Liquid Only Sewer - Bringing Two Communities Together

The Villages of Dupont and Cloverdale, two small rural towns located in Putnam County, Ohio, had a common problem, they were both polluting the Auglaize River with septic runoff. Coincidentally, they were both under consent by the Ohio EPA to replace the failing septic systems with a new wastewater collection and treatment system. Independently, providing a wastewater solution for each community was challenging. The Village of Dupont required service to 95 connections and the Village of Cloverdale required service to 75 connections. The Villages joined forces to form the Cloverdale Dupont Wastewater Authority, with the intent of developing an affordable, robust and sustainable solution that could serve both communities. An innovative solution was developed to interconnect both communities with a liquid only sewer system that discharged to a shared decentralized wastewater treatment plant. The liquid only sewer fronted all properties within the service boundaries and provided a 3-mile interconnect between the communities and the decentralized wastewater treatment facility. The system consisted of shallow, small diameter pipes and included a sub-aqueous directional bored crossing under the Auglaize River. Liquid-only sewer, as the name implies, is designed to only convey liquids from the wastewater source. Liquid-only sewer starts with an onsite unit at each connection, that provides primary treatment and filtration of raw wastewater. Solids, scum, inorganics, fats, oils, and grease are retained at the source, while liquids are conveyed away from the property for additional treatment. Liquid-only sewer effluent will have 90% to 95% fewer settleable solids, 70% to 90% less suspended solids, 60% to 70% less BOD, and 75% to 90% less fats, oil, and grease when compared to raw wastewater. Onsite units are manifolded together, and lines are sized similarly to water mains to provide conveyance to offsite for final treatment. Conveyance does not require any intermediate pumping or lift stations. Liquid only sewer allowed for additional savings at the wastewater treatment plant. Headworks were not required and a packed bed attached growth packed bed filter wastewater treatment plant was utilized. There were no aeration basins, blowers, clarifiers or digesters in the design. The treatment plant uses less energy and produces less biosolids by volume when compared to more traditional wastewater treatment approaches. The wastewater solution, completed in 2021, has demonstrated how small rural communities can utilize liquid only sewer to reduce capital cost and reduce operating costs while providing an easy to maintain, sustainable solution for two small neighboring communities.