Crews recently installed a new cover for a Liquid Effluent Retention Facility basin at the Hanford Site.
A Liquid Effluent Retention Facility basin at the Hanford site.

RICHLAND, Wash.EM Office of River Protection tank farms contractor Washington River Protection Solutions (WRPS) recently finished installing a new cover for a Liquid Effluent Retention Facility (LERF) basin at the Hanford Site.

   LERF stores wastewater generated by 242-A Evaporator campaigns, which create needed storage space in the double-shell tank storage system by periodically concentrating liquid tank waste, and other Hanford cleanup activities.

   The wastewater is stored in three basins at the Effluent Treatment Facility (ETF) complex until it can be treated for disposal. Each basin is permitted to hold about 7.8 million gallons of material. 

   In July and August, workers rolled out panels of the rubber cover material and bonded them together inside the massive basin, roughly the length of a football field and nearly twice as wide. Last month, equipment was reinstalled around the basin perimeter to allow movement of the cover as it floats on the surface of the wastewater in the basin.

   Work on the project began in June with removal of the previous cover that had been in use for more than 20 years.

   The new cover material is resistant to chemicals, temperature extremes, and ultraviolet light. Basin covers have a variety of functions including helping to prevent potential contamination being spread by birds or other animals and keeping foreign materials out of the wastewater, which could affect its processing at ETF.

   The cover for another LERF basin was replaced last year. Replacement of the third basin cover is planned for fiscal 2019.

   “ORP is encouraged by the team’s efforts and ability to overcome challenges in safely completing the second cover replacement project,” said Richard Valle, ORP’s LERF and ETF program manager. “Lessons learned from this project will aid in planning and performance when work begins to replace the third and final basin cover this fiscal year.”