State of Rhode Island 

Department of Environmental Management 

Office of Air Resources 

In Re: Adoption of the "Providence Carbon Monoxide Limited Maintenance Plan" and 

amendments to the "Rhode Island Air Pollution Control General Definitions" regulation 

and to Air Pollution Control Regulations Nos. 9, 11, 22 and 36. 

DECISION 

Introduction 

On 8 July 2008 a notice was published in the Providence Journal-Bulletin and was mailed to 

interested parties announcing a public hearing and comment period to accept comments on the 

proposed adoption the "Providence Carbon Monoxide Limited Maintenance Plan" and 

amendments to the "Rhode Island Air Pollution Control General Definitions" regulation and to 

Air Pollution Control Regulation Nos. 9, 11, 22 and 36. The public hearing was held on 

8 August 2008 in Room 300 of the Department of Environmental Management Building, 235 

Promenade Street, Providence, Rhode Island . The public comment period extended until 4:00 

PM on 8 August 2008 . 

The proposed "Providence Carbon Monoxide Limited Maintenance Plan" specifies measures that 

will be used by the Rhode Island Department of Environmental Management (RI DEM) to ensure 

that Providence remains in attainment of the National Ambient Air Quality Standard for carbon 

monoxide through 2011 . The proposed revisions to Regulation No. 11, "Petroleum Liquids 

Marketing and Storage," would allow gasoline dispensing facilities that exclusively fuel rental 

cars or corporate or commercial fleets to apply for exemption from Stage II vapor recovery 

requirements and would require annual testing of pressure vacuum caps on Stage II systems. 

The proposed revisions to Regulation No . 22, "Air Toxics" would update several Acceptable 

Ambient Levels and Minimum Quantity thresholds in that regulation; add an additional 

substance, n-propyl bromide, to the list of regulated air toxics ; exempt existing fuel burning 

sources, including those burning biodiesel, as well as water pollution control systems and small 

organic solvent cleaning sources; and clarify reporting requirements . The Minimum Quantities 

listed in Regulation No . 9, "Air Pollution Control Permits," would be changed to be consistent 

with those in Regulation No. 22 . Two guidelines that are referenced in Regulation No. 22, the 

"Rhode Island Air Toxics Guideline" and the "Rhode Island Guideline for Air Quality Modeling 

for Air Toxics Sources," would also be updated. The proposed update to the modeling guideline 

specifies that, henceforth, RI DEM will perform only screening level modeling when evaluating 

permit applications . 
The proposed revision to Regulation No . 36, "Control of Emissions from Organic Solvent 

Cleaning," would exempt cold cleaners using solvents containing 5% or less volatile organic 

compounds and volatile hazardous air pollutants, clarify work practice and reporting 

requirements, regulate vapor cleaners using trans 1,2-dichloroethylene or n-propyl bromide, 

adopt federal facility-wide emissions limits and establish a vapor pressure limit for solvents used 

for cold cleaning . The General Definitions regulation would be amended to include definitions 

consistent with the proposed updates of Regulations No. 22 and 36. 

Decision 

It is the decision of the Hearing Officer to adopt the proposed "Providence Carbon Monoxide 

Limited Maintenance Plan" and amendments to the "Rhode Island Air Pollution Control General 

Definitions" regulation and to Air Pollution Control Regulation Nos. 9, 11, 22 and 36, modified 

as discussed in the response to comments that follows. The final amended regulations and plan 

are appended to this Decision. 

'~ 5' 

Date St~ en Ma3kut, 

Hearing Officer 

Approved: 

Date 

r_= 

W. Michael Sullivan 

Director 
Response to Comments 

This section will present the Rhode Island Department of Environmental Management's (RI 

DEM's) response to the comments received at the public hearing and during the public comment 

period. Each comment has been paraphrased and is followed by RI DEM's response. Similar 

comments have been grouped together. A list of commenters is attached . 

Carbon Monoxide Limited Maintenance Plan Comments 

Comment: EPA generally agrees with Rhode Island's approach of establishing alternative 

criteria for identifying potential CO problems in Providence, in lieu of operating a CO monitor. 

(EPA) 

Response: No response required . 

Comment: RI DEM is proposing to use the East Providence photochemical assessment 

monitoring site (PAMS) as one indicator of a potential carbon monoxide (CO) problem in 

Providence. In order to be more protective, RI DEM should reestablish CO monitoring in 

Providence if the East Providence design value exceeds 5 ppm, rather than the proposed 6.5 ppm. 

(EPA) 

Response: While RI DEM believes that the method used to derive the 6.5 ppm Action Level 

is logical and appropriate, that level has been changed to 5 ppm, as suggested in this comment, in 

order to be more protective . Note that the current CO design value at the East Providence site is 

1 .6 ppm. 

