Attachment_4_-_GTWPP_Process_Description.pdf

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Attachment 4 Wastewater Pretreatment Plant (WWPP) Chemical Treatment Process

Grease Trap Wastewater Pretreatment Plant (GTWPP)

PROCESS DESCRIPTION: The Grease Trap Wastewater Pretreatment Plant (GTWPP) is designed to remove the oil and grease in the Bureau’s Annex cafeteria wastewater discharge. The influent to the GTWPP consists of a waste stream that is composed of detergents, rinse water, food solids, non-food solids, oils and grease. The grease trap is located in Room 156-1A. The wastewater enters the system by gravity flow through a set of basket strainers, which must be manually cleaned on a daily basis.

After passing through the strainers the wastewater enters the main chamber. Inside the main chamber there are paddles, heating units, transfer screens, and troughs connected to drums with piping. The heaters and moving parts are controlled by timers mounted in the room. The Contractor may adjust the timer settings to optimize the operation of the unit. Any changes must be documented in the log book.

PROCESS OPERATION: The Contractor shall operate the GTWPP with prudent engineering and operating practices. Operating the GTWPP includes, but is not limited to, the following tasks:

(1) The Contractor will examine the operation of the grease trap, complete a base line cleaning, and propose a schedule for routine cleaning.

(2) The Contractor shall legibly document the cleaning and maintenance/repair of equipment during each visit and provide a copy to the COR on a monthly basis.

(3) The Contractor shall clean the walls, floor, and the exterior of the equipment on a regular basis to the satisfaction of the COR.

(4) The Contractor shall clean the troughs from the screens, and the pipes leading to the drum that collect the used grease/oil. The Contractor shall dip any floating oil/grease from the top of the reservoir, and dispose in the oil collection drum before starting to clean the grease trap.

(5) The Contractor shall assure that the grease trap is operating as per manufacturer’s recommendations and in accordance with prudent operating practices.

(6) The Contractor shall maintain the equipment in a clean and operational manner to meet the satisfaction of the COR.

(7) The Contractor shall assure that the electrical elements are cleaned during each cleaning.

(8) The Contractor shall examine the premises and satisfy himself with the

Page 2 of 2 Pages conditions which would in any manner affect the work under the contract, and have sufficient and adequate materials available to repair and replace defective parts.

(9) Cleaning and maintenance on the grease trap shall be scheduled for periods of time when the flow through the grease trap has stopped, and shall be scheduled to minimize exposure of BEP personnel to the odors from the cleaning. Work schedules for cleaning and maintenance shall be approved by the COR at least three days in advance. The Contractor shall be able to respond to work for emergency maintenance within 24 hours after a call for malfunctions of the grease trap.

(10) This work does not include the disposal of the grease/water collected in drums. This is performed under a separate contract.

(11) The Contractor shall pump water from the collection drums back into the oil/water separator to concentrate the oil/grease collected and to minimize the amount of water shipped out when the drum is full.

(12) No more than 3” of water is allowed to remain in the drum when the drum is considered full and ready for shipment. If there is more than 3” of water, the material must be pumped off of the top of the liquid as described above.

(13) The screens in the grease trap will be cleaned on a daily basis by the

Contractor, and records of the cleaning will be maintained by the Contractor in a log book. The material from the cleaning will be placed in the lined trash can and discarded on a daily basis. At no time shall the material to be discarded remain in the trash can and cause any infestations. If any infestations occur, the COR must be notified immediately.

(14) The Contractor will examine the mechanical condition of the grease trap and maintain the equipment in operation in accordance to manufactures recommendations. The Contractor shall have on site adequate materials in sufficient quantity to clean, and maintain the equipment and to assure continuous and efficient operation of the system.