Lake Tranquility
Sussex County, New Jersey51 acresView mapDirections
NJDEP publishes the water-quality measurements for Lake Tranquility. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
Lake Tranquility in Sussex County, New Jersey has water-quality measurements published by NJDEP, shown here as reported. Water clarity: 8.5 ft visibility. Phosphorus: 15.2 µg/L. Chlorophyll-a (algae): 6.4 µg/L. Surface area: 51 acres.
Lake Tranquility is a 51-acre mesotrophic lake in Sussex County, New Jersey. Compared to the 17 other monitored lakes in Sussex County, Lake Tranquility ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-11-19. Methodology: how these readings are compared.
Swimming conditions
Readings onlyBacteria advisory
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. Lake Tranquility is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury), pathogens (E. coli, fecal), pH / acidity, pCBs. Check local advisories before you swim.
Whether Lake Tranquility is safe to swim in today is a call for the New Jersey Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Tranquility
These are the measurements NJDEP publishes for Lake Tranquility, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 8.5 ft. Phosphorus 15.2 µg/L. Chlorophyll-a 6.4 µg/L. TSI 46.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 8.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 15.2µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 6.4µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 46 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lake Tranquility
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
51 acres
No bathymetric survey has been published for Lake Tranquility, so its depth is not documented here.
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Stays near Lake Tranquility
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Fishing Lake Tranquility
Reservoir Info (USACE NID)
Lake Tranquility is a man-made reservoir impounded by the Lake Tranquility Dam (completed 1932), built primarily for recreation on the Trout Brook; earth-type dam, 14 ft tall and 170 ft long.
- Surface area
- 51 ac
- Normal storage
- 495 ac-ft
- Drainage area
- 3 sq mi
- Hazard class
- High
- Owner
- Township of Green
Source: USACE National Inventory of Dams, NID ID NJ00275 · Operator website
EPA Impairment Status
Lake Tranquility is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Drinking water, Aquatic life, Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NJ02040105070050-01 · Official waterbody report
Nearby Lakes in Sussex County
Frequently asked questions about Lake Tranquility
Where is Lake Tranquility?
- Lake Tranquility is a lake in Sussex County, New Jersey. Its water-quality measurements are published by NJDEP and shown on this page as reported.
What is the water quality of Lake Tranquility?
- Lake Tranquility in Sussex County, New Jersey has water-quality measurements published by NJDEP, shown here as reported. Water clarity: 8.5 ft visibility. Phosphorus: 15.2 µg/L. Chlorophyll-a (algae): 6.4 µg/L. Surface area: 51 acres.
Is Lake Tranquility safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Tranquility is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury), pathogens (E. coli, fecal), pH / acidity, pCBs. Check local advisories before you swim.
Explore Lake Tranquility across LakeQuality
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Where this data comes from
50 measurements from 2 monitoring stations, 2023–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- NJDEP Bureau of Freshwater and Biological Monitoring
NJDEP_BFBM50 samples · 2023–2024
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
Monitoring station identifiers (2)
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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database