About WERI

Dr. John W. Jenson

WERI Director 
Professor of Environmental Geology 
Chief Hydrogeologist 

Hafa Adai

We at WERI are proud to provide reliable research and first-rate teaching and outreach on freshwater resources to the citizens of Guam, the Commonwealth of the Northern Mariana Islands, and the Federated States of Micronesia. We have faculty expertise in all the major fields pertinent to the management of water resources in the tropical Pacific region: tropical meteorology, surface-water hydrology, island hydrogeology, groundwater hydrology, water-quality engineering, and geospatial environmental analysis. We take special pride in our Water Quality Laboratory, which supports not only our research programs, but also provides a wide range of public and commercial services to other laboratories, agencies, businesses, and citizens throughout the region.

WERI is also the central supporter of the University of Guam’s graduate Environmental Science Program. Our faculty teach courses and advise students, many of whom derive theses from WERI-funded projects on which they serve as research assistants. We collaborate with the US Geological Survey, Guam Waterworks Authority, Guam Environmental Protection Agency, Naval Facilities Engineering Systems Command Marianas, and other local, regional, and federal agencies to provide reliable and honest scientific research, advice, and training on water-related interests.

We invite you to contact us for services to support informed and effective stewardship of water resources.


John W. Jenson
WERI Director

WERI Faculty

Dr. Mark A. Lander

Assistant Professor of Metereology

Dr. Yuming Wen

Professor of GIS

Dr. Joseph D. Rouse, PE

Professor of Environmental Engineering

Dr. Nathan C. Habana

Associate Professor of Groundwater Hydrology
Chief Hydrologist

Dr. Barry (Yong Sang) Kim

Assistant Professor of Water Engineering

Dr. Myeong-Ho Yeo

Assistant Professor of Surface Water Hydrology

Institutional History

The Water and Environmental Research Institute of the Western Pacific (WERI) was established at the University of Guam in May 1975. It is one of 55 institutes established by U.S. Congressional legislation at each Land Grant University in the United States and in several territories. Originally named Water and Energy Research Institute of the Western Pacific, WERI changed its name in 1998 in line with expanding research interests in water related areas of other disciplines, e.g., meteorology, geology, hydrology, geohydrology, engineering, environmental toxicology, environmental chemistry, mapping and modeling. An account of WERI during this time period was documented by Dr. Stephen J. Winters in a keynote speech at the University of Guam, which details some of the early problems they have encountered, research projects, and his vision of the institution’s progress towards to the future. 

The role of the Institute is to facilitate and conduct high quality research that addresses water problems and water-related phenomena; train students, teachers and future water resource professionals, and disseminate research results to the community at large. Base support for WERI comes from the Water Resources Research Institute (WRRI) 104-B Program administered through the U.S. Geological Survey. The Institute also seeks funding for research projects from local and other federal sources.

Consistent with the regional role of the University, the Institute devotes part of its program effort to Western Pacific islands other than Guam. It is the only research center of its type in this geographic area and endeavors to respond to the unique conditions that exist here. WERI officially became the first Regional Water Resources Research Institute in the WRRI program by extending its mission to the Federated States of Micronesia (FSM) in 1991 and to the Commonwealth of the Northern Marianas (CNMI) in 1997. This designation has opened a broad new spectrum of research and service opportunities for the University of Guam.

WERI works closely with an Advisory Council established for each of its three regional entities. Each council is composed of representatives from various government departments that deal with water and water related issues, public and private sector engineers, environmentalists and planners as well as academics and interested members of the community. The Institute draws from the varied expertise of its research faculty members, University of Guam faculty, research affiliates from other universities, and local professionals.

