Zachary D. Weller, PhD

Contact Information

Senior Data Scientist

Pacific Northwest National Labs

zachary.weller 'at' pnnl.gov


  • Ph.D., Statistics, Colorado State University, Fort Collins, CO. January 2017.

  • M.S., Statistics, Colorado State University, Fort Collins, CO. December 2013.

  • B.A., Mathematics, Concordia College, Moorhead, MN. May 2011.


I am a senior data scientist at Pacific Northwest National Lab where I am part of the Applied Statistics and Math group in the National Security Directorate. At PNNL, I work on projects related to environmental impacts and remediation associated with energy and national security. My primary research interests lie in spatial, Bayesian, and non-parametric statistical methods with applications in ecological, environmental, and biological problems. I am also interested in applications in energy and wildlife management. In addition to my research, I am also interested in scientific communication, the intersection of science and policy, and statistics education.

Before joining PNNL, I was an assistant professor of Statistics at Colorado State University where I worked in the Graybill Statistics and Data Science Laboratory and taught statistics courses. At CSU, I was involved in a long term research project to locate natural gas leaks and quantify their methane emissions.

Selected Publications and Manuscripts

  • Characterizing detection probabilities of advanced mobile leak surveys: implications for sampling effort and leak size estimation in natural gas distribution systems. Luetschwager, E., von Fischer, J.C., Weller, Z.D. (2021). Elementa. doi: 10.1525/elementa.2020.00143

  • A National Estimate of Methane Leakage from Pipeline Mains in Natural Gas Local Distribution Systems. Weller, Z.D., Hamburg, S.P., von Fischer, J.C. (2020). Environmental Science and Technology, 54: 89548-8967. doi: 10.1021/acs.est.0c00437.

  • A Nonparametric Spectral Domain Test of Spatial Isotropy. Weller, Z.D & Hoeting, J.A. (2020). Journal of Statistical Planning and Inference, 204: 177-186. doi: 10.1016/j.jspi.2019.05.005.

  • A Calibration-Capture-Recapture Model for Inferring Natural Gas Leak Population Characteristics Using Data From Google Street View Cars. Weller, Z.D., Hoeting, J.A., von Fischer, J.C. (2018). Environmetrics, 29(7): e2519. doi: 10.1002/env.2519

  • Vehicle-based Methane Surveys Help Find Natural Gas Leaks and Prioritize Leak Repairs. Weller, Z.D., Roscioli, J.R., Daube, W.C., Lamb, B.K., Ferrara, T.W., Brewer, P.E., von Fischer, J.C. (2018). To appear, Environmental Science and Technology, 52(20): 11922-11930. doi: 10.1021/acs.est.8b03135

  • spTest: an R package implementing nonparametric tests of isotropy. Weller, Z.D. (2018). Journal of Statistical Software, 83(4), 1-24. doi: 10.18637/jss.v083.i04.

  • A Review of Nonparametric Hypothesis Tests of Isotropy Properties in Spatial Data. Weller, Z.D. & Hoeting, J.A. (2016). Statistical Science, 31(3), 305-324. doi: 10.1214/16-STS547

Selected Forthcoming Works

  • Environmental Justice Analysis of Urban Natural Gas Leaks. Im, S., Palacios, V., Stuchiner, E., von Fischer, J.C., Weller, Z.D. (2021+). In preparation.

  • Association of inflammatory biomarkers with bioaerosol exposure in livestock workers. Schaeffer, J.W., Williams, E., Weller, Z.D., Wilson, A., Bradford, M., Reynolds, S.J., Magzamen, S. (2021+) In preparation.

You can find more information about my publications on my Google Scholar page.


Below is a video from a seminar I gave in the fall of 2020 to discuss our recent national assessment paper.

Here is a news clip about our methane mapping project from China Global News.

Here is a link to a story about our collaboration with Consolidated Edison, a NY utility company that used advanced leak detection technology to help prioritize leak repairs.

My colleague Joe von Fischer and I were featured on a CSU Research podcast to discuss the methane mapping project:

Below is a write-up of the Methane Emissions Symposium hosted by the Stanford Natural Gas Initiative that I participated in during Spring 2021.

NGI-Brief_2021-06_Methane Emissions Symposium.pdf

Last update: 02/08/2022