Massachusetts lake · state assessment record

Long Island Pond

Assessment decisions reported by Massachusetts to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle, a cycle that is open for public comment.

33
Assessed acres
Lake, Freshwater
Water type
View watchlist

This waterbody in one line

Long Island Pond, a lake in Massachusetts, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2026), a cycle that is open for public comment. By assessed acreage it sits below the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.

Not Supporting
overall status
P45
Assessed size nationally
P10
Shorter cause list
Not Supporting
aquatic life

Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.

F
Water Quality Standing
38/100
Long Island Pond

A composite of this record's EPA ATTAINS designated-use verdicts, filed impairment count, and assessment currency, weighted and benchmarked against the national corpus of assessed active waterbodies. This is a water-quality standing, not a human-recreation or property-value judgment, and dimensions with no filed verdict drop out rather than count against the score.

RecreationN/A
Not assessed
Swimming, boating, and other primary/secondary contact recreation
Drinking WaterN/A
Not assessed
Suitability as a public drinking-water source
Aquatic LifeF
Not supporting
Support for fish, invertebrates, and other aquatic organisms
Fish ConsumptionN/A
Not assessed
Safety of eating fish caught in this water
Impairment BurdenF
2 causes
Filed pollutant/stressor causes, vs. the national corpus of assessed active units
Assessment CurrencyA+
2026
Reporting cycle this record’s verdicts were last decided in

Reading Long Island Pond's filed record

Paragraphs are selected by this unit's percentiles and use matrix: different lakes lead with different dimensions. Figures are ATTAINS / portal register arithmetic, not advice.

The signature stat: cause-list length

The standout filed fact is cause-list length: 2 listed impairment causes, a longer list than 80% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.

Every filed use falls short

On the uses this filer ruled on, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.

Long Island Pond: Category 4C reading

Category 4C marks impairment from pollution that is not a pollutant (for example habitat or flow alteration) on Long Island Pond. A classic TMDL load model often does not apply; the cause list should name the non-pollutant stressor.

Overall status: not supporting

The filer's overall status for Long Island Pond is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.

Mid-pack inside Massachusetts

Size rank 387 of 678 inside Massachusetts is mid-pack; the national percentile is the better scale comparison for this unit.

According to the U.S. Environmental Protection Agency's ATTAINS program, Massachusetts carries 1,191 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Long Island Pond without modification. See our methodology for reporting-unit limits and gauge linking rules.

Cycle open for public comment. Massachusetts decided this in its 2026 Integrated Report, which is open for public comment and has not been finalized. The decisions below are what Massachusetts has proposed for that cycle; they can change before the cycle is submitted to EPA.
Reporting cycle
2026
Cycle open for public comment
Listing category
Category 4C
Uses with verdicts
1
Definitive use assessments
Sources retrieved
2026-08-17
Portal-wide ATTAINS + NWIS pull

The record

Designated-use assessments

Fully Supporting and Not Supporting are the state's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle. For the one definitive verdict on this record, Massachusetts filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them.

Designated use Group Verdict
Fish, Other Aquatic Life and Wildlife Aquatic-life or related Not Supporting
Aesthetic Other Not Assessed
Fish Consumption Fish-consumption or fishery Not Assessed
Primary Contact Recreation Recreation Insufficient Information
Secondary Contact Recreation Recreation Not Assessed

The record

Listed impairment causes

Causes the state listed as impairing designated uses of this lake, with the cycle each was first listed. None is a pollutant, so none carries a TMDL cleanup plan.

Cause Affected uses First listed Cleanup standing
Non-Native Aquatic Plants Fish, Other Aquatic Life and Wildlife 2002 Not applicable (non-pollutant)
Fanwort Fish, Other Aquatic Life and Wildlife 2020 Not applicable (non-pollutant)

Probable sources named by the state

Each source below is listed under the cause the state filed it against, and carries the word the state filed with it — confirmed, or suspected.

