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    <title>Research in Progress (RIP)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Research in Progress (RIP)</title>
      <url>https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg</url>
      <link>https://rip.trb.org/</link>
    </image>
    <item>
      <title>Thermal Treatment Method to Remediate Hydrocarbon-Contaminated Soils</title>
      <link>https://rip.trb.org/View/2442007</link>
      <description><![CDATA[Bioremediation, a promising technology, utilizes microbes to break down, transform, and ultimately eliminate specific pollutants such as petroleum hydrocarbons from contaminated soil. This process can be carried out in-situ, directly within the affected environment. However, in-situ bioremediation faces challenges due to varying soil types, moisture levels, heterogeneities, and resident microorganisms. Despite these complexities, it offers significant economic and environmental benefits. Research in the literature has shown that increasing temperature accelerates microbial activity. In-situ thermal treatment for contaminated soil is gaining popularity as hazards posed by light nonaqueous phase liquids continue to grow. While numerous remediation methods are available, there is a particular emphasis on technologies capable of swiftly addressing soil contamination by diverse petroleum hydrocarbons. Thermal treatment offers rapid and efficient remediation, often achieving removal rates exceeding 99% across a broad spectrum of hydrocarbon fractions. 
The overall objectives of the current project are to: (1) provide a comprehensive review of the microbial organisms present in soil and their ideal temperature requirements for activity, (2) explore thermally-enhanced bioremediation techniques utilizing a solar-underground borehole system as a renewable energy source to augment the remediation of contaminated sites, (3) develop a finite element model for analyzing the thermal treatment method, and (4) investigate the efficacy of the thermal treatment method in remediating hydrocarbon-contaminated soils.

US DOT Priorities: This project directly supports the US DOT strategic goal related to climate and sustainability:
“Tackle the climate crisis by ensuring that transportation plays a central role in the solution. Substantially reduce greenhouse gas emissions and transportation-related pollution and build more resilient and sustainable transportation systems to benefit and protect communities.”
More than fifty percent of the US population depends on groundwater as its primary source of drinking water. Consequently, the introduction of contaminants from transportation sectors, such as leaks from aboveground storage tanks, spills from gas stations, and the use of road salts and chemical deicers, poses a significant public health risk to groundwater. Contaminants originating from diverse sources have the potential to impact drinking water wells and other receptors. Once these contaminants infiltrate the groundwater, they can migrate toward water wells and drinking water supplies. The proposed project aims to evaluate the effectiveness of thermal treatment methods for remediating contaminated soil and groundwater and to investigate the feasibility of implementing solar-underground thermal systems to enhance bioremediation techniques.

Outputs: This study will provide a robust fully coupled finite element model that can be used to model if solar-underground systems can be used for enhancing bioremediation. 
The developed model can be used to understand the efficacy of thermal treatment under various conditions, including different subsurface geologies (homogeneous and layered), and temperature conditions (maximum subsurface temperature).  Additionally, the role of buoyant flow (natural convection and forced convection) on thermal treatment will be predicted.
The model developed in this study can be used to identify which parameters will have the most significant impact on bioremediation and thermal treatment. Additionally, by understanding the subsurface conditions that lead to buoyant flow and the influence of buoyant flow on contaminant transport, this research can inform the design and implementation of thermal treatment. The research findings will help us to better select the thermal treatment method and ideal temperature needed for bioremediation. 
The model that will be developed in this project can be used to analyze the efficiency of thermally enhanced bioremediation and thermal treatment on contaminant removal. If promising the method can be used by local DOTs and federal agencies to treat the areas that are subjected to contamination from transportation sectors.

