Maryland impoundment · state assessment record
Casselman River
Assessment decisions reported by Maryland to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.
- 22
- Assessed acres
- Impoundment
- Water type
This waterbody in one line
Casselman River, an impoundment in Maryland, is assessed as fully supporting its designated uses, with no impairment causes listed in the state's most recent Integrated Report cycle (2022). By assessed acreage it sits below the national median by assessed acreage (38,628 lakes); its impairment list is shorter than on half of assessed lakes (0 listed causes). Aquatic life is assessed as fully supporting.
- Fully Supporting
- overall status
- P35
- Assessed size nationally
- P51
- Shorter cause list
- Fully 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.
How Casselman River reads against 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: cause-list length
The standout filed fact is a short cause list: 0 causes, shorter than 51% of assessed lake-type units. A short list can mean a focused impairment, or a shallow assessment.
Every filed use clears the bar
The filed use determinations for aquatic life are all Fully Supporting. Where an overall IR category still flags the unit, look at the cause list and report standing rather than treating the use row as empty.
IR category in the supporting band
EPA's Integrated Report category for Casselman River is 1. In ATTAINS that band means the assessed uses are supporting (or supporting with other waters in the unit), so the narrative weight shifts to how deep the assessment went and whether monitoring is current, not to a restoration plan.
Overall status: fully supporting
Overall status is Fully Supporting. If an IR category or cause row still appears, it usually reflects a prior listing path or a use the overall rollup does not collapse, read those sections rather than stopping at the tile.
Mid-pack assessed size
22.2 acres lands in the middle tercile of units with an area filed. Acreage is not what distinguishes this record from its peers.
According to the U.S. Environmental Protection Agency's ATTAINS program, Maryland carries 63 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Casselman River 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.
| Designated use | Group | Verdict |
|---|---|---|
| Aquatic Life and Wildlife | Aquatic-life or related | Fully Supporting |
The record
Listed impairment causes
The state's reported assessment lists no impairment causes for this impoundment.
Reading the record
Casselman River: Category 1 reading
1 Category 1: all designated uses supported
Maryland filed this assessment unit as Category 1: every designated use assessed here was reported as supported. That is the filer's Integrated Report classification, not a PlainLakes score.
Scale and rank
Casselman River is one of 63 lake-type waterbodies reported to EPA from Maryland. It is not among the 37 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 22 assessed acres it ranks 25,153rd 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 25,152 lakes with a larger one.
What this record holds
Maryland completed an assessment here and listed no impairment cause, so the record holds a verdict and its supporting use rows but no pollutant to track over time. The state has not yet filed a definitive fish-consumption verdict and a definitive recreation verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
In context
Where Casselman River 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
22 Top 65% larger than 35% 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
0 Among the shortest cause lists fewer listed causes than 51% 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 Casselman River. Hover or tap any bar for its full count and share.
In context
Maryland context
ATTAINS carries 63 lake-type waterbodies in Maryland, 32 assessed as not supporting at least one use and 18 fully supporting.
| Other large assessed lakes in Maryland | Assessed acres |
|---|---|
| Deep Creek Lake Not Supporting | 3,887 |
| Conowingo Reservoir Not Supporting | 3,070 |
| Liberty Reservoir Not Supporting | 2,933 |
| Loch Raven Reservoir Not Supporting | 2,236 |
| Prettyboy Reservoir Not Supporting | 1,472 |
| Jennings Randolph Reservoir Fully Supporting | 941 |
Peers near Casselman River's size or cause load
Similar assessed acres
Nearest filed extents (22 acres here).
- Bear · 22 acres · MN
- <Null> · 22 acres · OR
- Lake Washington · 22 acres · WA
- <Null> · 22 acres · OR
Similar cause load
Nearest listed-cause counts (0 here). Peers already in the acreage column are omitted.
- 31st Street Harbor · 0 causes · IL
- 42nd Avenue East Beach · 0 causes · MN
- 59th Street Harbor · 0 causes · IL
- 657 Dunleavy (Beach) · 0 causes · MI
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 MD-050202040030-Cunningham_Lake. 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.