Project: Thermal Treatment of SRSNE Superfund Site
Location
Southington, CT
Contaminants
CVOCs, VOCs, DNAPL, and NAPL
Volume
57,770 cy
Goal
NAPL and Mass Removal. Targeted COC goals
Number of Heaters
607
Mass Removed
496,400 lbs.
Technologies
Important Project Details
Approach: A total of 607 thermal conduction heaters, 551 vapor extraction wells, and over 300 linear feet of horizontal vapor extraction wells were installed to heat and capture the volatilized contaminants. Heating and treatment were staged over two overlapping treatment periods to manage peak mass removal rates and make the design and procurement of the off-gas treatment system practical.
Challenges: During the installation of the thermal wells, it was discovered that the bedrock surface elevation varied much more than previously anticipated. To address the variances in the bedrock depth, all heater borings were installed and then heaters were custom designed and fabricated the appropriate lengths.
Results: The project was successfully completed with over 496,000 lbs of VOC contamination removed. This resulted in >99% reduction in COC mass and achievement of all soil cleanup goals.
What Makes this Project Unique
To address the large amount of contaminant mass (estimated to range between 0.5 and 1M lbs), the wellfield was operated in two phases with an overlap in the middle to minimize the size of the vapor treatment system and optimize utilization of treatment capacity. Daily peak contaminant loading ranged around 10,000 lbs./day.