Outcomes/Impacts: a. The application of the research output will lead to significant changes in soil and groundwater contaminant removal. The developed model will be useful for local Departments of Transportation and federal-level agencies to predict the efficacy of thermal treatment methods depending on the types of soil and contaminant. This will inform regulatory bodies and policymakers in developing effective strategies to remediate pollution and protect soil and the environment. This project helps prevent issues raised by soil and groundwater contamination. The proposed research can model subsurface contamination removal and perform necessary remediation actions to prevent pollution risks in groundwater and drinking water.
b. The outputs and technology developed in this research can be transferred to practice through collaboration with local Department of Transportations and federal agencies. By sharing the predictive model and findings, transportation authorities can incorporate them into their decision-making processes and remediation efforts. This will lead to changes in practice by improving the monitoring and management of soil and groundwater pollution, thereby informing policy decisions related to environmental protection and public health.
c. The research outputs will positively impact the transportation system in several ways. By accurately predicting contamination levels and identifying subsurface contaminated zones, the transportation sector can implement targeted remediation efforts, enhancing safety and reliability. Additionally, by preventing pollution from reaching drinking water supplies, the research contributes to the durability and sustainability of the transportation infrastructure. 
The proposed project provides an excellent opportunity to train undergraduate and graduate students in performing geoenvironmental modeling. One undergraduate and one graduate student will be hired to conduct hydro-thermal-chemical modeling and explore the flow of subsurface contaminants in the ground. The outcomes of the project will be presented at national and international conferences, including the American Society of Civil Engineering – Geo-congress (GI), American Geophysical Union (AGU), and Transportation Research Board (TRB) meetings. The results will be disseminated through journal and conference proceedings. By training undergraduate and graduate students in geoenvironmental modeling, the project ensures a sustainable workforce capable of addressing future challenges in soil and groundwater remediation. The dissemination of research outcomes through conferences and publications ensures that the knowledge generated from the project reaches a wide audience and informs future research and practice in the transportation sector.
]]></description>
      <pubDate>Thu, 17 Oct 2024 11:14:26 GMT</pubDate>
      <guid>https://rip.trb.org/View/2442007</guid>
    </item>
    <item>
      <title>Quantitative Study of Environmental Condition and PFAS Impacts on Microplastic (MP) Fate and Transport due to Effects on MP Flocculation</title>
      <link>https://rip.trb.org/View/2442011</link>
      <description><![CDATA[Microplastics (MPs) are a class of emerging contaminants of concern that result from the degradation products of plastic-based fibers, particles, and films. Transportation related pollution contributes notably to MP pollution in the environment, particularly in urban areas where pollutants such as anthropogenic debris and tire wear particles are exported to rivers and streams through urban stormwater and roadway runoff. Moreover, MPs are increasingly found in drinking water and drinking water sources, which may contribute to disproportionate impacts on communities of concern located near urban areas. Despite the abundance of MPs and their impacts to health and the environment, there are currently notable knowledge gaps related to MP fate and transport processes. Addressing these knowledge gaps is needed to support the design of approaches for mitigating transportation related MP pollution through improved process-based understanding. 
	The focus of this project is specifically on the process of MP flocculation, or aggregation, with other MPs and/or other nearby materials occurring in the surface water environment. Figure 1 conceptually illustrates the transport of MP pollution from transportation related sources and through surface waters. MPs will settle to the sediment bed at different rates depending on their settling velocity, which can be notably impacted by the flocculation of MPs with other material (e.g., sediment, organic material) into larger composite particles known as “flocs”. The flocculation process can increase settling velocities and even cause otherwise buoyant MPs to settle. While the process of MP flocculation has been highlighted in recent studies, quantitative understanding of the impacts of environmental parameters (e.g., suspended sediment, salinity) on MP flocculation are lacking. In addition, the potential impacts of chemicals of concern, such as per- and polyfluoroalkyl substances (PFAS), on the MP flocculation process has not been investigated. Hydrophobicity and surface chemistry affect flocculation processes as MPs interact with nearby material and may be further impacted by PFAS sorption to MP surfaces. This project will experimentally examine the effects of environmental conditions PFAS on MP floc sizes and settling velocities by using an imaging-based MP floc measurement system. These results will provide new quantitative information about MP fate and transport that can be used in future modeling efforts and to inform design of pollution mitigation strategies.

