Abstract: Magnitude, Distribution and Impacts of Accidental Brine Spills in the Louisiana Coastal Wetland Conservation Plan Area 

Abstract

ABSTRACT Accidental brine spills cause varying degrees of environmental damage in ecologically sensitive areas of coastal Louisiana. The objectives of this study were to determine the location, frequency, and causes of brine spills in coastal Louisiana, and to identify areas most susceptible to spills. The study was limited to the Louisiana Coastal Wetlands Conservation Plan Area (Conservation Area) as defined by the Louisiana Department of Natural Resources. I obtained digital spill report data the Louisiana Department of Environmental Quality (LADEQ), Water Quality Management Division in Baton Rouge. This database contained spill reports from 1990 through the early part of 1998, and included spill date, quantity, location (parish, oil and gas field), source, facility, and receiving water. I also obtained the locations and volumes of saltwater disposal wells from the Louisiana Department of Natural Resources, Office of Conservation. LADEQ field investigators with the Southwest, Southeast, and Lafourche regional offices were interviewed. Based on their recommendations, twenty-two spill sites were selected for field investigations. These spill sites represented a diversity of ages, quantities, and affected habitats. I documented the condition of each site with photographs, and detailed field notes. The history of each spill and clean-up efforts was also included. Five hundred sixty-seven spills were reported, or discovered by the LADEQ between 1990 and the first half of 1998. Eighty percent of the spills were concentrated in eight parishes. St. Mary and Vermilion parishes each had 14%, while Terrebonne, St. Martin, Plaquemines, Lafourche, Iberia, and Cameron parishes had between 8% and 9%. Fifty-nine percent of the spills resulted from line ruptures and 19% resulted from other equipment failures. Over two hundred sixty million barrels of produced water were injected into disposal wells in the seventeen-parish region located in the Conservation Area in 1996. Plaquemines, Cameron, Terrebonne, and Lafourche parishes made up 60% of the total. Forty-three percent of the wells were located in open water, 23% in marsh, 20% in uplands, and 13% in either cypress or deciduous forest. Visible ecological impacts at the spill sites that I visited ranged from small areas of dead vegetation to hundreds of acres of dead cypress trees. Some of the sites were impacted by chronic exposure to leaking lines and other sites were impacted by isolated events. Figure 1 is a photograph of a brine spill site in a bottomland hardwood forest in St. James Parish that is approximately five years old. A line rupture between the gathering facilities and the injection well caused this spill, and most of the other spills I investigated. Figure 1. Brine spill site in St. James Parish. The spill was approximately five years old at the time the photograph was taken. The findings in this study can be practically applied to spill prevention and detection by focusing inspection efforts in sensitive habitats where high volume injection wells are located. End_of_Record - Last_Page 10-------