Environmental remediation project uses advance odour control

A pioneer in odor control technology helped a large urban renewal project in Massachusetts suppress odor emitted by contaminated soil. Environmental consulting company TRC Companies (TRC) found coal tar waste had leached into the ground of the 11-acre site, an old manufactured gas plant intended to become the new location of the Worcester Regional Transit Authority’s (WRTA) 156,000-square-foot maintenance and operations facility. 

During remediation, operators chose to use the OdorBoss® DB-60G -- manufactured by Dust Control Technology (DCT) -- and its innovative biodegradable and environmentally safe chemical air deodorizer to control naphthalene odor emissions. The result was a dramatic reduction in fugitive odor, producing a safer workplace, eliminating complaints from neighbors and allowing the demolition project to avoid long, disruptive periods of downtime.

Coal tar can contain of up to 50 percent naphthalene, a volatile organic compound (VOC) described as an acrid, bitter chemical, similar to the odor emitted by roofing tar. Tests had revealed that the contamination penetrated between 10 feet (3 meters) and 15 feet (4.5 meters) deep across the entire site. The estimated 85,000 tons (77,110 metric tons) of extracted soil was piled into storage mounds approximately 30-40 feet (9-12 meters) high.
“The deeper we dug and the more soil we exposed, the worse the odor became,” explained Brian Burk, Field Technician for TRC. “When summer temperatures heated the soil, complaints from neighbors started coming in, so we immediately implemented our odor strategy.”

Two areas of operation on the worksite were identified as the primary sources of the smell: the exhumed zones and the storage piles. As excavators and front loaders disrupted material in the ground or stored in piles, the odor was released and immediately carried on air currents. Higher temperatures increased the intensity of the smell.

TRC worked closely with the local community and DEP officials. Managers agreed to halt operations, cover all exposed material with foam and/or plastic sheeting. A few frustrating days of downtime had already passed when TRC site managers discovered the OdorBoss line of odor suppression systems.

The OB-60G introduces an engineered mist of the air treatment agent solution, comprised of millions of tiny droplets approximately the size of airborne plant spores. Safe for humans, animals and plants, this biodegradable chemical travels on air currents with the odor-causing molecules. It attaches to molecules and alters their composition, eliminating the component that causes the smell.

The process applies to a host of other odor-causing elements, such as sulfides, mercaptans, ammonia and amines. Since VOCs -- like naphthalene -- are particularly volatile during hot periods, the water droplets are merely used as a delivery system to introduce the chemical over a large area. Once the droplets evaporate, the chemical remains airborne for a period of time, further treating lingering odor molecules.

At a 1000:1 water-to-chemical ratio, the 500-gallon tank and ½ gallon of (1.9 L) OdorBoss additive container provide a full day of odor suppression at a volume of about .5 gallons of solution per minute (1.89 LPM). At that rate, the tank delivers about 16 hours of run time between refills, depending on the level of activity.

The special open-cylinder cannon design is mounted with a large water tank on a towable trailer with foam-filled tires. Just 8.8 feet (2.68 meters) wide, 19.8 feet (6.03 meters) long and 8.4 feet (2.56 meters) tall, the entire unit can be quickly positioned anywhere on the WRTA site by a single worker, using a pickup truck or other towing vehicle. The 25 HP fan generates 30,000 cubic feet per minute (152.4 CMS) of air flow, which propels a long cone of vapor that provides expansive coverage when using the standard 180° built-in electric oscillator with a vertical angle adjustment of 0-50º. 

Since adding the OB-60G into TRC’s odor control plan, the site has not experienced any downtime due to odor. Positioning the unit upwind using oscillation and the vertical adjustment, the chemical can be distributed in the path of the fugitive odor -- even emissions from the top of the storage piles -- neutralizing the odor molecules before they reach the site line. This ensures a sustainable workplace and better relations with the surrounding community.

“Before we implemented this solution, every morning there would be at least one odor complaint on my voicemail, but from the moment we turned the OdorBoss on, they stopped completely,” Chris McDermott, Sr. Project Manager for TRC. “We are extremely happy with the results and the service DCT provided, and will definitely use this solution on other projects.”
After a decade of innovating atomized mist technology for dust suppression, Dust Control Technology has extended its knowledge and expertise toward odor solutions for applications such as landfills, sewage treatment, recycling and manufacturing. Headquartered in Peoria, IL (USA), the company’s dust and odor control units are designed and manufactured in the USA and delivered to customers around the world, with its equipment sold to users in 45 different countries to date. With an industry-leading 3-year/3000-hour warranty, a robust rental fleet and expert service, the company has established itself as the forerunner in odor control equipment.