-8- 



Table 2. - Costs Incurred, Each Pile (1975) 



Item Cost 



ADS flexible plastic pipe (37c/foot) $ 56.00 



Wood chips ($3.25/cubic yd.) 585.00 



Mixing equipment and labor 210.00 



Monitoring of pile 52.00 



Electric power 3.00 



Capital Costs _6^_00 



Total $912.00 



Cost per wet ton of sludge 21.70 



■''Capital expenditures spread over the life of the project; does not include 

 construction of compost pad. 



One wet ton equals approximately 1.4 cubic yards. 



1977 Operations 



Since initiation of the composting project, the cost of composting in 

 Durham has been reduced considerably. Part of this reduction in cost has 

 been realized by re-using the wood chips, so it must be determined whether 

 the savings gained by re-using the chips offset the cost of screening. 

 Durham had purchased a chipper at a cost of $7,180 to chip wood products 

 that come to the town's incinerator site, but suspended operation of the 

 machine when it was determined to be dangerous to operate. It has a ten- 

 dency to snap branches when they are fed into the mechanism, and occasion- 

 ally to kick back the material that is fed in. At this writing, Durham is 

 purchasing wood chips for the composting process at a cost of $3.15 per 

 cubic yard. 



