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API Interactive LNAPL Guide Version 2.0.4

Release 2.0.4

Prepared under contract to API by: Environmental Systems & Technology (A Division of Groundwater & Environmental Services, Inc.) of Blacksburg, VA and Aqui-Ver, Inc. of Park City, UT.

To download this software, begin by submitting the form below.


The API Interactive LNAPL Guide is an easy-to-use electronic information system to provide better understanding and tools in evaluating LNAPL mobility, stability, and recoverability. The Guide is designed to provide an overall approach for evaluating LNAPL at a site; assessing its potential risk, quantitatively defining mobility and recoverability, developing remedial strategies, and examining methods to enhance site closure opportunities.

Currently, the remediation community (industry, consultants, and regulators) is beginning to perceive the existence of LNAPL at a site in a different light than during the past decade. Whereas in the past, LNAPL removal was considered fundamental to site closure, the advent of understanding intrinsic LNAPL removal limitations, and natural attenuation/dissolved plume stability has enabled new perspectives on impacts related to LNAPL. Questions such as "What percentage of LNAPL will be left behind despite best remedial efforts?", "Can LNAPL plume stability and recoverability be quantitatively evaluated?" and, if so, "What is the value of recovering LNAPL when the LNAPL plume and resultant dissolved plume are stable due to capillary forces and natural attenuation?" are being asked with greater frequency.

The LNAPL Guide provides technical information, quantitative tools, and methods to evaluate the management of LNAPL at sites. The following educational primers are provided in the Guide and, although the general order provides increasing levels of understanding, the user is free to interact with any component of the Guide.

  • NAPL Basics
  • Soil Properties
  • Product Types
  • Release Conditions
  • Mobility, Stability, and Recoverability
  • Water Table Fluctuations
  • Heterogeneous Conditions
  • Volatilization
  • Dissolution and Transport
  • Modeling
  • Remediation Technologies

In addition, the Guide provides a number of tools to more effectively evaluate LNAPL. These tools include analyses to calculate LNAPL saturation, volume, mobility, stability, and recoverability. Copies of the "Charbeneau" LNAPL recovery spreadsheets and the API LNAPL Parameters Database are included in the Guide along with an updated version of API - LNAST utility.

The Guide has been designed to meet the needs of very busy professionals. As such, the primers and tools can be utilized within 15 to 25 minutes so that information can be gained rapidly. A list of references is also provided to enable more detailed understanding.

System Requirements:

To obtain The Guide, choose one of the following options:

  • Complete and submit the form below to download this document.
  • Request a CD by sending an email to

(Note: The setup file is approximately 155 MB)

Terms & Conditions

  • You expressly acknowledge and agree that the information contained in the software is being provided on an "as-is" basis, without warranty of any kind, express or implied, including without limitation any warranty regarding the accuracy or content of the information.
  • You further understand and agree that use of any and all information contained in the software is at your own sole risk.
  • You understand that the software is the copyrighted property of API and cannot be sold by you or another party without the prior written approval of API.
  • You release API, its members and employees, from any claims and damages you may have from accessing, using the information contained herein, and you agree to defend and indemnify API for any claims and/or damages that arise directly or indirectly from your use of the software or the information contained therein.

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