Sanderson Lift Station pit and wet well to be recoated


On Dec. 18, the Eastern Municipal Water District’s Sanderson Lift Station Septage Receiving Pit experienced a failure due to the delamination of the lining which protects the concrete structure. On Aug. 5, the EMWD board voted 5-0 to award National Coating and Lining Company a $93,918 contract to recoat the receiving pit and wet well.

The board action authorized a cost of $144,000 for the project. The full amount will cover staff labor, inspection services and contingencies as well as the contract.

The Sanderson Lift Station Septage Receiving Pit is on Sanderson Avenue in San Jacinto. The receiving pit, which includes a wet well, was constructed in 2004. Commercial septage haulers offload septage into the receiving pit where it is ground up and then pumped by the Sanderson Lift Station to the San Jacinto Valley Regional Water Reclamation Facility.

The septage pit remained in operation following the failure, but a new liner will be required. Eastern issued a request for proposals, June 9. The request for proposals included technical requirements on the offered coating system to ensure compatibility with the existing environment of the septage pit and the overall efficiency of the product. Bidders were required to propose a coating system which has been in service for at least 36 months and is compatible with the lift station’s adverse environment. The district hosted a non-mandatory job walk, June 17. Four bids were received by the June 30 deadline.

The bids were evaluated based on the coating system, price, lead time, exceptions, company qualifications and experience, company performance history and proposal work plan. National Coating & Lining Company had the highest score. National Coating & Lining Company will use the Raven 405 coating system that EMWD has found to be reliable under similar conditions. EMWD first used the Raven 405 coating system for the Olive Avenue Sewer in Winchester and also used the Raven 405 system for the Whitewood Gravity Project in Murrieta, and no problems with the coating have occurred.

Raven 405 is intended to provide structural renewal for severely deteriorated wastewater infrastructure. The solvent-free epoxy coating was designed with exceptionally high physical strengths and broad range chemical resistance. It is designed for operating temperatures up to 200 F and can be applied on vertical and overhead surfaces. The surface tolerance and high physical strengths of Raven 405 allow it to be designed as a structural lining in maintenance holes, pipelines, tanks and other deteriorated structures. The typical uses are surfaces where rehabilitation of an existing structure requires enhancement of the structural integrity and where exposure to concentrated acids and caustics may be expected. National Coating & Lining Company has been in business for more than 30 years and has been utilizing the Raven system since 2006.

EMWD staff will perform the removal and re-installation of the pumps and guide rails which exist in both the septage receiving pit and wet well. Coating Specialists and Inspection Services Inc., which is a third-party inspector, will certify the application of the coating system before the septage receiving pit being brought back online to ensure that all technical and contractual requirements are adequately met and that the quality and regulatory standards are achieved.

Joe Naiman can be reached by email at