Remedial Objectives Research Articles

Design of Pump-and-Treat Strategies for Contaminated Groundwater Remediation Using Numerical Modeling: A Case Study

Pump-and-treat (P&T) techniques are among the most commonly applied methods for groundwater contamination remediation. This study develops a groundwater flow model and a solute transport model using MODFLOW and RT3D to design and optimize P&T strategies for a polluted chemical park in northern China. Five scenarios were analyzed to evaluate the effects of well placement and pumping rates on remediation performance. Simulation results indicate that the existing number of extraction wells is inadequate to meet remediation targets. While increasing the pumping rate of individual wells accelerates remediation, it also increases the total extracted water volume. Similarly, higher extraction rates in heavily contaminated areas shorten remediation times but lead to greater water extraction. The findings demonstrate that numerical modeling can effectively optimize P&T designs, enabling the minimization of water extraction volumes while achieving remediation objectives within the required timeframe.

Modeling the Influence of Coastal Site Characteristics on PFAS in Situ Remediation.

The potential performance of a hypothetical colloidal-activated carbon (CAC) in situ remedy for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in groundwater in coastal zones was evaluated using estimated hydrogeologic and geochemical parameters for a coastal site in the United States. With these parameters, a reactive transport model (ISR-MT3DMS) was used to assess the effects of tidal fluctuations and near-shore geochemistry on CAC performance. The average near-shore ionic strength of 84 mM at the site was conservatively estimated to result in an increase in the adsorption of PFOA to CAC by about 50% relative to non-coastal sites with ionic strength <10 mM. The modeling also confirmed the hypothesis that tidally induced groundwater flow reversals near the shore would result in the accumulation of PFOA at the downgradient edge of the CAC zone. Slow desorption of PFOA from this downgradient CAC boundary may sustain downgradient plume concentrations above a strict cleanup criterion (e.g., USEPA MCL of 0.004 μg/L), for decades; however, there was still a large PFOA mass flux reduction (>99.9%) achieved after several decades at the shore. CAC longevity was substantially greater for PFOS with a similar source concentration; however, the higher PFOS distribution coefficient (Kd) in soil downgradient from the CAC zone resulted in substantially longer flushing times. It is recommended that short-term remedial action objectives for CAC remedies at coastal sites be based on mass flux reduction targets over a period of several decades, given the demonstrated challenges in trying to achieve very low cleanup criteria downgradient of a CAC zone in the short term.

Puget Sound sediment cleanup remedy effectiveness retrospective.

The monitoring of completed large-scale sediment remediation projects has revealed mixed effectiveness at reducing risks, thus highlighting uncertainties regarding whether and which remedial measures are necessary to achieve protective goals. To support valid statements about changes over time and the overall effectiveness of sediment remedial action, robust pre- and postremediation monitoring is required with sufficient time points, reference sites, and biological metrics. The five completed Puget Sound sediment remediation case studies reviewed here (Bellingham Bay, St. Paul Waterway, Eagle Harbor, Hylebos Waterway, and Sinclair Inlet) employed particularly robust remedy effectiveness monitoring programs that spanned decades, revealing common lessons for improving remediation outcomes. First, although sediment remediation can play an important role in reducing contaminant exposure in areas with higher sediment concentrations, at lower levels, sediment links with fish tissue concentrations diminish. As water column exposure from diverse sources becomes predominant, remediating sediments with lower concentrations yields proportionately less risk reduction. Second, timely monitoring of effective source controls achieving substantial (i.e., >80%) contaminant source load reductions as well as large-scale capping projects have revealed rapid changes in Puget Sound surface sediment concentrations and biological recovery metrics with an average recovery half-time of 1.6 ± 0.8 years. The weight of evidence suggests that natural recovery of Puget Sound surface sediments is significantly accelerated by exchange across the sediment-water interface from benthic organism feeding behaviors, porewater flux, and tide-generated currents. As a result, effective source controls in Puget Sound have rapidly improved surface sediment quality and achieved more significant risk reductions than broadscale sediment remediation. Going forward, comprehensive Puget Sound source control efforts that incorporate robust monitoring in an adaptive management framework are the best way to achieve protective remediation objectives. These lessons may apply more broadly across similar complex urban aquatic ecosystems. Integr Environ Assess Manag 2024;20:1355-1365. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Quantitative assessment of the impact factors upon remediation performance of the PRB technique in conjunction with pumping/recharge