US DOT Priorities: This project is an investment in fundamental research that advances basic understanding of microplastics transport from transportation related pollution sources, through rivers and streams, and to potential accumulation zones. This work addresses critical needs for improved quantitative understanding of MP transport mechanics and supports future modeling efforts for MP fate. Settling velocity is a critical input parameter in these models and uncertainty concerning MP floc formation notably hinders current prediction accuracy. Through the impacts of this research on future modeling of MP pollution in the environment and of the effectiveness of mitigation strategies, this work supports the USDOT Strategic Goals for “Transformation” and “Climate and Sustainability.” Addressing MP pollution in surface water and stormwater is also important for community health since MPs are increasingly found in drinking water and drinking water sources. Since MP pollution tends to be highest near urban areas, addressing these issues is a matter of concern for equity since nearby communities of concern in densely populated urban areas may be disproportionately affected by MPs. The improved understanding of MP pollutant transport provided here will thus support the strategic goal for “Safety” and “Equity” by informing pollution mitigation strategies.

Outputs: This project will result in new quantitative data that provides insight about fate and transport mechanics of MPs that are input to the environment via transportation related pollution. The datasets will quantify reference settling velocities for isolated MPs. The datasets will also quantify the effects of environmental conditions and the presence of PFAS on MP flocculation and settling velocity. Quantification of these effects is limited in the literature. This dataset will enable future modeling of MP transport with evidence-based consideration of processes and environmental factors that may drive MP settling and accumulation in the sediment beds of inland, estuarine, and marine waters. Additionally, a white paper will be produced to present correlations between PFAS adsorption and MP transport based on the study results. 

Outcomes/Impacts: By advancing the quantitative accuracy of MP transport modeling efforts, this work will support informed design of microplastic mitigation strategies that can preserve environmental resources and improve the sustainability of transportation infrastructure designs. Moreover, this work can enable evidence-based cost-benefit assessment of various pollution mitigation designs used to mitigate transportation related microplastic pollution. This type of MP transport modeling can be used to assess the risks associated with a continuation of “business as usual” practice and support future regulatory and policy decisions concerning the mitigation of MP pollution, particularly in urban environments. This project will also inform regulations focused on multiple environmental contaminants, namely MPs and PFAS, which are both emerging contaminants of concern that may affect both environmental and public health. 
]]></description>
      <pubDate>Thu, 17 Oct 2024 11:04:32 GMT</pubDate>
      <guid>https://rip.trb.org/View/2442011</guid>
    </item>
    <item>
      <title>Methods to Measure Emerging Contaminants in Stormwater

</title>
      <link>https://rip.trb.org/View/2381713</link>
      <description><![CDATA[Recent data on emerging contaminants has prompted state departments of transportation (DOTs) and water authorities to explore significant investments in stormwater sampling and treatment infrastructure. This proactive approach aims to more fully understand the occurrence and impact of emerging contaminants and the effectiveness of stormwater treatment systems. By gathering this data, decision-makers can offer more accurate, informed strategies for managing stormwater, leading to more efficient design, construction, and maintenance of treatment systems.

Research is needed to determine the methods and materials needed to measure concentrations of emerging contaminants in runoff, stormwater-treatment system effluent, and receiving waters to support cost-effective quantitative threat assessments and treatment decisions. 

OBJECTIVE: The objective of this project is to develop recommended practices for state DOTs for assessing sampling methods used to measure emerging contaminants as well as new contaminants identified in the future. 

