Placer County Water Agency
2011 – 2013
Placer County Water Agency (PCWA) engaged Blackburn Consulting for another commission to perform a subsurface investigation and prepare design and construction recommendations for a 5 MG water tank and approximately 3,400 linear feet of 30-inch diameter ductile iron transmission pipe. The new tank is 175 feet in diameter and replaces an existing reservoir constructed in 1953. The new water line replaces an existing 20-inch diameter line and will be constructed primarily within existing roadway.
Blackburn’s investigation included thirteen borings (some cored into rock) and four seismic refraction surveys lines along the pipeline alignment. Blackburn’s recommendations helped mitigate project challenges including surcharging existing structures during construction, considerations for demolition and excavation adjacent to existing structures, rock depth and excavatability, steep slopes, and areas with shallow groundwater.
During construction, Blackburn provided geotechnical support and quality assurance materials testing.