Scott K. Leafe, Principal Scientist/President/Managing Partner

Mr. Leafe is the founder and President/Managing Partner of SKA. His more than 38 years of practical environmental and nuclear engineering experience has included direction, management, and coordination of Phase I Environmental Site Assessments, Phase II Investigations, Risk-Assessment, and remedial construction projects. He has served as Project Director/Manager for hundreds of environmental assessments, property cleanups, and regulatory closures for all facets of public and private-sector clients. Scott has unique, in-depth knowledge of community redevelopment programs and property redevelopment strategies, especially regarding Brownfields properties.

Following three years of initial studies in chemical engineering at Texas A&M University, Scott entered the U.S. Navy Nuclear Power program in 1984. He served four years as a navy instructor at the naval nuclear power plant prototype facility at the Idaho National Engineering Laboratory in Idaho Falls, Idaho. His follow-on four-year tour was aboard the USS Gurnard, SSN 622 fast attack nuclear submarine homeported in San Diego, California. As a Non-Commission Officer, Scott served as the lead chemist and radiological controls/radiation health physics supervisor, and a nuclear power/propulsion plant supervisor. He was awarded the Navy Achievement Medal for his distinguished service and received an Honorable Discharge in 1992.

Following his naval service, Scott joined International Technology Corporation in the Groundwater Services Division in Houston, Texas. His responsibilities included assisting in the design, installation, operation, and maintenance of soil-vapor extraction and vacuum-enhanced pumping, total fluids, and skimming groundwater remediation systems throughout the U.S. In 1993, Mr. Leafe was recruited by Carter & Burgess, Inc. (C&B) and was rapidly promoted to Project Manager in the Houston Environmental Services Division. In 2000, Mr. Leafe was promoted to Associate by the Board of Directors.

Building on his vision to provide timely and high-quality environmental services to a wide variety of private and governmental clients and further expand his capabilities in Brownfields redevelopment, Mr. Leafe formed SKA in June of 2001. Since its inception, SKA has become renowned for its superior service and quality and its ability to provide real-world solutions to complex environmental challenges. Moreover, in the past two decades, Mr. Leafe has developed specific expertise in the assessment and return-to-re-use of environmentally impaired commercial and industrial properties. In addition, he has created and implemented pro forma estimating methodologies that allow expedited site assessment, property acquisition, and site redevelopment while maintaining cost efficiency and timely project completion.

Scott graduated from LeTourneau University with a B.A. in Business Administration. In addition, he received a Master of Divinity in Theological Studies from Liberty University Baptist Theological Seminary and a Doctor of Ministry in Theology and Apologetics from the John W. Rawlings School of Divinity at Liberty University. As an ardent supporter of community outreach programs, Mr. Leafe has served on the Board of Directors of Scriptel Ministries, a private non-profit corporation, since 1995. He is presently the President and Executive Director. This organization provides classroom-style Christian education and training to communities in and surrounding Houston. Mr. Leafe also serves as Chairman of the Board of Directors for Fort Bend County Improvement District No. 24 in Katy, Texas.


Mike Schultz, P.E., CAPM, Principal Engineer/Executive Vice President/Partner

Mr. Schultz is an Executive Vice President and Partner of SKA, having joined the firm in 2004. He has over 36 years of environmental experience, including 33 years in environmental consulting, widely ranging from large-scale Superfund and surface mining facilities to retail petroleum properties and due diligence.

Mike spent the first five years of his career involved in environmental permitting studies for surface mining operations. Initially, he was on staff with the Railroad Commission of Texas, Surface Mining and Reclamation Division for about two years. He then joined Hall Southwest Corporation in Austin, Texas as a private consultant conducting baseline studies for proposed and existing mining operations. These studies included overburden characterization, hydrogeologic and surface water hydrologic investigations, climatological studies, alternative water supply investigations, modeling for estimation of the probable hydrologic consequences of mining, and permitting services for water rights permits, wastewater discharge permits, and levee permits. While at Hall Southwest, Mike also developed extensive experience in the assessment and remediation of PCBs and spent two years managing a PCB and oil spill emergency response contract for the City of Austin Electric Utility Department. Under this contract, crews were on call 24/7 to remediate PCB and oil spill sites in commercial, industrial, and residential areas. More than 150 spill sites were remediated under this contract.

