Michigan Great Lakes waterbody · state assessment record
Gay Stamp Sands Area of Impact
Assessment decisions reported by Michigan to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2018 reporting cycle.
- 4.30
- Assessed square miles
- Great Lakes Open Water
- Water type
This waterbody in one line
Gay Stamp Sands Area of Impact, a Great Lakes waterbody in Michigan, is assessed as not supporting one or more designated uses, with 9 listed impairment causes in the state's most recent Integrated Report cycle (2018). By assessed acreage it sits among the largest 5% by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (9 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting. Fish consumption is assessed as not supporting.
- Not Supporting
- overall status
- P97
- Assessed size nationally
- P0
- 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.
Gay Stamp Sands Area of Impact against the ATTAINS register
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: 9 listed impairment causes, a longer list than 100% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.
Large assessed unit
At 2,752 acres, Gay Stamp Sands Area of Impact clears the upper tercile of assessed lake-type units with an area on file (1,062 still larger). Size comparisons use the portal's deduplicated lake ranking population, not raw ATTAINS row counts.
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.
Gay Stamp Sands Area of Impact: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Gay Stamp Sands Area of Impact. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Large within Michigan
Among Michigan's 493 indexed units with an area, Gay Stamp Sands Area of Impact ranks 38 by assessed size, toward the large end of that state file.
According to the U.S. Environmental Protection Agency's ATTAINS program, Michigan carries 4,307 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Gay Stamp Sands Area of Impact 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 definitive verdicts on this record, Michigan filed the assessment bases as Monitored & Extrapolated Data and Monitored Data. Those are EPA's own words, not PlainLakes' summary of them; where a verdict is filed as extrapolated, the state did not reach it from monitoring alone. Michigan filed its own confidence on the 5 definitive verdicts it rated: Good. That rating is the filer's, in EPA's own field, and EPA publishes no definition of the four words it offers.
| Designated use | Group | Verdict |
|---|---|---|
| Agriculture | Other | Fully Supporting Filer confidence: Good |
| Fish Consumption | Fish-consumption or fishery | Not Supporting Filer confidence: Good |
| Industrial Water Supply | Other | Fully Supporting Filer confidence: Good |
| Navigation | Other | Fully Supporting Filer confidence: Good |
| Other Indigenous Aquatic Life and Wildlife | Aquatic-life or related | Not Supporting Filer confidence: Good |
| Cold Water Fishery | Aquatic-life or related | Not Assessed |
| Partial Body Contact Recreation | Recreation | Not Assessed |
| Total Body Contact Recreation | Recreation | Not Assessed |
| Warm Water Fishery | Aquatic-life or related | Not Assessed |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this Great Lakes waterbody, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Chlordane | Fish Consumption | 2002 | None reported |
| Dioxin (Including 2,3,7,8-Tcdd) | Fish Consumption | 2002 | None reported |
| Mercury in Fish Tissue | Fish Consumption | 2002 | None reported |
| PCBs in Fish Tissue | Fish Consumption | 2002 | None reported |
| Copper in Sediment | Other Indigenous Aquatic Life and Wildlife | 2020 | TMDL priority: Low |
| Perfluorooctane Sulfonate (PFOS) in Fish Tissue | Fish Consumption | 2020 | TMDL priority: Low |
| Sediment Screening Value (Exceedance) | Other Indigenous Aquatic Life and Wildlife | 2020 | TMDL priority: Low |
| Sediment Toxicity | Other Indigenous Aquatic Life and Wildlife | 2020 | TMDL priority: Low |
| Toxaphene in Fish Tissue | Fish Consumption | 2020 | TMDL priority: Low |
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.
