Långträsk Lake
Långträsk Lake in Siuntio, Finland has official water-quality measurements, not a LakeQuality A–F grade. Water clarity: 0.8 m visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 38.5 µg/L. Maximum depth: 13.1 ft.
- Clarity
- 0.8 m
- Max depth
- 4 m
Why Långträsk Lake has no A–F grade
Långträsk Lake in Finland is published with the authority's own measurements, not a LakeQuality letter. official authority class; not a LakeQuality A–F letter Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
A letter on the LakeQuality scale would be an invention, not an official class. Everything below that has been measured is still reported on this page.
Monitoring: the Finnish Environment Institute (Syke) and the ELY Centres.
Långträsk Lake is a lake in Siuntio County, Finland with a maximum depth of 13 feet.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-07-31. 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 Långträsk Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 2.6 ft of visibility. Phosphorus level: 30 µg/L. Chlorophyll-a: 38.5 µg/L. Trophic State Index: 61.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.8 m | Not graded |
| Phosphorus | 30 µg/L | Not graded |
| Chlorophyll-a (Algae) | 38.5 µg/L | Not graded |
| Trophic State Index (TSI) | 61 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 4 m |
Where to stay near Långträsk Lake
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Fishing Långträsk Lake
Frequently asked questions about Långträsk Lake
What is the water quality of Långträsk Lake?
- Långträsk Lake in Siuntio, Finland has official water-quality measurements, not a LakeQuality A–F grade. Water clarity: 0.8 m visibility. Phosphorus: 30 µg/L. Chlorophyll-a (algae): 38.5 µg/L. Maximum depth: 13.1 ft.
Is Långträsk Lake safe to swim in?
- Långträsk Lake has official nutrient and clarity measurements, not a bacteria swim class and not a safety clearance. Algal blooms, currents, and depth are not covered. Always check local notices before swimming.
How deep is Långträsk Lake?
- Långträsk Lake has a maximum depth of 13.1 feet.
Explore Långträsk Lake across LakeGrade
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Where this data comes from
25 measurements from 2 monitoring stations, 2018–2025. Retrieved from Syke VESLA (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- Finnish Environment Institute (Syke) and ELY Centres
syke-vesla25 samples · 2018–2025
Analytical methods
- SYKE VESLA
Monitoring station identifiers (2)
5089887792
Authority classifications are stored separately from LakeQuality A–F letters and are never blended. See methodology and data sources.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2025-07-31
Monitoring stations: 2