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Date Permissions Signed

9-10-2015

Date of Award

Spring 2000

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Geology

First Advisor

Mitchell, Robert J. (Geologist)

Second Advisor

Babcock, R. Scott (Randall Scott)

Third Advisor

Matthews, Robin A., 1952-

Abstract

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.

Type

Text

Publisher

Western Washington University

OCLC Number

45118911

Digital Format

application/pdf

Geographic Coverage

Whatcom County (Wash.)

Genre/Form

Academic theses

Language

English

Rights

Copying of this thesis 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.

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Geology Commons

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