DD: Compliance and Assessment Support: Southern Star Central Gas Pipeline
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Compliance & Site Assessments: Southern Star Central Gas Pipeline



Emily Smart


Service Lines

Project Summary

Blackstone has a Master Service Agreement in place with Southern Star Central Gas Pipeline (SSCGP). We have assisted the client with site assessment and monitoring, mitigation concepts, and reporting. Services provided include: SPCC Plans, Site Assessments, Work Plan and Quality Assurance Project Plan Preparation, Compressor Station Site Assessments, Soil, Ground Water and Surface Water Sampling, Mitigations Concepts and Construction Cost Estimates, Remediation, and Health and Safety.

Services Provided

Former Compressor Station Consent Order Final Remediation: Former Compressor Station Consent Order Final Remediation: Blackstone worked with Southern Star Central Gas Pipeline to complete remedial activities as a former compressor station located in south-central Kansas. Initial cleanup of polychlorinated biphenyl (PCB) and polycyclic aromatic hydrocarbon (PAH) contamination was completed at the facility in August of 1998 under a U.S. EPA Region VII Consent Order. However, an area of approximately 1-acre containing PAHs above the cleanup levels specified in the Consent Order was fenced and left in place. Blackstone developed a Work Plan/Quality Assurance Project Plan (WP/QAPP) to delineate remaining PAHs in the top 18 inches of soil at the facility. Based on the results of the soil investigation activities, soil sample PAH results were below their respective EPA Action Levels, and additional excavation/remediation was not required for the facility. Additionally, PCB impacted concrete flooring remained in the compressor station building. Blackstone provided oversight of concrete excavation. PCB concentrations in concrete samples were well below the Toxic Substances Control Act (TSCA) regulatory level of 50 mg/kg. Once the remedial investigation was completed, Blackstone worked with SSGCP and the EPA Project Manager to finalize closure requirements for the consent order.

Former Compressor Station Limited Phase II Site Assessment: Blackstone conducted Limited Phase II Site Assessment for a former compressor station located in Northeastern Missouri. It was understood that historical activities conducted by a prior owner may have resulted in petroleum impacts to the soil at the facility. Blackstone prepared a Work Plan, outlining the elements necessary to evaluate and characterize potential soil impacts at the facility. Field work conducted by Blackstone personnel included the installation of soil borings and the analysis of soil samples for contaminants of concern (CoCs) including benzene, toluene, ethylbenzene, xylenes, (MtBE), and total petroleum hydrocarbons. Sample results for borings installed closest to the property boundary adjacent to a residence were either non-detect or detections of CoCs or were below the Missouri Tier 1 Risked-Based Target Levels (RBTLs) for Residential Soil Type 3 (Clayey). Benzene was detected above the Tier 1 RBTL for Residential Soil Type 3 in one sample, located in the central portion of the site. However, as the site is likely to be in non-residential use for the foreseeable future, Blackstone determined that additional site characterization and/or remedial activities, such as the removal of impacted soil, did not appear warranted at this time.