Publication Summary

A Class II Inspection was conducted February 28 and March 1, 1994 at the Shell Oil Company Petroleum Refinery (Shell) at March Point near Anacortes, Washington. The inspection investigated the Shell process wastewater, chemical wastewater, sanitary sewage, and stormwater treatment system.

A Class II Inspection was conducted February 28 and March 1, 1994 at the Shell Oil Company Petroleum Refinery (Shell) at March Point near Anacortes, Washington. The inspection investigated the Shell process wastewater, chemical wastewater, sanitary sewage, and stormwater treatment system.

The inspection found that on the first day of the inspection Shell was not timely in containing floating oil that resulted from a stormwater contamination event. General chemistry results suggest that the system's API separator was functioning normally. Removal efficiency by the system's aeration basins and sedimentation tanks was good for all parameters except TSS. This low TSS removal efficiency was attributed to poor secondary clarifier performance. Removal efficiency across the entire system was good for most parameters with the exception of ammonia nitrogen, which showed increased concentration across the detention ponds. Cyanide concentration in the receiving water at the acute boundary was projected to exceed the State acute water quality criterion for marine receiving waters. Refinery effluent concentrations were all within NPDES permit limits. Whole effluent organic and metal concentrations were generally within state and EPA water quality criteria except for copper, mercury, and nickel. With the exception of cyanide, dilution within the receiving water reduced concentrations to below all criteria.

Bioassays found toxicity in two out of four sensitive species and subacute toxicity in a third. Sediment analyses found that organic and metal concentrations did not exceed the marine sediment quality standards. Bioassays revealed no significant toxicity in the sediment.