Biosolids Beneficial Use and Disposal Trends in South Carolina and Georgia

Background Wastewater Treatment Plants (WWTPs) in South Carolina and Georgia have been historically dependent on landfill disposal for the management of the wastewater solids generated through their respective treatment processes. In Georgia and South Carolina nearly 65% of wastewater solids are sent to landfill. In recent years, landfills in both states have undergone policy changes that include steep increases in tipping fees for wastewater solids and a reduction in wet waste acceptance. The reduction of wet waste acceptance limits the percent wet waste (>40% moisture) accepted into landfills. In Georgia, landfills are required to develop a detailed Sludge Management Plan (SMP) if they accept more than a 5% wet waste to 95% Municipal Solid Waste (MSW) ratio. The changing landscape surrounding landfill disposal creates significant challenges for WWTPs in both states. The uncertainties resulting from these changes have served as the impetus for four WWTPs (two in Georgia and two in South Carolina) to evaluate new biosolids management technologies, beneficial use markets, and management methods. Objective Four utilities located in Gainesville, GA, Douglasville, GA, Beaufort, SC, and East Richland, SC underwent Biosolids Regulatory and Market Assessments for their respective WWTPs. The assessment worked to identify opportunities and challenges resulting from state regulations, local markets, and corresponding economics, associated with managing various biosolids products under consideration. Comprehensively, the Regulatory and Market Assessments for all of the utilities serve as a guide to the biosolids beneficial use and disposal outlets and management methods to achieve the following three objectives. 1. Identify permitting pathway for several biosolids products and management methods in Georgia and South Carolina; 2. Identify beneficial use and disposal outlets in the region for the respective baseline products generated by each WWTP; 3. Identify beneficial use and disposal outlets in the region for proposed products; and 4. Define market details including market capacity, storage requirements, and revenues and expenses associated with product management. Methodology The Biosolids Regulatory Assessments included a detailed review of existing Federal and state biosolids beneficial use and disposal regulations, as well as future regulatory federal and state regulatory considerations. Encompassed in the Market Assessment for each utility, the baseline solids management program was examined to understand existing practices and costs associated with solids disposal. Information about the local market preferences and demand for the biosolids products being considered for each utility was gathered through market research and interviews with potential market outlets. Collected data was used to identify the opportunities, challenges, and outside-the-gate program expenses (those expenses associated with product management only) associated with each market/product combination. The data from each utility was further analyzed to develop an idea of the current biosolids beneficial use and disposal trends relating to the management of several biosolids products in both South Carolina and Georgia. Four main products were evaluated including Class B digested cake, Class B and A/EQ alkaline stabilized cake, Class A/EQ compost, and Class A/EQ thermally dried granules. Findings and Current Status Assessment findings reveal that the development of beneficial use programs, both self-managed programs (SMP) and Third-Party Contractor (TPC) managed programs are available and viable in South Carolina and Georgia. Listed below are the main recommendations and findings that were consistent for each Market Assessment: 1. High Level of Interest in Class A/EQ Thermally Dried Granules: In each Market Assessment, thermally dried granules scored higher than other products due to the high level of interest noted in outlet surveys as well as the increased product flexibility within several different markets. Although interest level is high, many interested market outlets require a high-quality product, which is typically generated from rotary drum dryers. 2. Availability of Off-Site Stabilization Facilities: Off-site stabilization facilities are currently available with more coming online in the coming years. The majority of stabilization facilities in Georgia and South Carolina are composting facilities which product Class A/EQ compost for several markets. 3. On-Site Storage Requirement: 3 months of on-site storage is highly recommended, regardless of which market/product combination is pursued. The increase of on-site storage presents each utility with increased flexibility and resiliency. A summary of the selected products, most promising markets, relative outside-the-gate costs, opportunities, and considerations are summarized in Table 1. Furthermore, a summary of the regulatory considerations for Georgia and South Carolina can be found in Table 2. The Market Assessment findings indicate the current market conditions are strongly favorable for beneficial use of Class A/EQ compost and dried granule biosolids products. The presentation will further discuss the relative outside-the-gate costs associated with the management of each product as well as growing trends relating to the beneficial use of biosolids in this region.