Our work at the maintenance stations has required EPA and ADEC review of the injection well closure work plans prior to removal. To streamline the process, we facilitated meetings with the stakeholders to discuss the development of a generic work plan to guide closure and sampling activities, quality assurance and quality control, and worker health and safety. We prepared a generic work plan and site-specific addenda to describe unique conditions for the individual sites. In addition, we created a GIS database for storage of site-specific details to streamline the map-making process. 

During the closures, our staff facilitates client and subcontractor coordination, guides excavation, and observes and documents injection well demolition, source removal, and stockpile construction. They field screen and segregate soil, collect water, soil, and sediment samples required by EPA and ADEC for well closure and investigation-derived waste (IDW) characterization. Our staff aides DOT&PF with the classification and disposal of IDW to the appropriate facilities; soil contaminated with petroleum hydrocarbons is often encountered and, at several sites, the removal of Injection Well (IW) systems and associated contamination generated RCRA hazardous waste that required special classification and handling. 

Due to the historical sites and remote locations, IW construction and location details were often unknown. In addition, many of the systems were classified as “combined-use” meaning domestic wastewater and floor drain effluent discharged to the same structure. Shannon & Wilson assisted DOT&PF in request to the EPA to approve several reclassifications of the systems following complete separation of floor drains and domestic wastewater lines and cleanup of contaminated soil and water where applicable. 

Our staff prepares final injection well closure reports for each site detailing field activities, site conditions, deviations from known or assumed conditions, analytical sample results, and recommendations for continued work at the site if necessary. The final reports are required to be reviewed and approved by EPA, after which any additional cleanup at the site is continued under ADEC approval. If additional work is required, we prepare addenda to the generic work plan describing further planned site characterization activities including soil borings, test pits, temporary well points, and groundwater monitoring wells.