]]></description>
      <pubDate>Tue, 21 May 2024 15:52:38 GMT</pubDate>
      <guid>https://rip.trb.org/View/2381713</guid>
    </item>
    <item>
      <title>Identifying and Quantifying Microplastics Generated from the Roadway Environment: Method Development and Preliminary Field Monitoring</title>
      <link>https://rip.trb.org/View/2364999</link>
      <description><![CDATA[Transportation infrastructure relies heavily on many plastic or plastic containing products for applications ranging from common erosion control products to more novel practices including recycled plastic modified (RPM) asphalt mixtures. While the use of these materials provides a benefit to Virginia Department of Transportation (VDOT), concern has been growing regarding these materials propensity to shed microplastics (MPs) into the environment. Previous research has indicated that stormwater runoff is one of the primary modes of transporting this emerging pollutant throughout the environment, however additional research is needed to understand the potential sources of MPs from a DOT perspective. Further, the analytical methods that have been developed for MPs analysis vary widely with many not being applicable to MPs derived from materials like RPM asphalts. A previous study conducted at Virginia Transportation Research Council
(VTRC) addressed this issue by developing sample preparation and analysis methods tailored for material artificially abraded RPM asphalt samples. This research seeks to build off of that previous work by (1) developing method detection limits, (2) adapting these methods to other sample types (i.e., stormwater runoff and soils) and (3) conducting field sampling of stormwater runoff, road deposited sediment, and roadside soils at sites in Virginia. This research expands on the scope of the previous effort by not only focusing on MPs that might be generated from RPM asphalt, but also other materials commonly used by VDOT, specifically rolled erosion control matting. The methodologies developed during this research and the collected field data could prove valuable to VDOT leadership should regulations regarding this emerging contaminant change. Additionally, field data from RPM asphalt pavement sites will provide the department with further insights into the propensity for this material to shed MPs back into the environment over time. This information is vital to VDOT's adoption of this material into standard practice.]]></description>
      <pubDate>Thu, 11 Apr 2024 08:30:38 GMT</pubDate>
      <guid>https://rip.trb.org/View/2364999</guid>
    </item>
    <item>
      <title>Remediation of Deicer Salt Contaminated Soils using Native Montana Plants</title>
      <link>https://rip.trb.org/View/2342033</link>
      <description><![CDATA[Montana Department of Transportation (MDT) uses deicing salts in winter operations to ensure roadways are safe and passable for the driving public. These same deicing salts, once in the environment, can accumulate in the soils, surface and ground water. One promising method to remediate soils and reduce the amount of deicing salts in surface and ground water, is the use of salt tolerant plants to remove the salt from the soils and shallow water sources. 

MDT conducted a preliminary literature search that found salt tolerant species may be used to aid in remediation of soils, surface and shallow ground water contamination from salts. While the bulk of the literature was related to agricultural saline contamination, a few research projects assessed the feasibility of using salt tolerant plant species for remediation of deicer contaminated soils. Greenhouse and laboratory results were promising, but the next step of finding significant results in field were limited to non-existent.

The proposed research effort will (1) identify potential native and non-native salt tolerant plant species that could be used for remediation of deicer contaminated soils in Montana, (2) conducted a systematic greenhouse study to determine ideal performing plant species and remediation rates, and (3) make recommendations on field trials locations and methods.]]></description>
      <pubDate>Mon, 19 Feb 2024 17:14:22 GMT</pubDate>
      <guid>https://rip.trb.org/View/2342033</guid>
    </item>
    <item>
      <title>Subsurface Contamination Modeling and Remediation Techniques </title>
      <link>https://rip.trb.org/View/2263741</link>
      <description><![CDATA[More than half of the US population consumes groundwater for drinking. Thus, introducing any type of contaminants into the groundwater table can risk the lives of more than half of the population. Contaminants from multiple sources can impact the drinking water wells and other receptors. When contaminants are transferred to the groundwater, they will make their way to water wells and drinking water supplies. Soluble contaminants, such as road salts, can easily migrate into the ground, reach the groundwater, and negatively affect the shallow groundwater and freshwater systems. An increase in road salts will have a negative effect on groundwater. Recently, several private wells in the town of Orleans in New York State reported the presence of road salts that were transferred through the groundwater flow. However, non-aqueous phase liquids (NAPLs) that are not highly soluble may have considerably longer residence times in the soil zone. NAPLs are hydrocarbons and are classified into two categories: (i) light non-aqueous phase liquids (LNAPLs), which have less density than water, and (ii) dense non-aqueous phase liquids (DNAPLs), which are denser than water. In either case, a physical interface between the water and NAPLs prevents the mixing of groundwater and contaminants.
In this proposed study, a finite element model (FEM) will be developed to analyze contaminant transport within the vadose zone and saturated zone. The developed multiphase fluid flow models will be used to study the movement of soluble contaminants, such as road salts, as they precipitate downward to the groundwater table. Additionally, the FEM model will be further modified to capture the flow of NAPL contaminants through the soil medium. The proposed research project consists of three phases: (1) Developing and validating an FEM that can simulate the movement of precipitation and rainfall from the ground surface and unsaturated zone into the groundwater. (2) Modifying the developed FEM model to analyze the contaminants flow in the soil medium by considering the advection and the interplay of diffusion limitation, adsorption, and partitioning between contaminants and soil. (3) Reviewing and proposing several remediation techniques for various contaminants, depending on the specific job site, to be employed in practical sites selected by local and state level departments of transportation (DOTs).
]]></description>
      <pubDate>Fri, 06 Oct 2023 19:00:39 GMT</pubDate>
      <guid>https://rip.trb.org/View/2263741</guid>
    </item>
    <item>
      <title>Transport and Mitigation of Tire and Road Wear Microparticles in Stormwater Runoff from Highways</title>
      <link>https://rip.trb.org/View/2263200</link>
      <description><![CDATA[This proposed project aims to identify the transport and mitigation of tire and road wear microparticles in highway stormwater runoff. We will mainly focus on tire wear microplastics containing 6-PPD.  The composition of the tire is a chemically complex and heterogeneous mixture having about 5–10% additives required for its stability and durability. Therefore, a tire can contain as many as 200 various additives. That can be leached from tire and road wear particles (TRWPs) into the aquatic environment. Although predicting material leachability from tires and their subsequent potential risk for the ecosystem was indicated in the early nineties, very few studies have been reported investigating TRWP leachates. Very recently, a study has published an oxidation product of tire antioxidant N-(1,3-dimethylbutyl)-N′-phenyl-pphenylenediamine (6-PPD), 6-PPD-quinone, as the lethal cause of coho salmon mortality(1).  6PPD quinone (the transformation product of 6PPD) has been reported in roadway runoff, tire rubber leachates, and road dust. Although very little information exists regarding the occurrence and fate of 6PPD quinone in the environment, this chemical is assumed to be present in surface waters globally because of the widespread use of the parent compound. The toxicity of 6PPD quinone could be a global threat to aquatic species and may not be limited to coho salmon only. 

