AWWA ACE69015

This powerpoint presentation begins by presenting the project goal: develop cost curves for residuals management at water treatment plants. The experimental process included the following: determine residuals production based on plant size, treatment type, and source water quality; use production to size residual management facilities; two engineering firms develop cost estimates for the facilities that were sized; and, third engineering firm independently costs facilities to validate cost estimates. Summary of basis for sizing includes the following: Population Selection - selected to cover range considered by U.S. Environmental Protection Agency (USEPA), three values selected in 10,000 - 100,000 population range, six values selected above 100,000, with maximum population of 1,000,000 considered; Flow Estimates - from analysis of WaterStats database; average per capita flow found to be 150 gpcd; design - average flow ratio found to be 2:1; Residuals Production - solids production calculated for over 4,300 WTP records in ICR database, high solids production defined as 90th percentile of production from river sources, low solids production defined as 50th percentile of production from lake/reservoir sources. Capital Cost Summary includes the following: the largest driver of capital costs for residuals management facilities is the dewatering facility; and, pound for pound, it is less capital intensive to treat softening residuals; however, softening plants generate significantly more residuals than coagulation plants. Validation summary: validation cost estimates generally within 25% of cost curves; validation cost estimates generally higher than points on cost curves - consistent with the increased level of detail available in CH2M Hill's costing tool; and, validation shows cost curves do not overestimate cost of constructing residuals management facilities. Further information: results of the costing analysis were presented in March 2008 Journal AWWA paper "Implementing residuals management: Cost implications for coagulation and softening plants" by Roth et al; analysis presented to USEPA in report "Costing Analysis to Support National Drinking water Treatment Plant Residuals Management Regulatory Options". AwwaRF Project #4086: the cost curves presented here and in the Journal article can be used to estimate budget level costs for plants looking to implement residuals management: and, AwwaRF Project #4086 "Minimizing Water Treatment Residual Discharges to Surface Waters" will expand on this work to make it easier for utilities to estimate costs of residuals management. Includes figures.