Virginia reservoir · state assessment record
Harwoods Mill Reservoir (PWS)
Assessment decisions reported by Virginia to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle, a cycle that is open for public comment.
- 258
- Assessed acres
- Reservoir
- Water type
This waterbody in one line
Harwoods Mill Reservoir (PWS), a reservoir in Virginia, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2026), a cycle that is open for public comment. By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P85
- Assessed size nationally
- P10
- 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.
Harwoods Mill Reservoir (PWS) 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: assessed size
The number that most separates Harwoods Mill Reservoir (PWS) nationally is assessed size: 257.7 acres, larger than 85% of the 38,628 lake-type units with an area on file.
Every filed use falls short
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.
Harwoods Mill Reservoir (PWS): Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Harwoods Mill Reservoir (PWS). Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
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 Harwoods Mill Reservoir (PWS) 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, Virginia carries 275 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Harwoods Mill Reservoir (PWS) 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. Virginia filed its own confidence on the 3 definitive verdicts it rated: Fair and 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 |
|---|---|---|
| Aquatic Life | Aquatic-life or related | Not Supporting Filer confidence: Fair on toxicological; Good on physical/chemical |
| Public Water Supply | Drinking-water supply designation | Fully Supporting Filer confidence: Good |
| Wildlife | Other | Not Supporting Filer confidence: Fair |
| Fish Consumption | Fish-consumption or fishery | Not Assessed |
| Recreation | Recreation | Insufficient Information Filer confidence: Good |
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 |
|---|---|---|---|
| Copper | Aquatic Life, Wildlife | 2004 | TMDL priority: Low |
| Dissolved Oxygen | Aquatic Life | 2004 | TMDL priority: Low |
Probable sources
Virginia listed the source of the impairment as unknown. That is the state's own filed value, not a gap in this record: the cause has been identified, the origin has not.
Reading the record
Where Harwoods Mill Reservoir (PWS) sits among peers
71% of Virginia's lakes assessed this deeply also came out mixed
Virginia ruled definitively on 3 designated uses at Harwoods Mill Reservoir (PWS) and found 2 of 3 not supported. The dataset shows 93 Virginia lakes judged to that same depth.
Virginia's assessed lakes are most often judged on 3 uses, as this one was.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 7 | 15 | 26 | 2 | 0 |
| Mixed | Not possible | 14 | 66 (this record) | 48 | 4 |
| None supported | 45 | 3 | 1 | 0 | 0 |
Ringed cell: Harwoods Mill Reservoir (PWS). Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Harwoods Mill Reservoir (PWS) is one of 275 lake-type waterbodies reported to EPA from Virginia, and one of 193 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 258 assessed acres it ranks 5,950th 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 5,949 lakes with a larger one.
Open in the register
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.
Reported trophic class
Virginia 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 Harwoods Mill Reservoir (PWS) 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
258 Top 15% larger than 85% 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 Harwoods Mill Reservoir (PWS). Hover or tap any bar for its full count and share.
In context
Virginia context
ATTAINS carries 275 lake-type waterbodies in Virginia, 181 assessed as not supporting at least one use and 50 fully supporting. Among the 193 indexed units there, Harwoods Mill Reservoir (PWS) ranks 61st by listed-cause count (2 listed causes) and 77th by assessed size among the 193 with an area filed; it sits in the not-supporting set (181 statewide) . Its listed causes include Dissolved Oxygen, which also appears among Virginia's most-filed impairment causes (led by PCBs in Fish Tissue). It also lists Copper, outside that top-five list.
| Other large assessed lakes in Virginia | Assessed acres |
|---|---|
| Kerr Reservoir Assessment unit VAW-L75L_ROA05M22 Not Supporting | 14,828 |
| Kerr Reservoir Assessment unit VAW-L75L_ROA05L98 Not Supporting | 7,018 |
| Kerr Reservoir Assessment unit VAW-L75L_ROA05N22 Not Supporting | 4,182 |
| Lake Drummond Not Supporting | 3,242 |
| Lake Chesdin Not Supporting | 3,164 |
| Lake Gaston Not Supporting | 3,072 |
Peers near Harwoods Mill Reservoir (PWS)'s size or cause load
Similar assessed acres
Nearest filed extents (258 acres here).
- Horseshoe · 258 acres · MN
- Pine · 258 acres · MN
- Trout Lake · 258 acres · NY
- Dusenberry Lake · 258 acres · OR
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
- 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 VAT-C07L_POQ01A04. 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.