and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Long Lake
These are the measurements Ontario MECP publishes for Long Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 16.9 ft down. Phosphorus 5.6 µg/L. TSI 33.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.15 m | Measured, not scored |
| Phosphorus | 5.6 µg/L | Measured, not scored |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 33 | Oligotrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Fishing Long Lake
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Frequently asked questions about Long Lake
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Where is Long Lake?
- Long Lake is a lake in Peterborough, Ontario. Its water-quality measurements are published by Ontario MECP and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Peterborough, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 5.2 m visibility. Phosphorus: 5.6 µg/L.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
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Where this data comes from
Measurements for Long Lake come from Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring), not the EPA Water Quality Portal. Per-sample source details are not recorded for this lake. Contains information licensed under the Open Government Licence – Ontario. See data sources.