1991 WERI Building

WERI Directors

Dr. Shahram Khosrowpanah, PE

Civil Engineer, Hydraulics
Interim Dean School of Engineering
2 years | 2014 – 2016
2 years | 1990s, 3 years | 1980s,


Dr. Gary Denton

Environmental Toxicology
7 years | 2006 – 2014



Dr. Leroy F. Heitz, PE

Civil Engineer, Hydrologist
Emeritus Professor
 6 years | 2000 – 2006



Dr. Galt Siegrist

3 years | 1997 – 2000
Emeritus Professor

Dr. Peter Hontoon



Dr. Stephen J. Winters, PE



Dr. James Marsh

Marine Biologist
Emeritus Professor 


Water Quality Laboratory


The Water Quality Laboratory was started with the inception of the Water Resource Research Center in 1972. The laboratory’s current staffing includes a Laboratory Manager and one full time Laboratory Technician. Part time research assistants are hired as required by analysis workloads.

The laboratory is equipped to perform a variety of Water Quality/Environmental Analysis in support of WERI research faculty, as well as support of the teaching faculty in the Environmental Science Program; Chemistry Department; the University of Guam Marine Laboratory; and the College of Natural and Applied Sciences. In addition the laboratory is available for student thesis projects.

The laboratory also provides a variety of analytical services to public and private sectors of the community, and is USEPA certified to perform lead, copper and bacteriological analyses of drinking water. Various other physical and chemical tests are routinely carried out on aqueous samples and are available at commercially competitive rates. The laboratory also commonly conducts trace metal analysis on other environmental samples, particularly soils, sediments and biological materials.

The Guam Hydrologic Survey and Comprehensive Water Monitoring Program (GHS | CWMP)

Hydrology Laboratory | 1-671-735-2693

The Guam Hydrologic Survey (GHS) and the Comprehensive Water Monitoring Program (CWMP) P.L. 24-247 and 161 charges the Water and Environmental Research Institute of the Western Pacific (WERI) at the University of Guam to develop, operate, manage, and administer these two public law programs. The program was enacted in 1998 to address the need for access to accurate hydrological information and scientific advice for island growth and development with respect to water resources capacity. The mission of the GHS and CWMP is to collect and make accessible pertinent hydrologic information, establish interagency cooperation agreements for data acquisition, apply data analysis and make interpretation available in annual reports, provide water resource educational outreach (workshop, aquifer tours), produce the latest hydrologic information materials (poster, maps), and conduct scientific research into water resource problems, delivering sound recommendations for policy, regulations, and management decisions. The two public laws also provides details to drilling and geophysical data collection and develop annual budget for program appropriations. See the Guam Hydrologic Survey website for more information.

WERI Staff

Administration Staff | Front Office | 1-671-735-2685 | Fax: 1-671-734-8890

Gema C. Payumo

Program Coordinator IV

Anthony A. Agustin

Administrative Assistant 

Water Quality Lab Staff

Water Quality Lab | 1-671-735-2688

Mallary N. Duenas

Laboratory Manager / Research Assistant 

Mignon Tuazon

Chemist II / Analyst 

Elizabeth Weckel

Laboratory Technician 


Hydrology Lab | 1-671-735-2693

Kaylyn Bautista

Research Associate 

Dannika Valerio

Web Developer 

Undergraduate Research Assistants 2022

Jayvee Cacal

Research Assistant I
USGS Information Transfer

Hark Galarion

Research Assistant I 
USGS Information Transfer

Isaac Snively

Research Assistant I 
Advisor: Kim 

Photo of WERI RA Jovic Caasi

Jovic Caasi

Research Assistant I
Advisor: Habana

Photo of WERI RA Matt Wilson Zapata

Matt Wilson Zapata

Research Assistant II

Graduate Research Assistants 2021

April H. Schimmel

Research Assistant
Committee: Denton, Habana, and Ghosh

Mallary Duenas

Research Assistant – Staff 
Committee: Kim, Jenson, Habana, and Vuki 

Eliana Walker

Research Assistant II
Committee: King, Jenson, …

Natalie Bravo

Research Assistant 

Fagan Matthys

Research Assistant 

Hazelle Ko

Research Assistant 

April H. Schimmel
Research Assistant
Committee: Denton, Habana, and Ghosh


Mallary Duenas
Research Assistant – Staff
Committee: Kim, Jenson, Habana,
and Vuki


