Technology Innovation News Survey

U.S. Environmental Protection Agency, Region 5 Contracting Office, Chicago, IL
Contract Opportunities on SAM.gov, Solicitation 68HE0523R0021. 2023

When this solicitation is released sometime in late October or early November, it will be competed as a total small business set-aside under NAICS code 562910. EPA Region 5, in support of the Great Lakes National Program Office (GLNPO), requires a contractor for dredging in Great Lakes rivers and harbors and dredged material handling of sediments. The U.S. EPA anticipates five-year, Multiple Award Indefinite Delivery Indefinite Quantity (IDIQ) type contracts with Firm-Fixed-Price task orders. The estimated ceiling per IDIQ contract is $960 million (the value of ordered work for all contracts will not exceed $960 million total). GLNPO executes a budget to facilitate sediment remediation projects varied in scope between 10,000 cubic yards (CY) and 500,000 CY of contaminated sediment per project. Approximately three to six projects are anticipated per year, depending on the project size. The expected solicitation will be issued using the procedures of FAR Subpart 15. In response to the expected solicitation, an offeror must demonstrate the ability to perform under a large dollar IDIQ contract in addition to a sample potential project. There is no solicitation at this time. https://sam.gov/opp/c542ecfe0cf043afaa91859cda07c2f3/view

U.S. Department of the Navy, Naval Facilities Engineering Systems Command, Pacific Command, Southwest Division, San Diego, CA
Contract Opportunities on SAM.gov, Solicitation N62473-23-R-1209, 2023

When this solicitation is released, it will be competed as a total small business set-aside under NAICS code 562910. The Naval Facilities Engineering Systems Command, Southwest, in San Diego, CA, is preparing to release a solicitation for an Environmental Multiple Award Contract (EMAC) for environmental remediation of radiological contaminants services at various DoD installations in AK, AR, CA, CO, NV, NM, OR, UT, WA, and other installations within the NAVFAC area of responsibility. The services to be acquired include environmental remediation of radiological contaminants services. Typical activities under Contract Task Orders (CTOs) to this contract may include, but are not limited to the following examples and may be requested to be performed in terrestrial or aquatic environments: environmental remediation services primarily consisting of radiological surveys, remedial/removal actions of radiological contaminants, such as alpha-, beta-, gamma- and/or neutron-emitting radioactive materials; byproduct, source and special nuclear materials; naturally occurring radioactive materials (NORM); naturally or accelerator-product radioactive materials (NARM); and technologically-enhanced NORM (TENORM). In addition to the radiological contamination, hazardous contamination may be present, which may trigger mixed-waste handling procedures. Contractors will provide services to remediate, handle, and/or store hazardous contaminants regulated under RCRA, CERCLA, TSCA, Solid Waste Disposal Act, and petroleum oils and lubricants. The resulting contract will be Firm-Fixed-Price, Indefinite-Delivery/Indefinite-Quantity, multiple-award contract. There is no solicitation at this time. https://sam.gov/opp/1193bc10efa7499fb0876ad84f9d7a43/view

U.S. Army Corps of Engineers (USACE), Albuquerque District, Albuquerque, NM
Contract Opportunities on SAM.gov, Solicitation W912PP23R0002, 2023

When this solicitation is released on or about November 6, 2023, it will be competed as a total small business set-aside under NAICS code 562910. The USACE Albuquerque District requires a contractor to perform environmental compliance activities to support the following installation programs: Hazardous Waste Management, Hazardous Material Management, Air Quality, Wastewater, Stormwater, National Pollutant Discharge Elimination System, Cultural Resources, Solid Waste Management, Environmental Management Systems, Aboveground storage tanks, Petroleum, Oil and Lubricant Management, National Environmental Policy Act (NEPA) activities, and other compliance activities as needed by CAFB, HAFB, and KAFB. The Contractor will also perform PFAS monitoring of stormwater and Melrose Range groundwater monitoring for CAFB and landfill gas monitoring and landfill inspections at HAFB. The Contractor will conduct environmental sampling and analysis, inventory, data management, development of planning documents, waste characterization, survey, recordkeeping, spill response, training, reporting, and permit application. Regulatory oversight will be provided by EPA Region 6, the New Mexico Environment Department, and the Albuquerque Environmental Health Department. The period of performance is expected to include a one-year base period with four option years. The project will be advertised as a Request for Proposal. Competitive proposals will be evaluated based on the evaluation criteria set forth in the solicitation package. Evaluation by the Government will result in selecting a firm that represents the best value to the Government. The proposed procurement will result in a firm-fixed-price contract. There is no solicitation at this time. https://sam.gov/opp/a03d166403a440038b722cd0ecaa10aa/view

