Oxnard Harbor District Wins Honor

Monday, October 05, 2009

The American Association of Port Authorities has given an award of excellence to the Port of Hueneme Oxnard Harbor District for its extraordinary cooperative project to clean sediment from the harbor floor. Crafted through a partnership between the Oxnard Harbor District, U.S. Navy and U.S. Army Corps of Engineers, the Port of Hueneme Confined Aquatic Disposal (CAD) Facility project is an example of a harbor-wide contaminated sediment management strategy that provided a complete solution to the needs of all three project proponents.

Located approximately 60 miles northwest of Los Angeles, the Port of Hueneme is the only deep-water port between Los Angeles and the San Francisco Bay area and is the United States Port of Entry for California's central coast region. The port’s harbor consists of berths owned by the Oxnard Harbor District and the Navy, and a federal navigation channel that is maintained by the Corps. The Harbor District and Navy berths were last dredged more than 10 years ago and had accumulated between one and three meters of contaminated sediment in that time. Several open-water areas within the federal channel also contain contaminated sediments. These sediments came from chemicals on ship bottoms or from run-off in nearby agricultural fields. The sediments were found to be unsuitable for open ocean or beach disposal.

In 2007, the Harbor District, Navy and Corps began a collaborative effort to design and obtain regulatory approval for the construction of a CAD facility as a mechanism for managing the contaminated sediments within Port of Hueneme harbor. The on-site CAD facility is a highly cost-effective solution for all parties involved, as it entailed minimal transportation costs, no tipping fees and no need for sediment rehandling.

The dredging consisted of three phases:
1.    Hydraulic excavation of the subsurface CAD cell within the harbor with placement of the excavated clean sand on an adjacent beach that was severely eroded and in need of nourishment;
2.    Mechanical dredging of contaminated sediment from the Harbor District and Navy wharves and Corps open-water areas with barge placement of the sediments into the CAD cell;
3.    Capping and armoring the CAD cell, which consisted of dredging clean operations and maintenance areas from within the federal navigation channel and placing this material in the CAD cell to form a clean cap, a portion of which is covered by a rock armor layer to prevent scour of the cap.

The project’s significance to AAPA members is two-fold. First, it represents the first CAD site to be successfully permitted and constructed in California and is one of only a handful in the U.S., constructed for the sole purpose of harbor-wide sediment management. Second, it represents the first time a harbor district, the Navy and the Corps have proactively established a partnership to design and build a regional sediment management solution.