Quantitative assessment of the impact factors upon remediation performance of the PRB technique in conjunction with pumping/recharge

A Framework to Assess Natural Chloride Background in Coastal Aquifers Affected by Seawater Intrusion in Eastern Spain

The protection of groundwater resources in coastal aquifers is an increasingly important issue worldwide. To establish threshold values and remediation objectives, it is essential to know the natural background concentrations of relevant ions in groundwater. The rationale is to define the Natural Background Level (NBL) of chemical species determined by atmospheric and lithological forces. In many coastal aquifers, this evaluation worsens since atmospheric and lithological salinity combines with many other anthropogenic sources of salinity, including exogenous salinity induced by seawater intrusion (SWI). This paper presents a combination of six well-known statistical techniques and a new methodology (i.e., SITE index) in eight GWBs affected by SWI in Eastern Spain. The chloride ion was the selected conservative chemical specie to assess the qualitative status due to the variable SWI affection. The Natural Chloride Background (NCB) obtained from these methodologies at the GWB scale was compared with regional NCB data calculated with the Atmospheric Chloride Mass Balance (CMB) method in Continental Spain. The CMB method provides atmospherically derived NCB data that are not influenced by SWI or anthropogenic activities or lithological forces. This external evaluation can be considered the atmospheric fraction of NCB, which serves as a regional criterion to validate the more detailed statistical methodologies applied at the GWB scale. As a result, a conceptualization of NCB is obtained by means of a range of values between 115 mg L−1 and 261 mg L−1 in the studied coastal GWBs affected by SWI in Eastern Spain.

Application of a Novel Amendment for the Remediation of Mercury Mine Sites with Hydrologic Controls

MercLokTM P-640 (MercLok) is a proprietary product developed by Albemarle as a mercury (Hg) treatment technology. MercLok captures mercury and sequesters it for a long period under ambient environmental conditions. For this project, MercLok was applied to Hg-contaminated calcines at two abandoned Hg mine sites in northern California to evaluate its efficacy in rendering such contaminated materials less hazardous and thereby reducing remediation project costs. The first application (Site 1) consisted of two calcines amended with MercLok in isolated reactor buckets under two hydrologic remediation approaches (“repository cap” and “reactive barrier”) while exposed to ambient environmental conditions. Non-amended and amended calcines and their leachates were analyzed for Hg content and related conditions during a five-month study period, demonstrating &gt;95% reduction in leachable Hg. The second application (Site 2) involved full-scale site remediation with the application of both approaches and additional hydrologic controls to minimize run-on, erosion, and runoff. Confirmation sampling and subsequent observations indicate that the amendments and hydrologic controls effectively stabilized the site and minimized Hg releases. These application projects demonstrate the efficacy of MercLok as a component of hydrologic controls for treating Hg-contaminated material to achieve long-term mine site remediation objectives.

The effect of an e-learning-based remedial program on students' learning outcomes: The case of Fraction

