PFAS Soil Remediation Technologies - Revision history

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Jhurley: /* Excavation and Disposal */

2021-03-03T19:18:55Z

‎Excavation and Disposal

Jhurley: /* Soil Treatment */

2021-03-03T19:14:48Z

‎Soil Treatment

Jhurley at 19:04, 3 March 2021

2021-03-03T19:04:10Z

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Jhurley: /* Thermal Treatment */

2021-03-03T17:37:27Z

‎Thermal Treatment

Jhurley: /* Stabilization */

2021-03-03T17:35:02Z

‎Stabilization

Jhurley: /* Soil Washing */

2021-02-10T14:28:24Z

‎Soil Washing

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 *[[PFAS Transport and Fate]]
 *[[PFAS Sources]]
 '''Contributor(s):''' [[James Hatton]] and [[William DiGuiseppi]]
 '''Key Resource(s):'''

@@ Line 46: / Line 46: @@
 ==Conclusions==
-Several well-developed remedial technologies have been applied to address soil contaminated with PFAS.  Unfortunately, none of the available techniques are ideal, with some reducing leachability but leaving the PFAS-impacted soil in place, while others result in destruction of the contaminants but require high energy inputs with associated high cost.
+Several well-developed remedial technologies have been applied to address soil contaminated with PFAS (Figure 4). Unfortunately, none of the available techniques are ideal, with some reducing leachability but leaving the PFAS-impacted soil in place, while others result in destruction of the contaminants but require high energy inputs with associated high cost.
-[[File:DiGuiseppi1w2video.MP4|thumb|600px| Figure 4. PFAS Soil Remediation Technologies.]]
+[[File:DiGuiseppi1w2video.mp4|thumb|500px|left|Figure 4. PFAS Soil Remediation Technologies.]]
 ==References==

@@ Line 47: / Line 47: @@
 ==Conclusions==
 Several well-developed remedial technologies have been applied to address soil contaminated with PFAS.  Unfortunately, none of the available techniques are ideal, with some reducing leachability but leaving the PFAS-impacted soil in place, while others result in destruction of the contaminants but require high energy inputs with associated high cost.
 <br clear="right" />

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 ===Excavation and Disposal===
 [[File: DiGuiseppi1w2Fig1.PNG |thumb|600px| Figure 1. A full scale PFAS-impacted soil stabilization project at a military base in Australia. Image courtesy of RemBind&trade;.]]
-<onlyinclude>Excavation and off-site disposal or treatment of PFAS-impacted soils </onlyinclude>is the only well-developed treatment technology option and <onlyinclude>may be acceptable for small quantities of soil</onlyinclude>, such as those generated during characterization activities (i.e., investigation derived waste, IDW)<onlyinclude>. Disposal in non-hazardous landfills is allowable in most states. However, some landfill operators are choosing to restrict acceptance of PFAS-containing waste and soils as a protection against future liability. </onlyinclude> In addition, the US EPA and some states are considering or have designated PFOA and PFOS as hazardous substances,  which would reduce the number of facilities where disposal of PFAS-contaminated soil would be allowed<ref name="EPA2019">US Environmental Protection Agency (EPA), 2019. EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan: EPA 823R18004. Washington, DC.  [https://www.epa.gov/pfas/epas-pfas-action-plan Website]&nbsp;&nbsp; [[Media: EPA823R18004.pdf | Report.pdf]]&nbsp;&nbsp; [[Media: EPA100K20002.pdf | 2020 Update]]</ref>. Treatment of excavated soils is commonly performed using incineration or other high temperature thermal methods<ref name="ITRC2020"/>. Recent negative publicity regarding incomplete combustion of PFAS in incinerators<ref name="Hogue2020">Cheryl Hogue, 2020. Incineration may spread, not break down PFAS. Chemical and Engineering News, American Chemical Society.  [https://cen.acs.org/environment/persistent-pollutants/Incincerators-spread-break-down-PFAS/98/web/2020/04 Website]&nbsp;&nbsp; [[Media: Hogue2020.pdf | Report.pdf]]</ref> has caused some states to ban PFAS incineration in some circumstances<ref name="NYSS2020">New York State Senate, 2020. An ACT prohibiting the incineration of aqueous film-forming foam containing perfluoroalkyl and polyfluoroalkyl substances in certain cities. [https://www.nysenate.gov/legislation/bills/2019/s7880/amendment/b Website]&nbsp;&nbsp; [[Media: NYsenate2020.pdf | Report.pdf]]</ref>.
+<onlyinclude>
 ===Stabilization===