- Chlordane
- Atmospheric Deposition - Toxics (confirmed)
- Dioxin (Including 2,3,7,8-Tcdd)
- Atmospheric Deposition - Toxics (confirmed)
- Mercury in Fish Tissue
- Atmospheric Deposition - Toxics (confirmed)
- PCBs in Fish Tissue
- Atmospheric Deposition - Toxics (confirmed)
- Copper in Sediment
- Mining (confirmed)
- Sediment Screening Value (Exceedance)
- Mining (confirmed)
- Sediment Toxicity
- Mining (confirmed)
- Toxaphene in Fish Tissue
- Atmospheric Deposition - Toxics (confirmed)
Michigan also recorded the source of at least one listing here as unknown, including for Perfluorooctane Sulfonate (PFOS) in Fish Tissue.
Reading the record
Assessment basis on Gay Stamp Sands Area of Impact
2 filed assessment bases on this record
For the definitive verdicts on this record, Michigan filed the assessment bases as Monitored & Extrapolated Data and Monitored Data. Those are EPA's own words, not PlainLakes' summary of them; where a verdict is filed as extrapolated, the state did not reach it from monitoring alone.
The cycle is when the state reported; the monitoring year, where filed, is when it measured. How to read assessment currency.
Scale and rank
Gay Stamp Sands Area of Impact is one of 4,307 lake-type waterbodies reported to EPA from Michigan, and one of 776 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 4.30 square miles (2,752 acres) it ranks 1,063rd 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 1,062 lakes with a larger one.
Open in the register
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 Gay Stamp Sands Area of Impact 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
4 Top 3% larger than 97% 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
9 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 Gay Stamp Sands Area of Impact. Hover or tap any bar for its full count and share.
In context
Michigan context
ATTAINS carries 4,307 lake-type waterbodies in Michigan, 807 assessed as not supporting at least one use and 3,457 fully supporting. Among the 776 indexed units there, Gay Stamp Sands Area of Impact ranks 1st by listed-cause count (9 listed causes) and 38th by assessed size among the 493 with an area filed; it sits in the not-supporting set (807 statewide) . Its listed causes include Dioxin (Including 2,3,7,8-Tcdd); Mercury in Fish Tissue; PCBs in Fish Tissue; and Perfluorooctane Sulfonate (PFOS) in Fish Tissue, which also appear among Michigan's most-filed impairment causes (led by Mercury in Fish Tissue). It also lists Chlordane, Copper in Sediment, Sediment Screening Value (Exceedance), Sediment Toxicity, and Toxaphene in Fish Tissue, outside that top-five list.
| Other large assessed lakes in Michigan | Assessed acres |
|---|---|
| Lake Huron (Michigan Jurisdiction) Not Supporting | 5,815,360 |
| Lake Michigan South of Frankfort (Michigan Jurisdiction) Not Supporting | 5,665,920 |
| St. Marys River Not Supporting | 129,983 |
| Lake St. Clair (Michigan Jurisdiction) Not Supporting | 103,616 |
| Lake Erie (Michigan Jurisdiction) Not Supporting | 71,680 |
| Houghton Lake Not Supporting | 20,066 |
Peers near Gay Stamp Sands Area of Impact's size or cause load
Similar assessed acres
Nearest filed extents (2,752 acres here).
- Clear Lake and Smithport Lake; includes old Edwards Lake · 2,752 acres · LA
- Lake Lavon · 2,750 acres · TX
- Cabinet Gorge Reservoir · 2,756 acres · MT
- Little Tallapoosa River (R L Harris Lake) · 2,747 acres · AL
Similar cause load
Nearest listed-cause counts (9 here). Peers already in the acreage column are omitted.
- Brownlee Reservoir, Lower (Porters Flat to Brownlee Dam) · 9 causes · ID
- Eagle Lake (Lassen County) · 9 causes · CA
- Evergreen · 9 causes · IL
- Goose, Upper Lake · 9 causes · WA
What to do with this record
- The fish-consumption use is assessed as not supporting. Before eating fish from this Great Lakes waterbody, check your state fish-advisory program for species-specific meal limits. 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 MI040203000001-26. 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.