In 1994 Hall Southwest was sold to Groundwater Technology, Inc. (GTI), and Mr. Schultz moved to Houston, Texas, as GTI’s Houston Operations Manager. During his tenure with GTI, Mike developed particular expertise in the assessment and remediation of sites impacted by petroleum hydrocarbons and chlorinated solvents in soil and groundwater. His expertise included the design and implementation of many groundwater remediation systems as well as implementing monitored natural attenuation remedial strategies for groundwater contaminant plumes. A number of the chlorinated solvent sites were dry cleaning facilities. Mike also developed a particular expertise for inspecting and assessing dry cleaning facilities for poor waste management practices and environmental releases.

Mike joined Carter & Burgess, Inc. (C&B) in 1998 as a Senior Project Manager and continued to develop his expertise in site assessment and remediation and added Brownfields redevelopment assessments/cleanups to his portfolio of experience. Mike accepted a Senior Project Manager position with MFG, Inc. in 2001 and became heavily involved in federal and state Superfund projects along the Gulf Coast and at a former mineral processing facility in East St Louis, Illinois. He managed two Remedial Investigation/Feasibility Study projects and a Post Remedial Action Evaluation project.

Throughout his private consulting career, Mr. Schultz has also provided litigation support and served as an expert witness in many legal cases to include deposition and trial testimony in State and Federal court. These cases have often involved the source and extent of contamination and likely cleanup costs, and have dealt with both individual sites and class actions.

Mike brought his entrepreneurial vision and extensive technical and management experience to SKA in 2004 as Operations Manager. Mike became a Vice President of SKA in 2008, a Partner in January 2009, and Executive Vice President in 2019.

Mike is a 1985 graduate of the Colorado School of Mines with a B.S. in Mining Engineering. He holds engineering licenses in Texas (68765), Colorado (30797), Louisiana (26455), Oklahoma (17848), New Mexico (16145), and Wisconsin (35603-006), and is certified as a Corrective Action Project Manager (00944) by the Texas Commission on Environmental Quality. Mike is an Eagle Scout, the father of two Eagle Scouts, a former Scoutmaster and Crew Advisor, and is actively involved with the Boy Scouts of America on the local and Council level.


Brian T. Weaver, P.G., Principal Geologist/Executive Vice President/Partner

Mr. Weaver is a founding member and the Principal Geologist, Executive Vice President, and Partner of SKA, where he oversees the direction, management, and coordination of multiple environmental remediation and consulting projects. Mr. Weaver oversees staff mentoring, staffing, and contracts and is also responsible for client services, business development/marketing, and financial management. His more than 28 years of environmental consulting experience has included Phase I Environmental Site Assessments, Phase II Investigations, UST/LPST Investigations and Closures, Oil and Gas Site Assessments and Cleanups, Risk-Based Corrective Actions, Affected Property Assessments, Voluntary Cleanup Program and Innocent Owner/Operator Program Evaluations and Closures, Municipal Settings Designations, Remedial Design/Remedial Actions, Litigation Support/Expert Witness Testimony, Pro-Forma Evaluations and Feasibility Studies, and environmental construction projects. Brian has served as Principal Geologist and Project Director/Manager for hundreds of environmental assessments, property cleanups, and regulatory closures for all facets of public and private-sector clients.

Brian began his environmental career as a Geologist for KEI Consultants, Ltd., in Houston, Texas where he conducted numerous site assessments and soil and groundwater remediation projects across Texas, New Mexico, and Louisiana at oil/gas exploration and production (E&P) facilities, petrochemical and bulk storage tank farms, fuel terminals, refined and crude underground pipeline right-of-ways, and retail fueling stations. Brian then spent four years at Carter & Burgess, Inc. (C&B) in Houston, Texas, where he served as Geologist and Site Manager. While at C&B, Brian conducted site assessments, pre-acquisition due diligence, risk assessments, and remedial actions for environmental projects primarily involved with real estate transactions, development, or re-use (Brownfields) for commercial/industrial and residential property developers, managers, planners, banking/lending institutions, and attorneys.

In 2001, Brian brought his vision to SKA to apply exceptional personal attention and service along with superior regulatory knowledge to a broad base of public and private-sector clients. Brian strives to assist his clients in achieving their business goals by investing time to understand their vision and business objectives. By understanding the bigger picture, Brian provides his clients with opportunities where others have not. Brian brings to each project extensive experience in geology, hydrogeology, environmental construction and remedial actions, strategic planning/forecasting, operations, and regulatory affairs to meet and exceed client expectations. At SKA, Brian specializes in risk-based assessments and soil remedial actions for regulatory closures in both the Texas Commission on Environmental Quality (TCEQ) and the Railroad Commission of Texas (RRC) programs.

