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OAR Box 1313 

Prepped by LaTeia Shed 

Document Number: 

60) ll-B-34 

Docket Number: 

A-88-02 

Printed 6/12/2008 9:03:29 AM Sheet 60 of 99 
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VI Rl® MIOWEST RESEARCH INSTITUTE 

Suite 35C 

-•01 Harrison OaKs Bouievarr 

Carv. N.C 275'' 

A-88-02 

Date: 

Subject: 

April 18, 1988 

Response to Comments on Draft Capital Cost Estimates for the 

Trivalent Chromium Process Received from Mr. Bill Vatavuk, 

Standards Development Branch (SDB) ,~~—,r" 

Chromium Electroplating NESHAP •-""'•" '<• 

EPA Contract 68-02-3817; ESD Project 85/02a 

MRI Project 7717-K 

From: 

5^ m V\ 

To: 

Robin Barker 

Andy Smith ' ..... 

ESD/ISB/SSS (MD-13) 

U. S. Environmental Protection Agency 

Research Triangle Park, N.C. 27711 

I. Introduction 

Midwest Research Institute responses to Mr. Bill Vatavuk's comments 

on the draft Trivalent Chromium Process Capital Cost Memorandum are 

summarized below. Please review and forward a copy of this memorandum to 

Mr. Vatavuk and Mr. Don Gillette of SDB. 

II. Summary of Comments and Responses 

Comment: If the trivalent chromium process is "technically 

superior" to the hexavalent process, should we not attribute part of the 

cost difference between these two techniques to "process improvement"? 

(It does not seem reasonable to attribute the entire incremental cost to 

air pollution control.) 

Response: The cost savings generated by the trivalent chromium 

process improvements will be reflected in the annualized cost estimates 

for the process. There is no method for proportioning the capital cost of 

the trivalent process into two components, one for air pollution control 

and the other for process improvement; however, a note will be added to 

the text to indicate that the total capital cost should not be attributed 

solely to air pollution control. 

Comment: How well do the capital costs for the other trivalent 

processes compare to the "Tri-Chrome® LC Plus" process costs? (To this 

end, it might be helpful to add a table listing the capital costs for all 

trivalent processes on some common basis, say, $/gal of tank capacity.) 

Response: The revised capital cost memo will present the capital 

cost of conversion for each model plant based on a compilation of vendor 

estimates. 

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Comment: Where in Table 5 are the hexavalent chromium process 

costs? (Only costs for the trivalent process appear in Table 5.) 

Response: Table 5 shows the incremental cost of the trivalent 

process over the hexavalent process and the cost of equipment that would 

be associated only with the use of the trivalent process. Equipment 

requirements that were the same for both processes were not presented 

because the costs net each other out. 

Comment: If the trivalent plating facilities being studied used 

different chromium solutions., how can their costs be compared to the costs 

presented 1n Tables 3, 4, and 5? Explain, please. 

Response: The equipment cost is for the most part independent of 

the type of plating solution used in the process. The cost for the 

plating solution will vary between vendors. However, the chemical cost 

differential between the vendors will be considered before comparing the 

capital and annual costs. 

Comment: The tank capacities do not seem consistent with their 

dimensions. For example, the smaller tank [(12.0 ft)x(3.5 ft)x(6.0 ft) ] 

has a total volume of 1,885 gallons. However, a capacity of 1,730 gallons 

(or 91.8 percent full) is given. Even if we assume that each tank is 

operated at less than 100 percent full, the capacities given still are not 

consistent with each other. The total volume of the larger tank 1s 

4,850 gallons. However, the listed capacity, 4,580 gallons, is 

94.5 percent of the total volume. Why is the larger tank volume 

utilization higher than that of the smaller tank? 

Response: Six inches of freeboard space between the surface of the 

tank and the plating solution was assumed when calculating tank 

capacities. This assumption is based on good engineering practice as 

recommended by ACGIH industrial ventilation guidelines. The capacities 

stated were checked and are correct. 

Comment: Please list the references for all the costs in Table 3. 

(Presumably, the solution and equipments costs came from Harshaw. If so, 

please indicate.) 

Response: The costs are referenced in the text, but will be added 

to the table for clarity. 

Comment: The chromium solution purchased and waste disposal costs 

should be proportional to the tank capacities—but they are not. For 

instance, the large-to-small tank capacity ratio is 2.65, while the 

corresponding ratios of the solution purchased and disposal costs are 2.50 

and 2.21, respectively. Please correct this error. 

Response: The waste disposal costs presented in Tables 3 and 4 are 

correct. The reason the costs do not correlate to the capacity of the 

tanks is because the transportation costs are the same regardless of 

whether the truck capacity is fully utilized or not. 

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Comment: Similarly, the tank liner costs should be directly 

proportional to the interior surface area of the tank. However, the 

large-to-small tank surface area ratio is 1.74, while the tank liner cost 

ratio is 1.65. 

Response: There apparently is a cost savings generated by 

purchasing a larger quantity for the large model plant. The cost 

enclosure for Harshaw was checked and the prices listed for the liners are 

as reported by them. 

Comment: Based on the unit costs in footnote "a", the small and 

medium model plant startup costs should be $2,800 and $8,300, respectively 

(not $3,000 and $9,000, as shown). 

Response: The costs were rounded incorrectly for the small and 

medium plants. The error will be corrected in the table. 

Comment: The model tank direct installation costs seem quite low 

compared to the purchased equipment and indirect installation costs. How 

firm are these installation costs? 

Response: The vendor supplied the cost and amount of labor required 

to complete the process conversion. The validity of these numbers will be 

compared to the direct installation costs supplied by trivalent chromium 

plants to determine if the vendor estimates should be revised.