STP1053: How Flat Is Flat?—Termination of Remedial Ground-Water Pumping

    Spreizer, GM
    Senior scientist, senior associate, and associate, Geraghty & Miller, Inc., Andover, MA

    Maxim, D
    President, Everest Consulting Associates, Inc.,

    Valkenburg, N
    Senior scientist, senior associate, and associate, Geraghty & Miller, Inc., Andover, MA

    Hauptmann, M
    Senior scientist, senior associate, and associate, Geraghty & Miller, Inc., Andover, MA

    Pages: 9    Published: Jan 1990


    Abstract

    Remedial actions are being initiated at many Superfund sites, and the analyses of water-quality data from these sites are being performed. The start of remediation is obvious—the system used for cleaning up is turned on; however, the determination of when this remediation is “complete” may not be clear.

    With the initiation of a remedial measure, it is expected that the detected concentrations of characteristic contaminants will decrease rapidly and then level off to some asymptotic concentration. This is expected since the efficiency of remediation is generally considerably greater at higher concentrations than at lower concentrations. It is expected that some form of an exponential model, y = Cexp (-kx), will describe the system's behavior. This is especially true when ground-water pumping is the remedial measure used, as is considered in this paper.

    With Superfund remediation schemes, cleanup or performance goals are set for key compounds. The cleanup is complete when these goals are attained. However, attainment of cleanup goals may be technically infeasible in certain cases and alternative criteria may be appropriate.

    This paper presents a statistical methodology, based on an anticipated exponential decrease in the contaminant concentration resulting from ground-water pumping remediation. The methodology will initially predict when remedial measures can be terminated. As the remediation program continues and additional monitoring data become available, the methodology will determine whether and when preestablished concentration limits will be attained and when the equilibrium concentration can be estimated.

    Keywords:

    ground water, statistics, termination pumping, exponential model, asymptote, empirical model, technical infeasibility, compliance waiver, SARA


    Paper ID: STP23417S

    Committee/Subcommittee: D18.21

    DOI: 10.1520/STP23417S


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