@@ Line 23: / Line 23: @@
 ==Soil Treatment==
-Addressing recalcitrant contaminants in soil has traditionally been done through containment/capping or excavation and off-site disposal or treatment, typically by incineration.  Containment/capping may be an acceptable solution for PFAS in some locations.  However, containment/capping is not considered ideal given the history of releases from engineered landfills and restrictions on use of land containing capped soils.<onlyinclude> Innovative but less established treatment approaches for PFAS in soil include stabilization with amendments, soil washing, and low temperature thermal desorption. </onlyinclude>
+Addressing recalcitrant contaminants in soil has traditionally been done through containment/capping or excavation and off-site disposal or treatment, typically by incineration.  Containment/capping may be an acceptable solution for PFAS in some locations.  However, containment/capping is not considered ideal given the history of releases from engineered landfills and restrictions on use of land containing capped soils. Innovative but less established treatment approaches for PFAS in soil include stabilization with amendments, soil washing, and low temperature thermal desorption.
 ===Excavation and Disposal===

@@ Line 37: / Line 37: @@
 ''Incineration:'' Incineration is a well-developed technology for organics destruction, including PFAS-impacted soils. Incineration is generally defined as high temperature (>1,100&deg;C) thermal destruction of waste, and PFAS are thought to mineralize at high temperatures.  Generally, incinerators treat off-gasses by thermal oxidation with temperatures as high as 1,400&deg;C, and vaporized combustion products can be captured using condensation and wet scrubbing<ref name="ITRCwNs2020"/>. Some regulatory officials have expressed concern about possible PFAS emissions in off-gas from these incinerators, and the authors are not aware of any published evidence demonstrating complete mineralization of multiple PFAS in incinerators at the time of this posting.  In general, incineration is designed to provide “5 nines of destruction” – destruction of 99.999% of the contaminants, although incinerators are not designed to specifically treat PFAS to this standard.  In the absence of approved industry standard test methods, the US EPA is developing off-gas/stack testing procedures capable of detecting PFAS at the levels considered to be harmful<ref name="EPA2018">US Environmental Protection Agency (EPA), 2018. PFAS Research and Development, Community Engagement in Fayetteville, North Carolina.  [https://www.epa.gov/pfas/pfas-community-engagement-north-carolina-meeting-materials Website]&nbsp;&nbsp; [[Media: EPAFayetteville2018.pdf | Report.pdf]]</ref>.
-''Thermal Desorption:'' Thermal Desorption of PFAS from soil has been demonstrated at the field scale in the US (Alaska)<ref>NRC Alaska LLC, 2019. Moose Creek Facility, Thermal Remediation of PFAS-Contaminated Soil.  [https://dec.alaska.gov/media/18761/nrc-moose-creek-facility-pfas-sep-2019-case-study-v3f-191101.pdf Website]&nbsp;&nbsp; [[Media: nrcMooseCreek2019.pdf | Report.pdf]]</ref><ref name="Burke2015">Burke, Jill, 2019. Fairbanks incinerator shows promise for cleaning toxic soil. Channel 2-KTUU, October 8.  [https://www.ktuu.com/content/news/Fairbanks-incinerator-shows-promise-for-cleaning-toxic-soil-562593631.html Website]</ref> and Australia<ref name="Nolan2015"/> using rotary kilns operating at temperatures of up to 815&deg;C with off-gas treatment at up to 1200&deg;C, or in other cases using batch-fed systems (Figure 2) operating at lower tempreatures. At these temperatures, some PFAS are mineralized, releasing fluorine that must be captured in off-gas treatment systems.  Some PFAS would not be destroyed at these temperatures and therefore must be captured in off-gas treatment systems.  Several bench-scale tests have been performed that have established a minimal effective temperature for desorption of between 350&deg;C and 400&deg;C<ref name="Hatton2019">Hatton, J., Dasu, K., Richter, R., Fitzpatrick, T., and Higgins, C., 2019. Field Demonstration of Infrared Thermal Treatment of PFAS-impacted Soils from Subsurface Investigations. Strategic Environmental Research and Development Program (SERDP), Project ER18-1603, Alexandria, VA.  [https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/ER18-1603 Website]&nbsp;&nbsp; [[Media: SERDP ER18-1603.pdf | Report.pdf]]</ref><ref name="DiGuiseppi2019">DiGuiseppi, W., Richter, R., and Riggle, M., 2019. Low Temperature Desorption of Per- and Polyfluoroalkyl Substances. The Military Engineer, 111(719), pp. 52-53. Society of American Military Engineers, Washington, DC.  [http://online.fliphtml5.com/fedq/sdoo/#p=54 Open access article.]