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Guidance for Silica Gel Cleanup in Washington State

Publication number Date Published Date Revised
22-09-059September 2022November 2023
VIEW NOW Guidance for Silica Gel Cleanup in Washington State (Number of pages: 47) (Publication Size: 1370KB)
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Author(s) Andrew Kallus; Charles San Juan
Description This guidance document provides details on the use of silica gel cleanup (SGC) in analyzing diesel and heavy oil range organics when using the Ecology’s NWTPH-Dx analytical method for petroleum hydrocarbons at a cleanup site regulated under the Model Toxics Control Act (MTCA) Regulation, Chapter 173-340 WAC. SGC refers to a sample cleanup step in the analytical process where silica gel is used. Silica gel is a polar material that is used to adsorb (i.e., remove or cleanup) non-hydrocarbon polar organics during the sample extraction process).


November 2023: Published final guidance
September 13, 2022 – October 13, 2022: Draft open for public comment.
September 2022: Draft guidance published

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Keywords Diesel Range Organics (DRO), groundwater sampling, Total Petroleum Hydrocarbons (TPH)., Total Petroleum Hydrocarbons (TPH) analysis, biodegradation, Heavy Oil Range Organics (ORO), NWTPH-Dx analytical method, polar organic compounds, Silica Gel Cleanup (SGC), weathered groundwater, polar metabolites

User’s Guide for MTCATPH 12.0 & MTCASGL 12.0: Workbook tools for calculating soil and groundwater cleanup levels under the Model Toxics Control Act Cleanup Regulation

Guidance for Remediation of Petroleum Contaminated Sites

Analytical Methods for Petroleum Hydrocarbons

User's Manual: Natural Attenuation Analysis Tool Package for Petroleum-Contaminated Ground Water