Delaware reservoir · state assessment record
Silver Lake (168 acres)
Assessment decisions reported by Delaware to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle. One of the 2 cleanup plans below was established by EPA rather than by Delaware.
- 168
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Silver Lake, a reservoir in Delaware, is assessed as not supporting one or more designated uses, with 4 listed impairment causes in the state's most recent Integrated Report cycle (2026). By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (4 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as fully supporting. Fish consumption is assessed as not supporting.
- Not Supporting
- overall status
- P79
- Assessed size nationally
- P3
- 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.
Where Silver Lake 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: in-state cause rank
Inside Delaware, cause-list rank is the local separator: Silver Lake is 1 of 46 indexed units by listed-cause count, toward the top of that state's filed lists.
Longer than most cause lists
4 listed causes puts this unit above 95% 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.
The uses disagree
This record splits: Not Supporting on fish consumption, recreation, Fully Supporting on aquatic life. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Silver Lake: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Silver Lake. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Large within Delaware
Among Delaware's 46 indexed units with an area, Silver Lake ranks 4 by assessed size, toward the large end of that state file.
According to the U.S. Environmental Protection Agency's ATTAINS program, Delaware carries 47 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Silver Lake 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 |
|---|---|---|
| Fish Consumption | Fish-consumption or fishery | Not Supporting |
| Fish, Aquatic Life, and Wildlife | Aquatic-life or related | Fully Supporting |
| Primary Contact Recreation | Recreation | 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 |
|---|---|---|---|
| Polychlorinated Biphenyls (PCBs) | Fish Consumption | 1996 | TMDL established by EPA |
| Dioxin | Fish Consumption | 2002 | TMDL priority: Low |
| Furan Compounds | Fish Consumption | 2002 | TMDL priority: Low |
| Enterococcus | Primary Contact Recreation | 2006 | TMDL approved |
Reading the record
EPA plan standing on Silver Lake
1 cleanup plan EPA established here
EPA, not Delaware, established 1 of the 2 plans.
Scale and rank
Silver Lake is one of 47 lake-type waterbodies reported to EPA from Delaware, and one of 46 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 168 assessed acres it ranks 8,230th 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 8,229 lakes with a larger one.
In context
Where Silver Lake 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
168 Top 21% larger than 79% 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
4 Longer than most more listed causes than 95% 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 Silver Lake. Hover or tap any bar for its full count and share.
In context
Delaware context
ATTAINS carries 47 lake-type waterbodies in Delaware, 40 assessed as not supporting at least one use and 6 fully supporting. Among the 46 indexed units there, Silver Lake ranks 1st by listed-cause count (4 listed causes) and 4th by assessed size among the 46 with an area filed; it sits in the not-supporting set (40 statewide) . Its listed causes include Enterococcus, which also appears among Delaware's most-filed impairment causes (led by Enterococcus). It also lists Polychlorinated Biphenyls (PCBs), Dioxin, and Furan Compounds, outside that top-five list.
| Other large assessed lakes in Delaware | Assessed acres |
|---|---|
| Lums Pond Fully Supporting | 198 |
| Red Mill Pond Fully Supporting | 192 |
| Hoopes Reservoir Not Assessed | 188 |
| Noxontown Pond Fully Supporting | 178 |
| Millsboro Pond Not Supporting | 134 |
| Trap Pond Not Supporting | 95 |
Peers near Silver Lake's size or cause load
Similar assessed acres
Nearest filed extents (168 acres here).
- Loon Lake · 169 acres · NY
- Loon Lake · 169 acres · NY
- Upper Mud River Reservoir (a) · 168 acres · WV
- Vancouver Lake · 169 acres · WA
Similar cause load
Nearest listed-cause counts (4 here). Peers already in the acreage column are omitted.
- Agency Lake · 4 causes · OR
- Alachua Sink · 4 causes · FL
- Aldrich Pond · 4 causes · MA
- American Falls Reservoir (Snake River) · 4 causes · ID
What to do with this record
- The fish-consumption use is assessed as not supporting. Before eating fish from this reservoir, 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 DE290-L02. 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.