Installation of Monitoring Wells and Piezometers and Hydrogeologic Investigations for Various Landfills

Scope of Services Provided by AES

AES and the AES/WSP Team have performed hydrogeologic investigations and design and installation of monitoring wells and extraction wells at various landfill sites. The projects include:

Calabasas Landfill – Hydrogeologic Investigations – The AES/WSP Team performed hydrogeologic investigations for four subsurface barriers, including installation of monitoring wells and piezometers and performing aquifer tests as a part of the modification of the existing groundwater monitoring well network to bring it in compliance with detection and evaluation monitoring programs per regulatory requirements. The scope of work included drilling, logging, and sampling six borings to 115 feet deep; installation of monitoring wells and piezometers; preparing geologic cross sections at subsurface barrier sites; geotechnical testing of aquifer materials; aquifer stress tests in 27 monitoring wells/piezometers; four aquifer pumping tests, including step-drawdown and constant-rate pumping tests to evaluate aquifer properties; and preparation of report for submittal to regulatory agencies.

Calabasas Landfill – Design and Installation of Groundwater Extraction Well – The AES/WSP Team provided design and installation services for a new extraction well to expand the existing system of extraction wells upgradient of subsurface barriers. The scope of work included securing well permits; drilling, sampling, and logging 8-inch pilot borehole to 110-foot depth; geotechnical testing of aquifer materials and design of filter pack for extraction well; drilling a 16-inch diameter borehole and installation and development of extraction well; installing concrete well vault and cover over new extraction well; and submitting installation reports for regulatory agency review and approval.

Redevelopment, Abandonment, and Regrouting Services for Groundwater Extraction and Monitoring Wells for Various Landfills – AES provided groundwater extraction and monitoring well maintenance services at active sites Calabasas, Puente Hills, and Scholl Canyon Landfills and inactive sites Mission Canyon, Palos Verdes, and Spadra Landfills. Required maintenance activities for operation, monitoring, and maintenance of the groundwater protection systems included redevelopment of groundwater extraction wells, abandonment of monitoring wells, regrouting voids in annular seals and beneath surface completions of monitoring wells and extraction wells, and replacement of surface completions for monitoring wells. The scope of work included redevelopment of a total of 38 extraction wells and 3 monitoring wells; abandonment of a total of 12 monitoring wells; regrouting of a total of 7 monitoring wells and 11 extraction wells; replacement of monitoring well surface completions at a total of 45 locations; and containment, waste profile laboratory analytical testing, and disposal of solid and liquid waste generated during the various tasks.

Scholl Canyon Landfill – Design and Installation of Groundwater Extraction Well and Sump 2 Access Well – AES provided design and installation services for 2 existing extraction wells. The existing wells had experienced a decrease in extraction efficiency due to buildup of excessive amounts of sand and silt within the well casing. The scope of work included securing well permits; drilling, sampling, and logging 8-inch pilot borehole to 110-foot depth; geotechnical testing of aquifer materials and design of filter pack for extraction well; enlarging pilot borehole to 16-inch diameter and installation and development of extraction well; installing concrete well vault and cover over new extraction well; and submitting installation reports for regulatory agency review and approval.