Sunset Well Rehabilitation
South Tahoe Public Utility District, California

West Yost evaluated, rehabilitated, and tested the Sunset Well to reestablish well efficiency and normal flow conditions. This project included conducting a condition assessment of the well and down-hole equipment, measuring the well performance before and after rehabilitation including an assessment of the maximum sustainable yield, and sampling for Title 22 drinking water constituents. Based on our field observations and analysis of the existing well conditions it was determined that rehabilitating the existing well and refurbishing or replacing the down-hole equipment was preferable to constructing a replacement well. The existing pump was refurbished and a new submersible motor, drop pipe, and foot valve were installed in the well. As part of the rehabilitation program, well profiling, video logging, and aquifer testing was conducted. The well profiling included temperature and fluid resistivity logging, spinner logging, and collection of depth-discrete water quality samples to identify aquifer zones with the highest potential for both groundwater yield and quality. Following the well rehabilitation, groundwater quality results from the final Title 22 sampling indicate that the water obtained from the site meets all California and USEPA Primary and Secondary Maximum Contaminant Levels for municipal water supply under current and emerging regulations.