Microbial Source Tracking of Alberta's Irrigation Water

 
 
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 Introduction | Current water quality section projects | Objectives of microbial source tracking studies | Importance of the MST projects | Project partners | Publications | Links to other documents

Introduction

The recognition that irrigation water is a risk factor for microbial contamination of produce has resulted in increasingly stringent food safety demands for crop producers. For instance, the CanadaGAP food safety program provides Good Agricultural Practices (GAPs) for the production of fruits and vegetable and includes recommendations for assessing irrigation water quality. Microbial contamination of irrigation water is determined by testing for the presence of generic Escherichia coli, which is a fecal indicator. Although current methods typically measure the amount of E. coli present, they do not indicate the actual source of the contamination. Sources are vast – and include human, livestock, and wild life feces. In addition, there are also environmentally adapted E. coli that live predominantly in aquatic environments or soil, and are not indicators of recent fecal contamination.


Approximately 65% of the total irrigation across Canada is located in Alberta.

An irrigation water quality monitoring study conducted by Alberta Agriculture and Forestry has determined that irrigation water in Alberta is generally of good to excellent quality, largely owing to its origin in the Canadian Rocky Mountains. However, opportunities for improvement exist at some sites where E. coli densities regularly exceed the irrigation water quality guideline. Remedial action to reduce E. coli in irrigation water will depend on the source of contamination. Microbial Source Tracking (MST) is an emerging technology that allows researchers to identify the major source(s) of fecal contamination in surface water and is a useful tool for guiding water quality improvement projects.

MST technologies are generally based on comparing the similarity of microorganisms collected from surface water to microorganisms collected from the feces of nearby sources (livestock, wildlife, humans) in order to make inferences about the likely source of fecal contamination. Because MST is in the developmental phase, studies to determine the reliability and feasibility of these technologies for assessing water quality for various applications such as crop irrigation is required.


Current Water Quality Section Projects


Objectives of Microbial Source Tracking Studies

The primary objectives of current MST studies are:
    1. To utilize established MST methods and develop new methods for tracking the origin of fecal contamination in surface water. New methods will be compared to established methods in order to advance the evolving field of MST.
    2. To determine the feasibility of these methodologies for assessing microbial contamination of irrigation water as it pertains to food safety.
    3. To identify the major sources of fecal contamination in Alberta’s irrigation water at sites where E. coli densities regularly exceed irrigation water quality guidelines.

Importance of the MST Projects

The information generated in these studies will be used by the irrigation industry to identify site-specific and cost-effective mitigation options to ensure acceptable compliance with water quality requirements and assist producers in meeting their food safety requirements for the global marketplace. These studies will also identify opportunities where agri-environmental practices can be improved through the implementation of targeted mitigation measures (i.e., beneficial management practices).

Ultimately, the information generated by these studies will ensure continued production of high-value crops and maintenance of market-access along with reduction of unnecessary regulatory burdens and costs to the agriculture industry associated with mitigation.


Irrigation water samples are prepared for analysis.

Project Partners
  • Alberta Agriculture and Forestry
  • Alberta Irrigation Projects Association
  • Alberta’s Thirteen Irrigation Districts


Water sampling along Alberta's irrigation canals.

Publications

Tymensen LD, Pyrdok F, Coles D, Koning W, McAllister TA, Jokinen CC, Dowd SE, Neumann NF. Comparative accessory gene fingerprinting of surface water Escherichia coli reveals genetically diverse naturalized population. J Appl Microbiol. 2015 119(1):263-77.

Tymensen LD. CRISPR1 analysis of naturalized surface water and fecal Escherichia coli suggests common origin. MicrobiologyOpen. 2016 5(3):527-33.


Links to other documents

Irrigation Water Quality Safety for Fresh Field-grown Fruits and Vegetables


For further inquiries about this document, please contact
Arliss Boschee
Alberta Agriculture and Forestry
Irrigation and Farm Water Branch
( 403-381-5140) (Toll-free 310-0000)

 
 
 
 
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For more information about the content of this document, contact Lisa Tymensen.
This document is maintained by Bonnie Hofer.
This information published to the web on March 3, 2017.