U.S. Environmental Protection Agency, Funding Opportunity EPA-OLEM-OBLR-23-10, 2023

The EPA's Office of Brownfields and Land Revitalization (OBLR) is soliciting applications from eligible entities to provide technical assistance that directly benefits Tribal Nations and entities nationwide that are eligible for EPA Brownfield Grants funded under CERCLA 104(k) and 128(a) to build sustainable brownfield programs and strengthen capacity to manage successful brownfields reuse. This technical assistance should also help increase a Tribal Nation's capacity to establish, manage, and administer their CERCLA 128(a) response programs and conduct and oversee brownfield assessment and cleanup activities. EPA is committed to supporting research and technical assistance to further the program's goals and provide enhanced knowledge, tools, and processes to a broad range of Tribal communities nationwide. This technical assistance is intended to benefit Tribal communities eligible for funding. The closing date and time for receipt of applications is November 13, 2023, at 11:59 PM ET. https://www.grants.gov/web/grants/view-opportunity.html?oppId=350042

Ghandehari, S.S., S.-H. Cheng, C.J. Hapeman, A. Torrents, and B.V. Kjellerup.
Remediation [published online 3 August 2023 before print]

A biowall was installed at a TCE-contaminated landfill in Maryland in 2013 to promote the bioremediation of TCE and its degradation products. Six-year monitoring data indicated a steady removal of >99% TCE in groundwater at the wall; however, a concurrent buildup of intermediate byproducts was observed downgradient of the wall. The site's background, remediation plan, and installation were assessed to identify the cause of the biowall's inefficiency. Monitoring data, including the concentration of TCE and its degradation byproducts, and geochemical and physical characteristics were evaluated to understand project conditions and challenges and possible options to improve biowall efficacy. This article is Open Access at https://onlinelibrary.wiley.com/doi/epdf/10.1002/rem.21764.
See 2023 Five Year Review for more information: https://semspub.epa.gov/work/03/2350744.pdf

Woodward, D., O. El Sharnouby, and B. Malyk. ǀ 2023 Bioremediation Symposium Proceedings, 8-11 May, Austin, TX, 16 slides, 2023

This presentation provides lessons learned from the installation, management, and/or monitoring of >10,000 PFAS-contaminated Point of Entry Treatment Systems (POETs) and Point of Use Treatment Systems (POUTs) in the U.S., Canada, Europe, and Australia. Questions addressed include:

• What concentration should trigger treatment?
• Should bottled water always be offered?
• Does PFAS adsorb (i.e., stick) to and subsequently desorb from home water systems?
• What monitoring should be done following POET installation or after adding municipal water?
• What analytes should be monitored?
• Is biotransformation of analytes a concern?
• Is it important to be consistent across different sites?
What are best practices when removing treatment equipment?

Case studies are provided to show both positive and negative outcomes and the resulting impact on site-specific and portfolio procedures (i.e., SOPs). The role and impact of social media, new PFAS, lowered drinking water criteria, and widespread litigation on best practice procedures are also addressed.
Slides: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-presentations/track-b/b3_1555_418_woodward.pptx.pdf?sfvrsn=ffccc7b7_3
Longer abstract: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-abstracts/418.pdf?sfvrsn=fd196222_3
See video of presentation from 2022 Great Lakes PFAS Summit: https://us06web.zoom.us/rec/play/C7V_XFT8Zov3zmkToTNYesyoE8eYe10Zxcei6SYssF1qyu6jcGFZu4SKFwHjg-duEBXd-8P213dlSFE.oOWIpiyQMoRy7V4m?canPlayFromShare=true&from=share_recording_detail&startTime=1670440208000&componentName=rec-play&originRequestUrl=https%3A%2F%2Fus06web.zoom.us%2Frec%2Fshare%2FRRvicZLJYCiqxzQYtPrdYmOOw-7ur5bwEyew0gl9crJzufLtJLC0xCJZqf2U6sT9.YCCKul5AyZ1msHkE%3FstartTime%3D1670440208000

