Illinois Great Lakes waterbody · state assessment record
Jarvis Beach (Marion Mahoney Griffin Beach)
Assessment decisions reported by Illinois to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2024 reporting cycle.
- 0.26
- Miles of shoreline
- Great Lakes Shoreline
- Water type
This waterbody in one line
Jarvis Beach (Marion Mahoney Griffin Beach), a Great Lakes waterbody in Illinois, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2024). Its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Fish consumption is assessed as not supporting.
- Not Supporting
- overall status
- P10
- 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 Jarvis Beach (Marion Mahoney Griffin Beach) 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: monitoring lag
The signature tension is currency: the reporting cycle is 2024 while monitoring evidence runs through 2019, a 5-year gap. Cycle year and last-monitored year move independently in ATTAINS; this page shows both.
A split ruling across uses
This record splits: Not Supporting on fish consumption, Fully Supporting on recreation. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Jarvis Beach (Marion Mahoney Griffin Beach): Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Jarvis Beach (Marion Mahoney Griffin Beach). The remaining work is implementation and tracking, read the cleanup-standing and cause rows for what the state already committed to address.
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 Jarvis Beach (Marion Mahoney Griffin Beach) 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, Illinois carries 783 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Jarvis Beach (Marion Mahoney Griffin Beach) 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. Monitoring behind at least one of these designated-use verdicts ran through 2019, as Illinois filed it. Illinois filed its own confidence on the 2 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 |
|---|---|---|
| Fish Consumption | Fish-consumption or fishery | Not Supporting Filer confidence: Good |
| Primary Contact | Recreation | Fully Supporting Filer confidence: Good |
| Aesthetic Quality | Other | Not Assessed |
| Aquatic Life | 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 |
|---|---|---|---|
| Polychlorinated Biphenyls (PCBs) | Fish Consumption | 2006 | TMDL approved |
| Mercury | Fish Consumption | 2008 | TMDL approved |
Reading the record
Jarvis Beach (Marion Mahoney Griffin Beach): Category 4A reading
4A Category 4A: impaired, TMDL completed
Illinois filed this assessment unit as Category 4A: impaired, with a pollutant-budget TMDL already completed under 303(d). The listing remains an impairment finding; the plan is on file rather than still awaiting write-up.
Scale and rank
Jarvis Beach (Marion Mahoney Griffin Beach) is one of 783 lake-type waterbodies reported to EPA from Illinois, and one of 439 whose reported record carries enough populated assessment or gauge data for this site to list and index it. Illinois reports this unit as 0.26 miles of shoreline rather than a surface area, so it is not ranked against the acreage figures elsewhere on this site.
Awaiting a filing
The state has not yet filed a definitive aquatic-life verdict for this record; that field populates when it reports it in a future Integrated Report cycle.
In context
Where Jarvis Beach (Marion Mahoney Griffin Beach) sits nationally
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 Jarvis Beach (Marion Mahoney Griffin Beach). Hover or tap any bar for its full count and share.
In context
Illinois context
ATTAINS carries 783 lake-type waterbodies in Illinois, 434 assessed as not supporting at least one use and 63 fully supporting. Among the 439 indexed units there, Jarvis Beach (Marion Mahoney Griffin Beach) ranks 330th by listed-cause count (2 listed causes) ; it sits in the not-supporting set (434 statewide) . Its listed causes include Polychlorinated Biphenyls (PCBs) and Mercury, which also appear among Illinois's most-filed impairment causes (led by Phosphorus, Total).
| Other large assessed lakes in Illinois | Assessed acres |
|---|---|
| Lake Michigan Nearshore Not Supporting | 125,440 |
| Carlyle Not Supporting | 24,580 |
| Rend Not Supporting | 18,900 |
| Shelbyville Not Supporting | 11,000 |
| Crab Orchard Not Supporting | 6,965 |
| Clinton Not Supporting | 4,895 |
Lakes near Jarvis Beach (Marion Mahoney Griffin Beach)'s cause load
Similar cause load
Nearest listed-cause counts (2 here). Peers already in the acreage column are omitted.
- Aaron Mercer Reservoir · 2 causes · OR
- Abbotts Mill Pond · 2 causes · DE
- Adkins Pond · 2 causes · MD
- Adobe Creek Reservoir. · 2 causes · CO
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 IL_QN-09. 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.