Chronology of the Guadalupe Restoration Project

Late 1940s – The first commercial oil well was drilled at Guadalupe.

1951 – Unocal purchased 51 percent interest in the Guadalupe oil field.

1950s – A refined petroleum hydrocarbon, referred to as "diluent" (diesel/kerosene mix) was introduced at the site to assist in thinning the crude to facilitate production and transportation of the heavy crude oil. The diluent was transported to the site by pipeline and truck and distributed within the oil field by a system of storage tanks and pipelines.

March 1953 – The site produced up to 2,000 barrels per day from 34 oil wells.

June 1953 – Unocal purchased the remaining interest and became the operator.

January 1988 – Expansion of the oil field has resulted in up to 215 potential producing wells, with a peak production of approximately 4,500 barrels per day. Unocal makes its first report to state officials when employees note a petroleum smell on the beach next to the Guadalupe Oil Field. The source of the problem isn't determined, and the oil disappears from the water in a few days.

February 1990 – Unocal reported oil on the beach, shut down field operations and permanently discontinued use of diluent. For a short period of time, a segment of the field was put back on production using warm water - not diluent - to make oil flow.

September 1994 - February 1995 – Under order from the U.S. Coast Guard, Unocal conducted excavation activities at the 5X site. The County of San Luis Obispo issued Permit SLO P890275E (Modifications #4 and #5) for the 5X Excavation Support Facilities. Approximately 136,000 cubic yards of affected material was excavated and treated using thermal desorption units (TDUs). A total of ten extraction wells were installed on the upstream side of the excavation area to collect diluent approaching the excavation site. A total of about 250,000 gallons of diluent was removed from the excavation area.

Spring and summer of 1995 – The Santa Maria River changed course and migrated north. Unocal, concerned that the migration might continue and inundate the HDPE wall, developed a plan to install sheet pile at the southwest corner of the HDPE wall. A former production sump at the LeRoy Well #2 was exposed approximately 800 feet south of the 5X HDPE wall.

March 26, 1998 – County of San Luis Obispo certified the Final Environmental Impact Report.

April 3, 1998 – RWQCB issued Cleanup or Abatement Order No. 98-38, for the Unocal Guadalupe Oil Field, outlining remediation requirements for Phase 1.

May 15, 1998 –Unocal submitted to the RWQCB an Implementation Plan for the remedial actions mandated by Cleanup or Abatement Order 98-38.

July, 1998 – Unocal reached a settlement of a civil suit with the State of California stemming from diluent releases at the Guadalupe Oil Field. The $43.8 million settlement includes funding for restoration, replacement and rehabilitation efforts involving natural resources at the Guadalupe Oil Field.

August 13, 1998 – County Planning Commission approved Unocal's permit application for the project.

September 22, 1998 – The San Luis Obispo County Board of Supervisors approved Coastal Development Permit/Development Plan D890558D for the Unocal Guadalupe Oil Field Remediation Project with 252 conditions.

November 6, 1998 – RWQCB issued a revised Cleanup or Abatement Order 98-38.

December 10, 1998 – San Luis Obispo County Planning Commission approved CDP/DP D890558D, which had been revised by County Planning Staff in conjunction with the Coastal Commission Staff.

March 12, 1999 – Unocal contributed $285,000 to the Guadalupe Dunes Center, and $784,000 to Rancho Guadalupe Park as part of the company's mitigation requirements to begin Phase I work at the site.

August 20, 1999 – Three recovery systems at the Compressor Plant, Tank Battery 9, and Diluent Tanks areas and a biosparge system at the Tank Battery 8 area were placed in full-time operation.

February 2001 – All beach excavations were completed, a landmark event for the Guadalupe Restoration Project, which involved over 10 years of planning, permitting, and implementation.

September 2001 - Twelve additional excavations were completed, bringing the total of removed hydrocarbons to over two million (2,000,000) gallons.

October 2001 - Excavations were halted while Unocal prepared plans for 8 possible alternative methods of treatment and/or disposal of the growing stockpiles of excavated material and submitted them in a Supplemental EIR (SEIR) to be evaluated by the agencies.

December 2001 - Removal of approximately 145 miles of abandoned pipelines from the former Guadalupe Oil Field that were used for transporting oil, natural gas, water and steam was completed.

May 2002 - Unocal began construction of the Hot Water Flooding/Steam Injection Pilot Test. Numerous delays caused the actual test to be postponed until october 2003. The injection phase of the test was completed in April 2004, and was followed by post-steam monitoring and biosparge activities. The test site was fully decommissioned in August 2004. Final reports on the Steam Pilot Test were ratified in December 2005.

July 2002 – Unocal purchases the Guadalupe Oil Field, consistent with its commitments to provide a site-wide conservation easement that will assure permanent preservation of the unique coastal dune ecosystem.

March 2004 - The "Site-Wide Screening Level Ecological Risk Assessment" was ratified and a brochure was published for public distribution.

September 2004 - Unocal donated $100,000.00 to the Dunes Center in the town of Guadalupe toward construction of its new Visitor Center.

September 2004 - Unocal filed Irrevocable Offers to Dedicate, granting Conservation and Open Space Easements to the US Fish and Wildlife Service for the property's inclusion into the Guadalupe-Nipomo Dunes Complex. Unocal will provide habitat management support for 25 years following acceptance of the easements.

July 2005 - The San Luis Obispo County Planning Commission approved the Supplemental EIR (SEIR). In conjunction with approval of the Santa Maria Landfill's SEIR incorporating the trucking of Non-Hazardous Impacted Soil (NHIS) for use as capping material for closed landfill cells, off-site trucking of stockpiled and future excavated NHIS was determined the most appropriate method of disposal for the Guadalupe Restoration Project.

July 2005 - Requests for Proposal were distributed to 6 contractors for bids on off-site trucking and the remaining Phase I excavations. The contract was awarded to RECON in December 2005.

June 2006 - The California Coastal Commission ruled against an appeal brought by a group of Santa Maria residents in an attempt to halt trucking through the city.

August 2006 - Trucking operations began for the transfer of NHIS to the Santa Maria Landfill.