Image by: Andrew Shipley
An Engineers’ Opinion of Probable Construction Cost (EOPCC) for the proposed improvements to the SPA 1 WRF was generated based on the design work from this project. Capital costs for each respective treatment process were estimated through analysis of RSMeans, similar engineering projects, and consultation from experienced engineers. The total construction cost is estimated to be $1,455,000.
An estimate of annual operation and maintenance costs (O&M) for the SPA 1 WRF for proposed and existing conditions was generated. Items included in O&M costs include energy consumption costs, routine equipment replacement, and labor costs to operate the WRF. Labor costs were calculated based on three typical WRF operator hourly wage values. The facility is assumed to use three low and middle tier operators each and two senior rank operators for a total of eight operators. RSMeans and similar engineering projects were used to estimate the costs associated with routine equipment replacement. Energy was assumed to cost $0.15 per kilowatt hour. The routine replacement of disk filters and brush aerators were considered in O&M costs; the typical design life of a brush aerator was obtained at a site tour of the facility. The O&M costs and design life of equipment associated with advanced treatment were found from a similar engineering project in Riverside, California. The O&M costs related to solids handling were made on assumptions taken from a case study of anerobic digestion on a dairy farm. The total yearly O&M costs are estimated to be $3,103,000. This is a reduction of around $1,100,000 per year from current O&M costs.