Rothell, N., M. Cutler, and D. Leigh. ǀ 2023 Bioremediation Symposium Proceedings, 8-11 May, Austin, TX, 23 slides, 2023

A TCE groundwater plume at IR Site 1116 at MCB Camp Pendleton, San Diego, is approximately ½ mile long, 300 ft wide, up to 30 ft deep, and covers ~17 acres. Dissolved oxygen (DO) was >3 mg/L, and oxygen reduction potential (ORP) was correspondingly oxidizing. TCE was detected in the fractured bedrock aquifer at concentrations >2,000 µg/L. Enhanced in situ bioremediation (EISB) via injection wells was conducted by applying an easily distributed and long-lasting organic ELS™ substrate, a dechlorinating microbial consortium, and a soluble buffer, KHCO₃. Hydrant water for substrate mixing was deoxidized and dechlorinated before mixing using sodium ascorbate. A trailer with a 1,000-gal poly tank was used to transfer the substrate from the mixing area to the injection wells for pressure injection through a 10-well manifold system. The concentrated ELS was emulsified and injected into more than 200 wells screened in the fractured bedrock aquifer, followed by the addition of the microbial culture. Distribution of the reagents by a gravity flow system was also applied at several locations. A total of over 95,000 gals of reagents were applied at the site. Groundwater monitoring confirmed that the reagents were effectively distributed in the fractured granitic bedrock aquifer. Following reagent distribution, anerobic and highly reducing conditions conducive to biologically-mediated reductive dechlorination were established in the treatment zone. The presence of non-toxic ethene in treatment area wells confirmed the complete reductive dechlorination of TCE.
Slides: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-presentations/track-c/c6_0915_257_leigh.pptx.pdf?sfvrsn=ad8999ef_3
Longer abstract: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-abstracts/257_updabs.pdf?sfvrsn=7c2828c_3

Bokare, M., N. Lombard, S. Magee, D. Murali, and U. Ghosh.
Environmental Pollution 316(Part 1):120490(2023)

This study used polyethylene passive samplers to measure PCB concentrations in the air phase at six locations in Washington, DC, over one year to capture spatial and seasonal variations. Concurrent water phase PCB measurements were used to quantify the direction and magnitude of air-water exchange in the Anacostia River. Two locations had nearly an order of magnitude higher air phase PCB concentrations that could be related to localized sources. The remaining four locations provided similar air phase PCB concentrations that averaged from 270 ± 44 pg/m³ (summer) to 32 ± 4.3 pg/m³ (winter). ∑PCB water-air exchange fluxes were positive across all seasons, with net PCB volatilization of 180 ± 19 g/year from the surface water. The volatilization rate was an order of magnitude lower than previously estimated from a fate and transport model. Based on previous studies in this watershed, PCB load from atmospheric deposition was an order of magnitude lower than the volatilization rate. Results refuted a long-standing understanding of the air phase serving as a source of PCBs to the river as per the currently approved Total Maximum Daily Load assessment. The study demonstrates the utility of passive air phase measurements to delineate local terrestrial sources of pollution and provide estimates for air-water exchange to complete a robust mass balance for semivolatile pollutants in an urban river.

Dombrowski, P.M., P. Kakarla, S. Pittenger, P. Dennis, and J. Roberts. ǀ 2023 Bioremediation Symposium Proceedings, 8-11 May, Austin, TX, 22 slides, 2023

