The Sacramento Delta community of Locke is currently served by domestic water supply wells and is out-of-compliance with the State of California’s arsenic regulations. Residents are being supplied with bottled water. To provide a compliant water supply source to the Town, Coleman Engineering has designed a 4,300-foot long, 4-inch dia. HDPE intertie pipeline with Sacramento County Water Agency’s neighboring water system in Walnut Grove. For part of its route, the pipeline will cross the 180-foot wide Delta Channel.
Key Challenges & Solutions
Crossing the Delta Channel poses a couple of challenges. The Channel falls under the jurisdiction of the federal United States Bureau of Reclamation (USBR) and so a new crossing could involve extensive permitting. In addition, crossing beneath the channel using horizontal directional drilling or jack-and-bore trenchless methods, or over it on an independent pipe bridge, would be expensive. To resolve these issues, use was made of an existing, now-unused 10-inch dia. sewer force main currently attached to the side of USBR’s bridge and flood control structure that crosses the Channel. With the agreement of USBR, the existing force main will be removed, and its existing supports and ring hangers will be used to support a new 4-inch dia. ductile iron pipe.
February 14, 2022