East Twin Lake
Litchfield County, ConnecticutView mapDirections
CT DEEP publishes the water-quality measurements for East Twin Lake. Here is what has been measured.
- Oligotrophic
- Limited data
East Twin Lake in Litchfield County, Connecticut has water-quality measurements published by CT DEEP, shown here as reported. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 2.4 µg/L.
East Twin Lake is a cold, clear oligotrophic lake in Litchfield County, Connecticut. Compared to the 11 other monitored lakes in Litchfield County, East Twin Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-08-31. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether East Twin Lake is safe to swim in today is a call for the Connecticut Department of Energy and Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for East Twin Lake
These are the measurements CT DEEP publishes for East Twin Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 10 µg/L. Chlorophyll-a 2.4 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 10µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.4µg/L | Measured, 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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about East Twin Lake
Answers come straight from the public measurements and survey records on this page.
Stays via Stay22
Stays near East Twin Lake
Compare lakeside cabins, hotels, and vacation rentals near East Twin Lake in Litchfield County, Connecticut — 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.
Top-rated places to stay near East Twin Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Follow East Twin Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing East Twin Lake
Nearby Lakes in Litchfield County
Frequently asked questions about East Twin Lake
Where is East Twin Lake?
- East Twin Lake is a lake in Litchfield County, Connecticut. Its water-quality measurements are published by CT DEEP and shown on this page as reported.
What is the water quality of East Twin Lake?
- East Twin Lake in Litchfield County, Connecticut has water-quality measurements published by CT DEEP, shown here as reported. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 2.4 µg/L.
Is East Twin Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore East Twin Lake across LakeQuality
More lakes in Connecticut
Other Lakes in Connecticut
Oligotrophic Lakes in Connecticut
Where this data comes from
10 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- Connecticut Department Of Energy And Environmental Protection
CT_DEP01_WQX10 samples · 2023
Analytical methods
- Total Phosphorus After Block Digestion
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- Nitrate-Nitrite Nitrogen by Colorimetry
- Turbidity by Nephelometry
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.