This presentation reviews oxidant selection, oxidant persistence, reaction products, change in pH, and the potential increased demand for bioremediation amendments resulting from ISCO. Field- and bench-scale experience highlight evidence of increasing biodegradation after applying potassium permanganate, activated sodium persulfate, or catalyzed hydrogen peroxide with and without biostimulation. Two case studies detailed enhanced reductive dechlorination (ERD) performed nearly immediately after ISCO injections and rapidly establishing a reductive dechlorination environment to accelerate the achievement of project objectives. At one project, ERD was performed in 150 injection wells less than one month after ISCO utilizing catalyzed hydrogen peroxide. ERD injections were conducted 4 days after catalyzed hydrogen peroxide was performed at the same injection points at the second site. Combined approaches and treatment-train applications can benefit overall remediation timeframe and cost-effectiveness.
Slides: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-presentations/track-a/a5_0800_424_pittenger_rev.pptx.pdf?sfvrsn=ade32b5d_3
Longer abstract: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-abstracts/424.pdf?sfvrsn=eda6f27_3

Mankowski, L., J. Adams, and T. Repas. ǀ 2022 Great Lakes PFAS Summit, 5-7 December, virtual, 41 minutes, 2022

Elevated concentrations of PFOS and PFAS were detected in soil and groundwater at a former tannery along the Thunder Bay River in Alpena, MI, potentially from aqueous film forming foam (AFFF) use. Investigations revealed PFOS impacts in soil extending from the capillary fringe (0.5 ft below grade [bg]) to the base of the shallow aquifer (up to 8 ft bg) near a former building. PFAS-impacted groundwater in the source area migrated into the decaying stormwater infrastructure and was conveyed to the river. Seasonally, impacted groundwater vents to the ground surface, then is conveyed by ditches to municipal stormwater infrastructure, which also discharges to the river. The groundwater plume was also expanding toward Lake Huron. Pilot tests/corrective actions to mitigate PFAS impacts to surface water and reduce available source contaminant mass to control the PFAS groundwater plume included a benchtop study to demonstrate PFAS removal from site groundwater using biochar, a study to isolate candidate PFAS degrading microbes from soil and groundwater, a bioaugmentation pilot test with chemical enhancement (oxygen release compound) and solar-powered air sparge, and a phytoremediation pilot test with in situ immobilization and bioaugmentation. In situ biochar applied via soil mixing reduced PFOS levels in groundwater from 2,130 ng/L to 23.3 ng/L in 28 days and 179 ng/L (a 92% reduction) in 1 year. There was less reduction in short-chain PFAS (PFBA=39% and PFBS=57% in 1 year). Pilot test results indicate PFOS reductions of 35-100% in groundwater (varied by loading rate). Leachability tests indicate PFOS leaching in soil mixing decreased by 79 (SPLP) to 99% (TCLP) in 1 year. Endemic microbes isolated from the site demonstrated PFOS reductions of ≤70% with aeration in 8 weeks (bench top). Analyses indicate that two of the isolated candidate PFAS-degrading microbes produce free fluoride. During the limited bioaugmentation and oxygenation pilot test, PFOS levels decreased by >50% in the microbe/oxygen-treated area (2 weeks) but stalled when the oxygen level dropped. Lessons learned are being applied in conjunction with phytoremediation to depress the water table, contain groundwater onsite and reduce PFAS concentrations in groundwater before plant uptake. https://us06web.zoom.us/rec/play/GvDsFSjDE_vAoate3H6gzlhBEe9NHCCnXtMMTAqJOTLFKKZtqgPZ2Gxka7Cp_ZFAAY2pCL8rD9sTUL-k.0v--JEOw42op9324?canPlayFromShare=true&from=share_recording_detail&startTime=1670425864000&componentName=rec-play&originRequestUrl=https%3A%2F%2Fus06web.zoom.us%2Frec%2Fshare%2FudSHBfHx19DMK0TN51JVxpfkTJOBLLefh_xpe_0p3xJufXLWnoUmnmqaC3qmg5bo.AJq-7Ipp2VwIaTXL%3FstartTime%3D1670425864000

Navarro, D.A., S. Kabiri, J. Ho, K.C. Bowles, G. Davis, M.J. McLaughlin, and R.S. Kookana.
Environmental Pollution 323:121249(2023)

