Pipeline Decommissioning
Unocal has removed over 140 miles of abandoned pipelines from the Guadalupe oil field, which were used for transporting oil, natural gas, water and steam. With the approval of the agencies’ Onsite Environmental Monitor, pipeline has been left in place if it is buried more than 2 feet below the ground, could significantly disturb listed species or sensitive habitat if removed or could cause a significant physical disturbance. A map indicating the location of all the abandoned-in-place pipelines was provided to the San Luis Obispo County Planning and Building Department.

Removal of 26-inch pipeline

Other Facilities/Features:
The existing road network in the field provides access to ongoing groundwater sampling/monitoring, remediation, excavation and pipeline decommissioning activities and keeps equipment and personnel off environmentally sensitive terrain. The existing well pads provide necessary staging areas for equipment during the conduct of remediation projects, pilot studies, aquifer tests and decommissioning activities. As currently proposed, many roads and well pads will be removed upon completion of decommissioning and remediation activities. Monitoring wells have been installed throughout the site, and will be removed when no longer needed for groundwater monitoring or other studies. Oil spray lenses are present at the Field from sand stabilization efforts in the past. Many of the lenses have been buried beneath shifting sands, are no longer visible and have mature vegetation growing from the surface. In many instances, the disturbance caused by removing the lenses would be greater than leaving the site alone to naturally revegetate. However, in other areas where contiguous blocks of lens are large enough, treatment may consist of breaking up the surface with hand tools or heavy construction equipment to allow sand exposure and a possible opening for seed germination.