In 1995, Brian earned his Bachelor of Science degree in Geology from Stephen F. Austin State University, where he focused his geology degree in environmental geology and hydrogeology. He received his Texas Professional Geoscientist license in 2003 (P.G. No. 274) from the State of Texas Board of Professional Geoscientists. Away from the office, Brian is an avid outdoorsman and especially enjoys going on new adventures (always the “rockhound”) with his wife and two daughters.


Darrell R. Maudlin, P.G., CAPM, Vice President/Senior Project Manager/Asbestos Consultant

Mr. Maudlin is a Vice President and Senior Project Manager, having joined the firm in 2013. He has over 27 years of environmental consulting experience, ranging from large-scale Voluntary Cleanup Program and Corrective Action projects to retail petroleum properties and due diligence. He is also a licensed Asbestos Consultant in Texas with over 20 years of experience in the asbestos inspection and abatement industry.

Darrell began his career in 1996 by performing Phase I and Phase II Environmental Site Assessments (ESAs). Mr. Maudlin has assisted with property and business transactions by managing and performing hundreds of Phase I and Phase II ESAs of properties varying in use from vacant land to large industrial facilities. Over a short time, he developed expertise working on assessing and remediating sites impacted by petroleum hydrocarbons and chlorinated solvents in soil and groundwater. Darrell has managed and performed numerous soil and groundwater subsurface investigations at a wide variety of commercial properties, including (but not limited to) gasoline filling stations, bulk facilities, dry cleaner facilities, former UST sites, industrial/manufacturing facilities, pipeline easements, and oil exploration/production properties.

As a Texas Licensed Individual Asbestos Consultant, Darrell has performed asbestos surveys and comprehensive asbestos abatement support services for various public building types including hospitals, office/retail buildings, and industrial facilities, apartment buildings, and other commercial structures.

Darrell brought his extensive technical and management experience to SKA in 2013 as a Project Manager. Darrell advanced quickly, becoming a Senior Project Manager in 2016. Darrell was promoted to Vice President in 2019.

Darrell is a 1996 graduate of Southwest Texas State University (currently Texas State University) with a B.S. in Environmental Science. He holds Professional Geoscientist licenses in Texas (10023) and Louisiana (427) and is certified as a Corrective Action Project Manager (01620) by the Texas Commission on Environmental Quality. Darrell is also licensed as an Individual Asbestos Consultant (105792) with the Texas Department of State Health Services. Darrell enjoys snowboarding, water sports, and fishing the bays of the Texas coast.


John J. Mastroianni, P.G., CAPM, Senior Geologist

Mr. Mastroianni is a Senior Geologist consultant at SKA. He has more than 35 years of environmental consulting experience specializing in the restoration of environmentally impaired properties to beneficial use. His associated work experience has included: Active Surface Fault Investigations in Southeast Texas; Phase I Environmental Site Assessments; Phase II Site Investigations; UST/LPST Investigations, Remediations and Closures; Refinery Clean-ups and Closure; Risk-Based Corrective Actions; Affected Property Assessments; Voluntary Cleanup Program and Innocent Owner/Operator Program Evaluations and Closures; Municipal Setting Designations; Litigation Support; Remedial Design; and Remediation Technology Development and Implementation for which he has received numerous patents and recognitions.

As a graduate student at the University of Houston and research assistant to the renowned fault investigator and expert, the late Dr. Carl Norman, John completed a Thesis on “A Study of Active Fault Movement, Houston Texas and Vicinity” and was granted a Master of Science in Geology. He subsequently worked directly with his friend and mentor, Dr. Norman, on fault investigations and fault mapping, contributing valuable data to Dr. Norman’s expansive Active Fault Database that includes extensive mapping of known and possible active surface faults in the Gulf Coast area and data from over 1,000 of his authored reports. This reference material provides an invaluable resource for the continuation of geologic research, investigations, and consulting work in this area. Currently, John is focusing his career on this fault investigation work, having acquired the exclusive rights and ownership of the complete Active Fault Database and associated library from Dr. Norman’s estate.