Scope of Work: This will continue our current project for Year 2. We will accomplish the goal of this project through four tasks. We have already finished Task 1 and Task 2 and started Task 3. In Year 2, we plan to finish Task 2 by 7/31/2024 and Task 3 by 12/31/2024. We plan to begin Task 4 from 01/01/2025.
Task 1.  Literature Review  (completion date: 03/31/2024) 
Task 2. Measurement of Tire and Road Wear Microparticles in Stormwater  (Completion date: 07/31/2024)
Task 3 . Experimental Approaches for Mitigation Strategies (50% complete; expected end date: 12/31/2024)
Task 4. Modeling Approaches for Mitigation Strategies (estimated start date: 01/01/2025; estimated end date: 05/31/2025)

US DOT Priorities: The study effort aligns with the USDOT's dedication to sustainability and environmental preservation. The study advances knowledge about tire wear debris in the environment by examining the stability and removal of tire particles in water bodies. This information is essential for creating mitigation plans that work and encouraging environmentally friendly transportation behaviors. This study's results can influence policy choices and direct the creation of affordable mitigation infrastructure for this emerging pollution. The proper filtration media can be integrated into existing roadside structures, such as roadside shoulder, which will ultimately help create a more sustainable transportation system.

Outputs: Our technical deliverable will make recommendations concerning the types of best management practices (BMPs) and mitigation measures needed to remove tire and road wear microparticles containing 6-PPD as well as the resulting oxidized 6PPD-quinone potentially present during stormwater flows. 

Outcomes/Impacts: The research investigated the transport and removal of tire particles in various water bodies. The rate of aggregation and the zeta potential were measured in different synthetic water samples (Figure 2a). It was discovered that tire particles exhibited minimal aggregation in most aquatic environments including stormwater. High mobility of tire particles poses a significant environmental concern due to their widespread distribution. 

Figure 2: Findings from Task 2 and Task 3 show the lack of aggregation of tire wear particles in stormwater in Figure1a. Figure 1b presents the filtration pattern of tire wear particles through sand filter. Zn was used as marker for tire wear particles.

