Oklahoma lake · state assessment record
Clayton Lake
Assessment decisions reported by Oklahoma to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2018 reporting cycle.
- 95
- Assessed acres
- Lake, Freshwater
- Water type
- Mesotrophic
- Reported trophic class
This waterbody in one line
Clayton Lake, a lake in Oklahoma, is assessed as not supporting one or more designated uses, with one listed impairment cause in the state's most recent Integrated Report cycle (2018). By assessed acreage it sits above the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (one listed cause vs 23,610 assessed lakes). Fish consumption is assessed as not supporting.
- Not Supporting
- overall status
- P69
- Assessed size nationally
- P20
- Shorter cause list
- Not Supporting
- fish consumption
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.
Where Clayton Lake stands in the filed 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: in-state cause rank
Inside Oklahoma, this unit sits toward the short-list end: cause-list rank 142 of 173 indexed units.
Every filed use falls short
On the uses this filer ruled on, fish consumption, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Clayton Lake: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Clayton Lake. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Small within Oklahoma
State size rank 154 of 170 puts Clayton Lake toward the small end of Oklahoma's indexed lake-type units with an area.
Overall status: not supporting
The filer's overall status for Clayton Lake is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
According to the U.S. Environmental Protection Agency's ATTAINS program, Oklahoma carries 456 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Clayton Lake without modification. See our methodology for reporting-unit limits and gauge linking rules.
The record
Assessment entries
Fully Supporting and Not Supporting are the state's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle. Oklahoma filed its own confidence on the 2 definitive verdicts it rated: Excellent. That rating is the filer's, in EPA's own field, and EPA publishes no definition of the four words it offers.
| Assessment entry | Group | Verdict |
|---|---|---|
| Aesthetic | Other | Fully Supporting Filer confidence: Excellent |
| Fish Consumption | Fish-consumption or fishery | Not Supporting Filer confidence: Excellent |
| Agriculture | Other | Insufficient Information Filer confidence: Excellent |
| Fish and Wildlife Propagation-Warm Water Aquatic Community Subcategory | Aquatic-life or related | Insufficient Information Filer confidence: Excellent |
| Primary Body Contact Recreation | Recreation | Insufficient Information Filer confidence: Excellent |
| Public and Private Water Supply | Drinking-water supply designation | Not Assessed |
| Sws-Sensitive Water Supply | Other | Not Assessed |
Not every entry above is a designated use: Sws-Sensitive Water Supply is an antidegradation protection class, not a designated use. The state files it in the ATTAINS use column, so it carries whatever verdict the state recorded against it.
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 |
|---|---|---|---|
| Mercury | Fish Consumption | 2016 | None reported |
Probable sources
Oklahoma 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
Where Clayton Lake sits among peers
6 of 14 Oklahoma lakes assessed this deeply also came out mixed
Oklahoma ruled definitively on 2 designated uses at Clayton Lake and found 1 of 2 not supported. The dataset shows 14 Oklahoma lakes judged to that same depth.
Oklahoma's assessed lakes are most often judged on 5 or more uses; this one was judged on 2.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 13 | 8 | 7 | 8 | 9 |
| Mixed | Not possible | 6 (this record) | 12 | 30 | 92 |
| None supported | 13 | 0 | 0 | 0 | 0 |
Ringed cell: Clayton Lake. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Clayton Lake is one of 456 lake-type waterbodies reported to EPA from Oklahoma, and one of 173 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 95 assessed acres it ranks 12,096th 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 12,095 lakes with a larger one.
Not yet on record
The state has not yet filed a definitive recreation verdict and a definitive aquatic-life verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
Reported trophic class
Mesotrophic is the trophic class the filing agency reported to EPA ATTAINS for this assessment unit. It describes nutrient enrichment, not whether the water is safe, and it is not a PlainLakes inference. What the trophic scale measures.
In context
Where Clayton 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
95 Top 31% larger than 69% 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
1 Longer than most more listed causes than 49% 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 Clayton Lake. Hover or tap any bar for its full count and share.
In context
Oklahoma context
ATTAINS carries 456 lake-type waterbodies in Oklahoma, 153 assessed as not supporting at least one use and 45 fully supporting. Among the 173 indexed units there, Clayton Lake ranks 142nd by listed-cause count (one listed cause) and 154th by assessed size among the 170 with an area filed; it sits in the not-supporting set (153 statewide) . Its listed causes include Mercury, which also appears among Oklahoma's most-filed impairment causes (led by Mercury).
| Other large assessed lakes in Oklahoma | Assessed acres |
|---|---|
| Grand Lake Site 12 Not Supporting | 46,500 |
| Grand Lake Site 13 Not Supporting | 46,500 |
| Grand Lake Site 14 Fully Supporting | 46,500 |
| Grand Lake Site 15 Fully Supporting | 46,500 |
| Robert S. Kerr Lake Not Supporting | 43,380 |
| Texoma Lake, Red River Arm, Lower Not Supporting | 31,081 |
Peers near Clayton Lake's size or cause load
Similar assessed acres
Nearest filed extents (95 acres here).
- Bilby Ranch Lake · 95 acres · MO
- Dunlap · 95 acres · IL
- Kent · 95 acres · VT
- L. Prairie Comm. Lake · 95 acres · MO
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron · 1 causes · MN
- Aaron River Reservoir · 1 causes · MA
- Abbotts Creek (including Lexington-Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake) · 1 causes · NC
- Abeniki Lake · 1 causes · NH
What to do with this record
- The fish-consumption use is assessed as not supporting. Before eating fish from this lake, 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 OK410300030780_00. 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.