Washington reservoir · state assessment record

Stan Coffin Lake

Assessment decisions reported by Washington to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.

53
Assessed acres
Lake / Reservoir / Pond
Water type
View watchlist

This waterbody in one line

Stan Coffin Lake, a reservoir in Washington, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2022). By assessed acreage it sits above 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. Washington assesses harvesting as not supported; it reported no verdict on fish consumption itself.

Not Supporting
overall status
P56
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
19/100
Stan Coffin Lake

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 WaterF
Not supporting
Suitability as a public drinking-water source
Aquatic LifeF
Not supporting
Support for fish, invertebrates, and other aquatic organisms
Fish ConsumptionF
Not supporting
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 CurrencyB+
2022
Reporting cycle this record’s verdicts were last decided in

Reading Stan Coffin Lake'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.

No ruled-on use clears the bar

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

Stan Coffin Lake: Category 5, TMDL still owed

Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Stan Coffin Lake. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.

Overall status: not supporting

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

Mid-pack inside Washington

Size rank 234 of 385 inside Washington 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, Washington carries 832 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Stan Coffin Lake without modification. See our methodology for reporting-unit limits and gauge linking rules.

Reporting cycle
2022
Washington Integrated Report
Listing category
Category 5
Uses with verdicts
3
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.

Designated use Group Verdict
Aquatic Life - General Aquatic-life or related Not Supporting
Harvesting Fish-consumption or fishery Not Supporting
Water Supply - Domestic Water Drinking-water supply designation Not Supporting

The record

Listed impairment causes

Causes the state listed as impairing designated uses of this reservoir, with the cycle each was first listed and the Clean Water Act action recorded against it.

Cause Affected uses First listed Cleanup standing
Non-Native Aquatic Plants Aquatic Life - General 2004 None reported
Dioxin in Fish Tissue Harvesting, Water Supply - Domestic Water 2008 TMDL priority: Low

Reading the record

Where Stan Coffin Lake sits among peers

22 of 22 Washington lakes assessed this deeply also had no use supported (every lake judged to this depth, so the outcome does not set this record apart)

Washington ruled definitively on 3 designated uses at Stan Coffin Lake and found none of them supported. The dataset shows 22 Washington lakes judged to that same depth.

Washington's assessed lakes are most often judged on 1 use; this one was judged on 3.

Assessed lakes in Washington by how many uses were ruled on and how those rulings came out
Less More
Assessed lakes in Washington by how many uses were ruled on and how those rulings came out (lakes)
12345+
All supported 00000
Mixed Not possible0000
None supported 2728922 (this record)82

Ringed cell: Stan Coffin Lake. Source: EPA ATTAINS, Reporting cycles 1987–2026.

Scale and rank

Stan Coffin Lake is one of 832 lake-type waterbodies reported to EPA from Washington, and one of 385 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 53 assessed acres it ranks 17,027th 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 17,026 lakes with a larger one.

Awaiting a filing

The state has not yet filed a definitive recreation verdict for this record; that field populates when it reports it in a future Integrated Report cycle.

In context

Where Stan Coffin Lake 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

53 Top 44% larger than 56% 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 Stan Coffin Lake. Hover or tap any bar for its full count and share.

In context

Washington context

ATTAINS carries 832 lake-type waterbodies in Washington, 393 assessed as not supporting at least one use and 0 fully supporting. Among the 385 indexed units there, Stan Coffin Lake ranks 115th by listed-cause count (2 listed causes) and 234th by assessed size among the 385 with an area filed; it sits in the not-supporting set (393 statewide) . Its listed causes include Non-Native Aquatic Plants, which also appears among Washington's most-filed impairment causes (led by Non-Native Aquatic Plants). It also lists Dioxin in Fish Tissue, outside that top-five list.

Other large assessed lakes in Washington Assessed acres
Bumping Lake Not Assessed 1,354
Sullivan Lake Not Supporting 1,298
Deer Lake Not Supporting 1,146
Loon Lake Not Supporting 1,094
American Lake Not Supporting 1,092
Newman Lake Not Supporting 1,091

Peers near Stan Coffin Lake's size or cause load

Similar assessed acres

Nearest filed extents (53 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

  • The listing here is on a fishery use, not on fish consumption, and this state reported no consumption verdict for this reservoir. Your state fish-advisory program is the source for whether the catch is safe to eat. 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 WA17020010012451_001_001. 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.