New Peracetic Acid Disinfection System at Washburn Tunnel Working Well


Washburn Tunnel completed construction on the chemical disinfection system using peracetic acid (PAA) as the disinfectant. Peracetic acid is an emerging wastewater disinfection technology in the United States. After an extensive technology evaluation process including pilot testing in 2013, GCA selected the PAA technology for the Washburn Tunnel Facility. This technology provided the benefit of a smaller disinfection basin to meet available space constraints and elimination of potential undesirable disinfection byproducts. One of the challenges recognized from the beginning was the problem of fitting the technology in the limited available space so the smaller disinfection basin represented a distinct advantage.

Groundbreaking occurred in the fall of 2014 and construction continued through 2015. Challenges success- fully addressed during the construction included close coordination of construction space with GCA operations, shortages of concrete and technically difficult construction — all done without disruption of service to our customers. Construction occurred immediately adjacent to areas that operations personnel had to enter daily. Construction equipment had to be positioned in locations that required close coordination with facility personnel in order to maintain plant operations. Good communication was essential to successful teamwork for continuity of business operations and timely construction progress. The construction boom in the greater Houston area during 2015 posed logistical challenges for scheduling concrete pours so some of the pours had to be scheduled at night to maintain the schedule.

At the time of commissioning this PAA system was the largest industrial waste- water treatment application of its kind in the United States. During the spring of 2016 we collected data to optimize operation and assess the performance of the system. It has more than lived up to expectations.

Washburn Tunnel provides wastewater treatment service to several refineries, chemical plants and terminals located along the Houston Ship Channel as well as to the City of Pasadena. Clients comprise 26 percent of the refining capacity of Harris County and provide over 26 billion barrels of bulk liquid storage capacity for shipment through the Port of Houston. Most wastewater is received via pipeline, but Washburn Tunnel also receives wastewater via barge and trucked in wastewater via GCA’s Vince Bayou Receiving Station.