About Westwater Hydrology

Westwater Hydrology LLC is part of a community of independent consultants and small to international firms with a wide range of expertise and partnering mechanisms. Westwater can provide multi-disciplinary turnkey services for any water resources or environmental assessment or cleanup project, including soil and water testing and results interpretation, water well testing and groundwater resource due-diligence evaluations, dewatering permitting, and high water table investigation and mitigation. Please contact Westwater to discuss your project needs today.

environmental engineer

303-456-1981

Email Andy

Andy Horn, MS, PG

With over 30 years of experience, Westwater Hydrology’s Principal Hydrogeologist works with public and private sector clients executing water resources and environmental hydrologic consulting projects. Mr. Horn has worked on a wide variety of projects from inception through construction to final reporting and closure. He provides exceptional value for the expertise he brings to projects and prides himself on developing cost-effective and pragmatic solutions to help clients accomplish their goals. Please see below for Mr. Horn’s education and training, professional certifications, and selected publically-available presentations and publications.

Mr. Horn regularly participates in professional conferences, seminars, and other continuing education opportunities.

Mr. Horn has prepared numerous proprietary reports for private clients; select publicly-available reports can be obtained via internet, examples or directions for download are available on request.

Mr. Horn’s Education and Professional Development

  • M.S., Geological Sciences (Hydrogeology emphasis), The University of Colorado, 1997
  • B.S., Geology, The University of Alabama, 1990
  • Analysis and Design of Aquifer Tests, Including Slug Tests and Fracture Flow, 2004
  • Project Management Certification, 2001
  • Public Speaking and Presentation Skills Seminar, 2000
  • Technical Writing Seminar, 1999
  • Conflict Management and Effective Listening Seminar, 1998
  • MODFLOW for Simulation of Groundwater Flow and Advective Transport, 1993
  • MSHA New Miner Training (with underground training) 2015
  • PEC SafeLand Training, 2015.
  • OSHA Hazardous Waste Operations 8-hour Supervisor’s Training, 1993
  • OSHA Hazardous Waste Operations 40-hour Training, 1991 (annual refresher training current)

Professional Registrations, Committees, and Affiliations

  • Professional Geologist, Kansas, #707, Wyoming #PG-4087
  • National Groundwater Association (NGWA) Expert White Paper Group: Per- and Polyfluroalkyl Substance Guidance Document, 2016-2017
  • NGWA Expert White Paper Group: PFAS Risk Communication for (Water Well) Contractors, 2020
  • NGWA Expert White Paper Group: Practical Guide to PFAS Sampling, 2022 – 2023
  • NGWA Expert White Paper Group: PFAS Forensics (source identification), 2023 – 2024
  • Colorado Environmental Management Society, Board of Directors, 2017 – 2021
  • Colorado Ground Water Association (CGWA), Board of Directors, 2006 – 2012
  • State Engineer / Colorado Water Well Contractor Association / CGWA Water Well Technical Working Group, 2007 – 2022
  • Chairman, CGWA Ad Hoc Committee on EPA Proposed Carbon Sequestration Underground Injection Control Well Rule, 2008
  • Geological Society of America, Hydrogeology Division, 1989 – 2021
  • National Ground Water Association, Association of Groundwater Scientists and Engineers, 1991 – current

Select Publications and Presentations

Horn A., NGWA PFAS Forensics “State of the Science” Working Group Status Report, on behalf of the Colorado Groundwater Association, 15th Annual Geotech Field Days Conference, June 20, 2024.

Horn A., Finally: A Practical Guide to PFAS Sampling, Colorado Environmental Management Society, April 9, 2024.

National Ground Water Association. 2023. Practical Guide for PFAS Sampling, contributor. National Ground Water Association, Waterville, Ohio.

Horn, A. 2022. Per- and Polyfluoroalkyl Substances Overview and Legal and Regulatory Update, Colorado Water Rights and Regulation Seminar. February 9, 2022

Horn, A. 2020. Per- and Polyfluoroalkyl Substances Legal and Regulatory Overview, Colorado Bar Association Water Law Section. Denver, Colorado. May 14, 2020.

National Ground Water Association. 2020. PFAS Risk Communication for Contractors, contributor. National Ground Water Association, Waterville, Ohio.

Horn, A. 2018. Per- and Polyfluoroalkyl Substances (PFAS) – Overview and Implications for the Oil and Gas Industry. Colorado Oil and Gas Association, EHSR Committee, Denver, Colorado. Nov. 1, 2018.

Horn, A. 2018. PFAS Sampling: Will Your PFAS Data Stand Up in Court? Fountain Valley Clean Water Coalition, Fountain, Colorado, October 18, 2018.

Horn, A. 2018. Perfluoroalkyl Substance (PFAS) Sampling and Analysis: 2018 State of the Practice. American Association of Professional Geologists 2018 National Conference, 2018. Colorado Springs,  Colorado, September 8-11 2018.

