Construction Projects
Water Transport, Drainage, and Sewer

Upgrade Sewage Lagoon for Kofa Firing Range (KFR)

Yuma Proving Ground (YPG), Yuma, AZ

GCE was subcontracted to provide utility infrastructure improvements for the construction of one new 656,062-gallon facultative lagoon and one 365,200-gallon evaporative lagoon at the existing U.S. Army Corps of Engineers (USACE) KFR sewage lagoon complex at the YPG.

The new lagoons were constructed upon an earthen foundation protected on the northern and eastern sides with earthen protection berms reinforced with rip-rap rock erosion protection system to mitigate storm water damage to the new lagoon foundation. Storm water flows are routed to the east of the new lagoon expansion through a newly constructed storm water drainage channel constructed adjacent to the protection berms. Soil surface erosion control measures were provided at areas where cuts to existing earthen slopes were made during channel construction.

The new facultative and evaporative lagoons will be double-lined with a geocomposite interstitial drainage layer located between the two liner layers. The liners will consist of one 100-mil textured high-density polyethylene (HDPE) primary barrier layer over one 60-mil textured HDPE liner secondary barrier layer. The liner layers were welded seam and installed in accordance with liner manufacturers installation instructions by a manufacturer-approved installation contractor. The lagoon liners are protected from damage and degradation by minimum of 4-inch fiber-reinforced shotcrete at lagoon slopes and 8-inch fiber-reinforced shotcrete at lagoon bottoms, with thickened areas at various locations.

GCE provided modifications to existing sewer manhole #2, constructed a new sewer manhole, and extended a new 8-inch gravity sewer line to the new facultative pond. GCE provided isolation valves at the existing sewer manhole. GCE also provided piping for interconnection of the new facultative and evaporative lagoons, as well as overflow and bypass piping and valves.

GCE demolished the existing lagoon complex eastern fence line and constructed new fence line sections to enclose the lagoon expansion, which consisted of new 6'+1' three-strand barbed wire fencing and double-swing access gate in accordance with the drawings.

GCE provided modifications to the existing south access road to provide unimpeded access around the lagoons after construction of the lagoon foundation and slopes.