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Underground Storage Tank Site Closure

FORMER RETAIL GASOLINE FACILITY

Conneaut Lake, Pennsylvania

During July 1991, our client closed three out-of-service underground storage tanks (USTs) and sought to characterize the area surrounding two previously closed-in-place USTs at their former Conneaut Lake, Pennsylvania Service Station.  Analyses of the soil characterization samples indicated the presence of petroleum impacts in the tank excavation areas.  Results of a subsurface investigation, conducted in October 1991, confirmed the presence of benzene, toluene, ethylbenzene, and total xylenes (BTEX) in both the soil and groundwater in the former tank areas. The results of a soil gas survey performed in March 1992 determined these compounds did not migrate beyond the property boundaries.

 

A Remedial Action Plan was submitted to the Pennsylvania Department of Environmental Protection (DEP) during January 1993 and implemented August 1993.  A soil vapor extraction and air-sparge system was operated from August 1993 through October 1996.  Dissolved-phase hydrocarbons in groundwater were significantly reduced site-wide.  However, concentrations of benzene in groundwater at one monitoring well remained above the Act 2 Statewide Health Standards (SWHS) for Non-Residential Used (NR-U) Aquifers.  The point of compliance for soil is the area of contamination that was delineated during the soil gas survey.  The analytical data for soil samples collected during August 1995 remedial activities were below the July 1995 DEP SWHS for soil.  During August 1998, an oxygen releasing compound (ORC™) was applied in the vicinity of the impacted monitoring well to increase the dissolved oxygen concentration in the groundwater and, thereby, accelerate the microbial decomposition of hydrocarbons in the groundwater.  Subsequent groundwater monitoring results indicated that the contaminant plume had diminished.

 

Subsequent analytical data from these POC wells were compliant with the SWHS under Act 2.  However, groundwater monitoring was continued by the previous consultant, even after the DEP-required 8 consecutive quarters was achieved.  Based upon attainment at the POC and the diminishing plume observed at the aforementioned monitoring well, the CPEG team prepared and submitted a Remedial Action Completion Report (RACR) for the site, including statistical trend analysis to support environmental site closure.  DEP reviewed and approved the RACR, as submitted. 

 

Total cost of project: $12,000

 

CPEG Business Solutions… Yield Advantages   

 

Once the CPEG team was awarded the project, a strategy to obtain environmental site closure was quickly formulated and implemented.  The CPEG solution included no new site investigation, yielded site closure with minimal costs, eliminated client legal liability, and saved our client thousands of dollars associated with continued compliance monitoring.  These tasks included:

 

  • Submitting a request under the Freedom of Information Act (FOIA) and conducting a review of DEP Files to obtain adequate background information.
  • Assessing the content of the previously submitted reports and associated data to determine if sufficient information was available to close the site under DEP’s Chapter 245 regulations.
  • Preparing the Remedial Action Completion Report in accordance with DEP’s Chapter 245 regulations using available data.
  • Obtaining DEP Approval of Site Closure and Release of Liability at the subject site by preparing and submitting only one report.

Class V Injection Well and Oil/Water Separator Closure

RETAIL PETROLEUM / TRUCKING Company SITE

Zanesville, Ohio

CPEG provided environmental consulting and engineering services to prepare a work plan for closure of two oil/water separators and a Class V injection well system closure at truck maintenance facility.  The work plan was prepared in accordance with the American Petroleum Institute (API) Recommended Practice 1604, "Removal and Disposal of Used Underground Storage Tanks", CFR 280.70-74, Region 5 Guidelines on Conducting Site Assessments at Class IV and Class V Injection Well Facilities, and Class V Well Closure Requirements.  CPEG negotiations with the Ohio EPA were successful in eliminating excavation and removal of underground piping which saved significant costs on the project.

 

The project included CPEG oversight and coordination during closure activities.  Closure activities included removal of existing fluids and demolition of the two oil/water separators; scour jetting of the influent and effluent piping, Class V injection well distribution box and associated injection lines; and capping each of the lines at each of the ends.  Distribution injection lines were excavated and removed.  Impacted soils encountered during excavation activities were stockpiled, sampled and transported to an off-site facility for treatment.  Soil samples were collected from beneath each oil/water separator and from beneath the excavated distribution lines to verify impacted soils had been removed. A rinsate sample was collected from the scour jetting wash water to verify the lines had been cleaned.  Excavated soils which appeared non-impacted were stockpiled, sampled for verification, and then returned to the excavations as fill material.

 

A Class V and Injection Well Oil/water Separator Removal Report documenting the aforementioned activities was prepared and submitted to Region 5 of the Ohio EPA.  As a result, a “No Further Action” status was received for the site.  This status was considered a significant asset for the sale of the property. 

 

Total cost of project: $12,670

 

Underground Storage Tank Site Closure

FORMER RETAIL GASOLINE FACILITY

Oil City, Pennsylvania

The site consisted of a former facility that utilized two 1,000-gallon unleaded gasoline underground storage tanks (USTs).  During UST closure, one UST closure soil sample exceeded the then current Pennsylvania Department of Environmental Protection (DEP) cleanup standard.  A subsurface investigation (consisting of five soil borings) was then completed to delineate the extent of benzene, toluene, ethylbenzene and xylenes (BTEX) compounds identified during UST removal activities.

 

A Corrective Action Plan (CAP) was prepared in November 1992.  The implemented CAP involved the installation of a soil vapor extraction (SVE) system which consisted of three vapor extraction wells (VE-1 through VE-3) and presumably operated (by others) from 1993 until 1995, when it was permanently shut down because groundwater repeatedly entered the wells under the applied vacuum.  Additional site delineation activities were completed further downgradient of the former USTs in 1995.  Following system shut down, a quarterly groundwater monitoring program was implemented and continued unchanged until 2002.  Petroleum impacts to groundwater were indicated. 