Filtration of tire wear particles on the roadside shoulder was identified as a possible solution. Column filtration experiments were conducted. However, removing tire particles through filtration using a white quartz sand column was inefficient in the preliminary studies (Figure 2b). These findings highlight the need for developing more effective strategies to mitigate the environmental impact of tire wear particles. Based on these findings, we will explore additional filtration media for removal of tire wear particles from stormwater.  
]]></description>
      <pubDate>Fri, 06 Oct 2023 18:50:06 GMT</pubDate>
      <guid>https://rip.trb.org/View/2263200</guid>
    </item>
    <item>
      <title>Sorption, Leachability, and Transport of AFFF Impacted Concrete Materials</title>
      <link>https://rip.trb.org/View/2262779</link>
      <description><![CDATA[The mobility and subsequent release of PFAS within concrete structures has been identified as an immediate concern by air and maritime transportation industrial entities, however, very little is known about the rates of ingress and egress of PFAS. Identifying the rates of sorption/desorption from concrete will allow for a more thorough assessment of site remedial needs and help better understand the pathways of PFAS transport from release to concrete, soil, groundwater, etc. Regulation of several PFAS has occurred in many states, including states with production facilities and military sites. There are over 9,000 compounds in the PFAS family, of which many bioaccumulate and persist in the environment. Although the distribution of AFFF in concrete is dependent on the specific composition of the AFFF and the concrete, the overall controlling factors of vertical and lateral PFAS distribution are application rates, co-contaminants such as hydrocarbon fuels, and durability of the concrete. Even though there has been a transition away from PFOS and PFOA based AFFFs, application areas have already been contaminated, along with other perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs), and fluorotelomer sulfonates (FTSs). Extensive studies have been undergone to determine the fate and transport of PFAS in soil and water, however, extraordinarily little is known about PFAS in construction building materials, particularly with respect to concrete itself. This project will analyze the leaching potential in surrogate AFFF-impacted concrete samples and assess the continued leaching of PFAS undergoing carbonation, freeze-thaw cycling, salt penetration, and a combination thereof.]]></description>
      <pubDate>Fri, 06 Oct 2023 17:26:31 GMT</pubDate>
      <guid>https://rip.trb.org/View/2262779</guid>
    </item>
    <item>
      <title>Wet Pond Modeling for Contaminant Retention and Maintenance</title>
      <link>https://rip.trb.org/View/2166452</link>
      <description><![CDATA[Many of the more than 30,000 ponds in Minnesota are connected to stormwater pipes and act as a part of the stormwater treatment system by storing runoff and settling solids along with associated pollutants to the bottom of the pond. Many of these ponds are stratified at one-foot of depth, and have high organic matter levels, often creating a bottom region of low dissolved oxygen water resulting in re-release of phosphorus trapped in the bottom sediments back into the water column. Through modeling efforts and field measurements, this research will further investigate pond maintenance approaches to mitigate phosphorus pollution from ponds. Results from this study can be used to maintain and apply design retrofits to existing and new ponds to improve pond performance and benefits for use along roadways throughout Minnesota and the United States.]]></description>
      <pubDate>Wed, 03 May 2023 16:10:00 GMT</pubDate>
      <guid>https://rip.trb.org/View/2166452</guid>
    </item>
    <item>
      <title>Synthesis of Information Related to Highway Practices. Topic 54-01. Practices to Identify and Mitigate PFAS Impacts on Highway Construction Projects and Maintenance Operations</title>
      <link>https://rip.trb.org/View/1953232</link>
      <description><![CDATA[Per- and polyfluoroalkyl substances (PFAS) are a class of contaminants of emerging concern that can harm both ecosystems and human health. These anthropogenic compounds contain carbon-fluorine bonds, which make them stable and persistent in the environment, earning them the nickname “forever chemicals.” PFAS regularly migrate from sources of contamination, including fire training areas at military sites and airports, PFAS manufacturing sites, land-applied wastewater biosolids, and landfills. PFAS can be found at low levels in soils and water far from any likely source. There are currently no binding federal regulations for PFAS. However, the EPA has begun the process of designating several PFAS as hazardous substances. This designation would likely restrict the ways in which state departments of transportation (DOTs) handle and dispose of impacted materials. The objective of this synthesis was to document current state DOT practices for identifying locations of potential PFAS contamination and for mitigating the impacts of PFAS related to highway construction and maintenance operations. Information for this study was gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs. Case examples of eight state DOTs provide additional information on identifying and mitigating PFAS impacts on highway construction projects and maintenance operations.
]]></description>
      <pubDate>Mon, 16 May 2022 17:44:48 GMT</pubDate>
      <guid>https://rip.trb.org/View/1953232</guid>
    </item>
    <item>
      <title>Smart Chloride Mitigation System</title>
      <link>https://rip.trb.org/View/1895369</link>
      <description><![CDATA[Chloride has been identified as a stressor impairing stream water quality in Maine. Salt application due to winter maintenance of the impervious surfaces is the leading chloride source in the stream watersheds. Chloride is a challenging stormwater contaminant since:
(1) Chloride cannot be removed from the stormwater by the existing treatment measures due its high solubility,
(2) Unlike most stormwater contaminants, stormwater infiltration into soil is not a removal mechanism for chloride. Chloride stored in the soil column and shallow groundwater persistently contaminate the streams via baseflow: high chloride concentrations are commonly observed in the streams during summer months,
(3) Chloride source control is proven to be difficult since public safety, level of service concerns often outweigh the benefits of reduced winter salt application.
Considering the limitations of the current winter maintenance practices, new best management practices (BMPs) are desperately needed to alleviate the chloride pollution in the streams. Furthermore, MaineDOT is required to implement BMPs in seven chloride-impaired stream watersheds under the new Transportation Municipal Separate Storm Sewer System (MS4) General Permit issued by the Department of Environmental Protection (DEP).
A Smart Chloride Mitigation System has potential to provide a more controlled BMP. The proposed desktop research will answer the following questions using specialized software in the order given below:
(a) What will be the SCMS design criteria? “Continuous” stormwater models including snowmelt process (e.g. SWMM) will be used to develop the SCMS design criteria (e.g. detention volume criterion) and simulate SCMS performance as a function of logic control, salt application rate, and weather.
(b) Where can SCMS be implemented? Potential locations in seven chloride-impaired urban stream watersheds will be evaluated using GIS for the pilot SCMS implementation. Major evaluation criteria are the paved area that can be treated by SCMS, the area available for SCMS, the grade availability for positive drainage.
]]></description>
      <pubDate>Fri, 03 Dec 2021 13:14:43 GMT</pubDate>
      <guid>https://rip.trb.org/View/1895369</guid>
    </item>
    <item>
      <title>Affordable On-Demand Testing of Water Contamination Using a Portable Nanoelectronic Lead Detector</title>
      <link>https://rip.trb.org/View/1757057</link>
      <description><![CDATA[Recent issues regarding lead in urban drinking water system have arisen. Specifically, the water distribution system in Newark, NJ has attracted a great deal of attention prompting the City and State DEP to conduct widespread testing and even distribution of water treatment devices and bottled water. The water distribution is aged and contains lead fittings that may impact water quality. The primary goal of this study is to develop and deploy a rapid, accurate lead sensing system for lead analysis in drinking water. In addition to accuracy, it is expected to demonstrate that the system can be used to sample a high volume of samples in a field setting with all of the difficulties that may come along with it.

