Alabama reservoir · state assessment record
Olin Basin
Assessment decisions reported by Alabama Department of Environmental Management to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2018 reporting cycle.
- 86
- Assessed acres
- Reservoir
- Water type
This waterbody in one line
Olin Basin, a reservoir in Alabama, is assessed as not supporting one or more designated uses, with 2 listed impairment causes 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 (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting. Alabama assesses fishing as not supported; it reported no verdict on fish consumption itself.
- Not Supporting
- overall status
- P67
- 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 Olin Basin'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: in-state cause rank
Inside Alabama, cause-list rank is the local separator: Olin Basin is 52 of 263 indexed units by listed-cause count, toward the top of that state's filed lists.
No ruled-on use clears the bar
On the uses this filer ruled on, fish consumption, 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.
Olin Basin: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Olin Basin. 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 Olin Basin 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, Alabama carries 304 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Olin Basin 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, Alabama filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them.
| Designated use | Group | Verdict |
|---|---|---|
| Contact Recreation | Recreation | Not Supporting |
| Fishing | Fish-consumption or fishery | Not Supporting |
| Industrial and Agriculture Uses | Other | Not Supporting |
| Propagation of Fish and Wildlife | Aquatic-life or related | 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 |
|---|---|---|---|
| DDT (Dichlorodiphenyltrichloroethane) | Propagation of Fish and Wildlife; Industrial and Agriculture Uses; Contact Recreation; Fishing | 1996 | None reported |
| Mercury | Fishing | 1996 | 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.
- DDT (Dichlorodiphenyltrichloroethane)
- Contaminated Sediments (suspected)
- Mercury
- Contaminated Sediments (suspected)
Reading the record
Where Olin Basin sits among peers
7% of Alabama's lakes assessed this deeply also had no use supported
Alabama ruled definitively on 4 designated uses at Olin Basin and found none of them supported. The dataset shows 152 Alabama lakes judged to that same depth.
Alabama's assessed lakes are most often judged on 4 uses, as this one was.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 0 | 5 | 8 | 70 | 47 |
| Mixed | Not possible | 0 | 4 | 71 | 36 |
| None supported | 8 | 1 | 1 | 11 (this record) | 11 |
Ringed cell: Olin Basin. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Olin Basin is one of 304 lake-type waterbodies reported to EPA from Alabama, and one of 263 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 86 assessed acres it ranks 12,950th 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 12,949 lakes with a larger one.
Reported trophic class
Alabama carried the trophic field for this assessment unit and filed it as unclassified, which records that no class was determined rather than that the water is unenriched. What the trophic scale measures.
In context
Where Olin Basin 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
86 Top 33% larger than 67% 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 Olin Basin. Hover or tap any bar for its full count and share.
In context
Alabama context
ATTAINS carries 304 lake-type waterbodies in Alabama, 143 assessed as not supporting at least one use and 130 fully supporting. Among the 263 indexed units there, Olin Basin ranks 52nd by listed-cause count (2 listed causes) and 224th by assessed size among the 263 with an area filed; it sits in the not-supporting set (143 statewide) . Its listed causes include Mercury, which also appears among Alabama's most-filed impairment causes (led by Mercury). It also lists DDT (Dichlorodiphenyltrichloroethane), outside that top-five list.
| Other large assessed lakes in Alabama | Assessed acres |
|---|---|
| Tennessee River (Lake Guntersville) Fully Supporting | 20,440 |
| Wheeler Lake Not Supporting | 18,705 |
| Tallapoosa River (Lake Martin) Fully Supporting | 15,867 |
| Coosa River (Weiss Lake) Not Supporting | 15,066 |
| Tennessee River (Wheeler Lake) Not Supporting | 13,441 |
| Tennessee River (Wilson Lake) Not Supporting | 13,363 |
Peers near Olin Basin's size or cause load
Similar assessed acres
Nearest filed extents (86 acres here).
- Pine Lake · 86 acres · WA
- Camp Two · 86 acres · MN
- Whalen Lake · 86 acres · WI
- Nelson · 86 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
- 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 AL03160203-1103-800. 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.