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Flushing Home Plumbing Pipes Contaminated with Aqueous Film-Forming Foam Containing Per- and Polyfluoroalkyl Substances

APTIM Authors/Contributors Background/Objectives Per- and polyfluoroalkyl substances (PFAS) from aqueous film forming foam (AFFF) can be accidentally backflushed into drinking water systems during firefighting operations or at industrial facilities. If this contaminated water enters household plumbing systems, homeowners may need to decontaminate their plumbing. This study examines the persistence of…

https://www.aptim.com/media/publications/flushing-home-plumbing-pipes-contaminated-with-aqueous-film-forming-foam-containing-per-and-polyfluoroalkyl-substances/

Biological and Geochemical Groundwater Treatment Using Recirculation for Distribution to Prevent Excavation

APTIM Authors/Contributors Background/Objectives At the former Naval Air Station Moffett Field California Traffic Island Area past dry-cleaning operations and the discharging of chemicals into a compromised sanitary sewer line led to elevated levels of tetrachloroethene (PCE) in the subsurface. Groundwater investigations at this site have determined that DNAPL levels of…

https://www.aptim.com/media/publications/biological-and-geochemical-groundwater-treatment-using-recirculation-for-distribution-to-prevent-excavation/

Benzene Diffusion and Partitioning in Contaminated Drinking Water Pipes under Stagnant Conditions

APTIM Authors/Contributors Nicole Sojda, Environmental Scientist, QATS T&E Facility Donald A. Schupp, Project Manager, QATS T&E Facility Abstract Benzene contamination in drinking water systems affected by wildfires is a problem of emerging concern. Polyethylene pipes used in service lines and premise plumbing are vulnerable to permeation by benzene and can…

https://www.aptim.com/media/publications/benzene-diffusion-and-partitioning-in-contaminated-drinking-water-pipes-under-stagnant-conditions/

Excavation, Groundwater Extraction, In Situ Bioremediation, and In Situ Chemical Oxidation to Treat Large Commingled cVOC Plumes

APTIM Authors/Contributors Robert Mayer, Senior Environmental Scientist Jack Koelsch, Project Manager, Environmental Services Kimberly Chambers, Project Manager, Environmental Sciences Michael Gunderson, Senior Geologist Background/Objectives At the former Fort Gillem located in Forest Park, Georgia, a large chlorinated volatile organic (cVOC) groundwater plume is present and is being treated by addressing…

https://www.aptim.com/media/publications/excavation-groundwater-extraction-in-situ-bioremediation-and-in-situ-chemical-oxidation-to-treat-large-commingled-cvoc-plumes/

Analytical Model for 3D Solute Transport of Sequentially Decaying Species with Dual Porosity, Sorption, and Time-Varying Source

APTIM Authors/Contributors Tomas Perina, Project Manager, Environmental Services Background/Objectives U.S. Environmental Protection Agency (EPA) and its contractors performing oversight at Superfund Sites review numerical models developed to simulate contaminant transport and often could use an analytical solute transport model to perform checks on the numerical model results. An analytical transport…

https://www.aptim.com/media/publications/analytical-model-for-3d-solute-transport-of-sequentially-decaying-species-with-dual-porosity-sorption-and-time-varying-source/

Overcoming Challenging Site Conditions to Remediate High Perchlorate Concentrations in Groundwater Using In Situ Bioremediation

APTIM Authors/Contributors Background/Objectives At a former Army Ammunition Plant in Northeast, Texas, in situ bioremediation (ISB) was proposed to address elevated perchlorate concentrations in groundwater under a fixed price performance-based remediation (PBR) contract. The site is approximately ½ acre in size and consisted of a former pilot wastewater treatment plant…

https://www.aptim.com/media/publications/overcoming-challenging-site-conditions-to-remediate-high-perchlorate-concentrations-in-groundwater-using-in-situ-bioremediation/

The Significance of Filling Data Gaps and Developing Good Conceptual Site Models Prior to Remedy Implementation Under Fixed Price Performance Based Remediation Contracts

APTIM Authors/Contributors Background/Objectives At a former Air Force base in San Antonio, Texas, site closure (SC) was proposed for one of the sites, under a 10-year, fixed-price, performance-based remediation (PBR) contract, during the 2011-2021 period of performance (PoP). The site is approximately 3 acres and consisted of multiple disposal/evaporation pits.…

https://www.aptim.com/media/publications/the-significance-of-filling-data-gaps-and-developing-good-conceptual-site-models-prior-to-remedy-implementation-under-fixed-price-performance-based-remediation-contracts/

Groundwater flow near a recirculation well with mixed-type boundary condition along wellbore in confined, unconfined, leaky, or reservoir-covered aquifers.

APTIM Authors/Contributors Tomas Perina, Project Manager, Environmental Services Abstract Vertical recirculation wells used for remediation or heat recovery induce drawdown distribution that varies for confined, unconfined, leaky, and reservoir-covered aquifers. A recirculation well with arbitrary arrangement of extraction and injection screen intervals is simulated with the general well function of…

https://www.aptim.com/media/publications/groundwater-flow-near-a-recirculation-well-with-mixed-type-boundary-condition-along-wellbore-in-confined-unconfined-leaky-or-reservoir-covered-aquifers/

Linking water quality to drinking water treatment costs using time series analysis: Examining the effect of a treatment plant upgrade in Ohio

APTIM Authors/Contributors Donald Schupp, Project Manager, Quality Assessment Tasks Abstract We estimate a cost function for a water treatment plant in Ohio to assess the avoided-treatment costs resulting from improved source water quality. Regulations and source water concerns motivated the treatment plant to upgrade its treatment process by adding a…

https://www.aptim.com/media/publications/linking-water-quality-to-drinking-water-treatment-costs-using-time-series-analysis-examining-the-effect-of-a-treatment-plant-upgrade-in-ohio/

A field study to assess the role of air-water interfacial sorption on PFAS leaching in an AFFF source area.

APTIM Authors/Contributors Abstract Field-deployed lysimeters were used to measure the concentrations of poly- and perfluoroalkyl substances (PFASs) in soil porewater at a site historically impacted with aqueous film forming foam (AFFF). Samples collected over a 49-day period showed that perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were the PFASs with…

https://www.aptim.com/media/publications/a-field-study-to-assess-the-role-of-air-water-interfacial-sorption-on-pfas-leaching-in-an-afff-source-area/