The intended outcome of the project is a new portable electronic sensing platform for rapidly testing lead in water samples. The prototype developed during this research will be a potentially marketable product that will tap into a global market for water testing and analysis instruments valued at $3.5 billion in 2019. An on-site demonstration will be scheduled at the end of this project for various stakeholders to inform them of the availability and potential to this type of sensing system.]]></description>
      <pubDate>Thu, 10 Dec 2020 16:27:00 GMT</pubDate>
      <guid>https://rip.trb.org/View/1757057</guid>
    </item>
    <item>
      <title>Development of PFAS Source Differentiation Guidelines for Airports</title>
      <link>https://rip.trb.org/View/1729481</link>
      <description><![CDATA[Airports face increasing regulatory and technical challenges for addressing per- and polyfluoroalkyl substances (PFASs) found on or near their facilities. While the source of PFAS in an area may be attributable to airport activity, including the use of aqueous film forming foams (AFFF) during aircraft rescue and firefighting activities, or from tenants storing AFFF or other PFAS-containing materials, airports may also have neighbors who use products that contain PFAS. When PFAS is found at or near an airport, it is important to identify the source and to help manage the cost and liability of possible remediation. Yet source attribution can be a complex and difficult undertaking, particularly in an airport setting. Research is needed to advance the understanding and use of PFAS source differentiation so it can be applied to airports with greater confidence.


