Connecticut lake · state assessment record
Kenosia, Lake (Danbury)
Assessment decisions reported by Connecticut to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2014 reporting cycle.
- 57
- Assessed acres
- Lake, Freshwater
- Water type
This waterbody in one line
Kenosia, Lake (Danbury), a lake in Connecticut, is assessed as not supporting one or more designated uses, with 6 listed impairment causes in the state's most recent Integrated Report cycle (2014). By assessed acreage it sits above the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (6 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as fully supporting.
- Not Supporting
- overall status
- P58
- Assessed size nationally
- P1
- 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 Kenosia, Lake (Danbury) 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 cause-list length: 6 listed impairment causes, a longer list than 99% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.
A split ruling across uses
This record splits: Not Supporting on recreation, Fully Supporting on aquatic life. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Kenosia, Lake (Danbury): Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Kenosia, Lake (Danbury). The remaining work is implementation and tracking, read the cleanup-standing and cause rows for what the state already committed to address.
Overall status: not supporting
The filer's overall status for Kenosia, Lake (Danbury) is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Small within Connecticut
State size rank 72 of 97 puts Kenosia, Lake (Danbury) toward the small end of Connecticut's indexed lake-type units with an area.
According to the U.S. Environmental Protection Agency's ATTAINS program, Connecticut carries 182 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Kenosia, Lake (Danbury) 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. Connecticut filed its own confidence on the 3 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 |
|---|---|---|
| Existing or Proposed Drinking Water | Drinking-water supply designation | Fully Supporting Filer confidence: Good |
| Habitat for Fish, Other Aquatic Life and Wildlife | Aquatic-life or related | Fully Supporting Filer confidence: Good |
| Recreation | Recreation | Not Supporting Filer confidence: Good |
| Fish Consumption | Fish-consumption or fishery | Insufficient Information Filer confidence: Good on other public health indicators; Excellent on physical/chemical |
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 |
|---|---|---|---|
| Algae | Recreation | 1996 | TMDL approved |
| Chlorophyll-a | Recreation | 1996 | TMDL approved |
| Non-Native Aquatic Plants | Recreation | 2016 | TMDL priority: Low |
| Nitrogen, Total | Recreation | 2020 | TMDL approved |
| Nutrient/Eutrophication Biological Indicators | Recreation | 2020 | TMDL approved |
| Phosphorus, Total | Recreation | 2020 | TMDL approved |
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.
- Algae
- Unspecified Urban Stormwater (suspected) Natural Sources (suspected)
- Chlorophyll-a
- Unspecified Urban Stormwater (suspected) Natural Sources (suspected)
- Nitrogen, Total
- Unspecified Urban Stormwater (suspected)
- Nutrient/Eutrophication Biological Indicators
- Unspecified Urban Stormwater (suspected) Natural Sources (suspected)
- Phosphorus, Total
- Unspecified Urban Stormwater (suspected)
Connecticut also recorded the source of at least one listing here as unknown, including for Algae; Chlorophyll-a; Non-Native Aquatic Plants; Nitrogen, Total; and Phosphorus, Total.
Reading the record
Kenosia, Lake (Danbury): Category 4A reading
4A Category 4A: impaired, TMDL completed
Connecticut 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
Kenosia, Lake (Danbury) is one of 182 lake-type waterbodies reported to EPA from Connecticut, and one of 97 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 57 assessed acres it ranks 16,400th 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 16,399 lakes with a larger one.
Not yet on record
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.
In context
Where Kenosia, Lake (Danbury) 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
57 Top 42% larger than 58% 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
6 Longer than most more listed causes than 99% 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 Kenosia, Lake (Danbury). Hover or tap any bar for its full count and share.
In context
Connecticut context
ATTAINS carries 182 lake-type waterbodies in Connecticut, 44 assessed as not supporting at least one use and 95 fully supporting. Among the 97 indexed units there, Kenosia, Lake (Danbury) ranks 3rd by listed-cause count (6 listed causes) and 72nd by assessed size among the 97 with an area filed; it sits in the not-supporting set (44 statewide) . Its listed causes include Algae and Chlorophyll-a, which also appear among Connecticut's most-filed impairment causes (led by Algae). It also lists Non-Native Aquatic Plants; Nitrogen, Total; Nutrient/Eutrophication Biological Indicators; and Phosphorus, Total, outside that top-five list.
| Other large assessed lakes in Connecticut | Assessed acres |
|---|---|
| Candlewood, Lake (New Fairfield/Danbury/Sherman/New Milford) Fully Supporting | 5,086 |
| Lillinonah, Lake (Newtown/Southbury/Bridgewater/Brookfield) Not Supporting | 1,595 |
| Bantam Lake (Litchfield/Morris) Not Supporting | 955 |
| Colebrook River (Reservoir) Lake (Colebrook) Not Assessed | 852 |
| Pachaug Pond (Griswold) Fully Supporting | 837 |
| Saugatuck Reservoir (Weston/Easton/Redding) Fully Supporting | 823 |
Peers near Kenosia, Lake (Danbury)'s size or cause load
Similar assessed acres
Nearest filed extents (57 acres here).
- Dugout · 57 acres · MN
- Sly Lake-02040101001428 · 57 acres · PA
- Lynn Lake · 57 acres · SD
- Laura · 57 acres · MN
Similar cause load
Nearest listed-cause counts (6 here). Peers already in the acreage column are omitted.
- Allegan Lake · 6 causes · MI
- Almonesson Creek · 6 causes · NJ
- Ambrose Brook (below Lake Nelson) · 6 causes · NJ
- Assunpink Ck (below Shipetaukin Ck) · 6 causes · NJ
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 CT6600-01-1-L3_01. 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.