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Eric Tollefsrud

Pharmaceuticals in the Environment (PiE)

2026-07-02T07:32:56-06:00March 27th, 2026|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

Lead Practitioners Nothing Found

Geosyntec to Sponsor Minnesota State Bar Association Program Event

2026-03-15T10:20:07-06:00January 23rd, 2025|Tags: , |

Geosyntec will sponsor a Minnesota State Bar Association program event entitled "Environmental and Energy Law and Policy under a Trump Administration," a Continuing Legal Education (CLE) event for the Minnesota State Bar Association at the Lockridge Grindal Nauen PLLP in Minneapolis, Minnesota from 12:00 p.m. to 1:00 p.m. on January 19, 2017.

Jay Thompson Presents at the 2017 AIChE Annual Meeting

2026-03-15T10:20:40-06:00November 14th, 2017|Tags: , |

Jay Thompson (Minnesota) delivered a presentation at the 2017 American Institute of Chemical Engineers (AIChE) Annual Meeting, entitled "Development of an Analytical Modeling Framework for Matrix Diffusion in Multi-Layered Systems," at the Minneapolis Convention Center in Minnesota on November 1, 2017.

Paul Brookner and Eric Tollefsrud Lead a Continuing Legal Education Session on Environmental Science for Attorneys

2026-03-15T10:19:34-06:00February 1st, 2016|Tags: , |

On January 27, Paul Brookner and Eric Tollefsrud (Minneapolis) led a two-hour Continuing Legal Education (CLE) Session for the Minnesota State Bar Association that examined the environmental science behind some of the current regulatory and legal challenges facing environmental attorneys and other practitioners in the areas of vapor intrusion and vapor migration. This CLE addressed risk assessment, the science behind vapor intrusion and vapor migration, groundwater and surface water interactions and the use of big data. Paul and Eric are part of a panel of scientists and attorneys who addressed these topics and explored how lawyers, scientists and engineers can work together to help clients. For more information about the session, visit http://www.mnbar.org/Meetings/Meeting?ID=996#.VqZJA9iFOUl For information about the environmental science behind some of the current regulatory and legal challenges facing environmental attorneys and other practitioners in the areas of vapor intrusion and vapor migration, contact Paul Brookner at pbrookner@geosyntec.com or Eric Tollefsrud at etollefsrud@geosyntec.com.

Specialized In Situ Treatment Technologies

2026-09-22T12:43:54-06:00February 12th, 2015|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

Geosyntec is an industry leader in remediating difficult-to-treat environmental impacts to soil, groundwater, and sediments through the use of specialized in situ techniques. Our practitioners are adept at expediting site investigations, optimizing remediation solutions, and accelerating site closure through a wide range of innovative technology applications. Our expertise in the implementation of new, emerging, and conventional technologies allows our practitioners to frequently bridge the gap between the development and first-to-field stages of environmental solutions. Our expertise and industry leadership in the advanced application of microbiology-based solutions for the remediation of recalcitrant contaminants in soil and groundwater has established Geosyntec’s solutions as the preferred method, especially for sites with proven resistant to conventional remediation technologies or when compared to the comparatively high costs for the application of physical and chemical technologies that achieve similar results. Two of Geosyntec’s affiliated companies provide specialized services and technologies regarding in situ treatments:

Vapor Intrusion Assessment & Remediation

2026-09-30T13:29:12-06:00February 12th, 2015|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

When a site involves volatile organic compounds (VOCs) in soil or groundwater, those chemicals can volatilize and migrate into nearby buildings presenting a health hazard to those inside. Not only that, but most buildings also contain other sources of volatile contaminants that are related to ongoing operations or consumer products. Because the same chemicals can be present in the subsurface, in chemicals used on-site, and in other products, investigation and mitigation can become complicated.

Groundwater Assessment and Remediation

2026-06-30T09:11:21-06:00February 11th, 2015|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

Geosyntec’s expertise in efficient site characterization, including sites that exhibit complex groundwater-flow regimes, has distinguished our firm as a leader in groundwater assessment and groundwater remediation. Our practitioners address a broad suite of contaminants, including metals, chlorinated organic chemicals, petroleum hydrocarbons, and emerging contaminants, and use award-winning, technology-based remediation strategies that are often first-to-field. Many of our hydrogeologists specialize in modeling the fate and transport of contaminants through the most difficult types of media, including fractured and karst bedrock.

Overview of Contaminated Site Assessment and Cleanup

2026-08-18T14:34:36-06:00November 12th, 2014|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

Geosyntec practitioners rank among the world's top professionals in providing site assessment and remediation services at a wide range of impacted sites using innovative technologies and solutions that consistently advance the state of the practice. Through our use of innovative technologies and solutions, we provide our public and private sector clients with a wide array of services to address their toughest challenges. Our contaminated site practitioners guide our clients through a specialized remediation plan, consult on regulatory strategies, and develop a comprehensive cleanup approach. We can address numerous types of media, including contaminated soils, sediments, and groundwater. Advancing the State of the Practice Geosyntec's practitioners are pioneers in site assessment and remediation. Our senior practitioners have developed and authored guidance material and courses for local, state, and national agencies and associations on remediation techniques and technologies. Working with the Interstate Technical Regulatory Council, Geosyntec practitioners taught a training course on vapor intrusion, including mitigation options for the development of vapor-impacted brownfield sites. Geosyntec practitioners also wrote the guidance document on evaluating, optimizing, or ending post-closure care at impacted sites, including brownfield sites, and developed a patented approach for sub-slab vapor migration mitigation allowing residential, commercial, and industrial development on sites impacted by vapor intrusion. Our specialists routinely collaborate with prominent national researchers from academia and government agencies to provide innovative and defensible strategies for sites with contaminated sediments. For example, we collaborated with the United States Geological Survey (USGS) to remediate chlorinated solvent-contaminated marsh sediments by applying a bioreactive mat system embedded with a dehalogenating microbial consortium, a technology Geosyntec helped develop. This project and partnership earned our client recognition as a finalist for the Service to America Medal awarded by the Partnership for Public Service. Through a collaborative research project with the University of Florida, Geosyntec professionals helped develop the FLUCL software package for the Florida Department of Environmental Protection. This software is used to calculate exposure point concentration statistics in risk assessment and was the first of its kind to contain algorithms for censored datasets. FLUCL has received endorsements from several United States Environmental Protection Agency regions and the California Environmental Protection Agency. Geosyntec scientists also pioneered the use of genetic molecular tools to characterize microbes in environmental media and are engaged in applied research and development with top academic institutions around the world, including the University of Toronto, Cornell University, and the Georgia Institute of Technology.

Hydrogeological Characterization & Modeling

2026-04-29T11:41:56-06:00March 28th, 2014|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

Understanding how water interacts with the surface and subsurface environment at any contaminated location is critical to designing innovative and cost-effective remediation systems and site-management strategies. By delineating and understanding the geology and hydrogeology affecting contaminated sites, our experts design strong conceptual site models and groundwater-remediation programs. Ultimately, hydrogeological characterization and modeling affects the performance of any remediation technologies deployed as a solution.

Fate and Transport and Hydrogeological Characterization

2026-08-19T13:52:10-06:00March 28th, 2014|Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |

Hydrogeological characterization and fate and transport modeling affects the performance of any remediation technology deployed at a site. To effectively remediate a site and optimize the use of time and resources, contamination must be sufficiently characterized using sound judgment to interpret available data. By delineating and understanding the geology and hydrogeology, our experts design strong conceptual site models, remediate groundwater, and employ beneficial reuse of sediments.

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