Comment: The CO emissions trigger for reestablishing CO monitoring in Providence should 

be strengthened from the level corresponding to a 100% increase to the level corresponding to a 

30°1o increase in CO emissions in Providence County from 2002 levels . The CO design values in 

1989-1993 in Providence were approximately equal to 7.65 ppm, the value at which an area is 

eligible for a limited maintenance plan and CO emissions inventories in neighboring states show 

that CO emissions decreased approximately 30% between 1990 and 2002. (EPA) 

Response: The Action Level for CO emissions was changed from 293,666 tons per year 

(double the 2002 inventory) to 190,883 tons per year (30% higher than the 2002 inventory) in 

response to this comment. 
Regulation No. 11 Comments 

Comment: Rhode Island should consider also exempting facilities that dispense only E85 from Stage II requirements, as allowed EPA Guidance. (EPA) 

Response : RI DEM has not identified any facilities in Rhode Island that dispense E85 fuel. RI DEM will consider an exemption for such facilities at a future date. The regulation was not changed in response to this comment. 

Comment: Rhode Island may wish to consider requiring ORVR compatible Stage II systems. The cost associated with installation of ORVR nozzles and other hardware is between $5,000 and $10,000 per station, according to the California Air Resources Board. The incremental cost to 

new installations would be lower. Such controls should be considered as potential cost-effective control strategies. (EPA) 

Response: RI DEM is currently participating in an evaluation of available ORVR-compatible equipment in the State and will consider requiring such equipment in future amendments to 

Regulation No. 11 . The regulation was not changed in response to this comment. 

Comment: The version of Regulation No. 11 currently approved in the Rhode Island State Implementation Plan (SIP) requires all facilities that dispense greater than 10,000 gallons of 

gasoline per month as well as all gasoline dispensing facilities constructed or substantially 

modified after 15 November 1992 to install Stage II . However, the existing and proposed 

version allows a new or substantially modified facility to request an exemption if it dispenses less 

than 10,000 gallons per month and demonstrates that Stage II controls are not technically and/or 

economically feasible . When RI DEM submits this amended version of Regulation No . 11 as a 

SIP revision, information on the number and throughput of stations that have been granted an 

exemption should be included. (EPA) 

Response: That information will be included in the SIP submittal. The regulation was not 

changed in response to this comment. 

Regulation Nos. 9 and 22 Comments 

Comment: The proposed amendments to Regulation No. 22 will encourage the use of npropyl bromide (nPB) over less toxic solvents liked trans-dichloroethylene (t-DCE). A degreaser 

using between 200 and 10,000 pounds per year of solvent would be required to file an annual 

registration if that solvent is nPB, but not if it is t-DCE. Moreover, the air toxics modeling 

submitted as part of an Air Toxics Operating Permit would favor nPB over t-DCE, since the 

Acceptable Ambient Levels (AALs) for nPB are less stringent than those for t-DCE. This is 
inconsistent with toxicity data submitted to RI DEM, which shows that the rat 90-day inhalation 

No Adverse Effects Level (NOAEL) for t-DCE is 4,000 ppm, while that for nPB is 100-200 ppm. 

Moreover, the ACGIH recommended occupational limits are 200 ppm for t-DCE and only 10 

ppm for nPB. The ATSDR Minimal Risk Levels and EPA Rfl)s used as the basis of the Rhode 

Island AALs for t-DCE were developed in 1996 and 1989 respectively and do not reflect more 

current toxicity data, which were developed through the EPA's High Production Volume 

Challenge Program and have been made available to RI DEM. (3M and PPG) 

Response: The AALs for t-DCE and nPB were derived using the methodology specified in 

the Air Toxics Guideline. In reviewing the AAL for t-DCE, RI DEM has concluded that the RfD 

could be used as an annual average AAL rather than a 24-hour average AAL, since a safety factor 

to convert subchronic to chronic exposure times was used in the RfD derivation. This would 

result in an increase in the Minimum Quantity threshold value for that substance from 200 to 300 

pounds per year. The AALs and Minimum Quantities for t-DCE have been changed in 

Regulation Nos. 9 and 22 as well as in the two guideline documents to reflect that adjustment . 

RI DEM has reviewed the toxicological data for t-DCE provided by the commenters. Those 

studies, which have not been published in a peer reviewed journal, indicate that a less stringent 

interpretation of the earlier studies used to develop the EPA and ATSDR health benchmarks on 

which the Rhode Island AALs were based may be appropriate. RI DEM suggests that the new 

data be made available to those agencies and, if the EPA and/or ATSDR health benchmarks are 

updated, RI DEM will propose corresponding changes to the Rhode Island AALs. In addition, if 

updated health benchmarks are derived for nPB, RI DEM will update the AALs for that 

substance accordingly. 

RI DEM understands that the fact that the AALs for t-DCE are more stringent than those for nPB 

may cause some facilities to favor nPB over t-DCE. However, as the commenters point out, the 

more stringent requirements applies only to cleaners using more than 2,000 pounds of solvent per 

year, since smaller cleaners are exempt from Regulation Nos. 9 and 22 and the control 

requirements in Regulation No. 36 are the same for either solvent. Further, any advantage to 

using one solvent over the other may disappear in the future if the AALs are further revised when 

new health benchmarks are available. 

Comment: Change the definition of new major fuel burning source in 22.2 .2(c) to a source 

that begins operation as of the effective date or the new regulation, rather than retroactive to 27 

April 2004. (ESS) 

Response : The regulation was not changed in response to this comment. This is not a new 

specification; new major fuel burning sources have been subject to Regulation No. 22 since the 

2004 amendments.