Oklahoma lake · state assessment record
Maysville Lake (Wiley Post)
Assessment decisions reported by Oklahoma to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2020 reporting cycle.
- 302
- Assessed acres
- Lake, Freshwater
- Water type
- Eutrophic
- Reported trophic class
This waterbody in one line
Maysville Lake (Wiley Post), a lake in Oklahoma, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2020). By assessed acreage it sits in the upper quartile by assessed acreage nationally (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
- P86
- 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.
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 Maysville Lake (Wiley Post)'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: assessed size
The number that most separates Maysville Lake (Wiley Post) nationally is assessed size: 302 acres, larger than 86% of the 38,628 lake-type units with an area on file.
Every filed use falls short
On the uses this filer ruled on, recreation, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Maysville Lake (Wiley Post): Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Maysville Lake (Wiley Post). Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Longer than most cause lists
2 listed causes puts this unit above 80% of assessed lake-type records by list length. Treat that as a coding-and-sampling signal: states that split pollutants finely mint longer lists without proving worse water.
Overall status: not supporting
The filer's overall status for Maysville Lake (Wiley Post) 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 Maysville Lake (Wiley Post) 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. The latest monitoring Oklahoma filed against this record runs through 2018. Oklahoma filed its own confidence on the 4 definitive verdicts it rated: Good and Excellent. 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 |
|---|---|---|
| Aesthetic | Other | Fully Supporting Filer confidence: Good on other public health indicators; Excellent on physical/chemical |
| Agriculture | Other | Fully Supporting Filer confidence: Excellent |
| Fish and Wildlife Propagation-Warm Water Aquatic Community Subcategory | Aquatic-life or related | Not Supporting Filer confidence: Good on biological; Excellent on physical/chemical |
| Primary Body Contact Recreation | Recreation | Not Supporting Filer confidence: Good on physical/chemical; Excellent on pathogen indicators |
| Fish Consumption | Fish-consumption or fishery | Insufficient Information Filer confidence: Excellent |
| Public and Private Water Supply | Drinking-water supply designation | Insufficient Information Filer confidence: Excellent |
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 |
|---|---|---|---|
| Turbidity | Fish and Wildlife Propagation-Warm Water Aquatic Community Subcategory | 2005 | None reported |
| Enterococcus | Primary Body Contact Recreation | 2010 | 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 Maysville Lake (Wiley Post) sits among peers
79% of Oklahoma's lakes assessed this deeply also came out mixed
Oklahoma ruled definitively on 4 designated uses at Maysville Lake (Wiley Post) and found 2 of 4 not supported. The dataset shows 38 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 4.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 13 | 8 | 7 | 8 | 9 |
| Mixed | Not possible | 6 | 12 | 30 (this record) | 92 |
| None supported | 13 | 0 | 0 | 0 | 0 |
Ringed cell: Maysville Lake (Wiley Post). Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Maysville Lake (Wiley Post) 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 302 assessed acres it ranks 5,330th 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 5,329 lakes with a larger one.
Open in the register
The state has not yet filed a definitive fish-consumption verdict for this record; that field populates when it reports it in a future Integrated Report cycle.
Reported trophic class
Eutrophic 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 Maysville Lake (Wiley Post) 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
302 Top 14% larger than 86% 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 Maysville Lake (Wiley Post). 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, Maysville Lake (Wiley Post) ranks 81st by listed-cause count (2 listed causes) and 110th by assessed size among the 170 with an area filed; it sits in the not-supporting set (153 statewide) . Its listed causes include Turbidity, which also appears among Oklahoma's most-filed impairment causes (led by Mercury). It also lists Enterococcus, outside that top-five list.
| 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 Maysville Lake (Wiley Post)'s size or cause load
Similar assessed acres
Nearest filed extents (302 acres here).
- Cedar (Lake) · 302 acres · IL
- Bass · 302 acres · MN
- Adney · 302 acres · MN
- Sunset · 302 acres · MN
Similar cause load
Nearest listed-cause counts (2 here). Peers already in the acreage column are omitted.
- 12th St. Beach · 2 causes · IL
- 31st St. Beach · 2 causes · IL
- 49th St. Beach · 2 causes · IL
- 57th St. Beach · 2 causes · IL
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 OK310810010220_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.