Delaware reservoir · state assessment record
Moores Lake
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 3 cleanup plans below was established by EPA rather than by Delaware.
- 30
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Moores Lake, a reservoir in Delaware, is assessed as not supporting one or more designated uses, with 3 listed impairment causes in the state's most recent Integrated Report cycle (2026). By assessed acreage it sits below the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (3 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting. Fish consumption is assessed as not supporting.
- Not Supporting
- overall status
- P42
- Assessed size nationally
- P5
- 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.
Moores Lake against the ATTAINS 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: 3 listed impairment causes, a longer list than 90% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.
No ruled-on use clears the bar
On the uses this filer ruled on, fish consumption, recreation, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Moores Lake: Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Moores Lake. 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 Moores Lake is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Small within Delaware
State size rank 35 of 46 puts Moores Lake toward the small end of Delaware's indexed lake-type units with an area.
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 Moores 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 | Not 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 |
|---|---|---|---|
| Nitrogen | Fish, Aquatic Life, and Wildlife | 1996 | TMDL approved |
| Polychlorinated Biphenyls (PCBs) | Fish Consumption | 1996 | TMDL established by EPA |
| Enterococcus | Primary Contact Recreation | 2006 | TMDL approved |
Reading the record
Moores Lake: Category 4A reading
4A Category 4A: impaired, TMDL completed
Delaware 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
Moores 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 30 assessed acres it ranks 22,433rd 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 22,432 lakes with a larger one.
In context
Where Moores 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
30 Top 58% larger than 42% 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
3 Longer than most more listed causes than 90% 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 Moores 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, Moores Lake ranks 6th by listed-cause count (3 listed causes) and 35th by assessed size among the 46 with an area filed; it sits in the not-supporting set (40 statewide) . Its listed causes include Nitrogen and Enterococcus, which also appear among Delaware's most-filed impairment causes (led by Enterococcus). It also lists Polychlorinated Biphenyls (PCBs), 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 |
| Silver Lake Not Supporting | 168 |
| Millsboro Pond Not Supporting | 134 |
Peers near Moores Lake's size or cause load
Similar assessed acres
Nearest filed extents (30 acres here).
- Chub Lake · 30 acres · VA
- Wapoose Lake · 30 acres · WI
- Dawson Lake · 30 acres · ID
- Holiday · 30 acres · MN
Similar cause load
Nearest listed-cause counts (3 here). Peers already in the acreage column are omitted.
- 67th St. Beach · 3 causes · IL
- Abiquiu Reservoir · 3 causes · NM
- Absecon Creek (AC Reserviors) (gage to SB) · 3 causes · NJ
- Absecon Creek (below gage) · 3 causes · NJ
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-L01. 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.