Asphalt Treated Road Base
|Summary Date: March 25, 2004|
|Status: Active||Database Name: Kodiak Buskin Beach Asphalt DA|
|Location: Mile 10 to Mile 15 of the Rezanoff Highway, Kodiak, Alaska||Latitude/Longitude: See database entry|
| DEC Contaminated Sites Contact: Jeff Brownlee, Project Manager - 907-269-3053
Paving over the compacted Asphalt Treated Base.
Contaminated soils were used to help construct a road on Kodiak Island. About five miles of the Rezanoff Highway south of the city of Kodiak were paved from approximately mile 10 to mile 15. Over 34,000 tons of soil contaminated with asphalt, bunker fuel and diesel was crushed to 1 inch minus and placed as asphalt treated base (ATB) and paved with conventional asphalt pavement. The project originated with the Corps of Engineers Alaska District (COE) Formerly Used Defense Site (FUDS) program as an alternative to the use of thermal remediation or off-site landfill disposal for contaminated soils. This remedial approach realizes a cost savings over traditional remedial methods and provides a beneficial reuse of the material. The project was coordinated with the Alaska Department of Transportation.
The contaminated material originated from a site called the Asphalt Disposal Area which is south of the city of Kodiak a couple miles on the coast. The site was used by the Sea Bees for an asphalt batch plant in the 1940’s and 1950’s. The site was excavated and cleaned in 2001. The soil was stockpiles on Coast Guard property off Anton Larson Bay Road. This site was also used as the crushing and processing site for the mix plant. The contaminated material is mixed with about 4% warmed asphalt cement oil, about 2% lime and 1-2% water to make the asphalt base (foamed asphalt).
Groundwater moving through the contaminated material and forming leachate is the chief concern of this remedial method. An extensive leachate and geotech testing program was performed on the material to ensure that any water moving through the material would not pose a risk to the environment or human health. In addition the road design for the ATB places the material under an impermeable surface (pavement) greatly reducing the possibility of any leachate forming. ATB use was stopped within 100-feet of bridges or surface water and regular D-1 was used as the base course.
The long term life span of the road will of course have to be evaluated over time. The material should be able to be reused as road base in the future if the road needs rebuilding or should be able to be disposed of as solid waste in a landfill.
Road construction was completed in the fall of 2003. The chip coat shoulders will require annual inspection to evaluate how the material holds up with weathering and general wear. Guardrails are being installed at the needed corners during the spring of 2004.