79 Elm Street • Hartford, CT 06106-5127 www.ct.gov/deep Affirmative Action/Equal Opportunity Employer Bureau of Water Protection and Land Reuse Remediation Division

COMPLETION OF MILESTONE CONSTRUCTION CO~En;,JCAY; To: Dan Wainberg, EPA Region ~,o/9/J. g/J / Through: Jan Czeczotka, CT DEEP ~ q, 1-. 1· H., Edgar Davis, EPA Region ~ ~ 9/If/ Iv From: Sandy Brunelli, CT DEE~

copy: David Ringquist, CT DEEP

Date: September 26, 2016

Re: United Oil Recovery Inc. (Tradebe) 136 Gracey Avenue Meriden, Connecticut EPA ID No. CTD021816889

United Oil Recovery Inc. (ak.a Tradebe) (United Oil) located at 136 Gracey Avenue in Meriden, Connecticut has achieved the "Construction Complete" (CASSO) Corrective Action milestone. This site is subject to the requfrements of the Resource Conservation and Recovery Act (RCRA) Corrective Action Program since the facility formerly operated a greater than 90-day haz.ardous container storage area under RCRA Interim Status.

The site is situated on a 1.39 acre parcel and occupied by an approximately 24,000 ft2 building. In the early 1900s the site was used as a and consequently a majority of the site has been covered in fill containing coal ash with related metals (arsenic and lead) and polynuclear aromatic hydrocarbons. From 1929 through the 1960s the site was a florist. 1n the 1970s the site started heating the green houses with waste oil. In about 1976 the business switched over to waste oil and in the early 1990s expanded the business to include RCRA hazardous, non-hazardous, universal and mixed as well as used oil. Processes include container and tank storage and treatment, bulk loading and unloading, separation of liquids from solids and semi-solids, and truck-to-truck transfer of wastes. Specification and off-specification waste oils, fuels, solid and liquid hazardous wastes are shipped off-site for reuse, further treatment and/or disposal. These activities are permitted under the RCRA hazardous waste operating permit DEP/HMW-080-002 issued by the Department.

Twenty-five areas of concern (AOCs) were identified on-site. Ten of the AOCs have either been rernediated or did not require remediation. Approximately 800 cubic yards of contaminated soil were excavated from the exterior AOCs and disposed of off-site. The remaining AOCs are the Outdoor Wastewater Tanlc Fann, the Trailer Storage Area, and AOCs within the building. United Oil does not want to damage the integrity of these structures and has instead made the assumption that contamination is present in or beneath these AOCs and has requested and received concurrence with the Department that these structures will be maintained as engineered controls in association with an Environmental Land Use Restriction.

Tradebe public noticed the final Remedial Action Plan and Engineered Control Variance Request (RAP/EC) on June 30, 2015. No comments were received. The engineered controls were approved on September 3, 2015. The RAP/EC proposes to use the following three engineered controls (EC): 1) Use of the building to render the soils beneath it inaccessible. 2) The Outside Wastewater Treatment Area would remain intact to render the soils beneath it as inaccessible and environmentally isolated. The remedy for this area is an impermeable coating which was applied during September and October of 2015. 3) The Trailer Storage Area (TSA) was to have an impermeable coating applied to its base to render the soils beneath it as inaccessible and environmentally isolated. Upon further research it was determined that the coating proposed was not compatible with the asphalt in the TSA so a modification to the RAP/EC was submitted on June 28, 2016. The modification was to remove the asphalt and concrete in the TSA and pour an eight-inch thick concrete pad which will be underlain by a HDPE liner that has a woyen geotextile fabric layered above and below it. The modification was approved following Department input on August 2, 2016. The approved modification was constructed and completed during September of 2016.

An Environmental Land Use Restriction (ELUR) will be filed for the property to prohibit residential use of the site and prohibit disturbance of the engineered controls.

An Ecological Receptor Exposure Pathway Scoping Checklist was submitted to the Department for review in January 2015. In addition, the groundwater monitoring network was expanded and additional sampling conducted to provide multiple lines of evidence to support the use of the engineered control and to further define the downgradient extent of the plume. It was determined that the plume contaminant concentrations exhibited a downward trend and that no surface water bodies were impacted. Therefore, no further risk assessment is warranted at this time.

The Current Human Exposures Under Control Environmental Indicator (CA725) was completed in 2002. The Migration of Contaminated Groundwater Under Control (CA750) Environmental Indicator was completed in 2002.

Achievement of constmction of the remedy and does not necessarily mean that final clean-up levels or other requirements have been achieved as required by the Remediation Standard Regulations.