Students experienced difficulty in studying the topic of fraction during the covid-19 pandemic resulted in incomplete learning so remedial learning was necessary. So far, remedial learning has not been optimally implemented. Therefore, to achieve optimal remedial learning objectives, e-learning based remedial learning is needed. The aims of this study were 1) to find out the effect of e-learning-based remedial learning on the topic of fraction on learning outcomes in junior high schools in Banda Aceh, 2) to examine the improvement in student learning outcomes through e-learning based remedial learning on the topic of fraction on learning outcomes in junior high schools in Banda Aceh. This experimental study used quantitative approach. This study was designed following the pre-experimental design using one-group pretest-posttest. One-group pretest-posttest is a design that includes a pretest followed by treatment and a posttest for one group. The population of this study was all eighth grade students in Banda Aceh. The sample was randomly selected. They were the eighth grade students at four junior high schools whose pretest scores had not yet reached the KKM score of 60. The instruments used were diagnostic test questions and remedial questions on the topic of fraction. Diagnostic and remedial test results data were analyzed with SPSS. The results shows that there is a significant effect of e-learning based remedial learning on the topic of fraction on learning outcomes in junior high schools in Banda Aceh, 2) e-learning based remedial learning on the topic of fraction improves the students’ learning outcomes. The implication of this research is that teachers can implement the remedial learning based on e-learning on other learning topics, so that they has alternative solutions to the problem of implementing remedial learning outside of mathematics learning.

Model development and probabilistic risks of cadmium transport in slag-soil-groundwater systems with heterogeneous conditions

Prediction of the long-term risk of trace metals leaching from soils at smelting sites is essential for groundwater protection. Herein, a mass balance-based stochastic model was developed to simulate the transport and probabilistic risks of trace metals in heterogeneous slag-soil-groundwater systems. The model was applied to a smelting slag yard with three stacking scenarios, including (A) fixed stacking amount, (B) stacking amount increasing yearly, and (C) slag removal after 20years. The simulations suggested that the leaching flux and net accumulation of Cd in soils of the slag yard and abandoned farmland were greatest for scenario (B), which was followed by scenarios (A) and (C). In the slag yard, a plateau occurred in the Cd leaching flux curves, followed by a sharp increase. After 100years of leaching, only scenario (B) had a high probabilistic risk (>99.9%) of threatening groundwater safety under heterogeneous conditions. <11.1% of the exogenous Cd may leach into groundwater under the worst scenario. The key parameters affecting Cd leaching risk include runoff interception rate (IRCR), input flux from slag release (I), and stacking time (ST). The simulation results were consistent with the values measured in a field investigation and laboratory leaching experiments. The results should help guide remediation objectives and measures to minimize the leaching risk at smelting sites.

Bismuth oxychloride microcrystals decorated carbon foams based on waste polyurethane elastomer for enhanced removal of methylene blue

Multicomponent materials containing nanoscale structures, the so-called “nanocomposites” are one of the fastest-growing areas of photocatalytic research. In this study, the nanocomposites of bismuth oxychloride (BiOCl) with porous carbon foam (CF) derived from waste polyurethane (PU) elastomers were developed by a simple hydrothermal method, and the photocatalytic performance of the as-prepared materials was investigated. The structure, morphology and optical properties of the composites were characterized in detail. The photocatalytic activity of the samples was evaluated by studying the degradation of methylene blue (MB) under UV-A irradiation. Even at a high MB concentration (0.5 mmol/L), excellent photocatalytic activity was observed, with an overall removal efficiency of 99.0% in 100 min of irradiation. Kinetic studies were also carried out for the degradation of MB by pristine BiOCl and CF-BiOCl. The photodegradation rate constants were evaluated by fitting the kinetic data with a pseudo-first-order model, and the rate constants of CF-BiOCl composites were higher than that of pristine BiOCl. The enhanced activity of the composites was due to the well-connected heterojunction interface, improved hydrophilicity, more reactive sites, and effective separation of photo-generated charges. Thus, our work combines the valuable waste PU-derived CFs with BiOCl, which provides a strategy to achieve circular economy and environmental remediation objectives.

Use of Censored Multiple Regression to Interpret Temporal Environmental Data and Assess Remedy Progress.

