Successful Implementation of a Process Control System Automation Project at DC Water’s Blue Plains Advanced Wastewater Treatment Plant. A Fifteen (15) Year Journey

In 2002 DC Water entered into a Process Control System (PCS) automation contract. The objective of this project was to implement a new PCS for the entire Blue Plains Advanced Wastewater Treatment (AWTP). The 34 Million, ten-year project was scheduled to be implemented in multiple phases that were dependent on the schedules of ongoing Capital Improvement Projects (CIP) at the Blue Plains AWTP. Some of the goals and objectives included:Gaining stakeholder acceptance and meeting their goals, including the operations and maintenance groups for the control and operation of the overall facilityCoordinating with a large and changing Capital Improvement Plan (CIP) for planned plant upgrades and modificationsTraining and knowledge transfer to DC Water, to be self-sufficient and not reliant on the vendor for ongoing maintenance of the systemFor the phased approach to be successful, PCS aspects such as installation and configuration of the Distributed Controllers Units (DCU) had to be closely coordinated with ongoing design and construction projects. The PCS program was developed with flexibility to accommodate future expansion and new processes. The Filtrate Treatment Facility, Combined Heat and Power (CHP), and Enhanced Clarification Facility are significant new processes that have recently been added to PCS network. These processes were not envisioned or included in the Facilities Plan when the PCS project started in 2002. However, the built-in system flexibility allowed these large and complex projects to be incorporated into the overall PCS with no negative impact on system-performance.During 1980s and 1990s there were various attempts to implement PCS automation systems with no success, primarily due to lack of stakeholders’ involvement and buy-in. Other previous automation pitfalls at the Blue Plains AWTP included: no user or team commitments, no human factors considerations, and lack of buy-in because the implementation was vendor and technology driven vs. plant operations driven.To avoid repeating past mistakes, DC Water implemented a rigorous Witness Combined Loop Testing (WCLT) process where all the stakeholders not only participate in testing but also offer suggestions for improvements. The main intent of WCLT was to validate continuity of input/output (I/O) points from the field to the Central Control Room Human Machine Interface (HMI). In addition, PCS configurations standards were created to enforce consistency from design through post construction.This paper is an attempt to share valuable lessons learned through the phases and evolution of the project: procurement and vendor selection processes, design and quality assurance, construction and coordination requirements, WCLT, and training. Other items that will be covered include: tangible and intangible benefits achieved from implementation of the PCS automation project, and ongoing optimization of the treatment processes including energy management. Training is hands on, continuous, and pragmatic. On-the-job training has been invaluable.In 2012 DC Water approved Emerson Process Management (EPM) as a sole source provider of the PCS equipment and services at BPAWWTP. Around two years after this approval, the initial EPM contract work with DC Water was completed. At that point, new projects and expansion work switched from Emerson being under a prime contract with DC Water to a subcontractor working thru general contractors . Although overlapping for a period, both forms of contract delivery coexisted without interference. The initial EPM contract developed the “Core” system on which all recent expansion has taken place.The basics of data from the core system provided comprehensive monitoring with historical data storage of the plant hydraulics from influent to final discharge. It also included alarm states, equipment on/off condition, flows, tank levels, and qualitative conditions such as DO, chlorine residual, and NH3. Also, collection and storage of historical data performance began as soon as loop testing confirmed that inputs received by PCS were valid. This data monitoring and historical record represented a significant leap in the type of information available for process control, operations, and maintenance decision making prior to PCS.Key lessons contributed to the PCS becoming integral to the operation at the Blue Plains facility and can provide insight to utilities about to embark on significant plant upgrade and/or control projects.