&nbsp;&nbsp; [[Media: DiGuiseppi2019.pdf | Report.pdf]]</ref>. A US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) field-scale demonstration was performed in Oregon, where ''ex situ'' thermal desorption was conducted at 400&deg;C over several days, and the PFAS were captured on vapor-phase activated carbon and subsequently incinerated off site<ref name="Hatton2019"/>. Two field-scale thermal desorption pilot projects (one ''in situ'' and the other ''ex situ'') have been funded under the US DoD’s Environmental Security Technology Certification Program (ESTCP) to demonstrate that source zone soil can be heated to the requisite 350&deg;C and held there for the appropriate length of time to fully desorb and capture PFAS<ref name="Iery2020">Iery, R., 2020. In Situ Thermal Treatment of PFAS in the Vadose Zone, Project ER20-5250. US Department of Defense, Environmental Security Technology Certification Program (ESTCP).   [https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Emerging-Issues/ER20-5250 Website]</ref><ref>Jennifer Wehrmann, 2020. Ex Situ Thermal Treatment of Perfluoroalkyl and Polyfluoroalkyl Substances, ER20-5198. US Department of Defense, Environmental Security Technology Certification Program (ESTCP).  [https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Emerging-Issues/ER20-5198/ER20-5198/(language)/eng-US Website]</ref>.
+''Thermal Desorption:'' Thermal Desorption of PFAS from soil has been demonstrated at the field scale in the US (Alaska)<ref>NRC Alaska LLC, 2019. Moose Creek Facility, Thermal Remediation of PFAS-Contaminated Soil.  [https://dec.alaska.gov/media/18761/nrc-moose-creek-facility-pfas-sep-2019-case-study-v3f-191101.pdf Website]&nbsp;&nbsp; [[Media: nrcMooseCreek2019.pdf | Report.pdf]]</ref><ref name="Burke2015">Burke, Jill, 2019. Fairbanks incinerator shows promise for cleaning toxic soil. Channel 2-KTUU, October 8.  [https://www.ktuu.com/content/news/Fairbanks-incinerator-shows-promise-for-cleaning-toxic-soil-562593631.html Website]</ref> and Australia<ref name="Nolan2015"/> using rotary kilns operating at temperatures of up to 815&deg;C with off-gas treatment at up to 1200&deg;C, or in other cases using batch-fed systems (Figure 2) operating at lower temperatures. At these temperatures, some PFAS are mineralized, releasing fluorine that must be captured in off-gas treatment systems.  Some PFAS would not be destroyed at these temperatures and therefore must be captured in off-gas treatment systems.  Several bench-scale tests have been performed that have established a minimal effective temperature for desorption of between 350&deg;C and 400&deg;C<ref name="Hatton2019">Hatton, J., Dasu, K., Richter, R., Fitzpatrick, T., and Higgins, C., 2019. Field Demonstration of Infrared Thermal Treatment of PFAS-impacted Soils from Subsurface Investigations. Strategic Environmental Research and Development Program (SERDP), Project ER18-1603, Alexandria, VA.  [https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/ER18-1603 Website]&nbsp;&nbsp; [[Media: SERDP ER18-1603.pdf | Report.pdf]]</ref><ref name="DiGuiseppi2019">DiGuiseppi, W., Richter, R., and Riggle, M., 2019. Low Temperature Desorption of Per- and Polyfluoroalkyl Substances. The Military Engineer, 111(719), pp. 52-53. Society of American Military Engineers, Washington, DC.  [http://online.fliphtml5.com/fedq/sdoo/#p=54 Open access article.]&nbsp;&nbsp; [[Media: DiGuiseppi2019.pdf | Report.pdf]]</ref>. A US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) field-scale demonstration was performed in Oregon, where ''ex situ'' thermal desorption was conducted at 400&deg;C over several days, and the PFAS were captured on vapor-phase activated carbon and subsequently incinerated off site<ref name="Hatton2019"/>. Two field-scale thermal desorption pilot projects (one ''in situ'' and the other ''ex situ'') have been funded under the US DoD’s Environmental Security Technology Certification Program (ESTCP) to demonstrate that source zone soil can be heated to the requisite 350&deg;C and held there for the appropriate length of time to fully desorb and capture PFAS<ref name="Iery2020">Iery, R., 2020. In Situ Thermal Treatment of PFAS in the Vadose Zone, Project ER20-5250. US Department of Defense, Environmental Security Technology Certification Program (ESTCP).   [https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Emerging-Issues/ER20-5250 Website]</ref><ref>Jennifer Wehrmann, 2020. Ex Situ Thermal Treatment of Perfluoroalkyl and Polyfluoroalkyl Substances, ER20-5198. US Department of Defense, Environmental Security Technology Certification Program (ESTCP).  [https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Emerging-Issues/ER20-5198/ER20-5198/(language)/eng-US Website]</ref>.
 ===Soil Washing===

