USACE Ocean Cape CON/HTRW Removal Action
Ahtna completed a removal action at the Former Radio Relay Station at Ocean Cape in Yakutat, Alaska. Our scope of work required management of waste and storm water onsite, hazardous materials and solid waste management resulting from the excavation and disposal of 1,100-lf of concrete and cast iron sewer piping that connected the Former Radio Relay Building and the former Composite Building to a septic tank. We removed three concrete manholes and a concrete lift station that were present along the sewer line. We also performed sampling, testing, and analysis to confirm no residual contamination after excavation completion. Ahtna completed all work on time and within budget. We also completed the project with zero safety incidents, and received the USACE Alaska Celebrate Safety Award for outstanding safety practices and record.
Ahtna conducted field screening of the soils left in place beneath the pipeline, manholes, lift station, and leach crib. We collected analytical samples from under each structure, down gradient of each structure, and beneath each 100-feet of sewer line at the location of the highest field screening result. We also collected analytical samples from soil excavated from the former Radio Relay Building, the former Composite Building, and the former Garage Building to evaluate the presence and magnitude of PCBs.
We performed sampling to provide the data to characterize several of the waste streams, which included both RCRA and TSCA-regulated waste. This expedited waste manifesting included Canadian Notification and Manifesting for transport of waste through Canadian waters. In excavation areas, high contaminant results triggered waste characterization analyses. We sampled concrete sewer pipe for analysis of PCBs to characterize specific sections of pipes. A Waste Tracking Log was kept with waste descriptions, container, sampling, characterization transportation, and disposal data. Waste Streams containerized, transported offsite, and disposed in approved TSDFs included: Non-Hazardous concrete/cast iron pipe – 38,798 lbs; Non-hazardous solids/liquids – 42,429 lbs; TSCA-regulated waste – 135.5 Kg; RCRA-regulated waste – 6,299 lbs.
Ahtna also constructed and operated a temporary, onsite water treatment system to process approximately 2,000 gallons of liquid that was removed from a large concrete septic tank. After testing, the water was approved for discharge and pumped to an area upgradient of the septic tank. Effective stormwater control was a must in Yakutat, AK, with an annual precipitation of 155 inches.
- Hazardous materials and solid waste management
- Transportation and disposal
- Wastewater and stormwater management