 

In August 2002, the CP Environmental Group team (CPEG) was retained to obtain environmental closure of the site.  Two soil borings were drilled adjacent to locations previously exhibiting soil concentrations above residential, used aquifer (R-U) standards to collect post-remediation soil samples from the same interval.  Analytical results from these soil samples indicated no compounds detected above the laboratory reporting limits.

 

A Remedial Action Plan (RAP) Addendum was developed by the CPEG team to remediate the remaining isolated impacts in groundwater detected at monitoring well VE-3.  The DEP-approved RAP addendum was implemented on November 26, 2002.  Enhanced vacuum extraction (EVE) was used to recover groundwater and associated soil vapor from VE-3 using a mobile system.  Following completion of the EVE event, three additional quarters of groundwater sampling were performed at site monitoring wells to verify concentrations within the interior plume and at the Point of Compliance.  Based on groundwater analytical results favorable to site closure, use of 4 quarters of data (instead of 8 quarters) in order to demonstrate attainment of the statewide health standards (SWHS) for the site groundwater was requested.  The DEP approved the request in its correspondence dated August 7, 2003.

 

Fate and transport model results indicated that remaining constituents of concern would degrade before reaching the POC and remain below their respective R-U medium-specific concentrations (MSCs).  Attainment of the R-U statewide health standard was achieved based upon these data and the DEP’s written acceptance of four consecutive quarters of groundwater monitoring for attainment demonstration.  The DEP approved the Remedial Action Completion Report, as submitted in December 2003. 

 

Total cost of project: $46,000

 

CPEG Business Solutions… Yield Advantages   

The CPEG team evaluated existing site data and formulated a plan to achieve site closure while reducing the client’s long-term costs and liability.  A Remedial Action Plan Addendum was prepared and submitted that outlined the CPEG plan to re-evaluate site conditions and facilitate closure of the site under DEP’s Chapter 245 regulations.  Fate and transport modeling was used along with statistical analysis to achieve a reduction in the number of groundwater sampling events required by DEP to demonstrate closure (by negotiating with the DEP representative and subsequently submitting a DEP request in accordance with Chapter 250.704d).  This strategy saved our client thousands of dollars associated with continued compliance monitoring.  Total time to environmental site closure from the start of CPEG involvement was just over 1 year.

Remediation System Design Evaluation, Installation, O&M

BULK TERMINAL

Pittsburgh, Pennsylvania

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

Soil and Groundwater Remediation / Construction Management

FORMER Truck Maintenance Facility

Cheektowaga, New York

CPEG provided on-site construction management services and regulatory reporting for a project performed as a result of the pending sale of a trucking facility.  Responsibilities included coordination and supervision of the removal of three, 12,000-gallon diesel fuel underground storage tanks (USTs), one 12,000-gallon gasoline UST, and one 1,000-gallon oil/water separator.  The site was located in Cheektowaga, New York which falls under the jurisdiction of the New York State Department of Environmental Conversation (NYSDEC) – Region 9. 

 

Based on previous site characterization data and the buyer’s accelerated construction schedule for the 10-acre property, an extensive impacted soil excavation, transport, and treatment plan was implemented.  The project included dewatering of the excavations, demolition of the existing fuel islands, excavation of approximately 10,000 tons of petroleum impacted soil, and confirmation soil sampling.  Successful negotiations with the Buffalo Sewer Authority regarding discharge of removed groundwater to the local sewer authority before excavation activities proved to be a cost saving to the client.  Although NYSDEC regulations required a NYSDEC-approved landfill for disposal of the impacted soil, negotiations with NYSDEC regarding the use of an out-of-state, previously unapproved biotreatment facility proved successful and demonstrated a substantial cost savings along with protection from future liability.

 

Field activities were conducted 24-hours per day to meet the real estate developer’s construction schedule, with soil being direct-loaded for transport to further reduce the schedule.  Regulatory oversight included daily visits by NYSDEC personnel, with no violations realized.  During this time, further negotiating with NYSDEC personnel including schedules, sampling locations and intervals, and additional site data collection requirements were conducted.  Field testing kits were used to help delineate excavation limits, with subsequent confirmation soil samples submitted to a laboratory for analysis per NYSDEC requirements.  Although pressure was high to meet the developer’s accelerated construction schedule, zero safety incidents were recorded during site work.

 

Total cost of project: $700,000

 

CPEG Business Solutions… Yield Advantages

 

If the schedule on this project had not been achieved, the client would have forfeited a $500,000 bond as part of the real estate deal.  The CPEG team found a way to complete this project within the extremely tight 10-day project completion deadline and, thereby, avoided bond forfeiture.  In addition, successful negotiation with the Buffalo Sewer Authority to allow discharging groundwater removed from the excavation saved the client approximately $5,000 in groundwater disposal costs.  In addition, approximately $100,000 was saved in soil disposal costs by negotiating NYSDEC approval of the out-of-state biotreatment facility, in addition to the negation of liability associated by disposing of the soil at a landfill, which would have made the client a potentially responsible party for future action.  Project costs for CPEG excluded the excavation contractor, transportation, disposal, and laboratory analysis which were direct-billed to the client to further reduce costs.

 

The CPEG team received a letter of commendation on this project from the client which stated, in part, the CPEG team was “selected because of their Type A, take-charge staff.  (They) met this challenge – field activities were completed, on-time.  Please express (our) appreciation… Well Done!”

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