MEMORANDUM 

TO : Board of Environmental Protection 

FROM: Jeff Crawford, Bureau of Air Quality 

DATE: April 16, 2009 

RE : Post to Public Hearing: Chapter 131 Cutback Asphalt and Emulsified Asphalt 

Statutory and Regulatory Reference: 

A. Statutory authority. 

38 MRSA Section 585-A provides that the Board of Environmental Protection "may 

establish and amend regulations to implement ambient air quality standards and emission 

standards. These regulations shall be designed to achieve and maintain ambient air 

quality standards and emission standards within any region and prevent air pollution." 

B. Specific legal mandates requiring adoption. 

Section 184 of the Clean Air Act requires states to implement or update reasonably 

available control technology (RACT) controls on all major VOC and NOx emission 

sources and on source categories covered by a control technique guideline document. 

EPA developed a control technique guideline (CTG), Control of Volatile Organic 

Compounds from the Use of CutbackAsphalt (1977), covering cutback and emulsified 

asphalt paving operations . 

Location/Applicability: 

The proposed regulation will apply statewide. 

Description: 

Background: Section 184 of the Clean Air Act requires states to implement or update reasonably 

available control technology (RACT) controls on all major VOC and NOx emission sources and 

on source categories covered by a Control Technique Guideline (CTG) document. EPA defines 

RACT as the lowest emission limit that a particular source is capable of meeting by the 

application of control technology that is reasonably available considering technological and 

economic feasibility. In December 1977, EPA published a CTG for the use of cutback asphalt 

which recommended replacing cutback asphalt binders with emulsified asphalt during the ozone 

season . Since asphalt paving operations occur predominantly during warm weather, when 
formation of ozone is most prevalent, the decreased use of cutback asphalt greatly reduces the 

VOC emissions from paving operations . 

Asphalt used for paving is grouped into three general categories: hot-mix, cutback and 

emulsified. Hot-mix asphalt, the most commonly used asphalt, produces minimal VOC 

emissions because its organic components have high molecular weights and low vapor pressures. 

Cutback asphalt has traditionally been used as a tack coat between old and new layers of hot-mix 

asphalt, in seal operations, in priming new roadbed for hot-mix applications and cold-mix 

applications for pavement repair . In preparing cutback asphalt, asphalt cement is blended or "cut 

back" with a diluent, typically from 25 to 45 percent by volume of petroleum distillates, 

depending on the desired viscosity. Emulsified asphalt is now used in most of the same 

applications as cutback asphalt, but is a lower VOC alternative to cutback asphalt. Instead of 

blending asphalt cement with petroleum distillates, emulsified asphalts use a blend of asphalt 

cement, water and an emulsifying agent. 

Discussion : The Department is proposing these amendments as part of its effort to satisfy the 

RACT requirements mandated under the CAA and regulations related to the 1997 8-hour ozone 

NAAQS. According to the EPA's Final Rule to Implement the 8-Hour Ozone NAAQS (70 FR 

71612, November 29, 2005), areas classified as "moderate" nonattainment or higherl must 

submit a demonstration, as a revision to the SIP, that their current rules fulfill 8-hour ozone 

RACT requirements for all CTG categories and all major, non-CTG sources. This demonstration 

can be made with either a new RACT determination or a certification that previously-required 

RACT controls represent RACT for the 8-hour ozone NAAQS. For those cases in which states 

have new stationary sources not covered by existing RACT regulations, or when new data or 

technical information indicates that a previously adopted RACT measure does not represent a 

newly-available RACT control level, states are required to update their rules. 

As part of its 8-hour ozone RACT review, Maine has determined that its previous asphalt paving 

regulations no longer constituted RACT under the 8-hour ozone standard . Chapter 131 was 

originally adopted in 1993, and was based on 1977 and 1979 CTGs published by EPA. Maine's 

regulation, Chapter 131 Cutback Asphalt and Emulsified Asphalt, prohibited the use of cutback 

asphalt on public roads during the ozone season, but allowed for a number of exemptions. 

As part of the regional effort to address the Federal 1997 8-hour NAAQS for ozone, the OTC 

commissioned a study (MACTEC Report February 2007) to quantify the emission reduction 

benefits from potential new controls, which they deemed to be reasonable . The Department's 

proposed amendments are based on the OTC control measure summary (which serves as 

guidance to OTC member states to use to develop rules), included in the MACTEC Report and 

RACT regulations in other northeast states . Maine is proposing to amend its Chapter 131 

Cutback and Emulsified Asphalt rule to prohibit the use of cutback asphalt during the ozone 

season and limit the use of emulsified asphalt to that which contains not more than 6.0 ml of oil 

distillate (as determined using the American Society for Testing and Materials Methods or 

American Association of State Highway and Transportation Officials Methods) for all asphalt 

paving activities . 

1 Because Maine is included in the OTC under section 184 of the CAA, the RACT requirements apply statewide. 
Environmental Issues : 

Volatile organic compounds contribute to ground-level ozone formation or smog which 

aggravates respiratory ailments such as asthma, bronchitis, and emphysema. The presence of 

ozone impedes the breathing of even healthy people. 

Departmental Recommendation: 

The Department recommends that the Board hold a public hearing on this proposal on June 1$, 

2009. 

Estimated Time of Presentation : 

15 minutes