This article presents results on the effectiveness of select carbon-based sorbents to stabilize PFAS in soil over 4 years under multiple lab leaching conditions. Standard batch leaching tests simulating aggressive, worst-case scenario conditions for leaching (i.e., shaking for 24-48 h at high liquid/solid ratios) were employed to test longevity and durability of stabilization in clay-loam and sandy-loam soil contaminated with PFAS (2 and 14 mg/kg ∑28 PFAS). The different sorbents were applied at 1-6% (w/w), reduced PFAS leaching from the soil to varying degrees. Among the 5 sorbents tested, initial assessments completed 1 week after treatment revealed that 2 powdered activated carbon (PAC) sorbents and 1 biochar could reduce PFAS leaching in the soil by > 95%. Four years after treatment, PAC sorbent performance did not significantly change, while colloidal AC improved and reduced PFAS leaching by at least 94%. The AC-treated soil also appeared to be durable, achieving ≥95% reduction in PFAS leaching under repetitive leaching events (5 times extraction) and with minimal effect of pH (pH 4-10.5). In contrast, the biochars were affected by aging and were at least 22% less effective in reducing PFAS leaching across a range of leaching conditions. Sorbent performance was generally consistent with the sorbent's physical and chemical characteristics. Overall, the AC sorbents used in this study appeared to perform better than the biochars in stabilizing PFAS long-term.

Snook, J., J. Becanova, S. Vojta, and R. Lohmann. ACS ES&T Water 3(8):2355-2362(2023)

Several batch experiments that systematically varied from a general procedure were conducted to determine the sorbent-water distribution of PFAS and evaluate the "best-practice" experimental setup. A selection of PFAS (6-carbon fluorinated chain length with differing functional groups) and two sorbents were used to test variations of a solution/sorbent ratio, methanol content, and PFAS initial concentration and compare derived K_swvalues. Each methodological component affected log(K_sw), usually by suppressing the value (by 0-48%), when compared with a "best design" procedure. Thus, a reference procedure for PFAS and sorbents and general guidelines for batch experiment design with different compounds and sorbents is suggested.

Wan, H.Y., M.S. Islam, T. Tarannum, K. Shi, R. Mills, Z.Y. Yi, F. Fang, L.F. Lei, S.Y. Li, L. Ormsbee, Z. Xu and D. Bhattacharyya
Separation and Purification Technology 320:123955(2023)

A nanocomposite membrane incorporating reactive Pd-Fe nanoparticles (NPs) was developed to remediate chlorinated aliphatic hydrocarbons (CAHs) in groundwater. The functionalized polyanions prevented NPs agglomeration, resulting in a spherical Fe⁰ core (55 nm, O/Fe = 0.05) and an oxidized shell (4 nm, O/Fe = 1.38), and recapturing the produced Fen+ for in situ regeneration. The reactive membranes degraded 92% of target CAHs with a residence time of 1.7 s. After long-term treatment and regeneration, reusability was confirmed through recovered reactivity, recurrence of Fe⁰ in X-ray photoelectron spectroscopy, and >96% Fe and Pd remaining. Based on an EPA work breakdown structure-based cost model, the total cost (adjusted present value for 20 years) was estimated to be 13.9% lower than the GAC system. However, non-target CAHs from groundwater can compete for active sites, leading to a decreased surface-area normalized dechlorination rate (k_sa) of 28.2-79.9%. A hybrid nanofiltration (NF)/reactive membrane was proposed to selectively intercept larger competitors, leading to 54% increased dechlorination efficiency and 1.3 to 1.9-fold enlarged k_sa.

Grubb, D.G., D.R.V. Berggren, R.W. Shannon, B.K. Schroth, C.D. Tsiamis, and J. Hess.
Journal of Hazardous, Toxic, and Radioactive Waste 27(3)(2023)

A study showed that using saltwater (SW) baths during EPA 1315 modified (M) testing can result in the formation of surface crusts on in situ stabilization (ISS) samples and mass-transfer reductions in naphthalene, which were very pronounced in Gowanus Canal sediments. At the same time, the SW bath pH can drop from >11 for a corresponding deionized water (DIW) bath to ~8, enabling biological activity. The newly formed ISS sample crusts (primarily aragonite and brucite) were similar in many respects to crusts that form on concrete under marine exposure conditions, based on mineralogical and x-ray-based analyses. However, while some SW baths were shown to be biologically active based on gene-probing analyses, petroleum hydrocarbon degraders, when present, did not necessarily reduce the observed leaching rates. While the surface crusts appear to be associated with mass-transfer reductions, to varying degrees, remedial design should conservatively proceed based on EPA 1315M tests utilizing DIW baths only, and any crusts potentially occurring under field conditions constitute an inherent benefit.

