UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION III 1650 Arch Street Philadelphia, Pennsylvania 19103 DATE: May

26, 2011 SUBJECT: Technical Support Document

– Commonwealth of Pennsylvania

– Control of

Emissions of Particular Matter from the Oper ation of Outdoor Wood - fired Boilers /s/ FROM: Rose Quinto, Environmental Engineer

Office of Air Program Planning TO: File /s/ THRU: Cristina Fernandez , Associate Director

Office of Air Program Planning A. BACKGROUND On Ju ly 18, 1997 (62 FR 3 8652), the Environmental P rotection Agency (EPA) amended the National Ambient Air Quality Standard (NAAQS) for particular matter (PM) to add a new standard for fine particles, using fine particulates equal to or less than 2.5 micrometers in diameter (PM 2.5 ) as the indicator. EPA set the health - based (primary ) and welfare - based (secondary

) PM 2.5 annual standard at a level of 15 micrograms per cubic meter (μg/m 3 ) and the 24 - hour standard at a level of 65 μg/m 3 . The health - based primary standard is designed to protect human health from elevated levels of PM 2.5 , which have been linked to premature mortality and other health effects. The secondary standard is designed to protect against major environmental effects of PM 2.5 such as visibility impairments, soili ng, and materials damage. On October 17, 2006 (71 FR 61236), EPA revised the primary and secondary

24 - hour NAAQS for PM 2.5 to 35 μg/m 3 from 65 μg/m 3

. A significant and growing source of PM 2.5 emissions in the Commonwealth of Pennsylvania is from outdoor wood - fired boilers (OWBs). OWBs, also referred to as outdoor wood - fired furnaces, outdoor wood - burning appliances, or outdoor hydronic heaters, are free - standing fuel burning devices designed: (1) to burn clean wood or other approved solid fuels; (2) spe cifically for outdoor installation or installation in structures not normally intended for habitation by humans or domestic animals, such as garages; and (3) to heat building space or water by means of distribution, ty

pically through pipes, of a fluid heat ed in the device, ty pically water , or a water and antifreeze mixture. They resemble a small shed or mini - barn with a short smokestack on top. OWBs are being sold to heat homes and buildings ; produce domestic hot water; heat swimming pools or hot tubs; an d provide heat to agricultural operations such as greenhouses and dairies.2

A concern associated with certain OWBs is the air pollution they may produce. Smoldering fires and short smokestacks may create heavy

smoke to the ground that sometimes causes a n eighborhood nuisance or an adverse impact on public health and the environment. Smoke from OWBs which form from incomplete combustion, contain emissions from fine partic le pollution, carbon monoxide, and other organic products, such as formaldehyde, be nze ne and aromatic hydrocarbons, all of which can cause cancer . When inhaled, fine particles from smoke emissions are carried deep into the lungs and can impair lung function and aggregate existing medical conditions such as asthma, lung or heart disease. Individuals particularly sensitive to PM 2.5 exposure include older adults, people with lung and heart disease, and children. Unlike indoor wood stoves that are regulated by EPA, OWBs are not required to meet a Federal emission standard, and the majority of them are not equipped with pollution controls. EPA initiated a voluntary

program that encourages manufacturers of OWBs to improve air quality through developing and distributing cleaner - burning, more efficient OWBs. Through this voluntary effort, OWBs are certified and labeled to meet EPA emissions performance levels in two phases. Phase 1 of the program was in place from January 2007 through October 15, 2008. To qualify

for Phase 1, manufacturers were required to develop an OWB model that was 70% cleaner - burning than unqualified models by meeting the EPA air emission standar d of 0.6 pound PM per million British thermal unit ( Btu ) heat input as tested by an independent accredited laboratory . Phase 1 OWB models are labeled with an orange tag . Phase 1 P artnership Agreements ended when Phase 2 Partnership Agreement s were initiated on October 16, 2008. To qualify

