Investigating Alternative Products and Markets to Enhance Capacity and Outlet Diversity for Citizens Energy Group (Indianapolis, IN)

Background Citizens Energy Group (Citizens) owns and operates two advanced wastewater treatment plants (AWTPs) that serve the City of Indianapolis, IN : Southport AWTP and Belmont AWTP. In total, the AWTPs treat a combined average annual daily flow of 210 million gallons per day (mgd). Solids management includes dewatering and incineration, with a small fraction of cake transported for landfill disposal. Approximately 220,000 wet tons (wt) of cake are processed each year. While incineration has been a reliable solids management option for the utility for many years, the existing incinerator capacity is projected to be insufficient for future loadings. Recognizing existing solids handling constraints, Citizens elected to embark on a WWTP Sludge Management Update to explore and understand the feasibility of other potential solids management practices and to identify opportunities to improve the existing program, reduce program costs, and provide flexibility to management options as the incinerators near capacity. Objective The WWTP Sludge Management Update was initiated to identify cost-effective and energy efficient solids processing technologies to supplement Citizens' existing technology, multiple hearth incineration. As part of the Project, Material Matters completed a biosolids market assessment and regulatory evaluation for the Southport AWTP to provide support to Citizens to better understand the biosolids end use market, and the demand for various biosolids products in and surrounding Indianapolis. The market assessment is of critical important for a utility of this size & with cake production of over 15 truckloads per day. The market findings will be utilized by Citizens in combination with the preliminary Arcadis Process Selection Memo, to achieve the following objectives: 1. Assess market demand for each product in agricultural and non-agricultural markets; and 2. Estimate costs associated with product management for each product considered. The Biosolids Market Assessment included six products (including unstabilized cake) from technologies which can be implemented for long-term planning, as summarized in Table 1. Methodology The in-depth market analysis established product quality characteristics, quantified production (Figure 1) and specifications for each Class A/EQ and Class B product and quantified outside-the-gate costs for product management. Additionally, Material Matters engaged with local utilities and state regulators current biosolids management practices and potential future regulatory requirements for beneficial use of both Class B and EQ biosolids products in Indiana. The analysis also included interviews with Indiana water pollution control facilities (WPCFs) with design flows greater than two million gallons per day (mgd), third-party contractors (TPCs), regulators, agricultural extension agents, and potential outlets identified within approximately a 50-mile radius of Indianapolis. Findings and Current Status Our effort revealed Indiana's unique local marketplace and state regulations strongly favor beneficial use of Class B biosolids, with robust Class B land application across the state (Figure 2), so there is no major end-use driver for Citizens to invest in costly Class A/EQ technologies for the successful development of a beneficial use program. Results from the project identified opportunities for Citizens to enhance pretreatment oversight and identified multiple low-cost outlet options, including Class B directly into the local agriculture market for various processing alternatives (Figure 3). Findings from the biosolids market assessment and regulatory review was a key economic input to Arcadis' Energy Flow Model tool, which is the interactive deliverable that compares the economic and energy balance of each technology considered. This presentation will discuss the project approach and unique market findings & where upgrading to Class A/EQ is not always the most cost effective option.