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Prescribed fire Agency determination

2025-02-25 prescribed-fire smoke episode affecting Augusta-Richmond County, GA-SC

February 25, 2025

Daily PM2.5 peaked at 47.2 µg/m³ near Augusta across 1 covered metro home to 636,760 people. 1 metro placed a top-ten day in their record.

Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 1.7 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 1.1 million cigarettes. An awareness illustration of outdoor exposure at 22 µg/m³ per cigarette (Berkeley Earth), counting only the event's ranked days; not a medical dose.

Why we think this happened

The basis for “Prescribed fire”

The supplied retained evidence supports prescribed-fire smoke for this event; no supplied evidence establishes membership in a broader time-bounded episode.

Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.

U.S. EPA Air Quality System and the submitting air monitoring agency · Feb 25, 2025 official

AQS PM2.5 qualifier IM — Prescribed Fire.

EPA AQS carries an agency-submitted informational qualifier (IM, Prescribed Fire.) on 29 PM2.5 samples in the candidate CBSA on 2025-02-25, identifying prescribed-fire smoke as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.

See every retained source and limitation ↓

Evidence path

From source to city

A cause is more convincing when the record connects three things: something happened, the air mass moved toward the region, and local instruments responded. Here is how much of that chain is documented for this event.

Open the evidence ledger ↓
  1. 1

    Source or mechanism

    Prescribed fire

    EPA AQS carries an agency-submitted informational qualifier (IM, Prescribed Fire.) on 29 PM2.5 samples in the candidate CBSA on 2025-02-25, identifying prescribed-fire smoke as affecting the samples. An informational qualifier is an official…

    View supporting source ↗
    Documented
  2. 2

    Air-mass movement

    The transport path has not been reconstructed

    The retained record does not yet show how air traveled from the proposed source to these metros. A trajectory replay or dated plume analysis belongs here.

    Research gap
  3. 3

    Local response

    47.2 µg/m³ near Augusta

    EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 2.1 cigarette-equivalents at the outdoor daily rate.

    Inspect the pollutant and weather signals ↓
    Documented

Event autopsy

What the instruments saw

Before, during, and after the episode: nearby pollutant monitors and surface-weather stations show what changed. This context tests the “Prescribed fire” explanation; it does not assign the cause by itself.

Observed context · not attribution

Augusta-Richmond County, GA-SC

Monitor comparison window 2025-02-22 to 2025-02-28 · PM2.5 target: Augusta

4 pollutant signals
Fine-particle pulse 40.7 µg/m³

82% above nearby days

Air movement 1.74 kt

22% higher than surrounding days

PM10 59 µg/m³

51% higher than surrounding days

Pollution fingerprint

Metro-wide median of reporting monitors
PM2.5 40.7 µg/m³

82% higher than surrounding days

Before22.3 µg/m³ Event40.7 µg/m³ After20.1 µg/m³
2 monitors · 1 HOUR
PM10 59 µg/m³

51% higher than surrounding days

Before40 µg/m³ Event59 µg/m³ After39 µg/m³
1 monitor · 24-HR BLK AVG
Sulfur dioxide 0.567 ppb

46% higher than surrounding days

Before0.596 ppb Event0.567 ppb After0.325 ppb
1 monitor · 1 HOUR
Ozone 0.049 ppm

5% higher than surrounding days

Before0.040 ppm Event0.049 ppm After0.049 ppm
3 monitors · 8-HR RUN AVG BEGIN HOUR

Atmospheric conditions

Nearby EPA weather observations
Humidity 64.9 %

About the same as surrounding days

Pressure 1005 Millibars

About the same as surrounding days

Temperature 58.2 °F

About the same as surrounding days

Wind 1.74 kt

22% higher than surrounding days

Source: U.S. EPA AirData daily observations and, where available, nearby ASOS/AWOS surface observations. Values are descriptive medians over the retained monitor set; missing measurements remain missing. Transport and source evidence remain separate layers because this instrument pattern does not assign a cause by itself.

Measured daily PM2.5 at EPA monitors, as cigarette-equivalents
EPA monitors sit in metro areas, so the colour clusters there. Land between and beyond them is unmeasured, not clean: this map shows where IAQng has readings, not the extent of the smoke.

Episode peak

-- cigarettes

The smoke map's scale, replayed over this event: the surface interpolates between covered metros' daily records, framed to the affected region. Hover for a reading, click a metro to pin it to the card. Days a monitor did not report draw nothing.

Affected metros

MetroPeak PM2.5Cigarettes, whole eventPeak dayAll-time standing
Augusta-Richmond County, GA-SC 47.2 µg/m³ 2.1 Feb 25, 2025 #9 of its top days

"Cigarettes, whole event" totals a metro's ranked event days at 22 µg/m³ per cigarette: what a person outdoors there breathed across the event, as the illustration. "All-time standing" is where this episode's days sit in each metro's ranked record (worst-area measure, since 1999). Full local context is on each metro's Air Records page.

Public evidence library

What supports this account

Each card states what a source supports—and what it does not. Official records, research, reporting, community observations, and transparent inferences remain visibly different kinds of evidence.

EPA AQS monitor qualifier 1

  • AQS PM2.5 qualifier IM — Prescribed Fire.

    U.S. EPA Air Quality System and the submitting air monitoring agency · Feb 25, 2025 official government

    EPA AQS carries an agency-submitted informational qualifier (IM, Prescribed Fire.) on 29 PM2.5 samples in the candidate CBSA on 2025-02-25, identifying prescribed-fire smoke as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.

NWS Air Quality Alert 1

  • Air Quality Alert for controlled-burn smoke in South Carolina and Georgia

    South Carolina Department · Feb 25, 2025 official government

    The state-originated alert said stagnant conditions would limit dispersion of smoke from numerous controlled burns in South Carolina and Georgia, applying to the Augusta-Richmond County event. IEM is the archive, not the official system of record.

gdelt-doc-api 1

Status and provenance

Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.

This episode was grouped from the monitor record by the catalog pipeline and given its cause from the evidence listed above. It has not been individually reviewed and signed off, so its boundaries, cause, and name may change as evidence accumulates. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula. If it is wrong, tell us.