Spy Pond
Middlesex County, MassachusettsView mapDirections
MassDEP publishes the water-quality measurements for Spy Pond. Here is what has been measured.
- Impaired · Algal growth
- Limited data
Spy Pond in Middlesex County, Massachusetts has water-quality measurements published by MassDEP, shown here as reported. Water clarity: 5 ft visibility.
Spy Pond is a lake in Middlesex County, Massachusetts. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2024-07-26. Methodology: how these readings are compared.
For a place on the water, look through cabin and lake-house rentals near Spy Pond on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Spy Pond is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants, nuisance exotic species, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pesticides. Check local advisories before you swim.
Whether Spy Pond is safe to swim in today is a call for the Massachusetts Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Spy Pond
These are the measurements MassDEP publishes for Spy Pond, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5 ft. TSI 54.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading 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. | 54 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Spy Pond
Answers come straight from the public measurements and survey records on this page.
Stays via Stay22
Stays near Spy Pond
Compare lakeside cabins, hotels, and vacation rentals near Spy 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.
Top-rated places to stay near Spy Pond
Prices for Oct 30–Nov 1, 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.
Planning a whole trip? See where to stay at Massachusetts’s top lakes →
Follow Spy Pond’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Spy Pond
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2024).
Water clarity
Worsening5 years
EPA Impairment Status
Spy Pond 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: Aquatic life, Fish consumption, Recreation, Other.
Source: EPA ATTAINS assessment unit MA71040 · Official waterbody report
Nearby Lakes in Middlesex County
Frequently asked questions about Spy Pond
Where is Spy Pond?
- Spy Pond is a lake in Middlesex County, Massachusetts. Its water-quality measurements are published by MassDEP and shown on this page as reported.
What is the water quality of Spy Pond?
- Spy Pond in Middlesex County, Massachusetts has water-quality measurements published by MassDEP, shown here as reported. Water clarity: 5 ft visibility.
Is Spy Pond safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Spy Pond is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants, nuisance exotic species, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pesticides. Check local advisories before you swim.
Explore Spy Pond across LakeQuality
More lakes in Massachusetts
Other Lakes in Massachusetts
Eutrophic Lakes in Massachusetts
Where this data comes from
9 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS9 samples · 2020–2024
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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database