Iso Onkijärvi
Iso Onkijärvi in Orimattila, Finland has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 14.2 µg/L. Chlorophyll-a (algae): 4.6 µg/L. Maximum depth: 14.8 ft.
- Max depth
- 4.5 m
Why Iso Onkijärvi has no A–F grade
Iso Onkijärvi 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 phosphorus and algae (chlorophyll-a), but not water clarity.
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.
Iso Onkijärvi is a lake in Orimattila County, Finland with a maximum depth of 15 feet.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2026-06-10. 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 Iso Onkijärvi
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 14.2 µg/L. Chlorophyll-a: 4.6 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 14.2 µg/L | Not graded |
| Chlorophyll-a (Algae) | 4.6 µg/L | Not graded |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 4.5 m |
Where to stay near Iso Onkijärvi
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Fishing Iso Onkijärvi
Frequently asked questions about Iso Onkijärvi
What is the water quality of Iso Onkijärvi?
- Iso Onkijärvi in Orimattila, Finland has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 14.2 µg/L. Chlorophyll-a (algae): 4.6 µg/L. Maximum depth: 14.8 ft.
Is Iso Onkijärvi safe to swim in?
- Iso Onkijärvi 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 Iso Onkijärvi?
- Iso Onkijärvi has a maximum depth of 14.8 feet.
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Where this data comes from
4 measurements from 1 monitoring station, 2026. 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-vesla4 samples · 2026
Analytical methods
- SYKE VESLA
Monitoring station identifiers (1)
486
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: 2026-06-10
Monitoring stations: 1