for Phase 2, manufacturers must develop an OWB model that is 90% cleaner - burning than the Phase 1 OWBs and meet the EPA air emissions standard o f 0.32 pound PM per million Btu heat output . The Phase 2 OWB models, just like the Phase 1 OWB models are tested by an independent accredited laboratory . Phase 2 OWB models are labeled with a white tag . Additional information about the EPA voluntary OWB program is available on EPA’s Web site at www.epa.gov/burnwise . Furthermore, the Northeast States for Coordinated Air Use Management (NESCAUM), which is a regional air pollution control organization, comprised of the air program directors of all the New England states, New York and New Jersey , in coordination with a number of states and EPA, developed a model rule for regulating OWBs (also known as outdoor hydronic heaters (OHHs)). The model rule was released i n January 2007 and is available at www.nescaum.org/topics/outdoor - hydronic - heaters . The purpose of the model rule is to assist state and local agencies in adopting requirements that wi ll reduce air pollution from OWBs. T he model rule establishes emission limits and labeling requirements for new OWBs and contains the following components for both new and existing OWB s: setback requirements from property lines, structures, and homes ; st ack height requirements ; and distributor and buyer notification requirements . On October 20, 2010, the Pennsylvania Department of Environmental Protection (PADEP) submitted a State Implementation Plan (SIP) revision pertaining to the control of emissions of particular matter (PM) from the operation of OWBs . This SI P revision is based on the NESCAUM model rule. The emission standard established in this SIP revision is the Phase 2 emission standard described in the EPA voluntary OWB program.3

B. STATE SU BMITTAL The SI P revision adds definitions and terms to Title 25 of the Pennsylvania Code (25 Pa. Code) Chapter 121.1, relating to definitions, used in the substantive provisions of this SIP revision. The SI P revision also adds a new regulation pertaining to the standards for contaminants on particulate matter emissions in 25 Pa. Code Chapter 123 (Standards of Contaminants), Section 123.14

– Outdoor Wood - Fired Boilers. The following definitions and terms were added in 25 Pa. Code 121.1 : Btu

– British thermal unit

– The amount of thermal energy necessary

to raise the temperature of 1 pound of pure liquid water by 1° Fahrenheit (F) at the temperature at which water has its greatest density (39°F). Clean wood

– The term includes the following: (1) wood that contains no paint, stains, or other ty pes of coatings; and (2) wood that has not been treated with preservatives or chemicals, including copper, chromium arsenate, creosote and pentachlorophenol. New Phase 2 outdoor wood - fired boiler

– A Phase 2 out door wood - fired boiler that is installed on or after October 2, 2010. Non - Phase 2 outdoor wood - fired boiler

– An outdoor wood - fired boiler that has not been certified or qualified by

EPA as meeting a particulate matter emission limit of 0.32 pounds per m illion Btu output or lower and is labeled accordingly . Outdoor wood

- fired boiler

– A fuel - burning device that: (1) is designed to burn, or is capable of burning, clean wood or other fuels listed under allowed fuels in this SI P revision; (2) has a rated thermal output of less than 350,000 Btu per hour; (3) the manufacturer designs or specifies for outdoor installation or installation in structures not normally intended for habitation by humans or domestic animals, including garages and sheds; and (4) heats building space or fluid, or both, through distribution, ty

pically through pipes, of a fluid heated in the device, ty pically water or a mixture of water and antifreeze. The fuel - burning device may also be known as an: outdoor wood - fired furnace; outdoor wood - burning appliance; and outdoor hydronic heater. Phase 2 outdoor wood

- fired boiler

– An outdoor wood - fired boiler that has been certified or qualified by

EPA as meeting a particular matter emission limit of 0.32 pounds per million Btu output or lower and is labeled accordingly . Summary of the SIP Revision The SI P revision adds a new regulation in 25 Pa. Code Chapter 123 (Standards for Contaminants, Particulate Matter Emissions), Section 123.14

