Dense Nonaqueous Phase Liquids (DNAPLs)

Halogenated Alkenes

Diffusion Samplers

Comparison of Diffusion- and Pumped-Sampling Methods to Monitor Volatile Organic Compounds in Ground Water, Massachusetts Military Reservation, Cape Cod, Massachusetts, July 1999-December 2002
S.A. Archfield and D.R. LeBlanc.
U.S. Geological Survey, Scientific Investigations Report 2005-5010, 60 pp, 2005

This report evaluates diffusion sampling as an alternative method to monitor volatile organic compound (VOC) concentrations in groundwater. Concentrations in samples collected by traditional pumped-sampling methods were compared to concentrations in samples collected by diffusion-sampling methods for 89 monitoring wells at or near the Massachusetts Military Reservation, Cape Cod. Samples were analyzed for 36 VOCs. The investigators found no substantial difference between the utility of diffusion and pumped samples to detect the presence or absence of a VOC. In wells where VOCs were detected, diffusion-sample concentrations of tetrachloroethene (PCE) and trichloroethene (TCE) were significantly lower than pumped-sample concentrations. Because PCE and TCE concentrations detected in the wells dominated the calculation of many of the total VOC concentrations, when VOC concentrations were summed and compared by sampling method, visual inspection also showed a downward concentration bias in the diffusion-sample concentration.

Comparison of Passive Diffusion Bag Samplers and Submersible Pump Sampling Methods for Monitoring Volatile Organic Compounds in Ground Water at Area 6, Naval Air Station Whidbey Island, Washington
R.L. Huffman.
U.S. Geological Survey, Water-Resources Investigations Report 02-4203, 32 pp, 2002

This report compares the concentrations of contaminants in samples taken in wells with 10-, 20-, and 40-foot screens with passive diffusion bags and pumps. In the 10-foot screened wells, one diffusion bag was used, and the results between the two sampling methods were comparable. Multiple bags using the 20- and 40-foot screens revealed that concentrations varied by depth and the results were not comparable with the pump sample. Vertical profiling is possible with diffusion bags.

Guidance on the Use of Passive-Vapor-Diffusion Samplers to Detect Volatile Organic Compounds in Ground-Water-Discharge Areas, and Example Applications in New England
P.E. Church, D.A.Vroblesky, F.P. Lyford, and R.E. Willey.
U.S. Geological Survey, Water-Resources Investigations Report 02-4186, 90 pp, 2002

Determining the location of discharging contaminated groundwater is important for plume mapping, evaluating risk potential to human health and the environment, and designing focused site-characterization and monitoring activities. Applications of PVD samplers at and near nine hazardous-waste sites in New England demonstrated the samplers' effectiveness in detecting and delineating VOCs in a variety of hydrologic settings, including rivers, streams, ponds, wetlands, and coastal shorelines. The PVD samplers also have been used successfully as passive soil-gas samplers in unsaturated zones to map groundwater contamination.

NEWMOA Technology Review Committee Advisory Opinion—Innovative Technology: Passive Diffusion Bag Samplers for VOC Sample Collection from Groundwater Monitoring Wells
Northeast Waste Management Officials' Association, 12 pp, 2002

This document provides a general discussion of passive diffusion samplers and lists advantages and limitations of the technology.

Passive Diffusion Bag Samplers
U.S. EPA, Hazardous Waste Clean-Up Information website.

This page provides a brief description of diffusion samplers and their use and performance.

Protocol for Use of Five Passive Samplers to Sample for a Variety of Contaminants in Groundwater
Interstate Technology and Regulatory Council (ITRC) Diffusion/Passive Sampler Team.
DSP-5, 121 pp, Feb 2007

This guidance contains protocols for five passive sampling technologies: the Snap Sampler™ and Hydrasleeve™ (grab-type well water samplers); a regenerated-cellulose dialysis membrane sampler and a rigid, porous polyethylene sampler (diffusion/equilibrium-type samplers); and the GORE™ Module (a diffusion and sorption-type sampler).

Technical and Regulatory Guidance for Using Polyethylene Diffusion Bag Samplers to Monitor Volatile Organic Compounds in Groundwater
Interstate Technology & Regulatory Council (ITRC). DSP-3, 78 pp, 2004.

This document provides a guide for regulators, technology users, and stakeholders to facilitate the use of polyethylene diffusion bag sampling, particularly for long term monitoring. The technical guidelines for implementation in Section 2 are a consensus of the ITRC Diffusion Sampler Team, which includes participants from nine different state regulatory agencies, as well as representatives from federal agencies, academia, and the private sector. Section 3 contains a set of sequenced questions to provide a quick preliminary screening of a site's potential for PDB sampling. Section 4 discusses regulatory issues related to PDB use, considers potential regulatory impediments to the implementation of PDB sampling, provides suggestions for expediting the process, and reports on a survey of state regulators' acceptance of the technology. No regulatory issues were identified that would restrict the application of PDBs in technically appropriate situations. The final sections provide a cost model to estimate the potential savings associated with conversion to PDB monitoring and present some case histories of the technology's implementation. Note that PDBs, unlike many other sampling methods, such as low flow pumping, provide a true vertical profile of contaminants within a well screen, which can be important in determining the potential DNAPL architecture of a source zone.

Technical Report for the Evaluation of Groundwater Diffusion Samplers
Air Force Center for Environmental Excellence (AFCEE), 54 pp, 1999

This report presents the results of a study to evaluate the performance of diffusion samplers as compared with conventional groundwater monitoring well sampling techniques. Field sampling was conducted using two types of diffusion samplers to collect groundwater samples from varying depths at selected monitoring wells. One of the diffusion samplers evaluated was the commercially available DMLS(tm) sampler. The other diffusion sampler evaluated is currently being developed and used by the U.S. Geological Survey. The standard sampling methods used for comparison to the diffusion sampling results were (1) groundwater sampling following conventional purging of at least three casing-volumes of water and stabilization of water quality parameters (i.e., conventional sampling), and (2) sampling following low-flow/minimal drawdown purging (i.e., micropurging).

Technology Application Analysis Report: Passive Diffusion Membrane Samplers
McClellan AFB Environmental Management Directorate, 84 pp, 2000

This cost and performance report evaluated passive diffusion samplers deployed at McClellan AFB. The contaminants of concern were chlorinated ethenes. It is a follow-on of the 1999 AFCEE report cited above.

User's Guide for Polyethylene-Based Passive Diffusion Bag Samplers to Obtain Volatile Organic Compound Concentrations in Wells. Part 1: Deployment, Recovery, Data Interpretation, and Quality Control and Assurance
D.A. Vroblesky.
U.S. Geological Survey, Water-Resources Investigations Report 01-4060, 25 pp, 2001

This guide covers the performance and use of diffusion samplers in monitoring wells.

User's Guide for Polyethylene-Based Passive Diffusion Bag Samplers to Obtain Volatile Organic Compound Concentrations in Wells. Part 2: Field Tests
D.A. Vroblesky (ed.).
U.S. Geological Survey, Water-Resources Investigations Report 01-4061, 102 pp, 2001

This guide describes field deployment of diffusion samplers at five sites.

Other Resources

Diffusion Sampler Information Center
Interstate Technology & Regulatory Council (ITRC) Diffusion Samplers Team.