Pennsylvania reservoir · state assessment record
Lake Nockamixon-02040105003977
Assessment decisions reported by Pennsylvania to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2014 reporting cycle.
- 1,420
- Assessed acres
- Lake / Reservoir / Pond
- Water type
- Eutrophic
- Reported trophic class
This waterbody in one line
Lake Nockamixon-02040105003977, a reservoir in Pennsylvania, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2014). By assessed acreage it sits among the largest 5% by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Pennsylvania assesses trout stocking as not supported; it reported no verdict on aquatic life itself. Pennsylvania assesses fishing as supported; it reported no verdict on fish consumption itself.
- Not Supporting
- overall status
- P96
- Assessed size nationally
- P10
- Shorter cause list
- Not Supporting
- aquatic-life or related
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 Lake Nockamixon-02040105003977 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: assessed size
The number that most separates Lake Nockamixon-02040105003977 nationally is assessed size: 1,420 acres, larger than 96% of the 38,628 lake-type units with an area on file.
Mixed use determinations
This record splits: Not Supporting on aquatic life, Fully Supporting on fish consumption, recreation. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Lake Nockamixon-02040105003977: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Lake Nockamixon-02040105003977. 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 Lake Nockamixon-02040105003977 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, Pennsylvania carries 516 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lake Nockamixon-02040105003977 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 |
|---|---|---|
| Aesthetics | Other | Fully Supporting |
| Boating | Recreation | Fully Supporting |
| Fishing | Fish-consumption or fishery | Fully Supporting |
| Potable Water Supply | Drinking-water supply designation | Fully Supporting |
| Trout Stocking | 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 |
|---|---|---|---|
| Nutrients | Trout Stocking | 1996 | TMDL approved |
| Total Suspended Solids (TSS) | Trout Stocking | 1996 | TMDL priority: Medium |
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.
- Nutrients
- On-Site Treatment Systems (Septic Systems and Similar Decentralized Systems) (confirmed) Municipal Point Source Discharges (confirmed) Agriculture (confirmed)
- Total Suspended Solids (TSS)
- On-Site Treatment Systems (Septic Systems and Similar Decentralized Systems) (confirmed) Municipal Point Source Discharges (confirmed) Agriculture (confirmed)
Reading the record
Where Lake Nockamixon-02040105003977 sits among peers
56% of Pennsylvania's lakes assessed this deeply also came out mixed
Pennsylvania ruled definitively on 5 designated uses at Lake Nockamixon-02040105003977 and found 1 of 5 not supported. The dataset shows 78 Pennsylvania lakes judged to that same depth.
Pennsylvania's assessed lakes are most often judged on 2 uses; this one was judged on 5.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 98 | 154 | 30 | 65 | 34 |
| Mixed | Not possible | 15 | 18 | 20 | 44 (this record) |
| None supported | 32 | 3 | 3 | 0 | 0 |
Ringed cell: Lake Nockamixon-02040105003977. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Lake Nockamixon-02040105003977 is one of 516 lake-type waterbodies reported to EPA from Pennsylvania, and one of 246 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 1,420 assessed acres it ranks 1,763rd 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 1,762 lakes with a larger one.
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 Lake Nockamixon-02040105003977 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
1,420 Top 4% larger than 96% 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 Lake Nockamixon-02040105003977. Hover or tap any bar for its full count and share.
In context
Pennsylvania context
ATTAINS carries 516 lake-type waterbodies in Pennsylvania, 135 assessed as not supporting at least one use and 381 fully supporting. Among the 246 indexed units there, Lake Nockamixon-02040105003977 ranks 20th by listed-cause count (2 listed causes) and 13th by assessed size among the 246 with an area filed; it sits in the not-supporting set (135 statewide) . Its listed causes include Nutrients and Total Suspended Solids (TSS), which also appear among Pennsylvania's most-filed impairment causes (led by Mercury).
| Other large assessed lakes in Pennsylvania | Assessed acres |
|---|---|
| Pymatuning Reservoir-05030102001826 Not Supporting | 15,995 |
| Allegheny Reservoir-05010001002698 Not Supporting | 12,211 |
| Raystown Lake-02050303001006 Fully Supporting | 8,127 |
| Lake Clark-02050306012077 Fully Supporting | 8,117 |
| Lake Wallenpaupack-02040103001053 Not Supporting | 5,461 |
| Presque Isle Bay-04120101000933 Not Supporting | 3,655 |
Peers near Lake Nockamixon-02040105003977's size or cause load
Similar assessed acres
Nearest filed extents (1,420 acres here).
- Seven Beaver · 1,420 acres · MN
- Annabessacook L · 1,420 acres · ME
- French Meadows Reservoir · 1,420 acres · CA
- Dequeen Lake · 1,419 acres · AR
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 PA-LRP-02040105003977. 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.