Presentation
Modified SCAT Procedures Developed for Oil Contaminated Mangrove Habitats in the Niger Delta
SessionMeet the Poster Authors
DescriptionMangroves are among the most sensitive environment to disturbances from oiling. Within the Niger Delta, large areas of mangrove habitat are oil-affected and in the process of remediation. The Bodo Remediation and Revegetation Project has pioneered a modified Shoreline Cleanup Assessment Technique (SCAT) to assess oil-damaged mangrove habitat and to close-out with regulatory agencies after remediation.
The visual distribution of oil is difficult to discern in dark-colored mangrove muds with high water content. Contamination is unequally distributed such that high oil concentrations may be found only meters away from low oiling concentrations. This required a new method for SCAT visual observations to address variability.
For each of multiple sites within a designated area (Grid), the procedure is to dig 3 pits within 5-7 meters, await the inflow of water and oil from the surrounding sediments, and visually estimate percent oil cover on each pit’s surface water using standard surface oil-level charts. An average of 25% or below for the 3 pits meets closeout for sediment remediation. Chemical sampling shows that SCAT observations are a reliable surrogate to meet sedimentary Site-Specific Target Levels (SSTLs) developed by the project team and approved by Nigerian regulatory agencies.
Additional SCAT criteria include no surface oil or garbage, breakup of surface algal mat and removal of Nypa palm. This modified SCAT provides a consistent and time-effective means to assess oiling levels and verify remediation actions over large areas of contamination in the Niger Delta.
The visual distribution of oil is difficult to discern in dark-colored mangrove muds with high water content. Contamination is unequally distributed such that high oil concentrations may be found only meters away from low oiling concentrations. This required a new method for SCAT visual observations to address variability.
For each of multiple sites within a designated area (Grid), the procedure is to dig 3 pits within 5-7 meters, await the inflow of water and oil from the surrounding sediments, and visually estimate percent oil cover on each pit’s surface water using standard surface oil-level charts. An average of 25% or below for the 3 pits meets closeout for sediment remediation. Chemical sampling shows that SCAT observations are a reliable surrogate to meet sedimentary Site-Specific Target Levels (SSTLs) developed by the project team and approved by Nigerian regulatory agencies.
Additional SCAT criteria include no surface oil or garbage, breakup of surface algal mat and removal of Nypa palm. This modified SCAT provides a consistent and time-effective means to assess oiling levels and verify remediation actions over large areas of contamination in the Niger Delta.
Authors
Deputy SCAT Lead
Environmental Scientist
Event Type
Poster
TimeMonday, May 13th5:00pm - 6:00pm CDT
LocationExhibit Hall G
Preparedness
Prevention
Remediation
Response
Restoration