National Ground Water Association. 2017. Groundwater and PFAS: State of Knowledge and Practice. Contributor to Section 5, Field Sampling and Analyses. National Ground Water Association, Waterville, Ohio.

Horn, A. and Clendenin, G. 2016. Drilling with the Stars: Lessons from a Southern California Urban Drilling Program. Colorado Environmental Management Society, January 12, 2016.

Horn, A. and Barkmann, P. 2015. Gilcrest/LaSalle Area Hydrogeologic Characterization. American Water Resources Association, Colorado Section Monthly Meeting, Denver, Colorado. March 31, 2015.

Barkmann, P.; Horn, A.; Moore, A.; Pike, J. and Curtiss, W. 2014. Gilcrest/LaSalle Pilot Project Hydrogeologic Characterization Report. Prepared for the Colorado Division of Water Resources and the Colorado Water Conservation Board by the Colorado Geological Survey, September 30, 2014.

Horn, A.; Sares, M.; Brown, C. and Haworth, M. 2013. South Platte Alluvial Aquifer Response to the September 2013 Colorado Flood Event. Geological Society of America National Meeting, GSA’s 125th Anniversary Annual Meeting & Exposition, GSA Abstracts with Programs, Late Breaking Session on 2013 Colorado Flood Event, Denver, Colorado, October 29, 2013.

Horn, A. 2014 – 2018. Field Documentation Basics and Data Defensibility. Guest lecture for graduate-level Hydrologic Field Methods classes at Colorado School of Mines, University of Colorado Boulder; various dates.

Horn, A. 2012 – 2018. Field Hydrogeology Basics. Guest lecture for undergraduate Hydrogeology classes at Colorado State University, University of Colorado Boulder, Colorado School of Mines, UC Denver, various dates.

Topper, R. and Horn, A. 2011. El Paso County Groundwater Quality Study, Phase 1. Prepared for the El Paso County Groundwater Quality Study Committee for presentation to the El Paso County Board of County Commissioners, March 2011.

Horn, A. 2010. Potential Environmental Implications of Geologic Carbon Storage. Colorado Ground Water Association, September 15, 2010.

Horn, A. and Avramenko, W. 2010. Movement Toward a Risk Management Approach To Ground Water Cleanups in Colorado. Colorado Ground Water Association Newsletter, Winter 2010.

Horn, A. 2009. Carbon Capture and Geologic Storage – Business Opportunities for the Environmental Industry. Colorado Hazardous Waste Management Society, Environmental Opportunities in the New Energy Economy, Denver, Colorado April 14, 2009.

Horn, A. 2008. Methods to Evaluate and Rank Potential Aquifer Recharge Sites: Colorado’s Experience. ASR VIII Conference, American Groundwater Trust, Orlando, Florida, September 22-23, 2008.

Horn, A. and McCurry, G. 2008. Innovative Methods and Approaches Add Value to a Regional Water Resources Study. Ground Water Summit, National Groundwater Association, Memphis, Tennessee. March 30-April 3, 2008.

Horn, A. 2008. Senate Bill 06-193 Underground Water Storage Study. American Water Resources Association, Colorado Section Monthly Meeting, Denver, Colorado. March 25, 2008.

McCurry, G.; Horn, A.; Smith, N. and A. Moore 2007. Results of a Regional Underground Water Storage Study in Colorado. American Water Resources Association, 2007 Annual Water Resources Conference, Albuquerque, New Mexico, November 12-15, 2007.

Horn, A. 2005. Denver Basin Bedrock Aquifer Testing and Data Collection, South Platte Decision Support System Project. Colorado Ground Water Association, Denver Colorado, October 28, 2005.

Horn, A.; Paschall, D. and McCurry, G. 2004. Availability of Aquifer Property Data in the Denver Basin. Geological Society of America National Meeting, Geoscience in a Changing World, Annual Meeting & Exposition, GSA Abstracts with Programs, Vol. 36, No. 5, Denver, Colorado, November 7-10, 2004.

McCurry, G.; Horn, A. and Paschall, D. 2004. Techniques for Developing an Effective Field Monitoring Program for Groundwater Data in the South Platte Basin of Northeast Colorado. Geological Society of America National Meeting, Geoscience in a Changing World, Annual Meeting & Exposition, GSA Abstracts with Programs, Vol. 36, No. 5, Denver, Colorado, November 7-10, 2004.

Horn, A.; Smith, M. and Blandon, A. 2003. Use of a Numerical Model for Artificial Recharge Decision Support in the Chino Basin, California. American Water Resources Association 2003 National Conference, San Diego, California, November 3-6, 2003.

SBE Status and Professional Liability Insurance

Westwater Hydrology LLC is a certified small business (CAGE Code: 7G2P6) based in Colorado. Westwater carries professional liability insurance suitable for most national clients; higher project-specific limits can be obtained as needed. Please contact us with any questions regarding this or any other matters.