Williams Pond
Barnstable County, MassachusettsView mapDirections
Clarity, phosphorus, and algae sit in the clean band for this region.
↑ up from C at the last regrade
- Eutrophic
- Impaired · Mercury
- #5 of 8 in the county
- Public access
- Limited data
Williams Pond in Barnstable County, Massachusetts has a water quality grade of B (Good). Chlorophyll-a (algae): 11 µg/L.
- Type
- Eutrophic
- Chlorophyll-a
- 11 µg/L
- Public access
- Yes
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Stays near Williams Pond
Compare lakeside cabins, hotels, and vacation rentals near Williams Pond in Barnstable 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.
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Watch Williams Pond’s letter
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Williams Pond is a productive, nutrient-rich eutrophic lake in Barnstable County, Massachusetts. Water quality is graded B based on 1 sampling years through 2018. Limited fish-species data available. Public access is available. Compared to the 7 other monitored lakes in Barnstable County, Williams Pond ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2018-08-29. Grade methodology: LakeQuality methodology.
What Williams Pond is good for
From access and monitoring records, not editorial picks.
- Camping1 public campground nearby
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 B is nutrients and algae, not a swimming clearance. Williams Pond is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Water Quality Grade: B (Good)
No clarity data. Chlorophyll-a 11 µg/L. TSI 54. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 11 µg/L | Good |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Recreation & Access
Public campgrounds near Williams Pond
- Wellfleet Hollow State Campground4.4 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Fishing Williams Pond
EPA Impairment Status
Williams Pond is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MA96298 · Official waterbody report · Matched by proximity (0.44 km)
County Ranking
Ranked #5 of 8 lakes in Barnstable County
Nearby Lakes in Barnstable County
Frequently asked questions about Williams Pond
Where is Williams Pond?
- Williams Pond is a lake in Barnstable County, Massachusetts. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Williams Pond?
- Williams Pond in Barnstable County, Massachusetts has a water quality grade of B (Good). Chlorophyll-a (algae): 11 µg/L.
Is Williams Pond safe to swim in?
- The B is nutrients and algae, not a swimming clearance. Williams Pond is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Are there campgrounds on Williams Pond?
- Williams Pond has 1 public campground from USGS The National Map within 5 km, including Wellfleet Hollow State Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Williams 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
Massachusetts's cleanest and most-polluted lakes, ranked
Planning a trip around Cape Cod?
Williams Pond is about 3 miles from Cape Cod National Seashore. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Cape Cod →More Massachusetts Lake Rankings
Other Grade B Lakes in Massachusetts
Eutrophic Lakes in Massachusetts
Where this data comes from
3 measurements from 1 monitoring station, 2018. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP3 samples · 2018
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
Public campgrounds from USGS The National Map Structures, within about 3 miles