Impact of Non-Aqueous Phase Liquids (NAPLs) on Groundwater Remediation

TRRP Training: 2022 Program

presented by: GSI Environmetal Inc.

Texas Risk Reduction Program regulations (TRRP; 30 TAC 350) establish consistent risk-based protocols for assessment and response to soil, groundwater, or surface water impacts associated with environmental releases of regulated wastes or substances.

Presented by GSI Environmental Inc., this popular and informative training series is a must for professionals who need a working understanding of TRRP and those needing to stay up-to-date with the latest TCEQ TRRP guidance and policies.

TRRP Training Course (2 Days): Provides an overview of the TRRP framework and step-by-step training on property assessment and response action procedures established under the TRRP rule

Attendees will become acquainted with rules, key guidance and policies covering affected property assessments, protective concentration levels, and response actions. The course material presents strategies for efficient project management in compliance with TRRP and explains the various report forms adopted by TCEQ.

Dates and Location

Dates

June 14th and 15th, 2022

Location

Crowne Plaza River Oaks 2712 SW Freeway Houston, Texas 77098 713.523.8448 http://www.crowneplaza.com/

Price and Registration

Early-Bird Price

(Paid by May 1, 2022)
$XXX

Standard Price

(Paid after May 1, 2022)
$XXX

TAEP Membership Price

$XXX

Government Price

$XXX

Lodging and meals are not
included in course cost

Authors: Charles J. Newell, Richard L. Bowers, Hanadi S. Rifai

Published: August 1994 in GSI volume N/A pages N/A.

Abstract

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Nonaqueous Phase Liquids (NAPLs) are immiscible (undissolved) hydrocarbons in the subsurface that exhibit different behavior and properties than dissolved contaminant plumes. NAPLs have a tremendous impact on the remediation of contaminated aquifers, as it is very difficult or impossible to remove all of the NAPL from a hazardous waste site once released to the subsurface. Although many NAPL removal technologies are currently being tested, to date there have been few field demonstrations where sufficient NAPL has been successfully removed from the subsurface to restore an aquifer to drinking water quality (EPA, 1992a). The residual NAPL that remains trapped in the soil/aquifer matrix acts as a continuing source of dissolved contaminants to ground water, and effectively prevents the restoration of NAPL-affected aquifers for tens or hundreds of years.

This is particularly true for groundwater pump-and-treat systems, the most common remediation technology for addressing contaminated aquifers. This technology pumps groundwater out of contaminated zones to remove dissolved contaminants and, if present, to slowly dissolve any trapped NAPLs. The pumped water is then treated on the surface to remove or destroy the dissolved contaminants.

To help designers of pump-and-treat systems evaluate the impact of NAPLs on groundwater remediation, a simple design model has been developed that provides the user with the number of recovery/injection wells and time required to reach cleanup standards. The method uses 1) dissolution data from a simplified dissolution model based on the work of Powers et al. (1994) or field data from dissolution pilot tests, 2) an assumed well configuration typical for pump-and-treat systems, and 3) relationships of concentration vs. pore volumes of clean water flushed. In addition, design charts for zones with only dissolved-phase groundwater contamination are also presented. These design tools are being incorporated into a large computerized Decision Support System now being developed by one of the authors (Rifai et al., 1994) for evaluating U.S. Air Force groundwater pump-and-treat systems.

The design models were used in an example application to evaluate remediation alternatives for a hypothetical NAPL-contaminated site. This example serves to demonstrate the simple use of the models for the rapid estimation of pump-and-treat system design requirements.