John Gardner

Senior Environmental Information Management Specialist

John joins Barr with 16 years of experience in the oil-and-gas industry. His expertise includes data management and database development for air emissions tracking and compliance with federal, state, and municipal regulatory requirements. He has developed and managed Oracle, SQL, and MS Access databases and is familiar with SPCC, SWPPs, and Colorado Oil & Gas Conservation Commission (COGCC) regulations. John’s previous project work also involved remediation of contaminated refinery sites, waste management, and preparation of emission inventories for environmental assessments and environmental impact assessments.

303-589-3961 |jgardner@barr.com

Sharon Dahl

Senior Environmental Scientist

With more than 25 years of nationwide experience in the areas of environmental permitting and regulatory compliance, Sharon offers Barr’s clients extensive insights and guidance on multimedia compliance audits, NPDES permitting, remediation programs. and management of stormwater and hazardous waste. She is well-versed in the requirements of the Clean Water Act, the Safe Drinking Water Act, and the Resource Conservation and Recovery Act, including waste regulations for facilities permitted under RCRA Part B.

Before gaining more than 15 years of experience at Flint Hills Resources’ Pine Bend Refinery—first as an environmental laboratory manager and then as a regulatory compliance specialist—Sharon worked at the Minnesota Department of Health as an environmental compliance officer and at a private laboratory as an analytical and quality assurance specialist.

952-842-3633 | sdahl@barr.com

Derek Seifert, PLA

Senior Landscape Architect

Derek joins Barr with nearly 13 years of experience in landscape architecture and sustainable design. His focus areas include site programming, master planning, environmental restoration, surface drainage and grading, and construction detailing of site amenities. Derek works on projects involving green infrastructure, innovative stormwater treatment, native plant community restoration, and natural resource management. He has served as landscape architect of record for multiple commercial projects in Minnesota and has coordinated with state and federal agencies, clients, and contractors on designs.

952-842-3695 | dseifert@barr.com

Lauren Dickerson

Senior Air Quality Consultant

Lauren returns to Barr after spending several months as the air resources manager at Twin Metals Minnesota, adding industry experience to her 15-year background in consulting and air-quality-permitting roles at municipal and state agencies. In addition to permitting, her career encompasses air-toxics risk analysis; dispersion modeling; analysis of best available control technology (BACT) and best available mercury-reduction technology (BAMRT); emission-inventory and greenhouse-gas reporting; and industry-group engagement in rule development.

Lauren’s dedication to research and process improvements is highly regarded, as is her commitment to delivering well-crafted work products. She especially welcomes opportunities involving ESG, sustainability, decarbonization, and greenhouse gas accounting.

952-832-2873 | ldickerson@barr.com

John Lennander, PE, LS

Senior Water Resources Engineer

Jon rejoins Barr with more than three decades of experience in civil, municipal, and water resources engineering, as well as real estate development. His focus areas have included hydrology, water quality management, limnology, flow monitoring and sampling, feasibility studies, design, permitting, and construction management and observation. Jon is also a licensed land surveyor. Most recently, he served as assistant city engineer for the City of Fridley, Minnesota, where he planned, designed, and constructed infrastructure projects.

952-832-3622 | jlennander@barr.com

Ryan Schipper, PE

Senior Water/Wastewater Engineer

Ryan joins Barr with 15 years of experience in active and passive water treatment projects. His projects have involved wastewater treatment for mining, oil and gas, manufacturing, waste management, and site remediation programs throughout the world. Prior to joining Barr, Ryan served as a senior engineer based out of Denver for a global consulting firm and led their South American mine water treatment group. His active water treatment projects have involved alternative evaluations, treatability studies, preliminary design, cost estimates, detailed design, construction oversight, and start-up support. Ryan’s passive water treatment projects have involved evaluation, design, construction, and operational support for pilot and full-scale treatment systems.

952-832-2677 (office), 720-412-5066 (cell) | rschipper@barr.com

In Salt Lake City

Andrew Dillon, PE

Senior Civil Engineer

Andy rejoins Barr after more than three years with the U.S. Army Corps of Engineers as a technical lead and civil engineer stationed in Wiesbaden, Germany, where he developed scopes of work as well as requests for proposals and provided engineering design review for design-build and design-bid-build projects throughout Europe and Africa. At Barr, Andy has focused on civil engineering for mining and lined facilities. He specializes in creating construction drawings and technical specifications for large earthwork projects such as earthen dams, landfills, ponds, and clay and geomembrane liners. Andy is skilled in creating three-dimensional models with AutoCAD Civil 3D. He also assists with construction management.

801-333-8430 | adillon@barr.com