Eliana Walker
Research Assistant II
Committee: King, Jenson, …

Ma. Jhonie Villareal
Research Assistant II
Committee: Jenson, …

Thomas-Ryan M. Aguilo
Research Assistant II
Committee: Habana, Jenson, and Aquino

2020-2021 Graduates
Master of Science in Environmental Science

WERI is proud to announce our recent Master of Environmental Science Graduates of 2020-2021. Ms. Maria Jhonnie Villareal and Mr. Paul Bourke are the products of the University of Guam’s Graduate Studies Program, Master of Science in Environmental Science who produced a WERI Master’s Thesis and Professional Thesis Projects. 

Ms. Maria Jhonnie Villareal

Graduated December 2021
Committee: Jenson, King, and Aban

Mr. Paul Bourke

Graduated May 2020
Committee: Jenson, Habana, Lander, and Ho

2019 Graduates
Master of Science in Environmental Science

WERI is proud to announce four new brilliant Masters of Environmental Science Graduates of 2019: Ms. Jennifer O. Cruz, Ms. Bekah Dougher, Ms. Lyuqin Liu, and Mr. Daniel G. Superales. These outstanding graduates are the product of the University of Guam’s Graduate Studies Program, Master of Science in Environmental Science who each produced a WERI Master’s Thesis Project. 

Read the Feature on the 2019 Graduates on WERI News. 

Ms. Jennifer O. Cruz

Graduated May 2019 
Committee: Denton, Biggs, Donaldson, and Jenson

Ms. Bekah Dougher

Graduated May 2019 
Presidential Thesis Award, NGWA – Farvolden Scholarship
Committee: Habana, Jenson, Lander, and Ho

Ms. Lyuqin Liu

Graduated December 2019 
Committee: Kim, Rouse, Jenson,
and Wu

Mr. Daniel G. Superales

Graduated December 2019 
Committee: Habana, Jenson, and Gingerich

MS in Environmental Science: WERI Graduates

To view feature stories on graduates, visit the WERI News: Graduates page. 

 YearMS Environmental Science GraduateAdvisor
2021Villareal, Maria JhonnieJenson
2020Bourke, PaulJenson
2019Superales, Daniel Vincent GarridoHabana
2019Liu, LyuqinKim
2019Dougher, RebekahHabana
2019Cruz, JenniferDenton
2019Arceo, CandiceDenton
2017Shalilian, IdaJenson
2017Bautista, Kaylyn K.Jenson
2015Martinez, JustinRouse
2015Whitman, William Khosrowpanah
2014Namazi, SaraDenton
2014Vann, DavidJenson
2013Welch, PaulinaDenton
2013Muller, LeenaRouse
2013Bendixson, ViviannaJenson
2012Schiable, BrianDenton
2012Simard, ChristineJenson
2012Manibusan, SydoniaKhosrowpanah
2011Bell, TomokoJenson
2010Kottermair, MariaWen
2009Miklavic, BlazJenson-Mylroie
2009Datuin, TheresaLander
2009Habana, NathanHeitz-Jenson
2008Bailey, RyanJenson
2007Moran, DaveJenson
2007Hoffman, MichelleJenson
2007Wexel, CurtisJenson
2007Park, MichaelKhosrowpanah
2006MacCracken, RobertJenson
2005Takase, ChieDenton-Shupp
2003Jano-Meno, JeanetteRaulerson
2002Scheman, NicoleKhosrowpanah
2001Smit, Karl-GustaafSeigrist
2001McDonald, MaurynJenson
2000Beausoliel, ColletteKhosrowpanah
2000Taborosi, DankoJenson
2000Lewis, RusselSeigrist
1997Jocson, JohnJenson
1997Dumaliang, Peter-PaulKhosrowpanah