Overview & History
In the beginning phases of a planned expansion of their cream cheese factory, our client in Shippensburg, PA, was faced with a significant list of restrictions and regulations for their wastewater treatment system.
The planned expansion included:
- A large increase in overall product volume
- The addition of cultured products
- The installation of a fully automated warehouse
The wastewater treatment facility was a critical item, standing in between the existing facility and the anticipated expansion. Construction of the expansion could not begin until the new wastewater treatment plant was operational and had demonstrated compliance with discharge limits. Discharge from the WWTP to the publicly owned treatment works (POTW) was subject to a site-specific permit – which carried significantly tighter discharge limits for a wide range of parameters and substantial surcharges and penalties for violations, based on the anticipated increased flows and the historical performance of the existing wastewater treatment plant.
To further complicate the design and permitting for the expansion, the majority of the production expansion was related to new product types that had no historical waste characteristic data available.
Working together, Probst and the client were able to establish a detailed wastewater design basis, reflecting several potential product mixes, development stages, and time tables. The evaluation showed the increased production would have a substantial impact on wastewater and also generate large amounts of high strength process wastewater.
While adapting our designs to ongoing changes and requirements, including the final size of the facility, our process team designed a complete biological treatment process, to be implemented in planned stages as production levels and resulting wastewater loadings increased. The treatment system was designed to include anaerobic and aerobic treatment, allowing for effective treatment of both normal and high strength process wastewaters from the facility. Additionally, the design included options for recovering renewable energy via an electric generator and boiler fuel blending.
Installing the aerobic components in the first phase of the project allowed for prompt start-up of the new WWTP and the new production facility. This also allowed for ongoing construction of the anaerobic treatment system with nearly no interruption to the aerobic treatment system, maximizing ongoing production for the client.
The custom-designed system includes the following:
- Multiple process wastewater lift stations
- Automated debris screening
- Aerobic activated sludge with advanced slot aeration technology
- Multi-mode solid-liquid separation
- Conventional dissolved air flotation (DAF) unit
Probst provided a fully automated process control scheme, with real-time process feedback on pH, oxidation-reduction potential (ORP), dissolved oxygen (DO), flow, levels, and effluent turbidity. Additionally, an automated effluent diversion system was installed to prevent discharge of non-compliant effluent, allowing the water to be reprocessed at the facility.
A process control laboratory was provided as part of the project, to ensure that plant operators were able to obtain required process control data on a daily basis and optimize system performance. The Probst Group engineers provided detailed training for operations personnel on the process, equipment, and lab procedures including chemical oxygen demand (COD), total suspended solids (TSS), pH, ORP, ammonia-N, nitrate-N, total-N, and phosphorus.
Completed and commissioned ahead of schedule, performance of the wastewater treatment plant continues to be exceptional, even with current loadings at or above the design values.