Ilana V. Nguyen

Staff Environmental Scientist, Business Development & Marketing Manager

Ms. Nguyen earned a Bachelor of Arts in Environmental Studies & Criminal Justice minor at Baylor University, Waco, TX 2020
Her skills and certifications include:

· Surveyed land; monitored and analyzed parcel maps and wastewater
· Collected and analyzed water and soil samples throughout
· Investigated long and short-term illegal dumping cases
· Supervised clean-up sites
· Evaluated and constructed Environmental Impact Statements
· Geographic Information System- Analyzed data in Excel and ArcGIS and earned 16 hours of ESRI Certifications
· Created maps using selection, geoprocessing, spatial analyst, and geostatistical analyst tools
· Produced a portfolio of maps about water changes on landscapes
Environmental Science: Watershed Assessment
· Earned the Watershed Academy’s watershed Management certification
Water Resources Skills
· Measuring water quality using OTT discharge meter, YSI Sonde EXO, and diel flux
· Gathering and analyzing field data

    Shannon J. Ware


    Shannon J. Ware Joined TSI in 2023. Shannon has a B.A. in Communication from Texas A&M University - Corpus Christi. She has been in managerial positions at a major Houston hotel and has vast experience in insurance. She adds her marketing and business skills to the team.

      Isabel Siahatgar

      Staff Geologist

      Ms. Siahatgar has a B.A. in Geological Sciences with a minor in business from the University of Texas at Austin. She joined TSI in 2023 and has prepared Phase I & II ESAs, Drinking Water Surveys, and IOP applications. Ms. Siahatgar supervises soil remedial actions, underground storage tank removals, soil and groundwater sampling, aquifer tests, and monitoring well installations. She is currently working on obtaining a GIT and has achieved a HAZWOPER certification.

        Priscilla Crowell

        Environmental Consultant/Technician

        Ms. Crowell has a Bachelors in Business Administration. She joined TSI in 2023 and performs Phase I ESAs and Drinking Water Surveys. She has performed low-flow sampling and field activities in support of our environmental assessments. She has managed an extensive soil remediation project 30 feet under the streets of Houston, Texas associate with utility replacement.

        Glenn R. Lowenstein

        P.G., CAPM, President

        An environmental professional since 1990, Mr. Lowenstein is both a licensed Professional Geoscientist with the State of Texas and a licensed Corrective Action Project Manager with the Texas Commission on Environmental Quality. Mr. Lowenstein has a Master of Science in Geology from Texas A&M University at College Station. He has performed hundreds of Environmental Site Assessments for both governmental and private interests.

        During the course of these assessments, he has supervised the installation of monitor wells, performed and overseen the collection of soil and groundwater samples, and has conducted numerous slug and pump tests. His experience also includes remediation projects, UST removals, and aquifer analysis.

        Glenn served as Chairman of the Houston Geological Society’s Environmental & Engineering Geology Committee for seven years and is a recipient of the Houston Geological Society’s prestigious President’s Award. The Governor of Texas appointed Mr. Lowenstein to the Texas Board of Professional Geoscientists in 2005.

          Matthew Cowan

          Chief Geologist

          Chief Geologist, PG

              Allison Johanson

              Project Geologist

              Ms. Johanson graduated from Baylor in 1986 with a B.S. and from Texas A&M with a MS in Geology in 2005. Ms. Johanson is OSHA 40-hour and Supervisor trained and is up-to-date in her first aid and CPR training.

              She has since worked in the environmental field in the Gulf Coast area performing environmental investigations of properties such as retail petroleum sites, former terminal facilities, retail commercial facilities, former plating and foundry sites, and retail manufacturing facilities. Her project experience includes environmental investigation, remediation, regulatory compliance and waste disposal. Allison’s expertise includes performance of Phase I and II ESA’s, well sampling and core evaluation, preparation of surface and subsurface maps and diagrams, supervision of drilling, monitoring well installation and core identification.