Skip to main content

Operating Cost Modeling for the New York City Biosolids Management Plan

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

An operating cost model was developed as part of the New York City Department of Environmental Protection's (NYCDEP) new biosolids management plan governing future construction and rehabilitation related to the solids handling processes for the City's water pollution control plants (WPCPs), which currently operate under a common gravity thickening – anaerobic digestion – centrifuge dewatering scheme. The operating cost model developed performs cost-benefit analysis to form recommendations from among eight universal and two plant-specific thickening and digestion process improvements. The model is a self-contained collection of cross-linked spreadsheets that allow input and storage of plant process data gleaned from discharge monitoring reports, performs mass balance and operating cost calculations, and outputs results in graphical and tabular form.

Model inputs were supplied from categories of data that are either specific to the plant analyzed (such as flow rates) or systematically common (such as intended operational parameters for a proposed improvement). Initial mass balance calculations were performed in order to determine flows and loads at each process stage and test the viability of each proposed improvement in meeting minimum process requirements. Subsequent mass balance and cost calculations projected the amounts of sludge generated with each improvement and the related costs of operation. Calculations incorporated flowcharts relating process viability to performance projections as well as convergence of a numerical model to quantify the impact of step loading on sludge mass flux. The model was also programmed with Visual Basic controls to automate the simulation of 104 combinations of plants and proposed improvements. In conjunction with the above, model inputs were structured to be conducive to sensitivity analyses and what-if scenarios by allowing overrides.

Model results included prepared process flow diagrams for each proposed improvement and operating cost projection tables influenced by WERF Publication 00-PUM-7, “Full Cost Accounting Protocol for Biosolids Management,” with additional customization to emphasize detail relevant to the improvement options evaluated. Cost groupings included factors related to energy consumption and emissions offsets, intra-system transportation, chemicals, maintenance, and biosolids disposal.

This paper will present the details of the NYCDEP biosolids management plan operating cost model, highlighting the overall framework, inputs, and test conditions, as well as describing theuser interface. The results will be presented as an example of the innovative use of cost modelingto manage the biosolids of a large system.

Keywords: Biosolids Master Planning; Cost Accounting; Operating Cost Model

Document Type: Research Article

DOI: https://doi.org/10.2175/193864709793846312

Publication date: 2009-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more