Air Permitting
Air Permitting That Keeps Equipment Installs on Schedule
New sterilizer, paint line, generator, boiler, plating tank — the equipment purchase is the easy part. In most states you need an air construction permit in hand before installation starts, and the applicability question underneath it decides whether your project waits weeks or quarters. iSi runs the potential-to-emit math, writes the application, and manages every agency that touches it — with a same-day response, and a fixed price for the determination.
Do You Need an Air Permit? The PTE Math Decides, Not the Nameplate
Permit applicability runs on potential to emit — what your equipment could put out running at full capacity, 8,760 hours a year, before controls you are not yet legally required to operate. Not what it actually emits. A paint booth that sprays four hours a day is evaluated as if it sprayed around the clock, which is how facilities that "obviously" need no permit end up over a threshold they never calculated.
The federal major-source lines — 100 tons per year for criteria pollutants in most categories, 10 tons of a single hazardous air pollutant or 25 tons combined — get the attention. The state lines matter more in practice: state construction-permit thresholds sit far below the federal numbers, and a facility nowhere near major-source status can still owe a state permit before the first anchor bolt goes in. Where the math lands close to a line, iSi evaluates synthetic minor limits — enforceable caps that keep a facility out of the major-source program it would otherwise drift into.
The determination itself is an afternoon-to-days engineering exercise: equipment inventory, emission factors, capacity math, a defensible applicability memo. It is cheap compared to what it decides — the federal penalty for operating without a required permit runs up to $124,426 per day per violation (40 CFR 19.4, 2026), and the state can separately order the equipment idle until the permit it should have had is issued.
Construction Permit First, Operating Permit Second — and the First One Owns Your Schedule
An air construction permit (in Kansas, the KDHE Air Construction Permit; every state has its equivalent) authorizes installing or modifying emitting equipment, and in most states it must be issued before construction or installation begins. Agency review time goes on your project's critical path whether your schedule acknowledges it or not — which is why the permit application should start when the equipment is specified, not when it ships.
The operating permit governs the equipment's working life: emission limits, monitoring, recordkeeping, deviation reporting, renewals. Larger sources fall under the Title V program (40 CFR Part 70) with its annual compliance certifications; smaller sources carry state operating permits with their own calendars. iSi builds the application for both stages, develops the emissions inventory that feeds them, and keeps the renewal dates from becoming surprises.
Which NESHAP Applies to Your Operation?
Federal NESHAP standards (40 CFR Part 63) attach by source category, on top of whatever state permits require — and several sit squarely on operations iSi works in every week:
Aerospace — Subpart GG
Coating, paint stripping, and chemical milling at aerospace manufacturing and rework facilities. iSi's home region builds airplanes, and Subpart GG applicability — which operations count, which coatings, which controls — is a determination iSi has run against real MRO and manufacturing floors.
Surface Coating — Subpart HHHHHH (6H)
Paint stripping and miscellaneous surface coating at area sources — the NESHAP that reaches ordinary paint booths: spray booth filters, painter certification, HVLP or equivalent transfer efficiency, and methylene chloride stripping restrictions.
Chromium Electroplating — Subpart N
Hard and decorative chromium plating and chromium anodizing tanks — surface tension limits, fume suppressants, and the monitoring that proves them. Pairs directly with the OSHA side of the same metal: see iSi's hexavalent chromium exposure guide.
Engines & Sterilizers — ZZZZ and O
Stationary reciprocating engines and generators (Subpart ZZZZ) and ethylene oxide sterilizers (Subpart O) each carry their own applicability tests — the latter now under active EPA reconsideration, covered in iSi's EtO sterilizer NESHAP analysis.
When Two Agencies Hold Your Permit: State Programs and County Air Districts
In most states, one agency issues the permit. In some, a county or local air program sits on top of the state's — with its own application, its own fees, and its own review clock. Miami-Dade County, for example, runs a county air program alongside the Florida DEP, so a new emitting unit there answers to both. Facilities discover this layering late, usually from a comment letter.
iSi has led permitting through exactly this structure — a multi-year aviation-sector project permitted through both the Florida DEP and the Miami-Dade county air program, iSi-led with a Florida PE partner handling the sealed engineering submittals. That is the standing model: iSi manages multi-agency permitting with licensed PE partners where a state requires a sealed submittal, so the certification requirement is a line item in the plan rather than a stall three months in. One point of contact, every agency handled.
What Air Permitting Support Costs
Scope drives price: an applicability determination with a PTE workbook is a different engagement than a full construction permit application with modeling and a county program on top. Every iSi engagement is quoted as a fixed price against a defined scope — no hourly meter — with a same-day response to your request. The comparison that matters isn't between consultants: it's the determination against the $124,426-per-day federal exposure and the production schedule that an unpermitted install puts at risk. The math is an afternoon. The penalty is a payroll.
Air Permitting Questions
Do I need an air permit for new equipment?
It depends on potential to emit — maximum-capacity emissions, not actual. State construction-permit thresholds sit well below the federal major-source lines, so the determination is worth running before any emitting equipment is ordered. It's an afternoon of engineering arithmetic against a $124,426-per-day federal exposure.
What's the difference between construction and operating permits?
The construction permit authorizes installing the equipment and usually must be issued before installation begins — it owns your project schedule. The operating permit governs the equipment once it runs: limits, monitoring, records, renewals. Many projects need both, in that order.
Does iSi handle permitting outside Kansas?
Yes — across iSi's 40-state footprint, including jurisdictions where a county air program layers on top of the state's. Where a state requires a sealed submittal, iSi manages the permitting with licensed PE partners, so the engineering certification never becomes the bottleneck.
My facility already operates. Is it too late for a determination?
No — and running it now is how facilities find out before an inspector does. A retroactive applicability review, a compliance-path memo, and where needed a synthetic minor strategy convert an unknown exposure into a managed one.
Air Permitting Rarely Travels Alone
Environmental Compliance
Emissions inventories, Tier II, SPCC, and the reporting calendar the permit creates.
Industrial Hygiene
The same processes that trigger NESHAPs create worker exposures — welding fume, chromium, solvents. One assessment covers both sides.
Paint Booth Services
6H NESHAP compliance meets booth maintenance — filters, housekeeping, and the records an inspector asks for first.
Start the Determination Before the Equipment Ships
Fixed-price applicability determinations and permit applications, same-day response, every agency handled. We Plug In. You Level Up.
Talk to a Permitting Consultant