Watermark.
Lima BOSC
Switch site 38 sites · 11 basins 8 open

Each site is one Watermark investigation. The page color says what opens; the campus line is the build on the ground — two different clocks.

MAU Maumee Basin 9 sites
2MI The Two Miamis 9 sites
SE Southeastern Basins 12 sites
NE Northeast Basins 8 sites
The page — what opens on Watermark Open · Draftfull record Queued · Watchingpreview page Restrictedrequest access
The campus — the build on the ground Investigating Confirmed Under construction Operational
All 38 sites — the network index →
Building

Air

The dispersion footprint of the campus's permitted generator fleet.

On the record

A real impact study models where the exhaust from the permitted generators goes. This chapter runs that model. It reports the AERMOD screening field and the peak concentration at each receptor, against the national ambient air quality standards. Every figure here is [inference]: a labeled screening estimate, built on stated stack assumptions because the permit withholds the stack geometry as confidential business information. No figure here is a monitor reading, and none is a finding of violation.

PollutantAveraging periodPeak modeled (µg/m³)NAAQS (µg/m³)ScreenEvidence
NOx1-hour188.00 [inference]
NOxAnnual100.00 [inference]
CO1-hour40000.00 [inference]
CO8-hour10000.00 [inference]

The full gridded field — switch pollutant and period, hover receptors, toggle the NAAQS isopleth — is in the air annex; the buildout itself is visible in the imagery annex.

Reading this chapter · Lima · updated 2026-08-02

The peak-concentration column above reads as dashes, and that is deliberate. The gridded dispersion field is not computed in this bundle, so the study prints no number there. It does not print an “under the standard” verdict either, because an uncomputed screen is not a passing screen.

The reason the field is hard to compute is itself the finding. A dispersion model needs the stack geometry: how tall the exhaust is, how wide, how hot, and how fast it leaves. Ohio EPA granted the applicant a trade-secret withholdingrec , and the issued permit does not carry the engine make or size. Every stack value in this screen is therefore a stated assumption for a typical large stationary diesel generator, not a disclosed figure.

What the permit does bound

Permit P0138965rec sets facility-wide caps: 235.62 tons per year of nitrogen oxides (NOx) and 96.06 tons per year of carbon monoxide. Those caps are the real limit on how much the generator fleet may run.

The study tests three runtime bands against them, for all 114 engines:

  • 100 hours per year, maintenance and readiness testing only — the routine allowance. Within the caps.
  • 18 hours per year of forced dispatch — the central reliability band. Within the caps.
  • 72 hours per year of forced dispatch — the high reliability band. This band breaks the NOx cap.

Why 72 hours is not a hypothetical

The high band is anchored to an event that happened. On 2026-06-30 the Department of Energy issued Order 202-26-33doc , a §202(c) emergency covering PJM through 2026-07-03. That is a 72-hour window in which grid operators may direct generation to run.

The window is on the record. What is not on the record is whether this campus’s fleet ran in it, or how often such orders will recur. Those remain open.

Two records would replace the assumptions in this chapter with measurements. The first is the architectural footprint sheets with the emission-unit plot plan, which would ground the stack locations and their geometry. The second is the engine rating that the final permit withholds. Both are tracked on the leads board.

The record behind this chapter

What this chapter stands on: the records it reads, the inputs its modeled figures rest on, and the reference data behind its baselines — the same pages the record screens serve, not a second copy. A figure the record does not support stays [open] and links nothing.

Record groups this chapter reads