Massachusetts lake · state assessment record
Lake Warner
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.
- 65
- Assessed acres
- Lake, Freshwater
- Water type
This waterbody in one line
Lake Warner, a lake in Massachusetts, is assessed as not supporting one or more designated uses, with 6 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 above the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (6 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P61
- Assessed size nationally
- P1
- 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.
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.
Reading Lake Warner'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: 6 listed impairment causes, a longer list than 99% 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.
Lake Warner: Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Lake Warner. The remaining work is implementation and tracking, read the cleanup-standing and cause rows for what the state already committed to address.
Overall status: not supporting
The filer's overall status for Lake Warner 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 253 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 Lake Warner without modification. See our methodology for reporting-unit limits and gauge linking rules.
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 | Insufficient Information |
| Fish Consumption | Fish-consumption or fishery | Not Assessed |
| Primary Contact Recreation | Recreation | Insufficient Information |
| Secondary Contact Recreation | Recreation | Insufficient Information |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this lake, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Algae | Fish, Other Aquatic Life and Wildlife | 1992 | TMDL approved |
| Dissolved Oxygen | Fish, Other Aquatic Life and Wildlife | 1992 | TMDL approved |
| Phosphorus, Total | Fish, Other Aquatic Life and Wildlife | 1992 | TMDL approved |
| Turbidity | Fish, Other Aquatic Life and Wildlife | 1996 | TMDL approved |
| Fanwort | Fish, Other Aquatic Life and Wildlife | 2020 | None reported |
| Water Chestnut | Fish, Other Aquatic Life and Wildlife | 2020 | None reported |
Probable sources
Massachusetts listed the source of the impairment as unknown. That is the state's own filed value, not a gap in this record: the cause has been identified, the origin has not.
Reading the record
Lake Warner: Category 4A reading
4A Category 4A: impaired, TMDL completed
Massachusetts filed this assessment unit as Category 4A: impaired, with a pollutant-budget TMDL already completed under 303(d). The listing remains an impairment finding; the plan is on file rather than still awaiting write-up.
Scale and rank
Lake Warner 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 65 assessed acres it ranks 15,223rd 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 15,222 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 Lake Warner 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
65 Top 39% larger than 61% 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
6 Longer than most more listed causes than 99% 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 Lake Warner. 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, Lake Warner ranks 44th by listed-cause count (6 listed causes) and 253rd by assessed size among the 678 with an area filed; it sits in the not-supporting set (678 statewide) . Its listed causes include Dissolved Oxygen and Fanwort, which also appear among Massachusetts's most-filed impairment causes (led by Mercury in Fish Tissue). It also lists Algae; Phosphorus, Total; Turbidity; and Water Chestnut, outside that top-five list.
| 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 Lake Warner's size or cause load
Similar assessed acres
Nearest filed extents (65 acres here).
- Barron Flowage No. 3 · 65 acres · WI
- Big Sioux Recreation Area (Lake Calliope) · 65 acres · IA
- Bunch Reservoir · 65 acres · AZ
- Butterfly Lake · 65 acres · MO
Similar cause load
Nearest listed-cause counts (6 here). Peers already in the acreage column are omitted.
- Allegan Lake · 6 causes · MI
- Almonesson Creek · 6 causes · NJ
- Ambrose Brook (below Lake Nelson) · 6 causes · NJ
- Assunpink Ck (below Shipetaukin Ck) · 6 causes · NJ
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 MA34098. 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.