Motkuri, R.K., S. Chatterjee, D. Barpaga, X. Zheng, Y. Ibrahim, C.W. Enderlin, B.E. Wells, and M. Reed. Pacific Northwest National Laboratory (PNNL) Report No. PNNL-33928, 14 pp, 2023

An engineered form of a Metal-Organic Framework (MOF) based material was developed to remove PFOS for real-world applications. The powdered MOF material was demonstrated at PNNL to selectively capture PFOS from distilled (DI) water with a large performance advantage over granulated activated carbon (GAC). Using a polymer, the material was transformed into an engineered form (granules) to demonstrate PFOS adsorption capacity in tap water. After thorough characterization and stability testing, the engineered MOF granules were provided to an industrial collaborator for testing and demonstration of continuous, long-term PFOS removal from tap water. Preliminary results showed PFOS sorption capacities at ppb concentrations in tap water under a flow system, providing insight into sorbent-based material utilization in a continuous flow system. https://www.osti.gov/servlets/purl/1984699

Wurth, A., M. Mechler, K. Menberg, M.A. Ikipinar, P. Martus, R. Sohlmann, R.S. Boeddinghaus, and P. Blum. ǀ Environmental Science & Technology 57(10):4122-4132(2023)

A study tested the applicability of phytoscreening for PFAS at a contaminated site in Germany. Foliage of white willow (Salix alba L.), black poplar (Populus nigra L.), and black alder (Alnus glutinosa L.) were sampled to evaluate seasonal and annual variations in PFAS concentrations. Results indicated species and specific differences, with the highest PFAS sum concentration ∑23 observed in October for white willow (0-1800 µg/kg), followed by black poplar (6.7-32 µg/kg) and black alder (0-13 µg/kg). The bulk substances in leaves were highly mobile short-chain PFCAs. In contrast, the PFAS composition in soil was dominated by long-chain PFCAs, PFOA, and PFDA, as a result of the lower mobility with ∑23PFAS ranging between 0.18 and 26 µg/L (eluate) and between 66 and 420 µg/kg (solid). However, the PFAS composition in groundwater was comparable to the spectrum observed in leaves. Spatial interpolations of PFAS in groundwater and foliage correspond well and demonstrate the successful application of phytoscreening to detect and delineate the impact of the studied PFAS in groundwater.

Wang, H., D. Hu, W. Wen, X. Lin, and X. Xia.
Environmental Science & Technology 57(9):3612-3622(2023)

The pelagic organisms Daphnia magna and zebrafish and the Chironomus plumosus benthic organism were exposed to 13 known amounts of PFAS in a sediment-water system at different temperatures (16, 20, and 24°C). Results showed that the steady-state body burden (C_b-ss) of PFAS in pelagic organisms increased with increasing temperatures, mainly attributed to increased water concentrations. The uptake rate constant (k_u) and elimination rate constant (k_e) in pelagic organisms increased with increasing temperature. In contrast, warming did not significantly change or mitigate C_b-ssChironomus plumosus, except for PFPeA and PFHpA, which was consistent with declined sediment concentrations. The decreased bioaccumulation factor could explain the mitigation due to a more significant percent increase in k_e than k_u, especially for long-chain PFAS. The study suggests that the warming effect on the PFAS concentration varies among different media, which should be considered for their ecological risk assessment under climate change.