Many methods to evaluate temporal trends in monitoring data focus on univariate techniques that account for changes in the response variable (e.g., concentration) by means of a single variable, namely time. When predictable site-specific factors, such as groundwater-surface water interactions, are associated with or may cause concentration changes, univariate methods may be insufficient for characterizing, estimating, and forecasting temporal trends. Multiple regression methods can incorporate additional explanatory variables, thereby minimizing the amount of unexplained variability that is relegated to the "error" term. However, the presence of sample results that are below laboratory reporting limits (i.e., censored) prohibits the direct application of the standard least-squares method for multiple regression. Maximum Likelihood Estimation (MLE) for multiple regression analysis can enhance temporal trend analysis in the presence of censored response data and improve characterizing, estimating and forecasting of temporal trends. Multiple regression using MLE (or censored multiple regression) was demonstrated at the U.S. Department of Energy Hanford Site where analyte concentrations in groundwater samples are negatively correlated with the stage of the nearby Columbia River. Incorporating a time-lagged stage variable in the regression analysis of these data provides more reliable estimates of future concentrations, reducing the uncertainty in evaluating the progress of remediation toward remedial action objectives. Censored multiple regression can identify significant changes over time; project when maxima and minima of interest are likely to occur; estimate average values and their confidence limits over time periods relevant to regulatory compliance; and thereby improve the management of remedial action monitoring programs. This article is protected by copyright. All rights reserved.

Quantitative analysis of the contribution of sources, diffusion pathways, and receptor attributes for the spatial distribution of soil heavy metals and their nested structure analysis in China

Investigation of heavy metal pollution degree, pollution sources, and spatial distribution structure is crucial for the country's soil pollution prevention, but relevant research is lacking. In this study, As, Cd, Cr, Cu, Pb and Zn in the national scope are taken as research objects. Among them, Cd has the highest pollution level. Four sources were quantitatively allocated as soil type, mining and dressing industry, GDP, and NDVI, which accounted for 92.93, 97.81, 99.30 and 96.24 % of Cr, Cd, Zn and As contamination, respectively. In addition, according to the geographical detector, the spatial distribution of As was affected by three diffusion pathways, whose influence degree were 0.822-0.947, especially the slope. Cadmium was primarily affected by both receptor attributes and diffusion pathways, with an influence degree of 0.010-0.175, especially soil water content and slope; Cr and Pb were affected by receptor attributes, with an influence degree of 0.886-0.986 and 0.007-0.288, respectively, especially for soil water content and soil organic carbon; Cu and Zn were affected by receptor attributes, with an influence degree of 0.182-0.823 and 0.002-0.150, respectively, especially for soil texture. There are two spatial distribution structures with nested scales in east-west and north-south directions. The large spatial structure has a more significant impact on the spatial distribution of heavy metals, especially in the east-west direction. Overall, the mining and dressing industry is the main source in Hunan, Yunnan, and Liaoning, where many mines exist and mining activities are frequent. GDP was the main source in Shanghai and Zhejiang areas, where the economy is developed. NDVI was the main source in Guangdong and Anhui areas, where agriculture is relatively developed. These results provide a basis for determining remediation and prevention objectives in soil pollution remediation and prevention in the national scope.

Increasing in situ bioremediation effectiveness through field-scale application of molecular biological tools.

