Page 352 - Wastewater Solids Incineration Systems

Appendix C Determination of Wastewater Solids Incineration Related Costs 313

year. For overtime pay, the fringe benefit multiplier is reduced from 1.4766 to 1.15,
which only includes retirement and Medicare. The cost for this overtime is $26,121.

3.3.3 Shift Manager
One shift manager $31.72/hr 1.4766 benefits 686 hr/yr $32,131

3.4 Scrubber Water
Plant process water (i.e., nonpotable water) is supplied to the scrubbers. The only
O&M cost associated with the scrubber water is the electrical cost to pump it to the
scrubbers. This cost is included in the electricity cost determination contained above.

3.5 Ash Disposal
The Westerly WWTP contains a dry ash handling system. As a result, the ash does
not contain any moisture. The dry ash is stored in a silo and hauled to a municipal
solids waste landfill two to three times per week. The district has a contract with a
local contractor for disposal of the ash at a municipal solid waste landfill located
approximately 120 km (75 miles) southeast of the plant. The ash disposal costs, which
include hauling costs, landfill tipping fees, and state and local solid waste taxes, aver-
aged $49.24/ton during 2004 (2005 dry tons $49.24/ton $98,717).

3.6 Maintenance by Plant Personnel
Plant maintenance is probably the most difficult incineration cost to determine
because of variability in accounting methods used by WWTPs. The Westerly WWTP
uses a SPL (formally Synergen) computerized maintenance management system pro-
gram to keep track of the equipment costs and plant personnel related labor costs
associated with all of the maintenance work conducted in its incineration complex.
Other facilities may use an alternate means of allocating maintenance expenses to
various plant processes. Westerly WWTP’s maintenance costs $39,589.

3.7 Amortized Capital Costs

Incineration capital improvements need to be amortized over the life of the equip-
ment to determine the annual costs (see Table C.4). A carrying charge factor may be
used in cases where incineration facilities have been financed by a combination of
cash reserves and long-term debt. Such a carrying charge, expressed as a percentage,
typically includes interest on debt and a return on equity.