The vast majority of theses in this collection are open access and freely available. There are a small number of theses that have access restricted to the WWU campus. For off-campus access to a thesis labeled "Campus Only Access," please log in here with your WWU universal ID, or talk to your librarian about requesting the restricted thesis through interlibrary loan.

Date Permissions Signed


Date of Award

Spring 2000

Document Type

Masters Thesis

Degree Name

Master of Science (MS)



First Advisor

Mitchell, Robert J. (Geologist)

Second Advisor

Babcock, R. Scott (Randall Scott)

Third Advisor

Matthews, Robin A., 1952-


The Abbotsford-Sumas aquifer is a primarily unconfined aquifer, located in Whatcom County, WA, with a history of nitrate contamination. Whatcom County is a large producer of raspberries and contains numerous dairy farms. Both of these agricultural practices involve large quantities of nitrates being produced or used for fertilization. A two-year ground water monitoring program was conducted in 1997 and 1998 by Western Washington University in order to determine the spatial and temporal extent of the nitrate contamination. Possible trends in nitrate concentrations may be associated with ground water movement, chemical and biological nitrate reduction processes, seasonality and land use. Exploratory univariate, bivariate and multivariate statistical analyses were utilized to determine the dominant processes affecting nitrate concentrations in the study area. Nitrate concentrations in shallow wells were associated with local agricultural practices and nitrate concentrations in deeper wells were associated with agricultural practices occurring up-gradient in Canada. Differentiating land use based on nitrate concentrations was determined to be inconclusive. Denitrification was occurring in over half of the wells in the study area. Several types of nitrate concentration trends were observed: higher nitrate concentrations in the fall and winter due to nitrification in the spring and summer; higher nitrate concentrations in the spring and summer due to nitrogen inputs; a steady increase or decrease in nitrate concentrations; no detectable nitrate concentration. Multivariate statistical analyses confirmed that there was not one dominant process affecting nitrate concentrations in the Abbotsford-Sumas study area; therefore, nitrate concentration trends are due to a combination of processes.





Western Washington University

OCLC Number


Subject – LCSH

Groundwater--Washington (State)--Whatcom County--Analysis; Groundwater--Pollution--Washington (State)--Whatcom County; Nitrates--Environmental aspects--Washington (State)--Whatcom County; Aquifers--Washington (State)--Whatcom County

Geographic Coverage

Whatcom County (Wash.)




masters theses




Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Included in

Geology Commons