A release of toluene (a listed hazardous waste) and Aromatic 100 from underground AST piping caused soil and groundwater impacts at the facility, including light non-aqueous phase liquid (LNAPL). The CP Environmental Group (CPEG) team evaluated the remediation system design prepared by others, modified the design within the constraints of the facility consent order with the Pennsylvania Department of Environmental Protection (DEP), installed and provided O&M of an AS/SVE system to treat contaminated groundwater at the Pennzoil-Quaker State Terminal. We initially conducted a third-party review of the proposed AS/SVE/DVE remediation system for the site designed by another consultant. Our hydrogeologists and design engineers reviewed the pilot testing data collected by the other consultant and their resulting design and identified several potential problems that would affect system design, performance, and life-cycle cost. We performed an independent SVE/AS pilot test and recommended several modifications to the remedial system design based upon our pilot test results. These modifications included:
- Installing additional AS points to effect more comprehensive coverage of the plume
- Reducing the number of SVE points
- Changing the well point material from PVC to stainless steel (to avoid compatibility problems with the toluene)
- Increasing the blower sizes to match the flow requirements indicated by the pilot test
- Changing the vapor treatment method from granular activated carbon (GAC) to catalytic oxidation (our air flow calculations showed a GAC life cycle of less than three days)
- Deletion of DVE from the design to avoid the need to treat very large quantities of water (in fact, no water treatment was included in the original design even though recovery of water/product was indicated), instead opting for product recovery pumps
The result of these efforts was a reduction in equipment, material, and LTO/LTM costs for the client, while still maintaining a viable remedial strategy for the site that met regulatory requirements while also working within the constraints of the consent order. The client, comfortable with our demonstrated expertise in remediation treatment systems and the proposed system modifications, subsequently awarded the CPEG team the installation and O&M/LTM portion of the work. At the client’s request, we led a project team that included the manufacturer of the equipment specified for the treatment system.
The treatment system installed was comprised of a rotary lobe AS blower, SVE blower, product recovery pumps, a catalytic oxidation unit for vapor treatment, a product recovery AST, 19 SVE wells, 29 AS points, and 16 recovery wells. The system was operated using a custom PLC unit, which provided remote/dial-in capability. Because this is an operational facility, we were also able to reduce the size of the treatment compound required to house the treatment system components, reducing impact to the client’s site operations.
As specified in the O&M Plan, our team monitored the remediation system weekly, collected PID readings for influent gases, documented vapor recovery rates, and took influent/effluent temperature readings from the catalytic oxidation unit. System optimization was performed weekly, either on site or from remote locations. The CPEG team also provided groundwater monitoring and gauging on a quarterly basis, and collected air discharge samples in compliance with the Allegheny County Health Department permit.
Design changes made during our peer review dramatically reduced equipment, material, and LTO/LTM costs for the client. For example, our airflow calculations indicated vapor treatment using GAC would have required change out every 1 to 3 days. We recommended changing the vapor treatment method from GAC to catalytic oxidation. Even though the catalytic oxidation unit is an expensive piece of equipment, in the long run it was proven to be less expensive that hundreds of GAC change outs.
Well cuttings and excavated materials generated during the system installation phase were to be disposed as a listed hazardous waste (U220). The CPEG team examined and researched a policy in the Pennsylvania regulations (not published) involving a “contained out” procedure. By using this procedure, we achieved an expedited delisting of the soil to non-hazardous. Further research indicated we could reuse the soil on site per Pennsylvania regulations once a contained-out determination was approved. We saved the client over $50,000 alone by avoiding transport and disposal of soil generated by system installation.
Finally, the system was designed to allow reduction of weekly on-site visits to monthly visits (with weekly remote dial-in checks) as the AS/SVE system reached optimal performance, which will significantly reduce O&M and LTM costs.
Quality of Work. The system was installed and operated as designed. System optimization and preventative maintenance logs were maintained to ensure quality system performance.
Customer Satisfaction. During our peer review of the system design, we proposed changing the vapor treatment method from GAC to catalytic oxidation, which decreased the size of the treatment compound required to house the system. Hence, the treatment compound took up less space at this operational facility, reducing any adverse impact to the client’s site operations. The Terminal Manager stated, “I thought all consultants were hard to work with until I worked with this one.”
Regulatory Compliance. The previous site consultant had established an adversarial relationship with the DEP, which not only put the client in a bad light, but also increased project costs and delayed report approvals. DEP continued to fine the client for non-performance during this period. Upon project award, we immediately opened lines of communication with DEP and kept them informed of site activities at regular intervals. This helped us take the regulatory relationship from an adversarial one to a good, cooperative working relationship. For example, during the installation phase, we were able to easily secure an extension from DEP to the consent order required start-up date after a storm delayed system startup and the local utility company indicated difficulties in providing the required power supply. Engineering design evaluation, system installation, and O&M cost was approximately $800,000, not including system components which were directly purchased by the client.
Total cost of project: $1,700,000