Non-Native Aquatic Plants
Introduction of Non-Native Organisms (Accidental or Intentional) (confirmed)
Fanwort
Introduction of Non-Native Organisms (Accidental or Intentional) (confirmed)

Reading the record

Long Island Pond: Category 4C reading

4C Category 4C: impaired by a non-pollutant; TMDL programme does not apply

Massachusetts filed this assessment unit as Category 4C: the impairment is not caused by a pollutant, so the Clean Water Act 303(d) cleanup-plan (TMDL) programme, which allocates pollutant loads, does not apply here.

A 4C listing is still an impairment finding about designated uses; it is not a clean bill of health. How listing and cleanup work.

Scale and rank

Long Island Pond is one of 1,191 lake-type waterbodies reported to EPA from Massachusetts, and one of 678 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 33 assessed acres it ranks 21,405th by assessed size among the 38,628 lakes the dataset carries an area for, counting a state’s repeated filings of one water once, behind 21,404 lakes with a larger one.

Not yet on record

The state has not yet filed a definitive fish-consumption verdict and a definitive recreation verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.

In context

Where Long Island Pond sits nationally

Assessed size among U.S. lakes

Distribution of assessed acreage across ATTAINS lakes filed with an area, counting a state’s repeated filings of one water once

33 Top 55% larger than 45% of 38,628 lakes

lakes the dataset carries an area for, counting a state’s repeated filings of one water once, bucketed by value

Source EPA ATTAINS · Reporting cycles 1987–2026

Listed causes vs waterbodies carrying a verdict

How many impairment causes U.S. waterbodies with a reported verdict carry

2 Longer than most more listed causes than 80% of 23,610 waterbodies carrying a verdict

named waterbodies carrying a verdict, bucketed by value

Source EPA ATTAINS · Reporting cycles 1987–2026

In both charts each bar is a band and taller bars hold more waterbodies; the dashed line and filled bar mark Long Island Pond. Hover or tap any bar for its full count and share.

In context

Massachusetts context

ATTAINS carries 1,191 lake-type waterbodies in Massachusetts, 678 assessed as not supporting at least one use and 40 fully supporting. Among the 678 indexed units there, Long Island Pond ranks 310th by listed-cause count (2 listed causes) and 387th by assessed size among the 678 with an area filed; it sits in the not-supporting set (678 statewide) . Its listed causes include Non-Native Aquatic Plants and Fanwort, which also appear among Massachusetts's most-filed impairment causes (led by Mercury in Fish Tissue).

Other large assessed lakes in Massachusetts Assessed acres
Quabbin Reservoir Not Supporting 24,010
Wachusett Reservoir Not Supporting 3,962
Assawompset Pond Not Assessed 2,034
North Watuppa Pond Not Supporting 1,728
Long Pond Not Supporting 1,728
South Watuppa Pond Not Supporting 1,473

Peers near Long Island Pond's size or cause load

Similar assessed acres

Nearest filed extents (33 acres here).

Similar cause load

Nearest listed-cause counts (2 here). Peers already in the acreage column are omitted.

How peers are picked

What to do with this record

  • Assessment verdicts are cycle-based, not real-time. For fish-consumption decisions, your state advisory program is the binding source. Consumption status guide
  • Impairment listings follow the Clean Water Act 303(d) process; a listing is a regulatory finding, not a closure notice. 303(d) explained

PlainLakes renders state assessment decisions and federal gauge observations without modification. It does not issue advisories.

Assessment decisions on this page are rendered directly from state Integrated Report records in EPA's ATTAINS system; gauge figures are daily-value observations from the USGS National Water Information System, no number is typed in by an editor. Overall status, use verdicts, and causes are the state's reported decisions for assessment unit MA94088. Counts and percentiles are computed across all lake-type records PlainLakes ingests from ATTAINS. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-08-17. Primary sources: EPA ATTAINS and USGS National Water Information System.