City Staff emptied and cleaned the Digester over a two-week period for inspection purposes. Upon inspection it was determined that the walls of the digester were showing signs of concrete deterioration.


Due to the very limited time that the Digester could be off-line and to maintain the structural integrity of the digester walls, the Mainstay Composite Liner was the product chosen to rehabilitate the structure.

Surface Prep:
– All areas to be lined were prepared using abrasive blasting and pressure washing to remove all contaminated and loose material.

Surface Rebuilding and Corrosion Protection:
– Mainstay ML-72 Microsilica Mortar was mixed and applied to the digester walls with a shotcrete nozzle where it was then hand troweled and finished with a sponge to achieve a textured finished.
– 100 mils of Mainstay DS-5 Epoxy was applied to the mortar for protection against further corrosion.
– The use of Mainstay DS-5 Epoxy over Mainstay ML-72 Restoration Mortar creates a lining that cures into a strong, highly corrosion resistant surface free of pinholes, holidays and voids.


This digester rehabilitation project not only restored the deteriorated concrete but also protects from further corrosion giving this structure many more useful years of service life.

Lebanon, Oregon

Installation Date:
September 2020

City of Lebanon Public Works