Rayloc, a division of Genuine Parts Company which operated an auto parts re-manufacturing facility in Atlanta, Georgia from the early 1960's to 1997, and RentRite Holdings Company, Inc., located adjacently, are the focus of this remedial action. The Rayloc site consists of approximately 12.27 acres of land while the adjacent RentRite property is a 9.84-acre parcel of land. Contaminants at the site consist of 18 volatile organic compounds that include, among others, PCE, TCE and acetone.
Beginning in the early 1960's and continuing for approximately 15 years, an unlined waste disposal pit approximately 20 feet long by 20 feet wide and 12 to 15 feet deep was utilized near the southern end of the Rayloc property to dispose of waste materials generated in the Rayloc plant. No record of the quantity of waste which accumulated in the pit was found. The waste produced at the site during that time period came from vapor degreasing, cleaning, and surface coating operations.
Soil and groundwater samples were collected at the site as well as around the known source area to delineate the waste pit both horizontally and vertically. Subsequently a total of eighteen groundwater monitoring wells were installed around the site to define horizontal delineation and five deep, double-cased wells were installed within and near the former waste pit for vertical delineation. Some of the vertical delineation wells were cored into bedrock beginning at depths of 60 feet to 70 feet bgs.
A Compliance Status Report (CSR) was completed in 2004 and submitted to the Georgia Hazardous Sites Response Program (HSRA) with a request to initiate the site source remediation.
Jack Wintle, the Project Manager, had experience with similar projects which was crucial to determining the most cost-effective and efficient source removal solution, resulting in the decision to conduct in-situ thermal remediation (Electrical Resistance Heating) of the source material at the site. This process included the installation of 35 electrodes and 18 multi-phase extraction wells which were used to heat the subsurface source area , from a depth of 74 feet to the surface, to a temperature above 100°C. The“stripped” volatiles were then vacuumed from the subsurface via a soil vapor extraction (SVE) system and total fluids pumps removed the impacted groundwater at a volume of approximately 18,000 gallons per day. The vapors were treated with carbon and the recovered liquids were treated through a low-profile air stripper prior to being pumped into the local POTW. During this stage, the project was contracted with Mr.Wintle’s employer at that time, PBS&J, whose personnel conducted operations and maintenance (O&M) at the facility. Due to the amount of electricity generated on site, one of Mr. Wintle’s major priorities was site security, which included not only safeguarding the site with fencing and appropriate signage, but also providing fundamental training as well as overnight security personnel.
Mr. Wintle oversaw a 15-month Pilot Study using Regenesis Hydrogen Release Compound (HRC®) injection which was conducted at the site to assist in mitigating the offsite migration of impacted groundwater. The Pilot Study was performed to determine the effectiveness of the HRC® in accelerating the biodegradation of the chlorinated solvents in the groundwater.
Adjacent to the HRC® Pilot Study, an additional Pilot Study, using In-Situ Chemical Oxidation (ISCO), was also performed. The oxidizer for this study was sodium persulfate, which was activated using sodium hydroxide (NaOH) as a catalyst.
To achieve a complete understanding of the level of impact from the site source, as well as the neighboring areas' geology and lithology, Oasis has initiated a six-month investigation into the off-site migration of contaminants that includes accessing up to 12 neighboring properties not only by collecting soil and groundwater samples but also by installing new monitoring wells and coring into the bedrock. Mr. Wintle, who is now Manager of the Environmental Division at Oasis, continues to provide key services at the site by overseeing this investigation. His history with this project provides an established continuity which will facilitate the design of the most efficient plan possible for mitigating the further migration of site contaminants once the investigation is complete.
