contaminated site Articles
-
Vapor Intrusion: Risks and Challenges
Vapor Intrusion (VI), defined as the migration of volatile contaminants from the subsurface into the indoor air of overlying buildings, is a major and challenging environmental issue for both regulators and the regulated community—one that continues to elicit heated debate among stakeholders. Eight factors associated with the VI pathway that contribute to its challenging nature are discussed ...
-
Wellboom - For groundwater well management and site remediation
UniRemTech's WELLBOOM® was designed to facilitate testing on Underground Storage Tank (UST) monitoring wells and is easier and less costly than traditional pre-test methods at keeping the well clean and test-ready. WELLBOOM® can also substantially reduce the remediation time for leaking USTs and other contaminated sites, resulting in faster handover and startup of these valuable assets. ...
-
A mixed-integer non-linear programming with surrogate model for optimal remediation design of NAPLs contaminated aquifer
A mixed-integer non-linear programming (MINLP) with surrogate model was introduced to derive the optimal surfactant enhanced aquifer remediation (SEAR) process (remediation cost minimisation and removal rate maximisation) at a nitrobenzene-contaminated site. First, a 3D multi-phase flow simulation model was developed to simulate the SEAR process; using a radial basis function artificial neural ...
-
Case study - Groundwater remediation of a contaminated site using enhanced anaerobic bioremediation
Chlorinated solvents are a common threat to drinking water sources throughout the United States. While handling and disposal practices today are more closely regulated and monitored, this has not always been the case. With dry cleaners using tetrachloroethene (PCE) and industrial manufacturing facilities commonly using a variety of solvents from trichloroethene (TCE) to methylene chloride, past ...
-
Modelling biological Cr(VI) reduction in aquifer microcosm column systems
Several chrome processing facilities in South Africa release hexavalent chromium (Cr(VI)) into groundwater resources. Pump-and-treat remediation processes have been implemented at some of the sites but have not been successful in reducing contamination levels. The current study is aimed at developing an environmentally friendly, cost-effective and self-sustained biological method to curb the ...
-
Comparison of Eight Innovative Site Characterization Tools Used to Investigate
Environmental assessment of contaminated sites often requires delineation of the pathways of contaminant migration. Often, the pathways are strongly affected by the subsurface geology. At Vandenberg AFB in California, an accidental release of gasoline containing MTBE occurred at a base gasoline station in 1994. Dissolution of the gasoline into groundwater has created a dissolved MTBE plume at ...
-
High-Resolution Site Characterization with Multilevel Systems
Within the last few years, the U.S. EPA added a new focus area on high-resolution site characterization (HRSC) to their Contaminated Site Clean-Up Information (CLU-IN) website. The U.S. EPA’s definition of HRSC is: “High-resolution site characterization (HRSC) strategies and techniques use scale-appropriate measurement and sample density to define contaminant distributions, and the ...
-
Effective distribution of edible oils
Edible oil was injected at five sites to promote reductive dechlorination. The edible oil was injected as a non-aqueous phase liquid (NAPL) or as an emulsion of oil, an emulsifier, and water. At Dover Air Force Base, injection of the emulsion into a barrier resulted in greater distribution of the total organic carbon (TOC) and more rapid dechlorination than direct injection of the edible oil into ...
-
Using Cl-Out to Finish Remediation Following Chemical Oxidation
CL-Out was used to complete the remediation of ground water contaminated by chlorinated solvents from a former dry cleaning site in Rockville, Maryland. The ground water contamination had migrated from leaking sewer lines to underlying bedrock fractures. Fenton’s Reagent was first applied to the site, but the PCE concentrations increased due to desorption. Subsequently, sodium ...
-
Standard Chlorine of Delaware Remediation
By designing a 70-foot deep barrier wall, Black & Veatch was able to cut off contaminant source areas from a creek near New Castle, Delaware. The groundwater treatment system that Black & Veatch designed prevents site contamination from reaching the underlying drinking water aquifer. The Standard Chlorine of Delaware Site is a 65 acre area including an abandoned chlorobenzene ...
