Vermont lake · state assessment record
Somerset
Assessment decisions reported by Vermont to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2016 reporting cycle.
- 1,568
- Assessed acres
- Lake, Freshwater
- Water type
This waterbody in one line
Somerset, a lake in Vermont, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2016). 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). Vermont rules it not supporting for aquatic habitat to support aquatic biota, wildlife, or plant life, while other aquatic-life uses are supported. Fish consumption is assessed as not supporting.
- 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.
Where Somerset 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: assessed size
The number that most separates Somerset nationally is assessed size: 1,568 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 fish consumption, aquatic life, Fully Supporting on recreation. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Somerset: Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Somerset. 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 Somerset 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, Vermont carries 712 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Somerset 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 Biota and Wildlife That May Utilize or Are Present in the Waters | Aquatic-life or related | Fully Supporting |
| Aquatic Habitat to Support Aquatic Biota, Wildlife, or Plant Life | Aquatic-life or related | Not Supporting |
| Fish Consumption | Fish-consumption or fishery | Not Supporting |
| The Use of Waters for Boating and Related Recreational Uses | Recreation | Fully Supporting |
| The Use of Waters for Fishing and Related Recreational Uses | Recreation | Fully Supporting |
| The Use of Waters for Swimming and Other Primary Contact Recreation | Recreation | Fully Supporting |
| The Use of Waters for the Enjoyment of Aesthetic Conditions | Other | Fully Supporting |
| The Use of Water for Irrigation of Crops and Other Agricultural Uses | Other | Not Assessed |
| The Use of the Water for Public Water Source | Drinking-water supply designation | Not Assessed |
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 |
|---|---|---|---|
| Mercury in Fish Tissue | Fish Consumption | 2006 | TMDL approved |
| pH | Aquatic Habitat to Support Aquatic Biota, Wildlife, or Plant Life | 2006 | 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.
- Mercury in Fish Tissue
- Atmospheric Deposition - Toxics (confirmed)
- pH
- Atmospheric Deposition - Acidity (confirmed)
Reading the record
Somerset: Category 4A reading
4A Category 4A: impaired, TMDL completed
Vermont 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
Somerset is one of 712 lake-type waterbodies reported to EPA from Vermont, and one of 712 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 1,568 assessed acres it ranks 1,645th 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 1,644 lakes with a larger one.
Reported trophic class
Vermont 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 Somerset 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
1,568 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 Somerset. Hover or tap any bar for its full count and share.
In context
Vermont context
ATTAINS carries 712 lake-type waterbodies in Vermont, 154 assessed as not supporting at least one use and 558 fully supporting. Among the 712 indexed units there, Somerset ranks 51st by listed-cause count (2 listed causes) and 20th by assessed size among the 712 with an area filed; it sits in the not-supporting set (154 statewide) . Its listed causes include Mercury in Fish Tissue and pH, which also appear among Vermont's most-filed impairment causes (led by Eurasian Water Milfoil, Myriophyllum Spicatum).
| Other large assessed lakes in Vermont | Assessed acres |
|---|---|
| Champ-Northeast Arm Not Supporting | 57,022 |
| Champ-Main Lake Not Supporting | 37,809 |
| Champ-Isle La Motte Not Supporting | 20,962 |
| Champ-Malletts Bay Not Supporting | 12,049 |
| Champ-Port Henry Not Supporting | 8,372 |
| Champ-Missisquoi Bay Not Supporting | 6,398 |
Peers near Somerset's size or cause load
Similar assessed acres
Nearest filed extents (1,568 acres here).
- Lake Wilheim-05010003001343 · 1,567 acres · PA
- West Rush · 1,567 acres · MN
- Kennebec River at Merrymeeting Bay · 1,569 acres · ME
- Elk River (Wheeler Lake) · 1,569 acres · AL
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 fish-consumption use is assessed as not supporting. Before eating fish from this lake, 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 VT12-03L02. 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.