Petroleum tank bottoms and petroleum contact water (PCW) are delivered via vacuum tank trucks to our facility and transferred at the offloading stations.
Tank bottoms are processed through a coarse screen to remove large debris that has worked its way into the tank. The sludge is sent to the solids holding facility where most of the liquids are removed. The remaining sludge continues to the solids processing building where a filter aid is added. The resulting slurry then goes to a plate and frame filter press. Leachate from the filter press is returned to the liquid treatment system and the filter cake proceeds to a dryer via a screw conveyor.
The dryer is a closed system using oil as the heat source. The filter cake is treated in a continuous process and the final result is a powder that is 99.5% dry. Solids from the system are shipped to a landfill as a non-hazardous waste. Vapors from the drying process are condensed using a two-stage vapor recovery system (VRS) and sent back to the liquid treatment system.
The PCW is sent to the liquid holding tanks. This liquid along with the leachate from the filter press and the condensate from the VRS flow to an oil-water separator (OWS) that removes the majority of free product and sends it to storage tanks. When enough product is collected, the material is transferred to our Transmix unit for processing. The final product is sold at the terminal as transportation fuel.
Water from the OWS is sent to the biological treatment system in which microbes are used to eliminate hydrocarbons prior to discharge to the POTW in accordance with a State Indirect Discharge Permit.