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LakeQuality

Large Lake

Herts and North London, EnglandView mapDirections

EA publishes the water-quality measurements for Large Lake. Here is what has been measured.

Phosphorus
360 µg/L
More phosphorus than most
Measured by EA
Chlorophyll-a
38.7 µg/L
More algae than most
Measured by EA
  • Limited data

Large Lake in Herts and North London, England has official water-quality measurements, shown as reported. Phosphorus: 360 µg/L. Chlorophyll-a (algae): 38.7 µg/L.

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How Large Lake is classified

Large Lake in England is published with the authority's own measurements and class. The measurements here are published by the agency that samples the lake, as reported. Sampling here has recorded phosphorus and algae (chlorophyll-a), but not water clarity.

LakeQuality publishes no grade of its own beside it. Everything below thathas been measured is reported on this page.

Monitoring: the Environment Agency (England).

Large Lake is a lake in Herts and North London County, England.

Source: the Environment Agency (England) — not the EPA Water Quality Portal, last sampled 2017-08-03. Methodology: how these readings are compared.

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Large Lake is safe to swim in today is a call for the Environment Agency (England) and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Large Lake

These are the measurements EA publishes for Large Lake. More on the source.

No clarity data. Phosphorus 360 µg/L. Chlorophyll-a 38.7 µg/L. TSI 78.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)No reading

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus360µg/LMeasured, not scored

The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.

Chlorophyll-a (algae)38.7µg/LMeasured, not scored

The green pigment in algae — a direct measure of how much algae is in the water.

Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.78Hypereutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Very high nutrients, dense algae, poor clarity

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Frequently asked questions about Large Lake

Where is Large Lake?

Large Lake is a lake in Herts and North London, England. This page reports official water-quality measurements, shown as reported.

What is the water quality of Large Lake?

Large Lake in Herts and North London, England has official water-quality measurements, shown as reported. Phosphorus: 360 µg/L. Chlorophyll-a (algae): 38.7 µg/L.

Measurements on this page ↑

Is Large Lake safe to swim in?

Large 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.

Swimming on this page ↑

Where this data comes from

8 measurements from 2 monitoring stations, 2017. Retrieved from the Environment Agency (England; not the EPA Water Quality Portal) on 2026-08-16.

Collected and reported by

  • Environment Agency (England)ea-wqa8 samples · 2017
Monitoring station identifiers (2)
  • TH-PGWL0200
  • TH-PGWL0201

Authority classifications are shown as the authority published them. See where the data comes from and data sources.