STP1118: Methodology for the In-Field Design of Monitoring Wells in Heterogeneous Fine-Grained Formations

    Reynolds, SD
    Geologist, Sacramento, CA

    Zemo, DA
    Geologist, Geomatrix Consultants, San Francisco, CA

    Pages: 11    Published: Jan 1992


    Abstract

    As part of the remedial investigation for a southern California Superfund site, clusters of depth-staggered monitoring wells were installed in heterogeneous unconsolidated alluvium. It was imperative that filter packs and well screens be properly designed such that ground-water samples and hydraulic head data would be suitable for use in litigation. The highly variable geometry and texture of the sediments precluded the use of a generic well design and suggested the need for a method of in-field design of monitoring wells.

    In order to provide timely well design parameters, representative core samples of intervals to be screened were analyzed on-site. Simultaneous with the geophysical logging of the core boring, samples were sieved and the grain-size distribution data were used to design the filter packs and well screens. This approach provided a means by which each individual well could be tailored to the specific zone of interest, without delaying the pace of drilling and well construction or incurring costs above those normally associated with the more conventional approach employing a generic well design.

    Keywords:

    well design, turbidity, sieve analysis, continuous wireline sampling


    Paper ID: STP19131S

    Committee/Subcommittee: D18.21

    DOI: 10.1520/STP19131S


    CrossRef ASTM International is a member of CrossRef.