@@ Line 31: / Line 31: @@
 ===Stabilization===
 [[File:DiGuiseppi1w2Fig2.PNG|thumb|600px| Figure 2. A portable infrared thermal treatment unit for PFAS-impacted soils<ref name="DiGuiseppi2019"/>.]]
-Various amendments have been manufactured to sorb PFAS to reduce leaching from soil.  Although this is a non-destructive approach, stabilization can reduce mass flux from a source area or allow soils to be placed in landfills with reduced potential for leaching. Amendments sorb PFAS through hydrophobic and electrostatic interactions and are applied to soil through ''in situ'' soil mixing or ''ex situ'' stabilization (Figure 1). Effectiveness of amendments varies depending on site conditions, PFAS types present, and mixing conditions<ref name="ITRCwNs2020"/>. Good results have been observed in bench and field scale tests with a variety of cationic clays (natural or chemically modified) and zeolites<ref name="OchoaHerrera2008">Ochoa-Herrera, V., and Sierra-Alvarez, R., 2008. Removal of perfluorinated surfactants by sorption onto granular activated carbon, zeolites and sludge. Chemosphere, 72(10), pp. 1588-1593.  [https://doi.org/10.1016/j.chemosphere.2008.04.029 DOI: 10.1016/j.chemosphere.2008.04.029]</ref><ref name="Rattanaoudom2012">Rattanaoudom, R., Visvanathan, C., and Boontanon, S.K., 2012. Removal of Concentrated PFOS and PFOA in Synthetic Industrial Wastewater by Powder Activated Carbon and Hydrotalcite. Journal of Water Sustainability, 2(4), pp. 245-248.  [http://www.jwsponline.com/uploadpic/Magazine/pp%20245-258.pdf Open access article.]&nbsp;&nbsp; [[Media: Rattanaoudom2012.pdf | Report.pdf]]</ref><ref name="Ziltek2017">Ziltek, 2017. RemBind: Frequently Asked Questions.  [https://static1.squarespace.com/static/5c5503db4d546e22f6d2feb2/t/5c733787f9619ae6c84674c9/1551054727451/RemBind+FAQs.pdf Free download]&nbsp;&nbsp; [[Media: RemBind2017.pdf | Report.pdf]]</ref>. Bench-scale tests have shown that activated carbon sorbents reduce leachability of PFAS from soils<ref name="Du2014">Du, Z., Deng, S., Bei, Y., Huang, Q., Wang, B., Huang, J. and Yu, G., 2014. Adsorption behavior and mechanism of perfluorinated compounds on various adsorbents – A review. Journal of Hazardous Materials, 274, pp. 443-454.  [https://doi.org/10.1016/j.jhazmat.2014.04.038 DOI: 10.1016/j.jhazmat.2014.04.038]</ref><ref name="Yu2009">Yu, Q., Zhang, R., Deng, S., Huang, J. and Yu, G., 2009. Sorption of perfluorooctane sulfonate and perfluorooctanoate on activated carbons and resin: Kinetic and isotherm study. Water Research, 43(4), pp. 1150-1158.  [https://doi.org/10.1016/j.watres.2008.12.001 DOI: 10.1016/j.watres.2008.12.001]</ref><ref name="Szabo2017">Szabo, J., Hall, J., Magnuson, M., Panguluri, S., and Meiners, G., 2017. Treatment of Perfluorinated Alkyl Substances in Wash Water Using Granular Activated Carbon and Mixed Media, EPA/600/R-17/175. US Environmental Protection Agency (EPA), Washington, DC.  [https://cfpub.epa.gov/si/si_public_record_report.cfm?Lab=NHSRC&direntryid=337098 Website]&nbsp;&nbsp; [[Media: EPA600R17175.PDF | Report.pdf]]</ref>.  Several commercial products have been developed to target PFAS, including CETCO’s [https://www.mineralstech.com/business-segments/performance-materials/cetco/environmental-products/products/fluoro-sorb Fluoro-Sorb&reg;] and Ziltek’s [https://rembind.com/ RemBind&trade;], the later of which combines the cation exchange binding capability of clays, the hydrophobic sorption and [[Wikipedia: Van der Waals force | van der Waals]] attraction of organic material, and the electrostatic interactions of aluminum hydroxide to create a highly effective soil stabilizer.  This material has been mixed into soil at 1 to 5% ratio by weight in ''ex situ'' applications and been demonstrated to reduce leachability by greater than 99 percent<ref name="Nolan2015">Nolan, A., Anderson, P., McKay, D., Cartwright, L., and McLean, C., 2015. Treatment of PFCs in Soils, Sediments and Water, WC35. Program and Proceedings, CleanUp Conference 2015. Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC Care), Melbourne, Australia. pp. 374-375.  [https://www.crccare.com/files/dmfile/CLEANUP_2015_PROCEEDINGS-web.pdf Free download]&nbsp;&nbsp; [[Media: CRCCare2015.pdf | Report.pdf]]</ref>.
+Various amendments have been manufactured to sorb PFAS to reduce leaching from soil.  Although this is a non-destructive approach, stabilization can reduce mass flux from a source area or allow soils to be placed in landfills with reduced potential for leaching. Amendments sorb PFAS through hydrophobic and electrostatic interactions and are applied to soil through ''in situ'' soil mixing or ''ex situ'' stabilization (Figure 1). Effectiveness of amendments varies depending on site conditions, PFAS types present, and mixing conditions<ref name="ITRCwNs2020"/>. Good results have been observed in bench and field scale tests with a variety of cationic clays (natural or chemically modified) and zeolites<ref name="OchoaHerrera2008">Ochoa-Herrera, V., and Sierra-Alvarez, R., 2008. Removal of perfluorinated surfactants by sorption onto granular activated carbon, zeolites and sludge. Chemosphere, 72(10), pp. 1588-1593.  [https://doi.org/10.1016/j.chemosphere.2008.04.029 DOI: 10.1016/j.chemosphere.2008.04.029]</ref><ref name="Rattanaoudom2012">Rattanaoudom, R., Visvanathan, C., and Boontanon, S.K., 2012. Removal of Concentrated PFOS and PFOA in Synthetic Industrial Wastewater by Powder Activated Carbon and Hydrotalcite. Journal of Water Sustainability, 2(4), pp. 245-248.  [http://www.jwsponline.com/uploadpic/Magazine/pp%20245-258.pdf Open access article.]&nbsp;&nbsp; [[Media: Rattanaoudom2012.pdf | Report.pdf]]</ref><ref name="Ziltek2017">Ziltek, 2017. RemBind: Frequently Asked Questions.  [https://static1.squarespace.com/static/5c5503db4d546e22f6d2feb2/t/5c733787f9619ae6c84674c9/1551054727451/RemBind+FAQs.pdf Free download]&nbsp;&nbsp; [[Media: RemBind2017.pdf | Report.pdf]]</ref>. Bench-scale tests have shown that activated carbon sorbents reduce leachability of PFAS from soils<ref name="Du2014">Du, Z., Deng, S., Bei, Y., Huang, Q., Wang, B., Huang, J. and Yu, G., 2014. Adsorption behavior and mechanism of perfluorinated compounds on various adsorbents – A review. Journal of Hazardous Materials, 274, pp. 443-454.  [https://doi.org/10.1016/j.jhazmat.2014.04.038 DOI: 10.1016/j.jhazmat.2014.04.038]</ref><ref name="Yu2009">Yu, Q., Zhang, R., Deng, S., Huang, J. and Yu, G., 2009. Sorption of perfluorooctane sulfonate and perfluorooctanoate on activated carbons and resin: Kinetic and isotherm study. Water Research, 43(4), pp. 1150-1158.  [https://doi.org/10.1016/j.watres.2008.12.001 DOI: 10.1016/j.watres.2008.12.001]</ref><ref name="Szabo2017">Szabo, J., Hall, J., Magnuson, M., Panguluri, S., and Meiners, G., 2017. Treatment of Perfluorinated Alkyl Substances in Wash Water Using Granular Activated Carbon and Mixed Media, EPA/600/R-17/175. US Environmental Protection Agency (EPA), Washington, DC.  [https://cfpub.epa.gov/si/si_public_record_report.cfm?Lab=NHSRC&direntryid=337098 Website]&nbsp;&nbsp; [[Media: EPA600R17175.PDF | Report.pdf]]</ref>.  Several commercial products have been developed to target PFAS, including CETCO’s [https://www.mineralstech.com/business-segments/performance-materials/cetco/environmental-products/products/fluoro-sorb Fluoro-Sorb&reg;] and Ziltek’s [https://rembind.com/ RemBind&trade;], the latter of which combines the cation exchange binding capability of clays, the hydrophobic sorption and [[Wikipedia: Van der Waals force | van der Waals]] attraction of organic material, and the electrostatic interactions of aluminum hydroxide to create a highly effective soil stabilizer.  This material has been mixed into soil at 1 to 5% ratio by weight in ''ex situ'' applications and been demonstrated to reduce leachability by greater than 99 percent<ref name="Nolan2015">Nolan, A., Anderson, P., McKay, D., Cartwright, L., and McLean, C., 2015. Treatment of PFCs in Soils, Sediments and Water, WC35. Program and Proceedings, CleanUp Conference 2015. Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC Care), Melbourne, Australia. pp. 374-375.  [https://www.crccare.com/files/dmfile/CLEANUP_2015_PROCEEDINGS-web.pdf Free download]&nbsp;&nbsp; [[Media: CRCCare2015.pdf | Report.pdf]]</ref>.
 ===Thermal Treatment===