Leveraging the capabilities of microorganisms to reduce (degrade or transform) concentrations of pollutants in soil and groundwater can be a cost-effective, natural remedial approach to manage contaminated sites. Traditional design and implementation of bioremediation strategies consist of lab-scale biodegradation studies or collection of field-scale geochemical data to infer associated biological processes. While both lab-scale biodegradation studies and field-scale geochemical data are useful for remedial decision-making, additional insights can be gained through the application of Molecular Biological Tools (MBTs) to directly measure contaminant-degrading microorganisms and associated bioremediation processes. Field-scale application of a standardized framework pairing MBTs with traditional contaminant and geochemical analyses was successfully performed at two contaminated sites. At a site with trichloroethene (TCE) impacted groundwater, framework application informed design of an enhanced bioremediation approach. Baseline abundances of 16S rRNA genes for a genus of obligate organohalide-respiring bacteria (i.e., Dehalococcoides) were measured at low abundances (101-102 cells/mL) within the TCE source and plume areas. In combination with geochemical analyses, these data suggested that intrinsic biodegradation (i.e., reductive dechlorination) may be occurring, but activities were limited by electron donor availability. The framework was utilized to support development of a full-scale enhanced bioremediation design (i.e., electron donor addition) and to monitor remedial performance. Additionally, the framework was applied at a second site with residual petroleum hydrocarbon (PHC) impacted soils and groundwater. MBTs, specifically qPCR and 16S gene amplicon rRNA sequencing, were used to characterize intrinsic bioremediation mechanisms. Functional genes associated with anaerobic biodegradation of diesel components (e.g., naphthyl-2-methyl-succinate synthase, naphthalene carboxylase, alkylsuccinate synthase, and benzoyl coenzyme A reductase) were measured to be 2-3 orders of magnitude greater than unimpacted, background samples. Intrinsic bioremediation mechanisms were determined to be sufficient to achieve groundwater remediation objectives. Nonetheless, the framework was further utilized to assess that an enhanced bioremediation could be a successful remedial alternative or complement to source area treatment. While bioremediation of chlorinated solvents, PHCs, and other contaminants has been demonstrated to successfully reduce environmental risk and reach site goals, the application of field-scale MBT data in combination with contaminant and geochemical data analyses to design, implement, and monitor a site-specific bioremediation approach can result in more consistent remedy effectiveness.

Influencing factors identification and the nested structure analysis of heavy metals in soils in entire city and surrounding the multiple pollution sources

Identifying the sources of pollutants and analyzing the nested structure of heavy metals is vital for the prevention and control of soil pollution. However, there is a lack of research on comparison the main sources and the nested structure at different scales. In this study, two spatial extent scales were taken as the research objects, the results showed that, (1) the point exceeding standard rate of As, Cr, Ni, and Pb is higher at the entire city scale; (2) As and Pb, while Cr, Ni, and Zn, have weaker spatial variability at the entire scale and surrounding the pollution sources, respectively; (3) the contribution of the larger structure of Cr and Ni, while Cr, Ni, and Zn, at the entire scale and surrounding the pollution sources, respectively, is bigger to the total variability. The representation of semivariogram is better when the general spatial variability is weaker and the contribution of the smaller structure is lower; (4) various factors with different influencing distance could lead to nested structure even at a small extent spatial scale. The results provide a basis for the determination of remediation and prevention objectives at different spatial scales.

Risk-based and sustainable approaches to remediation: Analysis and perspectives of the Italian and international context.

The management of contaminated areas is addressed at the international level with different regulatory instruments and approaches that can influence the selection of technologies, costs, and time for site recovery. The aim of this study was benchmarking the regulatory and technical approach to contaminated areas in both the Italian and international contexts, represented by eight European countries such as, among others, the United Kingdom, France, Germany, and the USA. An extensive international literature research was considered, including publications and reports by sector operators, legislators, and research groups, that enabled the identification of efficient and sustainable international practices and procedures for the contaminated site reclamation. Particular attention was paid to the status and costs of soil and groundwater remediation in Europe and in the United States. The outcomes of the study have shown that, from regulatory and administrative points of view, the remediation sector in Italy is among the most conservative, that is, more binding in the identification of contaminated sites and in the definition of remediation objectives. To reverse this trend and align it to the other countries that were the focus of this study, the concepts of mobility and/or bioavailability of contaminants, sustainability, and circular economy could be taken into account in the Italian administrative procedures. These concepts are currently only referred to in the Italian legislation but have not been yet made effectively applicable by codified procedures. In the Italian context, the conservative approach to site remediation may negatively affect the process of contaminated site reclamation and ecological transition. Further debate on the development of environmental regulations to align policies among the remediation stakeholders, particularly at the Italian and international regulatory level, is therefore needed. Integr Environ Assess Manag 2023;19:920-932. © 2022 SETAC.

