Lee Lake Water District EQ Basin – Containment System

LOCATION: Corona, California, USA DATE OF INSTALLATION: 2013 SCOPE OF WORK: Design-Build of Enviro Liner® 6060HD Geomembrane Base Liner and Floating Cover Containment System CUSTOMER: Lee Lake Water District

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The Lee Lake Water District was required by the California Regional Water Quality Control Board (CRWQCB) to tender the design and construction of a containment structure fully equipped with a geomembrane base-liner (to protect the groundwater) and a floating cover. The floating cover was required to control odor, eliminate evaporation and protect the E.Q. Basin from water fowl, animals and vector control. In an effort to manage high growth in Riverside County, the district needed to add capacity to store and treat wastewater. Budgetary constraints and timing were the district’s main driving force behind the selection of the geomembrane and floating cover system.

Layfield was selected to design-build the containment system. Layfield is recognized in the United States as the leader in the design and construction of engineered floating cover systems. During the past 30 years Layfield has installed over 180 floating cover systems representing approximately 25.5 million ft2 (241,600 m2) of cover material.

Solution and Results

The Lee Lake Water District evaluated and obtained cost proposals for several different types of geomembrane lining systems including Enviro Liner® 6060HD (1.5mm). EL 6060HD is a fortified polyolefin geomembrane manufactured from special prime grade resins and an advanced UV, antioxidant package. Budgetary considerations coupled with high performance demand were the main reasons why Enviro Liner® 6060HD was selected for this project. In total, three layers of geosynthetics where installed. A 10 oz. (285 grams) non-woven geotextile fabric was installed directly above the subgrade surface as a cushion fabric for the geomembrane liner. Layfield’s Enviro Liner 6040HD 40-mil (1.0 mm) was prefabricated (factory seamed into large panels) in Layfield’s San Diego fabrication plant and installed for the base-liner geomembrane followed by an Enviro Liner 6060HD 60-mil (1.5 mm) floating cover geomembrane. Other unique features and appurtenances included rainwater collection troughs, ballast weights and engineered floatation devises, access hatches, vents and attachment systems. Layfield provided this fully operational floating cover and base liner system at a very competitive cost when compared to equivalent systems and the client is very satisfied with their new E.Q. basin cover system.