Regulatory time constraints placed upon an energy company made engineer-procure-construct (EPC) delivery of an industrial water treatment facility appealing. During a routine permit renewal process, new effluent limits were specified for a variety of metals for both water and general plant drains. A zero discharge solution was selected for water with a limit on general plant drains that included mercury (12 ppt). A three-year compliance schedule was incorporated into the permit making traditional design-bid-build challenging. The company turned to Burns & McDonnell for the project, aiming to minimize their regulatory compliance and cost risks.
The project was delivered under a lump sum EPC agreement. The EPC contractor was selected based upon a competitive bid selection process. Throughout the project, the owner remained integrated in the project team and retained an owner’s engineer to represent its interests during design, construction and startup.
The 15,000-gpm general plant drains treatment system included several trains providing redundancy throughout the system. Side stream treatment within the water system allowed process units to increase cycles of concentration and reduce blowdown and pollution loading rates on the primary water treatment process. Water treatment technologies used: solids-contact clarification, chemical precipitation, evaporation, sorption, filtration and residuals dewatering. The feed stream to the evaporator is preheated with hot distillate generated by the process. The seeded slurry evaporator concentrates the stream using auxiliary steam and mechanical vapor compression.
During construction, the feedstock and the design water quality analysis for the water treatment process changed. Our design team accommodated the change by working with the owner and technology providers to identify minimum equipment modifications required and adjust processes chemistry. Even with the changed conditions, the project started up in compliance with regulatory requirements, on time and within budget. EPC delivery of the $250 million treatment plant was the largest in the industry’s history and met owner objectives.