Each year, the City of Columbus Division of Sewerage and Drainage (DOSD) must manage and dispose of approximately 25,000 dry tons of solids from their two wastewater treatment plants. The City’s solids management program consists of a diverse portfolio of environmentally friendly disposal methods, including composting, land application, strip-mine land reclamation and offsite digestion.
While overall resiliency of the program is aided by the presence of multiple management outlets, the current strategy also carries large inherent risks as private contractors are responsible for disposal of nearly two-thirds of the City’s solids. To assess program risks, DOSD’s Overall Engineering Consultant (OEC) team has developed a dynamic solids management risk evaluation tool. With the assistance of the risk tool, the City can now assess a full range of potential risks associated with each management outlet.
Working with Black & Veatch, B&N developed a model to help the Columbus DOSD evaluate their program capacities and budgetary needs. Considering the number of variables that had to be taken into account, B&N created the model using the Monte Carlo method. Named after the gambling hot spot in Monaco, the Monte Carlo method is used to model the range of possible outcomes given the random, unpredictable nature of the many variable inputs.
In this presentation, Kevin Campanella, PE, from B&N, and Tyler York, PE, from Black & Veatch, will provide an overview of the project, and discuss how the model was developed, applied, and how it is helping the City manage its sludge disposal risks.