REMEDIATION ACTIVITIES

RESTORATION ACTIVITIES

Sitewide Restoration

Restoration of areas disturbed during remediation and decommissioning activities is ongoing throughout the Field. Active restoration is currently underway in foredune habitat (22 acres), dune scrub habitat (18 acres), and dune swale habitat (5 acres). The primary goal of restoration is to establish self-sustaining plant communities that are native to the Guadalupe/Nipomo Dunes Complex and that are similar to habitats found in undisturbed areas of the dunes complex. Restoration sites are meticulously monitored to ensure that restoration is proceeding in accordance with site-specific performance standards. Recently more than 1,000 La Graciosa thistles propagated at the onsite Growing Facility were planted by a wetland near the beach, which will be carefully monitored to determine the best way to expand this listed plant species.

Outplanting La Graciosa thistles near B2 wetland

Beach Restoration:

In January 2001 Unocal began restoration of the beach and dunes that were affected by recent remediation activities at the southwestern area of the site. The purpose of the restoration activity is to restore naturally functioning, self-sustaining dune strand/beach and foredune habitats to the remediated sites. The restoration approach involves providing an environment suitable for the natural recruitment and restoration of disturbed areas. Also, as warranted, the restoration site is augmented with native seeds and plants, managed for erosion control, and weed abatement to facilitate natural restoration.

After remediation activities were completed toward the end of 2000, the beach area excavations were filled with clean sand from other areas of the site and the site returned to its approximate base level. Dune-like structures were created where natural foredunes once existed. The created dunes are smaller than those that existed prior to the excavation. Natural dunes can take up to 50 years to naturally develop and are anchored and reinforced with live and dead plant roots; the newly restored dunes began as only sculpted ridges of loose sand.

To stabilize these new dunes and to reduce the risk of harmful large-scale sand blowouts, clean rice straw plugs (free of weeds) were planted vertically into the sand. The rice straw plugs may also improve seedling establishment and enhance the survival of both seedlings and transplants. The rice straw plugs provide an effective windbreak for the seedling, as well as providing a vertical condensation surface for fog, which will run down the straw, and provide moisture to the seedlings. The use of straw plugs has been applied successfully at other restoration sites in California, including Oso Flaco Lake. However, we believe that this may be first time it has been used so close to the ocean and at such an exposed site.

The newly created dunes have remained stabilized since 2000 and most of the same plants that occurred on the dunes prior to the disturbance are found today at the restoration site. The newly created dunes have also been used by the endangered Western snowy plover during breeding season (March – September). The dunes are also providing habitat for kangaroo rats, which have established several burrows in the dunes.

Snowy plovers on restored beach dunes

Growing Facility

A growing facility has been constructed onsite to facilitate the propagation of plants to be used when restoring areas disturbed during remediation activities. Plants, cuttings and seeds are collected from remediation sites prior to disturbance and taken to the growing facility where they are cared for or germinated. Plants from the growing facility are used to augment seeding of the restoration areas. Research on various propagation techniques is also conducted on sensitive plants.

Weed Abatement

Invasive exotic plants, such as veldt grass and ice plant, are common to the Field, and the disturbance from site characterization, remediation, pilot study implementation, oil field abandonment and related activities may result in the increase of these species if not properly managed and controlled. More importantly, the presence of exotic species is a constraint to successful habitat restoration and management. Therefore, Unocal has implemented a Field-Wide Exotic Species Management and Eradication Program, with a full-time professional crew working to control the invasive exotic plants on site.

The areas of the Field that have been treated are included in the Weed Eradication Locations figure. An example of an area before and after weed abatement is shown below.

 

ECOLOGICAL ACTIVITIES

Mediation Group

Special studies are currently in progress under a technical mediation process with the goal of building consensus and resolving technical issues. Participants in the mediation process have included:

This team of agencies, company and consultants is performing studies that include defining treated backfill criteria that are protective of water quality and ecology. They are also performing a detailed study of oil well sumps, natural attenuation sustainability, plume stability, and are refining a groundwater model of the 2,700-acre site. The Site-Wide Screeninig-Level Ecological Risk Assessment was ratified in 2004.

Please refer to the Mediation Group's most recent Summary of Progress and Agreements.

Research and Studies

Research has recently been completed on two sensitive wildlife species present at the site, the western snowy plover and the California red-legged frog. The western snowy plover study was undertaken to determine the factors that influence nesting site selection. The information gleaned from the study was incorporated into the design of restored foredune areas to make them more suitable for nesting plovers. Plover study results indicate that the restored foredunes are providing good nesting habitat for the plovers.

The California red-legged frog study involved placing small radio transmitters on the frogs, relocating them from a drainage pond where they were at risk, and monitoring their movements. The results of this study will be used to better ensure their protection during remediation projects and to facilitate their reintroduction to restored wetlands.