How Do the Availability of Outlets and End Use of Solids Affect Solids Management Alternatives? A Case Study for Millville Facility in New Jersey

Thickened mixed primary and waste activated sludge of approximately 2% solids oncentration from the Millville Wastewater Treatment Facility in Southern New Jersey are dewatered using two belt filter presses (BFP) to approximately 18–20% total solids, before hauling to Atlantic County Utilities Authority (ACUA) for processing via incineration. Plant process evaluation showed that the dewatering facility is not capable of handling current and future solids loads. Rather than just replacing the existing BFP with newer, larger units, The City of Millville decided on conducting a solids study aiming at evaluating plant solids processing and studying available end use options and outlets for the produced solids.Initially, the available and viable solids outlets within the state of New Jersey were evaluated along with the established residuals characteristics for these outlets. Once these outlets were identified, the required in-plant processing changes that should be practiced to produce solids characteristics matching the available outlets were investigated. These outlets were evaluated based on cost and reliability. Eight in-plant solids processing alternatives, producing Class A, Class B or raw solids were identified based on the available outlets. Alternative configurations were then analyzed based on capital cost, operation and maintenance costs along with a qualitative comparison. This paper summarizes outcomes of the research on existing solids practices in NJ, particularly Southern New Jersey, technologies and alternatives for processing solids and recommended alternative for processing and accepting solids. Based on the available outlets and economic evaluation of alternatives, processing the solids to either Class A or B is not necessary. However, the plant needs to produce higher cake solids than currently practiced.