Formatted Title
Real-Time Data Management and Visualization for Well Screen Placement during Remedial Action at the Puchack Well Field Superfund Site
Background/Objectives
Real-time data management and visualization are being used at the Puchack Well Field Superfund site to ensure correct placement of extraction, injection, and monitoring well screens during remedial action (RA) at the site. The site is located north of Camden, New Jersey, covers approximately 180 acres, and is underlain by the unconsolidated Potomac-Raritan-Magothy system to a depth of 300 feet. In the 1980s hexavalent chromium contamination in groundwater shut down the well field. The U.S. Environmental Protection Agency (USEPA) began a Remedial Investigation (RI) in 2000. Using lithologic and natural gamma log data from borings completed at the site during the RI, the U.S. Geological Survey (USGS), USEPA, and CDM Smith developed a lithostratigraphic geologic model of the site. The RA involves the injection of sodium lactate (a reducing agent) in groundwater to reduce hexavalent chromium to trivalent chromium.
Approach/Activities
The correct vertical placement of injection well, extraction well, and monitoring well screens is critical to the success of the injection and in situ treatment remedial design (RD) and RA being implemented at the site. To accomplish this goal, four objectives must be met: (1) to guide drilling, the proposed screen placement for the planned well must be shown in cross section with the site hydrostratigraphy, lithology, natural gamma logs, and hexavalent chromium screening sample results from adjacent borings; (2) as soon as the new borehole is competed the cross section must be updated with the lithology, gamma log, hexavalent chromium screening sample results and final screened interval for the new well; (3) the proposed final well screen position must then be simultaneously reviewed by the U.S. Army Corps of Engineers (USACE), the EPA, CDM Smith, and the RA contractor, and (4) this review must be done as soon as the borehole is completed so that well construction may proceed without incurring standby charges from the driller. To accomplish this, during Phase II of the RA starting in 2019, CDM Smith shared the existing gINT software project file and report templates with the RA contractor and worked with them to implement a real-time borehole data management and visualization system using gINT software. During borehole drilling, the RA contractor’s field geologist conveyed the lithologic log field notes regularly to a geologist on their team to input the lithologic data into gINT. The geologist working with gINT was either onsite or remote. The geologist added the natural gamma log and hexavalent chromium results from in situ screening and confirmatory laboratory sample analyses as soon as they were available. When the data input was completed, the RA contractor prepared a “well package” including (1) the well construction plan for approval by the USACE, (2) a boring log showing lithology, screening sample results, and screened interval, and (3) a cross section showing the hydrostratigraphy, lithology, gamma logs, and screening sample results at both the new well and adjacent wells. The USACE, EPA, CDM Smith, and the RA contractor then reviewed the well package using Microsoft® Teams and adjusted the well screen position if necessary. The RA contractor then proceeded with well installation.
Results/Lessons Learned
The project team used this system to successfully guide the installation of 158 monitoring, injection, and extraction wells between October 2019 and July 2022. This collaborative process improved the quality of the remedy implementation by ensuring proper placement of the monitoring, injection, and extraction wells screens. Currently, the gINT project file contains data from 931 boreholes (e.g., lithology, well construction, natural gamma logs, sample results), hydrostratigraphic unit surfaces, and planned wells. This data are being used by the team to support current and planned RD/RA work in the Intermediate Sand aquifer. The benefits of this approach are that it can be scaled up or down and that it allows new data to be incorporated quickly into the conceptual site model and thereby support completion of project objectives.