-
Managing site data and the maintenance of conceptual model and time series outputs at a complex site over an extended period - Case Study
Background Leakages of TCE and the subsequent groundwater contamination at an industrial facility in Adelaide have led to an ongoing investigation and remediation program conducted since 1999. This work comprised site characterisation and remediation, including borehole drilling, monitoring well installation, soil, groundwater and vapour sampling, laboratory analysis and preliminary in-situ ...
-
Zerovalent Iron nanoparticles for treatment of ground water contaminated by Hexachlorocyclohexanes
Ground water and aquifer samples from a site contaminated by hexachlorocyclohexanes (HCHs; C6H6Cl6) were exposed to nanoscale iron particles to evaluate the technology as a potential remediation method. The summed concentration of the HCH isomers in ground water was approximately 5.16 µmol L–1 (1500 µg L–1). Batch experiments with 2.2 to 27.0 g L–1 iron nanoparticles showed that more than 95% of ...
-
Environmental Data Management for Groundwater Contamination
ESdat environmental data management software has been used to manage and report on large datasets generated from an investigation of groundwater contamination on an industrial facility in Adelaide. ESdat was used in managing site data and the maintenance of conceptual model and time series outputs at a complex site over an extended period. Leakages of TCE and the subsequent groundwater ...
-
Study: Coal-Fired Power Plants Are Polluting Groundwater
Environmental groups are pushing for tighter regulation and enforcement of EPA rules A new study shows that of the 265 coal-burning power plants it studied in the United States, 241 have dangerous levels of toxic metals in the groundwater around them, based on Environmental Protection Agency (EPA) standards. The figure, which comes to 91% of the plants, was derived only from plants that must ...
-
Dynamics of nitrate & perchlorate in groundwater.
The Apache Powder Superfund Site is located in Cochise County, Arizona, approximately 50 miles southeast of Tucson. The site was listed on the National Priorities List pursuant to CERCLA in 1990. Principal groundwater chemicals of concern (COCs) include nitrate-nitrogen (nitrate-N) and perchlorate. Concentrations of nitrate-N exceeding 500 mg/l and 2,300 mg/l have been detected in the “shallow ...
-
Assessing the transport and fate of MTBE
Untitled Document Abstract The ether oxygenates MTBE and TAME have been used in petroleum fuel formulations in the UK since the mid-1980s and have led to contamination of major aquifers with these chemicals, including the Chalk aquifer of southern England. An assessment is made of the controls on the fate of MTBE and BTEX compounds at a contaminated site on the Chalk aquifer, ...
-
Multiparameter sonde used in combined remedy approach and saves $200,000 in potential costs - Case Study
A former dry-cleaning site in the Pacific Northwest, Ultra Custom Care Cleaners, was found to be contaminated with PCE (perchloroethylene). According to the U.S. Geological Survey (USGS), PCE was widely used in the dry cleaning of fabrics since the 1940s. PCE is one of the most frequently detected VOCs (volatile organic carbons) in groundwater at a national scale (Moran 2004). PCE is highly ...
-
Risks from Renegade Nanoparticles during field deployments within NanoRem
The aim of NanoRem is to support and develop the appropriate use of nanotechnology for contaminated soil and groundwater remediation. NanoRem focuses on facilitating practical, economic and exploitable nanotechnology for in-situ remediation. This can only be achieved in parallel with a comprehensive understanding of the environmental risk-benefit balance for the use of nanoparticles (NPs). One ...
-
What Effect Does E-Waste Have On Groundwater?
Groundwater is one of the most precious resources on Earth. Its yields supply water to nearly every community in the country, and without it, most of us would be driven to drastic measures to accommodate drought conditions. In fact, that very situation is happening in communities across the nation. As groundwater is increasingly negatively affected by a number of environmental factors, ...
-
In Situ Biological Treatment for Ground Water, Surface Water, and Leachate
The main advantage of in situ treatment is that it allows ground water to be treated without being brought to the surface, resulting in significant cost savings. In situ treatment, however, generally requires longer time periods, and there is less certainty about the uniformity of treatment because of the variability in aquifer characteristics and because the efficacy of the process is more ...
Need help finding the right suppliers? Try XPRT Sourcing. Let the XPRTs do the work for you