Mr. Mastroianni earned a Bachelor of Science in Geology from Emory University in 1982 and his Master of Science in Geology from the University of Houston in 1992. He has a Professional Geoscientist License No. 834 from the State of Texas Board of Professional Geoscientists and a Professional Geoscientist License No. 262 from the State of Louisiana Board of Professional Geoscientists. He is also a Texas Commission on Environmental Quality (TCEQ) Leaking Petroleum Storage Tank (LPST) Corrective Action Project Manager (CAPM), License No. CAPM00660.

Away from the office, John enjoys racing his sailboat in Galveston Bay and going on travel and sailing adventures in the US and abroad with his family and friends.


Chris Siegel, P.E., Senior Project Manager/Senior Environmental Engineer

Mr. Siegel is a Senior Project Manager and Senior Environmental Engineer of SKA, having originally been with the firm from 2013 through 2020 and then returned to SKA in 2024. He has over 23 years of environmental experience, including 11 years in environmental consulting, focusing on the assessment and remediation of Brownfield properties to facilitate redevelopment.

Chris began his environmental career as an environmental regulator with the Texas Commission on Environmental Quality (TCEQ). At the TCEQ, he completed technical reviews for applications for Municipal Solid Waste landfills, transfer stations, and processing facilities. Chris was also a project manager in the TCEQ Voluntary Cleanup Program and Corrective Action section. He provided oversight on a variety of assessments and corrective action projects, including, but not limited to, gasoline filling stations, dry cleaner facilities, industrial/manufacturing facilities, chemical plants, military facilities, and Superfund sites. His corrective action projects included the use of excavation, caps, dual-phase extraction and pump-and-treat groundwater remediation, phytoremediation, and bioremediation.
While at SKA, Chris has used his expertise in environmental regulations and contaminant behavior to expedite the regulatory closure for sites impacted by petroleum hydrocarbons and chlorinated solvents in soil and groundwater. His expertise includes the design and implementation of water treatment systems and monitored natural attenuation remedial strategies for groundwater contaminant plumes.

Chris is a 2000 graduate of the University of Texas at Austin with a B.S. in Chemical Engineering and is a licensed professional engineer in Texas (136702).


Tory C. Balderrama, P.G., Senior Geologist/Project Manager

Ms. Balderrama is a Senior Geologist and Project Manager at SKA and has over 10 years of environmental consulting experience. She manages pre-acquisition due diligence studies, limited site assessments, affected property assessments, and remedial actions for properties as part of real estate transactions, development, or reuse of contaminated properties (Brownfields). Her project experience has included evaluating former and active petroleum exploration and production (E&P) fields, industrial manufacturing facilities, warehouse distribution facilities, retail fueling facilities, bulk fuel storage facilities, dry cleaners, automotive repair and other commercial businesses, and vacant and residential properties.

Tory began her environmental career in 2013 at SKA, rising as Staff, Project, and Lead Geologist before becoming a Project Manager in 2020 and Senior Geologist in 2023. Using her extensive geology experience and knowledge of environmental regulations, Tory develops effective strategies to achieve Client goals and obtain regulatory closure for both residential and commercial/industrial land uses through the Texas Commission on Environmental Quality (TCEQ) and Railroad Commission of Texas (RRC) regulatory programs (i.e., Voluntary Cleanup Programs and Corrective Action).

As a leading technical writer at SKA, Tory has prepared numerous complex regulatory reports, such as Affected Property Assessment Reports (APARs), Site Investigation Reports (SIRs), Response Action Plans (RAPs), Response Action Completion Reports (RACRs), Municipal Setting Designation Reports (MSDs), and response letters to TCEQ and RRC regulatory personnel. Tory has extensive knowledge of TCEQ Texas Risk Reduction Program (TRRP) rules codified in 30 Texas Administrative Code (TAC) §350. She uses these rules to effectively meet Client goals, reducing time, effort, and costs in obtaining regulatory closure of TCEQ TRRP sites.

In 2012, Tory earned her Bachelor of Earth Sciences in Geology from the University of South Alabama. She received her Texas Professional Geologist license (11609) in 2018 from the Texas Board of Professional Geoscientists and is a certified Leaking Petroleum Storage Tank (LPST) Project Manager (No. PM0000692) by the TCEQ. Outside the office, Tory enjoys reading, baking, and spending time with her husband and daughter.