Groundwater microbiology is the study of the microscopic organisms, mostly bacteria, that inhabit groundwater systems. Of the topics that make up groundwater science, groundwater microbiology has undergone immense advances in the past 40 years. Microbes live nearly everywhere in the subsurface, even under harsh conditions of high temperature and salinity at great depth. Microbes influence and often control geochemical processes and hence they are important to the natural quality of groundwater such as the concentrations of iron, manganese and arsenic, and, along with oxidation-reduction potential and pH, determine the odor and color of well water. Microbes determine when well clogging is a problem, and often they determine whether or not anthropogenic chemicals (contaminants) disappear or persist in groundwater.

Commonly, microbes have resided in a geological stratum over geologic time and are activated when conditions change. Like human beings, they require energy and nutrients (e.g., food) to survive but microbes can persist for millennia with little of these life essentials. However, when conditions provide more of their life sustaining needs, the microbes multiply and change the hydrochemistry. Changes can also occur in response to human alterations of the landscape and hydrology. As groundwater moves along its flow path from recharge to discharge areas, it may pass through strata that do not contain microbes and then enter a zone where conditions are more favorable to microbes that change the groundwater markedly. Groundwater chemistry may be governed by the minerals in contact with the water along its flow paths and or the microbes may control the chemistry. Zones of substantial microbial activity may occupy only a small portion of the groundwater system yet be the dominant influence on chemical composition of the water in much of the system. What groundwater transports into a zone, what happens in the zone and what is transported away from the zone are important. This book introduces the principles of groundwater microbiology, including microbe cell structure and growth, the bioenergetics and metabolism of microorganisms, the geochemical and physical influences on microbes with emphasis on natural water quality but also considering the role of microbes in contaminated groundwater.

This is the first Groundwater Project book written by a professor in collaboration with graduate students. The GW-P encourages this type of team effort. Dr. Grant Ferris is a senior professor in the Department of Earth Sciences at the University of Toronto, Canada, and conducts research in environmental microbiology at many locations around the globe. That department is also the academic home of Natalie Sponzar where, after a decade as a consulting hydrogeologist, she is a Doctor of Philosophy candidate focused on aqueous and isotope geochemistry. Brock Edwards, whose research is focused on gas emissions from active volcanoes, is a Doctor of Philosophy candidate at the Centre for Earth Observation Science at the University of Manitoba, Canada.

John Cherry, The Groundwater Project Leader
Guelph, Ontario, Canada, July 2021


Groundwater Microbiology Copyright © 2021 by F. Grant Ferris, Natalie Szponar, and Brock A. Edwards. All Rights Reserved.