Superfund / NPL site · EPA Superfund SEMS through latest publishNPL Final

Hocomonco Pond

This site is currently on the EPA Superfund National Priorities List and remains under federal cleanup oversight. Most-cited contaminant of concern: 1,2-Dihydroacenaphthylene.

Fisher St, Westborough, Massachusetts · ZIP 01581 · EPA ID MAD980732341

CLEANUP TIMELINE

Listing-date and cleanup-phase enrichment from EPA's per-site SEMS profile is queued for a follow-up ingest pass. Until then, this section will populate from EPA's published timeline data.

Anomaly engine

Notable Signals

No notable signals at this Superfund site for the current ingest. Cleanup-phase and SEMS-action flags are deferred to a follow-up engineering pass.

Contaminants of concern · per EPA SEMS

What's In This Site

Each row pairs a contaminant with the medium it was found in (the exposure pathway). Hover any named contaminant for an agency-cited health-risk summary. Cited count = number of SEMS decision records (RODs and related) that name the pair.

ContaminantPathwayCited
1,2-DihydroacenaphthyleneGroundwater1
1,2-DihydroacenaphthyleneSoil1
1,2-DihydroacenaphthyleneSurface Water1
2,4-DimethylphenolGroundwater1
2-ChlorophenolSediment1
2-MethylnaphthaleneGroundwater1
2-MethylnaphthaleneSediment1
2-MethylnaphthaleneSoil1
2-MethylnaphthaleneSurface Water1
2-Methylphenol (O-Cresol)Groundwater1
2-Methylphenol (O-Cresol)Surface Water1
4-Methylphenol (P-Cresol)Groundwater1
4-Methylphenol (P-Cresol)Surface Water1
9H-FluoreneGroundwater1
9H-FluoreneSediment1
9H-FluoreneSoil1
9H-FluoreneSurface Water1
AnthraceneSediment1
AnthraceneSoil1
AnthraceneSurface Water1
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Groundwater1
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Sediment1
ArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)Soil1
BenzeneHealth riskIARC Group 1 carcinogen. Long-term inhalation causes leukemia and bone-marrow disorders. (IARC, EPA)Groundwater1
BenzeneHealth riskIARC Group 1 carcinogen. Long-term inhalation causes leukemia and bone-marrow disorders. (IARC, EPA)Surface Water1
Benzo(Ghi)PeryleneGroundwater1
Benzo(Ghi)PeryleneSoil1
Benzo[A]AnthraceneHealth riskPAH; IARC Group 2B possible carcinogen; common combustion byproduct and creosote constituent. (IARC)Sediment1
Benzo[A]AnthraceneHealth riskPAH; IARC Group 2B possible carcinogen; common combustion byproduct and creosote constituent. (IARC)Soil1
Benzo[A]AnthraceneHealth riskPAH; IARC Group 2B possible carcinogen; common combustion byproduct and creosote constituent. (IARC)Surface Water1

Showing the top 30 pairs by SEMS citation count. 25 additional (contaminant, pathway) pairs are recorded for this site.

Drinking-water linkage · SDWIS

Groundwater Systems Serving Communities Within 3 Miles

The 7 systems below draw on groundwater (or mixed sources) and serve communities whose centroid sits within 3 miles of this site. Distance is to the served-city centroid — SDWIS does not expose individual wellhead locations, so this is a proximity screen, not a wellhead-impact assessment.

Water systemServesDistancePopulation servedSourceStatus
Sunset Ridge Condominiums PrivateWestborough1.7 mi42GROUNDWATERIn compliance
Regency At Bolton Condominiums PrivateWestborough1.7 mi148GROUNDWATERIn compliance
Charlton Manor Rest Home PrivateWestborough1.7 mi26GROUNDWATERIn compliance
Estates At Highland Ridge PrivateWestborough1.7 mi100GROUNDWATERIn compliance
Lancaster Woods Condominiums PrivateWestborough1.7 mi120GROUNDWATERIn compliance
Revel Pelham PrivateWestborough1.7 mi123GROUNDWATERIn compliance
Cedar Creek Mhp PrivateWestborough1.7 mi154GROUNDWATERIn compliance

Methodology: served-city centroid (TIGER 2020) is used as the PWS coordinate. Source-water classification from SDWIS primary_source_code; only groundwater and mixed-source systems are queried. Click any system above for its full SDWIS profile.

Equity context · ACS 2018-2022 block-group demographics

Who Lives Near This Site

Within 1 mile of this site (1 Census block groups, population-weighted demographics): a population of 2,207. Why we surface this →

POPULATION SHARE
4.4%

Low-income

POPULATION SHARE
77.6%

People of color

POPULATION SHARE
6.1%

Under age 5

POPULATION SHARE
6.3%

Over age 64

Source: Census ACS 2018-2022 block-group demographics, population-weighted across the 1-mile buffer around this site (from USEPA-clone/EJAM-open blockgroupstats). NPL site proximity contributes to the national EJ pattern; indicator-level percentile and disparity scores are surfaced on the county page and the state page.

Source. EPA Superfund Enterprise Management System (SEMS) · retrieved 2026-05-07. SEMS is a federal public-domain dataset under 17 USC §105.

What this is not. We report EPA's published Superfund record — site listing, status, and contaminants of concern as named in EPA's decision documents. We do not perform site visits, independent air or water sampling, or current-state health-risk assessment. NPL listing reflects EPA's Hazard Ranking Score at a point in time; it does not by itself describe present-day exposure.