PlumePrintthe air keeps its own recordsMethods

PlumePrint · HOWARD County

Big Spring

Monitor 48-227-1072, 2021 to 2025, against every emission event filed in HOWARD County. Wind is measured at the monitor itself.

Unexplained episodes

112 / 122

episodes with no matching report

Unseen releases

14 / 14

reported releases the monitor never clearly saw

Matched episodes

0

episodes a filed report does explain

PERIOD:
15 episodes · 1 reports (≥1,000 lb)
TOP — what facilities told the regulator: self-reported events listing SO2 (bar height ~ log of pounds)0 of 1 reported releases ≥ 1,000 lb SO2 never lifted the monitor above 2 ppbBig Spring Carbon BlackAlon Usa Big Spring RefineryOther facilitiesBIG SPRING CARBON BLACK PLANT · incident 400922 · 356,140 lb · FAINTseen by the monitorfaint bumpunseenBOTTOM — what the air recorded: hourly SO2 at EPA monitor; dots mark episodes of 5 ppb or more15 of 15 episodes have no overlapping SO2 report from any facility in the countySO2 at the monitor (ppb, sqrt scale)015153045131.5 ppb · 1 h · UNEXPLAINED128.6 ppb · 1 h · UNEXPLAINED186.1 ppb · 7 h · UNEXPLAINED323.3 ppb · 1 h · UNEXPLAINED160.6 ppb · 3 h · UNEXPLAINED99.9 ppb · 1 h · UNEXPLAINED140.5 ppb · 1 h · UNEXPLAINED110 ppb · 1 h · UNEXPLAINED161 ppb · 1 h · UNEXPLAINED106 ppb · 1 h · UNEXPLAINED101.2 ppb · 1 h · UNEXPLAINED101.4 ppb · 1 h · UNEXPLAINED110 ppb · 1 h · UNEXPLAINED109.7 ppb · 5 h · UNEXPLAINED117.2 ppb · 1 h · UNEXPLAINEDmatchedweak match (startup window)no matching reportJanFebMarAprMayJunJulAugSepOctNovDecJan
UNEXPLAINEDApr 3, 2024 · 11h duration
Peak: 438 ppb SO2 · Wind from WNW (298.7°)
no report overlaps this window · Upwind cone swept on satellite map below ↓
Open AI Case File →
UNEXPLAINEDUPWIND CONE ACTIVE

Air arrived from the WNW (298.7°) during this 438 ppb event. Facilities in the shaded cone were upwind.

Show the wind during:

The shaded arc is where the air came from during the selected episode, widened by the uncertainty of the wind reading. Anything inside it was upwind; the arc says nothing about how far along it a source sat.

The fingerprint

Where the worst hours come from.

The share of hours from each wind direction that land in this monitor’s worst five per cent. One trajectory can be wrong. A pattern that holds across years is evidence.

Peak direction 260°, from the W. Threshold 51.9 ppb. 97% of hours use wind measured on site. The pale outer band is the 90% interval.

170–180° · 0% of 1997 hours180–190° · 0% of 1972 hours200–210° · 0% of 2501 hours210–220° · 1% of 2510 hours220–230° · 3% of 2219 hours230–240° · 22% of 765 hours240–250° · 29% of 591 hours250–260° · 27% of 527 hours260–270° · 30% of 566 hours270–280° · 30% of 859 hours280–290° · 24% of 1839 hours290–300° · 25% of 1372 hours300–310° · 10% of 695 hours310–320° · 9% of 477 hours320–330° · 5% of 515 hours330–340° · 0% of 567 hoursNESW

Episodes with no matching report

Air recorded · No report filed · Click to inspect on map
DatePeakHoursWind fromActions
Apr 3, 2024438 ppb11WNW (298.7°)Open case →
May 25, 2024409.8 ppb15WNW (295°)Open case →
Apr 26, 2024378.6 ppb3WNW (295.2°)Open case →
Apr 11, 2024366.2 ppb7NW (308.3°)Open case →
Dec 14, 2022355.9 ppb1WNW (282.3°)Open case →
Apr 27, 2024343.2 ppb11WNW (302.8°)Open case →
Jan 6, 2023323.3 ppb1W (276.9°)Open case →
May 6, 2024319.9 ppb21WNW (295.2°)Open case →
Apr 7, 2024314.6 ppb23WNW (287.9°)Open case →
May 16, 2024291.6 ppb21WNW (300.5°)Open case →

Reported releases the monitor did not see

Filed by facilities · Not seen by monitor
FacilityFiledReportedMonitor peakStatusActions
Alon US Big Spring RefineryJun 25, 202510,758.36 lb0.2 ppbwind toward442600 ↗
Alon US Big Spring RefineryAug 1, 20213,595.64 lb0.2 ppbwind away364010 ↗

“Wind toward” means the monitor was downwind for part of the release and still recorded nothing unusual.