Comparative Evaluation of Technologies at a Heavy Metal Contaminated Site: The Role of Feasibility Studies

Many agricultural areas are contaminated by heavy metals to such a level that the growth of plants is drastically reduced. Based on the site’s specific characteristics, feasibility studies were carried out to choose the most effective technologies. Feasibility tests showed that soil washing and phytoremediation technologies could be used at the agricultural site under study. The efficiency of the technologies is highly dependent on soil characteristics, which determine the chemical form of the metals. The results indicate that water-based soil washing can be successfully used with the possibility of reaching the remediation objectives quickly. However, the technology in the first step essentially breaks down the soil. Moreover, phytoremediation cannot be used directly to overcome the toxicity derived from the very high bioavailability of the heavy metals. Still, there is the need to use “assisted” phytoremediation by adding compost that reduces metal bioavailability, allowing phytoextraction. In this case, a longer time is needed to reach the remediation target. The results provide a preliminary scenario for decision-makers and stakeholders to assess possible technologies applicable and a possible scheme to be applied in similar cases of polluted agricultural areas.

Optimizing pump-and-treat method by considering important remediation objectives

The efficiency of groundwater remediation by pump-and-treat (PAT) method is affected by several components. The most important of these components include the pumping wells location, pumping rate, and remediation period. In this research, hybrid optimization-simulation models were developed to find the appropriate groundwater remediation strategy by PAT method. The GA-FEM and NSGA-II-FEM models were used to solve four optimization problems for a hypothetical and real aquifer. These optimization problems were investigated from one objective problem to a four-objectives problem. In the multi-objective problems, in each step, one objective function is added to the previous set of objective functions. In the one-objective case, the objective function was defined as minimizing the contaminant concentration by pumping at a constant rate, while in the two-objectives problem, minimizing the drawdown of groundwater head by pumping at a constant rate was added. In the three-objectives problem, the pumping rate was variable and the mean pumping rate from all the wells is minimized. Finally, minimizing the remediation period is added in the four-objective case. The results indicated that locating the pumping wells in the path of the contaminant flow and close to the source improves the efficiency of the PAT system. The wells with higher pumping rates would be in the path of contamination flow and the wells with lower pumping rates should be located in nodes near the Dirichlet boundary. It is concluded that the remediation period in the hypothetical and real aquifer cannot be less than almost 3000 and 760 days, respectively. Finally, it can be said, the most important component in choosing the proper PAT strategy is the proper location of pumping wells.

Lemnaceae clones collected from a small geographic region display diverse traits relevant for the remediation of wastewater

The Lemnaceae (duckweed) are a family of aquatic plants which can be used as part of a circular economy approach to remediate and valorise wastewater. The suitability of duckweeds relates to their tolerance of wastewater conditions, fast growth rates and valuable biomass. Duckweed species and clones display a wide range of remediation abilities and nutritional composition. In order to find duckweed species and clones best suited for remediation and valorisation of dairy processing wastewater, plant samples were collected from a number of locations around southern Ireland. These species and clones were cultured on a synthetic dairy processing wastewater while growth, TN/TP removal and protein content were assessed. Synthetic dairy wastewater was found to be suitable for remediation by different species and clones. However, significant differences were found in relative growth rate (RGR), TN removal rate and protein content. As per PCA, it was found that species and clones with higher RGR tended to have a lower protein content. Furthermore, nutrient removal rate was not strongly associated with growth and protein content. The results demonstrate that remediation is not positively correlated with valorisation across duckweed species and clones. Thus, clonal selection for duckweed reactors will need to consider the prime objective of remediation i.e. biomass production or wastewater remediation. • Synthetic dairy processing wastewater is suitable medium for duckweed growth. • Significant diversity in remediation relevant traits between Lemnaceae clones. • Nitrogen uptake is only loosely associated with biomass yield. • High protein content is associated with lower growth. • No single duckweed clone is optimal for both remediation and valorisation.

