Turning Tree Debris To Useful Material
New York City, in partnership with the U.S. Army Corps of Engineers, have announced a plan to convert tree debris caused by Hurricane Sandy into reusable materials, including biofuel, mulch and landfill cover. More than 15,000 trees were downed in the storm, and the City has collected the trees and broken limbs at Floyd Bennett Field, where nearly 100,000 cubic yards of chipped and non-chipped tree debris is piled.
The City anticipates an additional 100,000 cubic yards to be collected as clean-up continues. The City and the Army Corps are encouraging companies and municipalities to take the chipped tree debris, and the Army Corps has already contacted more than 20 companies and has received offers from two companies. Contractors capable of hauling and further processing the wood debris may register with the Army Corps at https://apps.swf.usace. army.mil/Hurricane/. Recipients of the mulch will need to process it to less than one inch in two dimensions before May 1, 2013. The US Department of Agriculture and the New York State Department of Agriculture and Markets must approve the processing and location to ensure this standard is met.
In addition to recycling the debris for other uses, the City and Army Corps are working on other disposal options to limit combustion risk. The tree debris is processed into wood chips, and their natural decomposition causes temperatures to rise within the debris piles and creates a risk of combustion, which occurred last year with tree debris collected after Hurricane Irene. The City and NY State Department of Environmental Conservation have authorized ECC, a debris removal company contracted by the Army Corps, to begin a six-day pilot program to incinerate some of the debris using an air curtain burner. An air curtain burner is a ceramic lined firebox approximately the size of a shipping container that uses large fans to create a curtain of air that prevents embers and ash, which generate particulate matter, from escaping. The Army Corps has successfully used this disposal method in previous disasters in Texas and Alabama, and an air curtain burner is being used by the Town of Brookhaven on Long Island for debris generated by Hurricane Sandy. The pilot program began on Wednesday, November 28.
The material to be burned will be strictly controlled and limited to downed trees and limbs, both chipped and non-chipped. Air quality modeling based on the best available information shows that incinerating tree debris with an air curtain burner would generate less overall emissions of a primary pollutant of concern, fine particulate matter, than trucking the debris to sites outside of the city, although both would have little effect on overall air quality. The City and Army Corps will consider air quality results, along with wind speed and other factors, throughout the pilot’s operations.
The effects of the pilot operation will be closely monitored. The U.S. Environmental Protection Agency (EPA) will operate eight air quality monitoring stations within the boundaries of Floyd Bennett Field and the New York State Department of Environmental Conservation (DEC) will operate three in surrounding communities.