The objectives of this research are to develop: (1) a guidebook of recommended practices for determining the source(s) of PFAS detected in soil and water on or near an airport and (2) a primer for airport practitioners describing PFAS source attribution concepts and techniques in lay terms.]]></description>
      <pubDate>Mon, 17 Aug 2020 16:29:33 GMT</pubDate>
      <guid>https://rip.trb.org/View/1729481</guid>
    </item>
    <item>
      <title>2286 Compost Filter Socks for Storm Water and Erosion Control in Construction</title>
      <link>https://rip.trb.org/View/1667133</link>
      <description><![CDATA[ An update to the Standards Specifications for Highway Construction of
erosion and sediment control measures through the Storm Water Action Team is ongoing. Part of
this update includes reviewing and evaluating new erosion control products like compost filter
socks. It is not known if compost filter socks can function effectively as an erosion control product
without leaching contaminants to the environment. Research in conjunction with laboratory and data
analysis are needed to determine if compost filter socks do leach contaminants under conditions
identified at transportation construction sites in Oklahoma. This project will develop and refine a
simplified laboratory method for determining leaching potential of compost filter socks at Oklahoma
construction sites. This new standard will then be utilized to test various compost filter sock
compositions for leaching of contaminants. A cost-benefit analysis will be performed to compare
the use of compost filter socks to current practices. Results from field monitoring of filter sock
implementation will be used to inform the ODOT Storm Water Action Team for development of a
standard and specification to use on ODOT construction sites.]]></description>
      <pubDate>Tue, 19 Nov 2019 10:54:40 GMT</pubDate>
      <guid>https://rip.trb.org/View/1667133</guid>
    </item>
    <item>
      <title>Evaluation and optimization of engineered media amendments for contaminant removal in stormwater runoff filtration systems</title>
      <link>https://rip.trb.org/View/1530171</link>
      <description><![CDATA[Various contaminants exist in stormwater runoff, including nutrients, metals, pathogens and organic compounds. Filtration systems built with engineered media are used to manage stormwater runoff, but NCDOT’s current standard filtration media mix specification does not take the optimization of contaminant removal into consideration. To better meet regulatory compliance, it is beneficial for NCDOT to explore different material selections and mixing options to build filtration systems with better capacity of contaminant removal, while maintaining desirable support for plant growth and water infiltration. The objective of this project is to evaluate a variety of affordable media materials that can remove multiple contaminants simultaneously and maintain high performance in runoff filtration measures under various natural conditions. Up to 25 different filter materials identified from an extensive literature review will be screened to select the ones with the highest contaminant removal rate and capability. These materials will be tested with different mixing strategies to identify media mixtures that allow stormwater infiltration at a reasonable rate and have enough organic matter and water retention to support plant growth. The selected media mixtures will be tested in bench-scale columns for contaminant removal performance under various natural conditions, such as alternating concentrations, antecedent drought period, low temperature and presence of deicing agents. The best performing media mixture(s) will be recommended for future field tests, then be applied in NCDOT stormwater management systems. Information gained through this project will enable NCDOT to improve the performance of its stormwater filtration systems to effectively remove contaminants including nutrients, metals, pathogens, and organic contaminants. Such improvement will help NCDOT comply with the NPDES permit, state nutrient load reduction rules, future dissolved metals TMDLs, and potential regulations on organic contaminants in future.]]></description>
      <pubDate>Thu, 02 Aug 2018 15:12:15 GMT</pubDate>
      <guid>https://rip.trb.org/View/1530171</guid>
    </item>
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