Page 350 - Wastewater Solids Incineration Systems

Appendix C Determination of Wastewater Solids Incineration Related Costs 311

TABLE C.2 Pertinent information for Northeast Ohio Regional Sewer District case study.

Year of cost determination 2004
Quantity of wastewater solids incinerated 16 441 wet tons (5426 dry tons) a
Dewatering devices High solids centrifuges
Percent solids in dewatered wastewater solids 33%
Year MHFs constructed 1978
Year MHIs placed into service 1983 (startup was delayed for almost five years
because of construction-related problems associated
with the rest of the plant. This delayed the
production of the specified wastewater solids.)
Year of significant MHF system renovations 1994–1995
Service life of all major equipment 20 years
Total number of incinerator operators 4 at 2080 hr/yr
Normal operator overtime 15% (312 hr/yr)
Shift manager 1 at 33% of time (686 hr/yr)
Employee benefits 47.66% of hourly rate
Natural gas cost $6.18/MCF b
Electricity cost $0.060/kWh
Quantity of ash 2005 dry tons
Ash disposal method Municipal solids waste landfill
Ash hauling/tipping/solid waste fee $49.24 per wet ton
Source of scrubber water Plant process water (nonpotable)
a wet ton 0.907 metric tonne.
b MCF 1000 cu ft 28 m .
3

3.3 Labor
A total of four trained operators are assigned to the incineration process. Only one
operator, however, is scheduled per shift. In addition, there is a shift manager who
spends approximately 33% of his/her time per year on incineration-related issues.
Determining their annual compensation is relatively straightforward (i.e., hours
worked per year times hourly rate). However, another factor that has to be taken into
account is the cost of benefits, including vacation, sick leave, retirement, medical, and
health insurance. For this case, the benefits rate has been determined using U.S. Envi-
ronmental Protection Agency guidelines to be 47.66% of the hourly rate.