Sheen PAHs TPH Sheen Location ID Structure Area Crude Crude Type Color Oil* Oil* INLT-001 Possible Possible Brittle Streamer Metallic Dawson Streamer with Cove Inlet INLT-002 Yes Yes Non-Brittle Metallic oil spots Channel Dawson Cove Streamer with Metallic/ COVE-003 Yes Yes Non-Brittle Open Water oil spots Rainbow Notes: *Crude oil from the Pegasus Pipeline Dawson Cove B-On Water B-On Water sheens were consistent in observed locations, but the number of sheens observed declined with time. Two sheen samples collected within the B-On Water monitoring area did not resemble crude oil from the Pegasus Pipeline and may be associated with urban runoff and/or biogenic activity (see table below). About 50 percent of the observed sheens were non-brittle, and oil spots (0.1 to 1 inch in diameter) were observed with 15 sheen locations in the channel between the heavy vegetation in this monitoring area, indicating that some sheens may contain crude oil. Sheens observed in the downstream B-On Water area did not appear to contain crude oil. Sheen PAHs TPH Sheen Location ID Sheen Type Structure Area Crude Crude Color Oil* Oil* COVE-001 No No Non-Brittle Streamer Metallic B-On Water COVE-002 No No Brittle Patch Metallic Notes: *Crude oil from the Pegasus Pipeline Throughout the sheen monitoring period, only one brittle sheen location was observed at the Dawson Cove Outlet on November 5, 2013. Brittle sheens are often of natural biogenic origin indicating that the sheens may be associated with microbial activity. 11.3 Summary of Findings Based on the sheen monitoring activities and screening data evaluation, the limited areas with crude-oil-related sheens appear to be primarily located in the Dawson Cove Inlet Channel and the Open Water Area. Ongoing monitoring for sheens in the Dawson Cove is recommended, although at a reduced frequency. Additional investigation
Sheen Area Location ID PAHs Crude Oil* TPH Crude Oil* Type Sheen Structure Color Dawson Cove Inlet Channel INLT-001 Possible Possible Brittle Streamer Metallic INLT-002 Yes Yes Non-Brittle Streamer with oil spots Metallic Dawson Cove Open Water COVE-003 Yes Yes Non-Brittle Streamer with oil spots Metallic/ Rainbow Notes: *Crude oil from the Pegasus Pipeline Dawson Cove B-On Water B-On Water sheens were consistent in observed locations, but the number of sheens observed declined with time. Two sheen samples collected within the B-On Water monitoring area did not resemble crude oil from the Pegasus Pipeline and may be associated with urban runoff and/or biogenic activity (see table below). About 50 percent of the observed sheens were non-brittle, and oil spots (0.1 to 1 inch in diameter) were observed with 15 sheen locations in the channel between the heavy vegetation in this monitoring area, indicating that some sheens may contain crude oil. Sheens observed in the downstream B-On Water area did not appear to contain crude oil. Sheen Area Location ID PAHs Crude Oil* TPH Crude Oil* Sheen Type Sheen Structure Color B-On Water COVE-001 No No Non-Brittle Streamer Metallic COVE-002 No No Brittle Patch Metallic Notes: *Crude oil from the Pegasus Pipeline Throughout the sheen monitoring period, only one brittle sheen location was observed at the Dawson Cove Outlet on November 5, 2013. Brittle sheens are often of natural biogenic origin indicating that the sheens may be associated with microbial activity. 11.3 Summary of Findings Based on the sheen monitoring activities and screening data evaluation, the limited areas with crude-oil-related sheens appear to be primarily located in the Dawson Cove Inlet Channel and the Open Water Area. Ongoing monitoring for sheens in the Dawson Cove is recommended, although at a reduced frequency. Additional investigation
FINAL_Mayflower_DADAR_Rev_4_01_17_14.docx