– Outdoor Wood - Fired Boilers.4

The requirements of thi s SI P revision, beginning October 2, 2010 (effective date of the regulation) , applies to the following: (1) A person, manufacturer, supplier or distributor who sells, offers for sale, leases or distributes an OWB for use in this Commonwealth . (2) A pe rson who installs an OWB in this Commonwealth . (3) A person who purchases, receives, leases, owns, uses or operates an OWB in this Commonwealth . The SI P revision does not apply to a person, manufacturer, supplier, or distributor who sells, offers for sale, leases or distributes in this Commonwealth a non - Phase 2 OWB, if the person, manufacturer, supplier or distributor demonstrates the non - Phase 2 OWB is intended for shipment and use outside of this Commonwealth. The SIP revision also does not apply t o a permanently

installed OWB that was installed prior to October 2, 2010, and is transferred to a new owner as a result of a real estate transaction. Another exemption in this SI P revision states that a person may not sell, offer for sale, distribute or lease a non - Phase 2 OWB in this Commonwealth, unless the OWB was manufactured, distributed, purchase d or leased, and received in this Commonwealth before May 31, 2011. This exemption shall remain in effect until May 31, 2011. A non - Phase 2 OWB purchase d during the sell - through period shall meet the following requirements: (1) T he non - Phase 2 OWB shall be installed a minimum of 150 feet from the nearest property line. (2) H ave a permanently

attached stack that extends a minimum of 10 feet above the ground , and is installed according to the manufacturer’s specifications. Furthermore, a person may not sell, offer for sale, distribute or install an OWB for use in this Commonwealth, unless it is a Phase 2 OWB. A person may also not purchase, lease or receive an OWB for use in this Commonwealth unless it is a Phase 2 OWB. The requirements for a new Phase 2 OWB in this Commonwealth are the following: (1) A setback requirement for a new Phase 2 OWB is that a person may not install a new Phase 2 OWB unle ss the boiler is installed a minimum of 50 feet from the nearest property line. (2) The stack height requirement for a new Phase 2 OWB is that a person may not install , use or5

operate a new Phase 2 OWB, unless the boiler has a permanently attached stack that extends a minimum of 10 feet above the gro und and be installed according to the manufacturer’s specifications. Furthermore, a person that owns, leases, uses, or operates an OWB in this Commonwealth shall use only one or more of the following fuels: (1) Clean wood. (2) W oo d pellets made from clean wood. (3) H ome heating oil, natural gas or propane that complies with all applicable sulfur limits and is used as a starter or supplementa l fuel for dual - fired OWBs. (4) O ther ty

pes of fuel approved in writing by PADEP upon receipt of a written request. Inaddition, a person that owns, leases, uses, or operates an OWB in this Commonwealth shall not burn a fuel or material in that OWB other than those fuels listed above . Lastly , a person shall not us e or operate an OWB in this Commonwealth unless it complies with applicable Commonwealth, county and local laws. C . EPA EVALUATION The emission standard established in the SIP revision is the Phase 2 emission standard described in the EPA voluntary

p rogram. This SI P revision is also b ased on the NESCUAM model rule that assisted PADEP in adopting requirements that will reduce air pollution from OWBs. The PADEP’s SI P revision establishes emission limits and labeling requirements for new OWBs and conta ins the following components for both new and existing OWB s: setback requirements from property lines, structures, and homes ; s tack height requirements ; and distributor and buyer notification requirements. The Commonwealth will benefit from reduced emissi ons of fine particulate matter (PM 2.5 ) from OWBs by following the requirements of the Phase 2 emission standard s in the EPA voluntary program, and the NESCUAM model rule . Attaining and maintaining levels of PM 2.5 below the health - based NAAQS will reduce p remature mortality and other health effects associated with PM 2.5 exposure. This SI P revision will reduce the problems associated with the operation of OWBs, including smoke, odors and burning prohibited fuels, including garbage, tires, and hazardous wast e. Reductions in ambient levels of PM 2.5 will promote improved visibility , decreased soiling and materials damage, and decreased damage to plants and trees.6

D . CONCLUSION S AND RECOMMENDED AGENCY ACTION The regulation to control PM 2.5 emissions from OW Bs adopted by the Commonwealth of Pennsylvania will result in the reduction of PM 2.5 emissions from the operation of OWBs and w ill help the Commonwealth i n attaining compliance with PM 2.5 NAAQS . EPA approval of the SI P revision is recommen de d.