Millennium EMS Solutions Ltd.
December, 2013
Executive Summary
Introduction
The overall objective of this project was to examine the relative toxicity of chloride- and sulphate-based salinity to plants. A literature review was conducted to assess the information already available, and laboratory toxicity tests were commissioned using relevant plant species, Alberta soils and current Environment Canada Protocols.
Methodology
The effect of chloride and sulphate on plant growth endpoints was assessed in a series of ecotoxicity tests using the current Environment Canada protocol. Key elements of the experimental design
included:
Results
The weight of evidence from the literature suggests that sulphate is generally less toxic to plants than chloride.
Ecological direct contact guideline values were calculated from toxicity data collected in this project.
In most cases, the guidelines calculated for fine and coarse soils were similar and the datasets were combined. Guideline values calculated for sensitive land uses (natural area, agricultural and
agricultural) are as follows:
Complete results are available in Table 5 of this document, including guideline values for commercial and industrial land uses. Data from this project clearly indicate that sulphate is less toxic than
chloride to the plant species tested. It is also noted that the EC-based guideline values indicated above are significantly higher than the EC-based salinity guidelines in the current Alberta Tier 1
guidelines document (2dS/m and 3 dS/m for topsoil and subsoil, respectively).
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