Furnace Pond
Plymouth County, MassachusettsView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #11 of 12 in the county
- 38 ft max depth
- Public access
- Limited data
Furnace Pond in Plymouth County, Massachusetts has a water quality grade of F (Algae-prone). Chlorophyll-a (algae): 46.8 µg/L.
- Max depth
- ~38 ft est.
- Type
- Hypereutrophic
- Chlorophyll-a
- 46.8 µg/L
- Public access
- Yes
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Compare lakeside cabins, hotels, and vacation rentals near Furnace Pond in Plymouth County, Massachusetts — 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Furnace Pond are listed below.
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Watch Furnace Pond’s letter
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Furnace Pond is a highly nutrient-loaded hypereutrophic lake in Plymouth County, Massachusetts with an estimated average depth of about 38 feet. Water quality is graded F based on 1 sampling years through 2018. Limited fish-species data available. Public access is available. Compared to the 11 other monitored lakes in Plymouth County, Furnace Pond ranks #11 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2018-08-28. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The F is nutrients and algae, not a swimming clearance. Furnace Pond is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, oxygen depletion (low DO). Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
No clarity data. Chlorophyll-a 46.8 µg/L. TSI 68. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 46.8 µg/L | Poor |
| Trophic State Index (TSI) | 68 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~38 ft est. |
| Average Depth | ~11 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Massachusetts has not published bathymetry for Furnace Pond.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Furnace Pond
EPA Impairment Status
Furnace Pond is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MA94043 · Official waterbody report
County Ranking
Ranked #11 of 12 lakes in Plymouth County
Nearby Lakes in Plymouth County
Frequently asked questions about Furnace Pond
Where is Furnace Pond?
- Furnace Pond is a lake in Plymouth County, Massachusetts. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Furnace Pond?
- Furnace Pond in Plymouth County, Massachusetts has a water quality grade of F (Algae-prone). Chlorophyll-a (algae): 46.8 µg/L.
Is Furnace Pond safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Furnace Pond is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, oxygen depletion (low DO). Check local advisories before you swim.
How deep is Furnace Pond?
- No published bathymetric survey covers Furnace Pond, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 38 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Furnace Pond across LakeQuality
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Where this data comes from
4 measurements from 2 monitoring stations, 2018. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP4 samples · 2018
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)