New York reservoir · state assessment record
Saranac River, Union Falls Reservoir
Assessment decisions reported by New York to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle, a cycle that carries an interim EPA action.
- 1,571
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Saranac River, Union Falls Reservoir, a reservoir in New York, is assessed as not supporting one or more designated uses, with one listed impairment cause in the state's most recent Integrated Report cycle (2022), a cycle that carries an interim EPA action. By assessed acreage it sits among the largest 5% by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (one listed cause vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P96
- Assessed size nationally
- P20
- Shorter cause list
- Not 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.
Reading Saranac River, Union Falls Reservoir's filed record
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 Saranac River, Union Falls Reservoir nationally is assessed size: 1,571 acres, larger than 96% of the 38,628 lake-type units with an area on file.
No ruled-on use clears the bar
On the uses this filer ruled on, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Saranac River, Union Falls Reservoir: Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Saranac River, Union Falls Reservoir. 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 Saranac River, Union Falls Reservoir is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Typical cause-list length
1 listed cause is a middle-tercile list length among assessed lake-type units. Look to IR category and use outcomes for the distinctive reading.
According to the U.S. Environmental Protection Agency's ATTAINS program, New York carries 2,231 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Saranac River, Union Falls Reservoir 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 |
|---|---|---|
| Fishing | Aquatic-life or related | Not Supporting |
| Secondary Contact Recreation | Recreation | Insufficient Information |
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 |
|---|---|---|---|
| Mercury | Fishing Also assessed as meeting: Secondary Contact Recreation | 2010 | TMDL approved |
Reading the record
Saranac River, Union Falls Reservoir: Category 4A reading
4A Category 4A: impaired, TMDL completed
New York 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
Saranac River, Union Falls Reservoir is one of 2,231 lake-type waterbodies reported to EPA from New York, and one of 428 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 1,571 assessed acres it ranks 1,641st 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 1,640 lakes with a larger one.
Awaiting a filing
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 Saranac River, Union Falls Reservoir 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
1,571 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
1 Longer than most more listed causes than 49% 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 Saranac River, Union Falls Reservoir. Hover or tap any bar for its full count and share.
In context
New York context
ATTAINS carries 2,231 lake-type waterbodies in New York, 563 assessed as not supporting at least one use and 79 fully supporting. Among the 428 indexed units there, Saranac River, Union Falls Reservoir ranks 152nd by listed-cause count (one listed cause) and 45th by assessed size among the 392 with an area filed; it sits in the not-supporting set (563 statewide) . Its listed causes include Mercury, which also appears among New York's most-filed impairment causes (led by pH).
| Other large assessed lakes in New York | Assessed acres |
|---|---|
| Lake Champlain, Main Lake, Middle Not Supporting | 54,972 |
| Oneida Lake Not Supporting | 51,269 |
| Seneca Lake, Main Lake, Middle Fully Supporting | 40,290 |
| Cayuga Lake, Main Lake, Mid-South Fully Supporting | 33,083 |
| Lake George Not Supporting | 28,523 |
| Great Sacandaga Lake Not Supporting | 24,722 |
Peers near Saranac River, Union Falls Reservoir's size or cause load
Similar assessed acres
Nearest filed extents (1,571 acres here).
- Intermediate Lake · 1,571 acres · MI
- Pine Mountain · 1,571 acres · MN
- Lake Pat Cleburne · 1,572 acres · TX
- Twin Buttes Reservoir · 1,572 acres · TX
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron · 1 causes · MN
- Aaron River Reservoir · 1 causes · MA
- Abbotts Creek (including Lexington-Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake) · 1 causes · NC
- Abeniki Lake · 1 causes · NH
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 NY1003-0040. 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.