EPA's detection methods, the drinking water treatability database, and innovative technologies for PFAS remediation

AbstractPer‐ and polyfluoroalkyl substances (PFAS) are a large group of highly fluorinated, aliphatic chemicals detected throughout the environment, including in human serum. Several regulatory milestones have been achieved in the United States for these environmentally toxic chemicals linked to health problems in humans, the latest one being the US Environmental Protection Agency's (EPA's) PFAS Strategic Roadmap necessitating detection and remediation of PFAS. This article, in addition to briefly discussing these regulatory milestones, evaluates the EPA's detection methods for PFAS including EPA Methods 533, 537.1, and 8327 and other methods currently under development such as the total organic fluorine (TOF) and total organic precursor (TOP) methods. The article also mentions the methods used by other federal agencies for PFAS quantitation. The EPA's drinking water treatability database (TDB) is also described along with the advantages and challenges of the effective treatment methods for PFAS. Most of these treatment methods in the EPA's drinking water TDB face the challenge of disposing wastes containing PFAS, an issue not faced by innovative technologies, and some of these innovative technologies are also discussed. This article will help to understand the current status on the detection and remediation technologies for PFAS treatment in soil and water. It is imperative to have these technologies ready to assist with the remediation objectives in the PFAS Strategic Roadmap.

Concurrent 19. Presentation for: Developing an in-depth understanding of PFAS to deliver an effective remediation strategy

Presented on Wednesday 18 May: Session 19 Esso Australia Resources Pty Ltd and BHP Petroleum (Bass Strait) Pty Ltd own a range of offshore and onshore hydrocarbon production facilities, which have been operated by Esso Australia Pty Ltd (Esso) for over 50 years. The Longford Fire Training Ground (FTG) is located adjacent to the Longford Plants and has been utilised by Esso for many years to train personnel in practical hydrocarbon firefighting skills, including applying firefighting foams to extinguish liquid hydrocarbon pool fires. In line with historical standard oil-field practices, per and polyfluoroalkyl substance (PFAS) containing firefighting foams were used at the Longford FTG. In response to the reported use of these foams and the potential for contamination associated with historical site operations, the Longford premises were the subject of recent environmental audit and clean-up plans with oversight by an EPA Victoria auditor. Esso engaged a broad range of experts to complete the environmental investigation and develop a remediation action plan that complied with the PFAS National Environmental Management Plan. Key aspects of this project included: understanding the location and setting, with respect to geological conditions and groundwater impacts; development of remediation objectives and strategy; identification of practical remediation methods including short-term and longer-term measures to mitigate priority PFAS sources within the FTG; and a planning framework for future management of the premises. This paper shares how a responsible operator applies a disciplined and scientifically based environmental approach to further the state of knowledge on practical PFAS remediation methods and achieve a sustainable environmental outcome in the communities that they operate in. To access the presentation click the link on the right. To read the full paper click here

Developing an in-depth understanding of PFAS to deliver an effective remediation strategy

Esso Australia Resources Pty Ltd and BHP Petroleum (Bass Strait) Pty Ltd own a range of offshore and onshore hydrocarbon production facilities, which have been operated by Esso Australia Pty Ltd (Esso) for over 50 years. The Longford Fire Training Ground (FTG) is located adjacent to the Longford Plants and has been utilised by Esso for many years to train personnel in practical hydrocarbon firefighting skills, including applying firefighting foams to extinguish liquid hydrocarbon pool fires. In line with historical standard oil-field practices, per and polyfluoroalkyl substance (PFAS) containing firefighting foams were used at the Longford FTG. In response to the reported use of these foams and the potential for contamination associated with historical site operations, the Longford premises were the subject of recent environmental audit and clean-up plans with oversight by an EPA Victoria auditor. Esso engaged a broad range of experts to complete the environmental investigation and develop a remediation action plan that complied with the PFAS National Environmental Management Plan. Key aspects of this project included: understanding the location and setting, with respect to geological conditions and groundwater impacts; development of remediation objectives and strategy; identification of practical remediation methods including short-term and longer-term measures to mitigate priority PFAS sources within the FTG; and a planning framework for future management of the premises. This paper shares how a responsible operator applies a disciplined and scientifically based environmental approach to further the state of knowledge on practical PFAS remediation methods and achieve a sustainable environmental outcome in the communities that they operate in.