-:-­

-- rll**~­** , [( : i


## . ....." "-"

# ---
............ DEPARTMENT OF ENVIRONMENTAL QUALITY DIVISION OF AIR QUALITY
Michael O. Leavill 150Notth 1950WcsI Gown=

. P.O. Box 144820 Dianne R. Nielson, Ph.D. Salt Lake City, Utah 84114-4820 E=wive Oir=Dr (80I) 536-4000 Russell A. Robens (801) 536-4099 Fax Dir=Dr (801) 538-4414 T.D.D. DAQE-068-95 January 30, 1995

James R. Van Orman Director ofEnvironmental Management Headquarters Ogden Air Logistics Center Department ofthe Air Force Hill Air Force Base. Utah 84056 Re: Support Document for Approval Order DAQE-067-95 Dear Mr. Van Orman: This letter is 

### a support document for Approval Order (AO) DAQE-067-95, dated January 30, 1995, and it establishes reporting requirements when Hill Air Force Base intends to change paint/solvent/thinner used in their painting operations. Hill Air Force Base is permitted to change the paint/solvent/thinner used in their painting operations without prior approval from the Division ofAir Quality (DAQ), subject to the following conditions: A. IfHill Air Force Base intends to increase the rates ofemissions ofspecific noncriteria pollutants and/or change the chemical composition ofnon-criteria pollutant emissions. compared to the emissions listed in the 1993 Base-wide HAPs emissions inventory times ascaling factor of5.43 1

, then Risk Index (defined in D. below) needs to be calculated for those compounds that would contribute to the increase in the rates ofemissions and/or the chemical composition ofthe emissions. Ifthe calculated Risk Index exceeds 21.22 (current high value as per the Notice ofIntent (NOl) for this AO), a NOl shall he tiled in accordance with Section 3.1, 

### UACR. B. Ifthe AO is determined to require changes, Hill Air Force Base shall submit as pan ofthe NOI, the proposed rates and chemical composition ofthe new emissions, and screen modeling results to demonstrate that the proposed changes in the amounts and/or character ofthe emissions shall not cause an exceedance ofTLV1100 (for non1A scaling factor of5.43 is the ratio ofthe total Base-wide allowable HAP emissions (201.2 tons per year considering all HAP emissions as VOC emissions) to the total Base-wide HAP emissions listed in the 1993 (the latest Base-wide HAPs emissions inventory available before this AO was issued), which was reponed 

### as 74.076 pounds per year (37.04 tons per year). 201.2 TPY/37.04 TPY = 5.43 4.2.4-413DAQE-068-95 January 30. 1995 Page 2 carcinogens) and TLV1300 (for carcinogens). The present Maximum Risk Index of 21.22 shall then be revised (increased) to rer1ect the proposed change in the amounts andlor character ofemissions. C. IfHill Air Force Base intends to change the rates andlor chemical composition ofthe non-criteria pollutant emissions currently approved according to the information submitted from the 1993 emissions inventory as a part ofthe NOI for this AO, and determines that a change in the AO is not required because the maximum Risk Index of21.22 is not exceeded bythe changes. then Screen modeling is not required to be performed and a formal NOI is not required to be tiled. Hill Air Force Base is only required to submit to the Executive Secretary a Iist ofchanges in the chemical composition and emission rates. along with the annual HAPs emissions inventory submittal. D. Risk Index shall he cakulated according to the formula given below:

actual m:lXlln"m pounds oftOXICS cmltted per eight-hour period Risk Index = TLV/IOO or TLV/300 where. TLV represents the Threshold Limit Value ofthe chemical compound.

­ TLV1100 is used in the ahove equation when the chemical**con~:lound** is not .:onsidered to be a carcinogen and TLV/300 is used when the chemical compound is a suspected or a contirmed carcinogen. TLVvalues and the carcinogenicity ofchemical compounds can be found in a handbook published by the Association ofGovernmental and Industrial Hygienists (Technical Affairs Office, 6500 Glenway Ave., Bldg. D-7, Cincinnati. OH 45211-4438). Any other source ofTLVvalues shall be accepted, subject to approval by the Executive Secretary. To calculate the actual maximum pounds oftoxics emitted per eight-hour period (numerator in the Risk Index expression). the total scaled-up (to scale up, the proposed emissions are multiplied by J factor of5.43) emissions in pounds per year ofthe chemical comround after the proposed increase is divided by 2.000 hours oforeration per year (assumed at 40 hours per week**~nd** 50 weeks per year). Ifyou have any questions**or~oncerns.** please contact Arjun Ram at (801) 536-4066. "I Sincerelv. .I 

### I I ' . 

## ------. . .' f I i 

### I
I

### . I 

### I



## ... ! .**.~** Russell A. RobertS. Executive Secretary --Utah Air Qualitv Board

.

RAR:AR:<.Jn

cc: Davis CUtlnty Health Department EPA RegIOn V[II. Mike Owens 4.2.4-414