The Basics of Boiler Permitting in Pennsylvania

Posted by Kara Humes on Friday, May 17, 2024

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What is a boiler? Who regulates boiler permitting?

A boiler is a closed vessel in which water is heated, steam is generated, steam is superheated, or any combination thereof. Boilers are commonly found at industrial sites, healthcare facilities, and schools. Most boilers combust some type of fossil fuel, such as natural gas or heating oil. Boilers are defined as external combustion units and sources of air pollutant emissions subject to environmental regulation and possibly air permitting. In most of Pennsylvania, the Department of Environmental Protection (PADEP) regulates and issues air quality permits for a variety of industrial and commercial operations, including combustion sources like boilers. Sources located in Philadelphia and Allegheny Counties are permitted through the County agency.

Additionally, a boiler is classified as a “pressure vessel”, which is a container for the containment of pressure, either internal or external. In Pennsylvania, under the Boiler and Unfired Pressure Vessel Law and its regulations, the Department of Labor & Industry permits the installation or moving of all boilers and unfired pressure vessels, periodically inspects these units, and issues credentials for persons inspecting these units.

Both of these permits are crucial for compliance and safety in boiler operations, but there can be confusion when contracts simply refer to “obtaining permits” for boiler projects. It is important to understand the differences and be clear about what “permits” have been applied for. Typically, installers will apply for the pressure vessel permit during boiler installation. Air permits must be obtained PRIOR to beginning any construction at the site beyond ground clearing and grading.

Why the details matter in boiler permitting.

The air permit process can vary depending on the size of the boiler, type of fuel, and boiler location. Boiler size is defined by the design-rated heat input, typically expressed in Million British Thermal Units (MMBTUs) per hour. Small, natural gas or distillate oil-fired boilers with heat inputs less than 10 MMBtu/hr may be conditionally exempt from construction permitting (also known as “Plan Approval”), but all boilers are subject to operating permit requirements if the facility is required to have an operating permit.

Understanding PADEP General Permits

Because of the complexity of the Plan Approval process, PADEP has issued a number of “General Permits” for common air emissions source categories to expedite the permitting process and provide certainty for the permit requirements. General Permits have lower application fees and the permits are typically issued within 30 days after submittal of an application.

In January 2023, PADEP revised one of the most commonly used General Permits, “GP-1” for gas/oil-fired boilers. The GP-1 permit was first issued in 1995 and covered natural gas or distillate fuel oil boilers with rated heat inputs between 10-50 MMBtu/hr. A lower threshold of 2.5 MMBtu/hr applies to solid fuel (coal or biomass) or to waste oil boilers. The revised GP-1 includes more stringent emissions limits for nitrogen oxides (NOx) and for carbon monoxide (CO) and extends applicability to larger boilers up to 100 MMBtu/hr heat input.

The new GP-1 permit lowers the NOx limit for gas-fired boilers from 30 ppm to 9 ppm. This dictates that new boilers be equipped with “low-NOx” combustion technology which typically requires “flue gas recirculation” but does not require use of much more expensive catalytic technologies. The CO limit for gas-fired boilers has been lowered from 300 ppm to 130 ppm. The fuel oil boiler NOx limit remains 90 ppm but the CO limit has been lowered from 300 ppm to 130 ppm. Visible emissions (i.e., “opacity” or smoke) is limited to 10% opacity with up to 30% allowed for up to 3 minutes in any hour.

Annual reporting requirement added.

A new annual reporting requirement has been included in GP-1. An annual report certifying compliance with all the GP-1 permit conditions must be signed by a company “responsible official” (officer of the company or Plant Manager) and must include air emissions calculations to show that annual emissions from all boilers do not exceed major source levels (e.g., 100 tons/year for NOx or CO). This reporting requirement will require permittees to track monthly fuel usage in each boiler and to use a spreadsheet to track emissions using vendor-supplied emissions data and/or US EPA boiler emissions factors.

Source testing (i.e., initial “stack testing”) is required for large oil-fired boilers with heat inputs greater than 50 MMBtu/hr. Gas-fired boilers and dual fuel (gas/oil) boilers that only fire oil during gas curtailments are excluded from source testing requirements. All boilers are subject to annual tune-up requirements and must conduct tune-ups measuring NOx/CO once every 3 years.

Individual Plans

If the boiler cannot meet the requirements of the general permit, an individual Plan Approval will be required. The Plan Approval process is lengthy (6-8 months), costly ($2,500 – $7,500 fee depending on type of source), involves public notice and comment opportunity, and requires that applicants utilize “Best Available Technology” (BAT) on a case-by-case basis to minimize air emissions.

Don’t get steamed, reach out to me for boiler permitting support in Pennsylvania and beyond.

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Kara Humes

senior environmental manager

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Categories: Buildings & Campus  |  Industrial & Manufacturing

Tagged: Environmental

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