Lough Mask
Lough Mask in Mayo, Ireland has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 1.3 µg/L.
Why Lough Mask has no A–F grade
Lough Mask in Ireland 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 Environmental Protection Agency of Ireland, via UNEP GEMS/Water, with WFD lake names from EPA Ireland.
Lough Mask is a lake in Mayo County, Ireland.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2022-12-08. 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 Lough Mask
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 14 µg/L. Chlorophyll-a: 1.3 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 14 µg/L | Not graded |
| Chlorophyll-a (Algae) | 1.3 µg/L | Not graded |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Lough Mask
Compare lakeside cabins, hotels, and vacation rentals near Lough Mask in Mayo, Ireland — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Fishing Lough Mask
Frequently asked questions about Lough Mask
What is the water quality of Lough Mask?
- Lough Mask in Mayo, Ireland has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 1.3 µg/L.
Is Lough Mask safe to swim in?
- Lough Mask 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.
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Where this data comes from
125 measurements from 7 monitoring stations, 2018–2022. Retrieved from UNEP GEMS/Water GFQA (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- European Environment Agency
europeanenvironmentagenc125 samples · —
Analytical methods
- GEMStat OPEN / CC BY 4.0
- EPA Ireland WFD lake waterbodies CC BY 4.0
Monitoring station identifiers (7)
IRL00187IRL00188IRL00189IRL00190IRL00191IRL00192IRL00193
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: 2022-12-08
Monitoring stations: 7