We are thrilled to share the exciting news that our company’s remarkable Lake Forest reservoir relining and floating cover project has been featured as the cover story in Geosynthetics magazine’s August/September issue. This groundbreaking initiative represents a significant environmental sustainability and water resource management milestone.
Geosynthetic floating covers provide a highly sustainable and economical method of protecting and treating fresh and potable water. They are designed to protect freshwater from environmental contamination while eliminating water losses due to evaporation. Case in point is the Seattle Public Utilities, Lake Forest potable water storage reservoir. The reservoir was first built in 1962 as an open-top, concrete-lined 60-million-gallon (227-million-l) containment facility for potable water storage.
In 2002, the reservoir underwent multiple modifications and improvements, which included a 28 foot (8.5 m) vertical cast-in-place reinforced concrete center divider wall and the installation of a geomembrane liner and floating cover. With the divider wall, the reservoir was separated into two independent operating cells, each approximately 288 feet wide by 671 feet long by 24 feet deep (87.8 m × 204.5 m × 7.3 m). The reservoir operates as a potable drink-ing water storage facility and provides emergency water supply. A 45-mil (1.143-mm) reinforced polypropylene geomembrane liner and floating cover were installed in 2002 and were experiencing problems that required replacement.
In May 2021, phase 1 construction began on the new replacement geomembrane liner and floating cover system for the east cell of the Lake Forest reservoir and was completed in September 2021. Phase 2 included the installation of a new geomembrane liner and floating cover system on the west cell. This construction was completed September 2022.