Heart Pond
Middlesex County, MassachusettsView mapDirections
Nutrients and algae run above the regional average.
↓ down from C at the last regrade
- Eutrophic
- Impaired · Mercury
- #5 of 11 in the county
- 42 ft max depth
- Limited data
Heart Pond in Middlesex County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 14.6 µg/L.
- Max depth
- ~42 ft est.
- Type
- Eutrophic
- Chlorophyll-a
- 14.6 µg/L
Stays via Stay22
Stays near Heart Pond
Compare lakeside cabins, hotels, and vacation rentals near Heart Pond in Middlesex 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 Heart Pond are listed below.
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Watch Heart Pond’s letter
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Heart Pond is a productive, nutrient-rich eutrophic lake in Middlesex County, Massachusetts with an estimated average depth of about 42 feet. Water quality is graded D based on 1 sampling years through 2017. Compared to the 10 other monitored lakes in Middlesex County, Heart Pond ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2017-08-24. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyBacteria advisory
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 D is nutrients and algae, not a swimming clearance. Heart Pond is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, noxious aquatic plants, nuisance exotic species, pathogens (E. coli, fecal). Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
No clarity data. Chlorophyll-a 14.6 µg/L. TSI 57. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 14.6 µg/L | Poor |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~42 ft est. |
| Average Depth | ~12 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Massachusetts has not published bathymetry for Heart 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 Heart Pond
EPA Impairment Status
Heart 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 MA82059 · Official waterbody report
County Ranking
Ranked #5 of 11 lakes in Middlesex County
Nearby Lakes in Middlesex County
Frequently asked questions about Heart Pond
Where is Heart Pond?
- Heart Pond is a lake in Middlesex County, Massachusetts. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Heart Pond?
- Heart Pond in Middlesex County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 14.6 µg/L.
Is Heart Pond safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Heart Pond is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, noxious aquatic plants, nuisance exotic species, pathogens (E. coli, fecal). Check local advisories before you swim.
How deep is Heart Pond?
- No published bathymetric survey covers Heart Pond, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 42 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Heart Pond across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Massachusetts's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
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Where this data comes from
3 measurements from 1 monitoring station, 2017. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP3 samples · 2017
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Lake size & watershed from HydroLAKES (HydroSHEDS)