OAR Box 1313 

Prepped by LaTeia Shed 

Document Number: 

58) ll-B-32 

Docket Number: 

A-88-02 

Printed 6/12/2008 9:03:29 AM Sheet 58 of 99 

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t* #%, \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY A-88-0 2 

I ^tyl S Office of Air Quality Planning and Standards X-^-^o , 

\*dlk£f Research Triangle Park, North Carolina 27711 

2 2 OEC 1J37 

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MEMORANDUM j 

SUBJECT: Chromium Electroplating NESHAP: Trivalent Chromium Process 

Capital Costs (12/1/87 Draft) 

FROM: Bill Vatavuk 

CEIS, SDB, ESD (MD-13) 

TO: Don Gillette 

CEIS, SDB, ESD (MD-13) 

At your request, I have reviewed the subject costs, which supplement 

the cost data I reviewed for you last month. (See my November 30 memo.) 

My comments on these trivalent process costs are itemized below: 

Page 1,111: If the trivalent chromium process is "technically superior" to 

the hexavalent process, shouldn't we attribute part of the cost difference 

between these two techniques to "process improvement"? (It doesn't seem 

reasonable to attribute the entire incremental cost to air pollution control.) 

Page 2, 11 1: How well do the capital costs for the other trivalent processes 

compare with the "Tri-Chrome® LC Plus" process cost? (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.) 

Page 4, 11 1: Where in Table 5 are the hexavalent chromium process costs? (Only 

costs for the trivalent process appear in Table 5.) 

Page 4, 11 2: If the trivalent plating facilities being studied use different 

chromium solutions, how can their costs be compared to the costs presented 

in Tables 3, 4, and 5? Explain, please. 

Table 2: 

° The tank capacities don't 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 252yft3 = 1,885'gal. However, a capacity of 1,730 gal (or 91.8% 

full) is listed for it. Is this because the tank is never completely full 

when being used? 

° Even if we assume that each tank is operated at less than 100% full, 

the capacities given still are not consistent with each other. The total 

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volume of the larger tank is 648 ft3 = 4,850 gal (12.0 ft x 6.0 ft x 9.0 ft). 

However, the listed capacity, 4,580'gal, is 94.5%'of the total volume. Why 

is the larger tank volume utilization higher than that of the smaller tank? 

Table 3: 

o Please list the references for all the costs in this table. 

(Presumably, the solution and equipment costs came from Harshaw/Filtrol. 

If so, please so indicate.) 

o 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. 

° Similarly, the tank liner cost 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. 

Table 5: 

° 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). 

° The model tank direct installation costs seem quite low, compared 

to the purchased equipment and indirect installation costs. (How firm 

are these installation costs?) 

Please convey these comments to ISB at your convenience. In the 

meantime, if you have any questions, please phone or stop by. 

cc: Bob Ajax (MD-13) 

Al Wehe (MD-13) 

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