Fina Oil and Chemical Company is currently involved in a mitigation project which consists of two phases: earthwork and seagrass replanting. The Bird Island Mitigation Project is part of a mutual agreement between Fina and the US Army Corps of Engineers in retribution for seagrass damage in a 37 acre area during mobilization of a drilling rig to location in 1990.
The site is located in the Upper Laguna Madre, between the southern coast of Texas and Padre Island. It is among the largest of three high-salinity lagoons in the world and also one of the world's rarest marine environments. This area's extreme environmental sensitivity, coupled with an average water depth of 3 feet, caused deriving successful mitigation plans to be difficult.
The objective of the project was to place fill and recondition the bay bottom in two areas creating proper seagrass habitat. Upon completion of the earthwork, 74 acres of seagrasses would have to be harvested and planted in the habitat created.
This paper provides a chronological depiction of the development and procedure of one of the largest restoration and mitigation projects of its kind. Highlighted, are the new technologies researched, developed and tested to aid in the development and implementation of the earthwork phase completed in May 1998. This was the most challenging and difficult phase of the mitigation project.
Research conducted produced the negative effects of hydraulic dredging plumes on the environment. Studies show that plumes both distribute and re-supply areas with necessary nutrients, but consequently, block light penetration due to the suspended particles. Critical research concentrated on techniques developed primarily for hazardous substances and technology responsible for transportation of dried commodities. Both techniques researched minimized turbidity plumes and allowed for timely completion.