DWR's contractors will conduct ground penetrating radar surveys to locate 19 irrigation pipelines associated with the Aqueduct. The pipelines will be cleaned and Remote-Video Inspection (RVI) will be conducted. Each work area will be about 300 foot on both sides of the Aqueduct at each milepost.
Pipelines at MP 140.50 and MP 155.71 have open ends; standing water inside them will be drained and dispersed on site. The pipes will be cleaned by hydroblasting; water from this process will be dispersed on site. The pipes will be inspected by remotely operated vehicle.
The pipelines at MP 134.93, MP 135.98, MP 138.95, MP 140.50, MP 156.36, MP 157.42, MP 160.46, MP 164.98, MP 165.59, MP 166.69, MP 167.64, MP 168.56, MP 170.68, and MP 171.94 are not in service and have closed ends. These will be accessed with hydrovac excavation, which is equipment using high pressure water to break down the soil; a vacuum will be used to lift the slurry into a debris tank and an excavator will be used to unearth the pipe. Shoring will be installed so the pipelines can be safely accessed. After each pipe has been exposed and investigated, the pipelines will be depressurized, drained, inspected, blocked, and a section will be cut out and removed. Water encountered inside the pipelines during inspection will be tested before being dispersed on site.
Pipelines at MP 137.83, MP 143.21, and MP 166.99 appear to be in service. These pipelines will be located, excavated, inspected, depressurized, and drained. Water encountered inside the pipelines during inspection will be tested before being dispersed on site.
Excavated areas will be backfilled and recontoured to match existing conditions prior to inspections.