R-T-S^TM Aecon

R-T-S^TM Aecon Pilot Project Union Gas Pipeline
April 2008

PROJECT DETAILS
The purpose of the MetaFLO R-T-S^TM pilot was to allow Aecon to assess an alternative environmentally friendly treatment and disposal method for both contaminated and non-contaminated HDD drill muds.

The results of an environmental assessment performed by Aecon showed trace amounts of PCBs and Mercury at two different locations. Even though the environmental assessment only showed surface contamination Aecon decided they would rather error on the side of safety and contracted MetaFLO to do a pilot project using the R-T-S^TM process to solidify and stabilize the drill mud in preparation of possibly having to dispose of it as a contaminated waste.

MetaFLO came on site April 19th, 2008. Aecon had two 12,000 gal tanks in the ground for the vac truck dumping, and two 12,000 gal tanks above ground for MetaFLO to process into. As the vac trucks filled one tank MetaFLO would then come in and setup the PDM-300 R-T-S^TM solidification system to process the drill muds to one of the above ground tanks to be disposed of later as a solid.

Process Data for Total Pilot Project

• Mud Weight Average over pilot was 9.76 lb’s/us gal
• R-T-S^TM dosage averaged over pilot was 1.94% of Mud Weight  Total Drill Mud processed was 27,953 gals
• Total R-T-S^TM HDD used was 5320 lbs
• Total Process Time was less then 7 hours

RESULTS
Before we could dispose of the solidified processed drill mud we needed to have it tested by an accredited lab. Lab results would determine how we would dispose of the waste.

Worst case was that we exceed the PCB limit, which is a listed contaminant that must be disposed of in a Hazardous Land Fill ($250-300 plus/ton). If it had turned out to be contaminated our R-T-S^TM process would have been of benefit by:

• Lowering the cost of disposal. It is more cost effective to dispose of a solid hazardous waste vs. a liquid hazardous waste.
• Reducing the volume by 40-70% due to evaporation (results will vary depending on the water content). Hazardous waste can stay on-site up to 90 days, this allows the required time to maximize the evaporation. One hundred tons of waste could reduce to between 30-60 tons of waste; saving both trucking and tipping fees.
• Second possibility was if we exceeded the limit for mercury, which in this case would be considered a characteristic waste. The R-T-S^TM process can stabilize most metal so they pass the Leachate test allowing us to dispose of the waste at a standard landfill at $20-50/ton vs. the $250-300/ton at a hazardous landfill.
• The Best case was that we had no contamination. To verify that, we then needed to do a solids bulk test to determine which table we met in the MOE’s ‘Soil Sediment Standards’. The test results (Test #4 & #5 below) of the R-T-S^TM treated drill mud came back very clean, so clean in fact, that it exceeded the ‘Soil Sediment Standards’ for table 1 which allows us to dispose of it as clean fill (in this case you only have to pay for trucking @ $85/hr and a tipping fee from $0-$50/23 tons). As clean fill, there are a number of options for disposal, including the ability to leave it onsite.

  Test#1 – Liquid Sludge (raw drill mud) came back clean. No Contamination.
  Test#2 – Soil/Leachate (treated mud) for Metals. No Contamination.
  Test#3 – Soil/Leachate (treated mud) for BETX (Hydrocarbons). No Contamination.
  Test#4 – Soil Bulks (treated mud) for Metals. No Contamination.
  Test#5 – Soil Bulks (treated mud) for PCB’s. No Contamination.

CONCLUSION
By all reports the pilot project was a great success for all parties. For MetaFLO it was a great opportunity to workout some of the logistics of working on a site. For Aecon/Union Gas the pilot was an opportunity to see another disposal option for drill muds both contaminated and non-contaminated. It also demonstrated the convenience and flexibility of using a local disposal facility, allowing for better optimization of the hydro- vac trucks’ time on-site. With the final test results meeting the MOE’s Table 1 or clean fill requirements, Aecon/Union Gas now have a more flexible, simple, and cost efficient disposal option for their future wastes.

With the knowledge gained from this pilot, future jobs using the R-T-S^TM process will run more efficiently, and we now have an environmentally friendly solution for the treatment and disposal of drill muds that will satisfy both Aecon/Union Gas’ needs and the MOE’s requirements.

Download the R-T-S^TM Aecon presentation. Reference to Surface to Surface (MetaFLO) is on page 35 and photos on page 36.