Anaerobic Digester Cleaning

The New Hampshire Department of Environmental Services (NHDES) is soliciting proposals for the cleaning of two anaerobic digesters at the Franklin Wastewater Treatment Facility. The selected contractor will be responsible for removing material from the digesters, screening and macerating the material, dewatering it using a centrifuge, and transporting and disposing of the dewatered material and debris. The contractor will also be responsible for selecting an appropriate disposal site and obtaining any necessary permits. The contract work must be completed before May 15 in the years noted. Some key requirements include: • Removing material from the digesters and dewatering it to a minimum of 24% solids • Screening and macerating the material prior to dewatering • Transporting and disposing of the dewatered material and debris • Selecting an appropriate disposal site and obtaining any necessary permits • Maintaining a continuous, minimum 24% cake solids • Providing a watertight container or dump truck to receive the dewatered sludge • Ensuring that the digester material is screened and macerated to remove rags and plastics