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Lake Alcyon

NR
Not yet rated
4.3 ft clear · Eutrophic · 19 acres
Limited DataEutrophic

Lake Alcyon in Gloucester County, New Jersey is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.3 ft visibility. Surface area: 19 acres.

Clarity
4.3 ft
Area
19 acres

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Why Lake Alcyon has no grade

We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Lake Alcyon, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by your state environmental agency and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Lake Alcyon is a 19-acre lake in Gloucester County, New Jersey.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-10-21. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Bacteria advisory

Not rated for swimming — there is not enough monitoring data to judge this lake

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Water quality measurements for Lake Alcyon

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Murky, only visible to about 4.3 ft. Trophic State Index: 56.

MetricValueGrade
Water Clarity (Secchi Depth)4.3 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)56Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Lake Alcyon

Compare lakeside cabins, hotels, and vacation rentals near Lake Alcyon in Gloucester County, New Jersey — 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 Lake Alcyon

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Lake Details

CharacteristicValue
Surface Area19 acres

No bathymetric survey has been published for Lake Alcyon, so its depth is not documented here.

Fishing Lake Alcyon

Reservoir Info (USACE NID)

Lake Alcyon is a man-made reservoir impounded by the Alcyon Lake Dam (completed 1943), built primarily for recreation on the Chestnut Branch Mantua Creek; earth-type dam, 12 ft tall and 480 ft long.

Surface area
19 ac
Normal storage
66 ac-ft
Max storage
150 ac-ft
Drainage area
4 sq mi
Hazard class
Significant
Owner
Borough of Pitman

Source: USACE National Inventory of Dams, NID ID NJ00427 · Operator website

EPA Impairment Status

Lake Alcyon is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

MercuryNutrients (phosphorus, nitrogen)Pathogens (E. coli, fecal)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit NJ02040202130030-01 · Official waterbody report · Matched by proximity (0.66 km)

Graded lakes near Lake Alcyon

Lake Alcyon has no grade, but these lakes within a short drive do.

Nearby Lakes in Gloucester County

Frequently asked questions about Lake Alcyon

Where is Lake Alcyon?

Lake Alcyon is a lake in Gloucester County, New Jersey. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.

What is the water quality grade for Lake Alcyon?

Lake Alcyon in Gloucester County, New Jersey is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.3 ft visibility. Surface area: 19 acres.

Is Lake Alcyon safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Alcyon is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

Eutrophic Lakes in New Jersey

Where this data comes from

6 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.

Collected and reported by

  • Princeton Hydro LLCPRINCETONHYDRO6 samples · 2024–2025
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database