@@ Line 40: / Line 40: @@
 ===Soil Washing===
-Soil washing has been applied to PFAS in a handful of pilot projects<ref name="Torneman2012">Torneman, N., 2012. Remedial Methods and Strategies for PFCs. Fourth Joint Nordic Meeting on Remediation of Contaminated Sites, NORDROCS 2012, Oslo, Norway.  [http://nordrocs.org/wp-content/uploads/2012/09/Session-VI-torsdag-1-Torneman-short-paper.pdf Free download.]&nbsp;&nbsp; [[Media: Torneman2012.pdf | Report.pdf]]</ref><ref name="Toase2018">Toase, D., 2018. Application of enhanced soil washing techniques to PFAS contaminated source zones. Emerging Contaminants Summit 2018, Westminster, Colorado.</ref><ref name="Grimison2018">Grimison, C., Barthelme, S., Nolan, A., Cole, J., Morrell, C., 2018. Integrated Soil and Water System for Treatment of PFAS Impacted Source Areas, 18E138P. Australasian Land and Groundwater Association (ALGA), Sydney, Australia.  [https://landandgroundwater.com/media/18E138P_-_Charles_Grimison.pdf Free download.]&nbsp;&nbsp; [[Media: Grimison2018.pdf | Report.pdf]]</ref> and one full-scale implementation in Australia (Figure 3). This approach requires a large-scale engineered plant to handle the various liquid and solid waste streams generated. Soil washing is less suitable for clay-rich soils, where aggregation of the particulates occurs and is difficult to prevent or mitigate. Treatment of the liquid rinse water waste stream is required, which would then rely on conventional water treatment technologies such as granular activated carbon (GAC) or ion exchange. Additionally, in some cases flocculated sludge is generated, which would require treatment or disposal offsite. At present, the only full-scale soil washing demonstration is occurring in Australia, where a vendor has constructed and is operating a 10 million AUD$ treatment plant in anticipation of future treatment of soils generated from remedial actions at Australian Defense installations. Some Australian installations are stockpiling soils due to the lack of cost-effective soil treatment options. According to the vendor, this system generates no solid waste, instead feeding any solids back into the front end of the process for further removal of PFAS<ref name="Grimison2020">Grimison, C., Brookman, I., Hunt, J., and Lucas, J., 2020. Remediation of PFAS-related impacts – ongoing scrutiny and review, Ventia Submission to PFAS Subcommittee of the Joint Standing Committee on Foreign Affairs, Defence and Trade, Australia. [https://www.aph.gov.au/DocumentStore.ashx?id=a209e924-2b7e-4727-bccf-30bef5304bba&subId=691428  Free download.]&nbsp;&nbsp; [[Media: Grimison2020.pdf | Report.pdf]]</ref>.
+Soil washing has been applied to PFAS in a handful of pilot projects<ref name="Torneman2012">Torneman, N., 2012. Remedial Methods and Strategies for PFCs. Fourth Joint Nordic Meeting on Remediation of Contaminated Sites, NORDROCS 2012, Oslo, Norway.  [http://nordrocs.org/wp-content/uploads/2012/09/Session-VI-torsdag-1-Torneman-short-paper.pdf Free download.]&nbsp;&nbsp; [[Media: Torneman2012.pdf | Report.pdf]]</ref><ref name="Toase2018">Toase, D., 2018. Application of enhanced soil washing techniques to PFAS contaminated source zones. Emerging Contaminants Summit 2018, Westminster, Colorado.</ref><ref name="Grimison2018">Grimison, C., Barthelme, S., Nolan, A., Cole, J., Morrell, C., 2018. Integrated Soil and Water System for Treatment of PFAS Impacted Source Areas, 18E138P. Australasian Land and Groundwater Association (ALGA), Sydney, Australia.  [https://landandgroundwater.com/media/18E138P_-_Charles_Grimison.pdf Free download.]&nbsp;&nbsp; [[Media: Grimison2018.pdf | Report.pdf]]</ref> and one full-scale implementation in Australia (Figure 3). This approach requires a large-scale engineered plant to handle the various liquid and solid waste streams generated. Soil washing is less suitable for clay-rich soils, where aggregation of the particulates occurs and is difficult to prevent or mitigate. Treatment of the liquid rinse water waste stream is required, which would then rely on conventional water treatment technologies such as granular activated carbon (GAC) or ion exchange. Additionally, in some cases flocculated sludge is generated, which would require treatment or disposal offsite. At present, the only full-scale soil washing project is in Australia, where a vendor has constructed and is operating a AUD$ 10 million treatment plant primarily for treatment of soils generated from remedial actions at Australian Defense installations. Some Australian installations are stockpiling soils due to the lack of cost-effective soil treatment options. According to the vendor, this system generates no solid waste, instead feeding any solids back into the front end of the process for further removal of PFAS<ref name="Grimison2020">Grimison, C., Brookman, I., Hunt, J., and Lucas, J., 2020. Remediation of PFAS-related impacts – ongoing scrutiny and review, Ventia Submission to PFAS Subcommittee of the Joint Standing Committee on Foreign Affairs, Defence and Trade, Australia. [https://www.aph.gov.au/DocumentStore.ashx?id=a209e924-2b7e-4727-bccf-30bef5304bba&subId=691428  Free download.]&nbsp;&nbsp; [[Media: Grimison2020.pdf | Report.pdf]]</ref>.
 ==Conclusions==