Marvin, B. and N. Molitor. Pacific Northwest National Laboratory RemPlex-IAEA Seminar, 90 minutes August 2023

At any given site, selecting the most appropriate remedial alternative is driven by various environmental, technical, economic, social, regulatory, and policy-driven factors. In this seminar, aspects of remediation technologies, such as efficiency, effectiveness, sustainability, maturity and availability, complexity, plus long-term maintenance and monitoring requirements that should be considered in selecting a given soil remediation approach, are discussed. The seminar also covers technologies available to treat a broad array of contaminant categories such as radionuclides, metals, and organics. https://www.youtube.com/watch?v=eN7AdXR1T5Q

Grundy, J.S., M.K. Lambert, and R.M. Burgess.
Environmental Science & Technology 57(28):10151-10172(2023)

This review of passive sampling devices (PSDs) aims to: (1) identify sites where PSDs have been used to support cleanup efforts; (2) assess how PSD-derived remedial end points compare to conventional metrics; and (3) perform broad semiquantitative and selective quantitative concurrence analyses to evaluate the magnitude of agreement between metrics. Contaminated sediment remedies evaluated included capping, in situ amendment, dredging, and monitored natural recovery. One hundred and two sites globally, where PSDs were used to determine remedial efficacy are identified and discussed, resulting in the review of over 130 peer-reviewed scientific publications and numerous technical reports and conference proceedings. The most common conventional metrics assessed alongside PSDs in the peer-reviewed literature were bioaccumulation (39%), bulk sediments (40%), toxicity (14%), porewater grab samples (16%), and water column grab samples (16%), while ~25% of studies used PSDs as the sole metric. In a semiquantitative concurrence analysis, the PSD-based metrics agreed with conventional metrics in ~68% of remedy assessments. A more quantitative analysis of reductions in bioaccumulation after remediation (i.e., remediation was successful) showed that decreases in uptake into PSDs agreed with decreases in bioaccumulation (within a factor of 2) 61% of the time. Given the relatively good agreement between conventional and PSD-based metrics, several practices and areas for further study are proposed to enhance the utilization of PSDs throughout the remediation of contaminated sediment sites.

National Groundwater Association white paper, 13 pp, 2023

This NGWA white paper provides a practical guide to PFAS sample collection for those familiar with industry-standard environmental field sampling practices.

Padhye, L.P., P. Srivastava, T. Jasemizad, S. Bolan, D. Hou, S.M. Shaheen, J. Rinklebe, D. O'Connor, D. Lamb, H. Wang, K.H.M. Siddique, and N. Bolan.
Journal of Hazardous Materials 455:131575(2023)

This review of contaminant containment measures: 1) critically evaluates the sources of persistent contaminants, the different approaches to contaminant remediation, and the various physical-chemical-biological processes of contaminant containment and 2) provides case studies of contaminant containment operations under real or simulated field conditions.

Tillotson, J.M., M. McCaughey, S. Justicia-Leon, and C. Divine. ǀ 2023 Bioremediation Symposium Proceedings, 8-11 May, Austin, TX, 12 slides, 2023

The concept of aquifer tuning, or alignment of remedial optimization with site-specific conditions within the natural environment to the integration of in situ enhanced reduction (biotic-abiotic) remedies for chlorinated solvents, are applied and extended in this presentation to consider the remedy lifecycle in the design and operation. Long-term contaminant behavior at former enhanced reductive dechlorination (ERD) sites (with at least 7 years of post-injection data) and an empirical model of electron equivalents for aquifer tuning following organic carbon injection are reviewed. Conceptual design and monitoring frameworks to design and operate the active remedy phase in ways that specifically anticipate the persistence of resulting enhanced attenuation rates in the following transition and passive phases are considered. Long-term contaminant behavior at ERD sites indicates a general lack of back-diffusion-driven contaminant rebound. The empirical model indicates that most electron equivalents associated with carbon injections are stored in the aquifer in reduced forms of iron and sulfate, resulting in the formation of reactive iron minerals that can prolong contaminant treatment and mitigate rebound. Remedial design considerations can include adding ferrous iron and/or sulfate during injection, performance monitoring to better assess the contributions of abiotic processes, and adjusting the timing and frequency of injection events.
Slides:https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-presentations/track-a/a2_1005_227_tillotson.pptx.pdf?sfvrsn=302c0504_3
Longer abstract: https://www.battelle.org/docs/default-source/hidden/2023-bio-symp-abstracts/227.pdf?sfvrsn=edb7b28f_3
Also see article in Groundwater Monitoring & Remediation https://ngwa.onlinelibrary.wiley.com/doi/abs/10.1111/gwmr.12557