Everyday actions—such as applying fertilizer, storing and using fuels or solvents, or even maintaining gardens—can influence the quality of drinking water in the Thames-Sydenham and Region. Likewise, how we use water, from lawn irrigation to extended showers, can affect the availability of this vital resource.
To protect drinking water sources, the Clean Water Act, 2006 requires the identification of activities that may pose a risk within vulnerable areas of each source protection region. In response, a thorough evaluation was carried out to identify such activities across all vulnerable areas.
Water Quality Threats
The Province of Ontario has prescribed in regulation 21 activities that under certain circumstances could contaminate the quality of drinking water sources. The activities deemed to be drinking water quality threats are related to the following:
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Waste disposal sites – their establishment, operation, or maintenance
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Sewage systems – their establishment, operation, or maintenance
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Agricultural source material – application to land
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Agricultural source material – storage
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Agricultural source material – management
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Non-agricultural source material – application
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Non-agricultural source material – handling and storage
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Commercial fertilizer – application
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Commercial fertilizer – handling and storage
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Pesticide – application
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Pesticide – handling and storage
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Road salt – application
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Road salt – handling and storage
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Snow – storage
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Fuel – handling and storage
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Dense non-aqueous phase liquid – handling and storage
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Organic solvent – handling and storage
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Chemicals used to de-ice aircraft – management of runoff
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Land associated with livestock – use of for grazing, pasturing, confinement, or as a yard
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Establishment and operation of a liquid hydrocarbon pipeline
Water Quantity Threats
The Province of Ontario also identified two activities considered to be threats to the quantity of a water source.
These include:
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An activity that takes water from an aquifer or a surface water body without returning the water taken to the same aquifer or surface water body
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An activity that reduces the recharge of an aquifer
These threats are considered when a municipal well has undergone a Tier 3 local water quantity risk assessment.
Provincial Reference Tables
The Ministry of the Environment produced reference tables for each combination of vulnerable area and vulnerability score for three threat categories and three risk levels. Check out swpip.ca to for your reference of the circumstances.
The threat categories are:
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chemical
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pathogen
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dense non-aqueous phase liquid (DNAPL)
The risk levels are:
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significant
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moderate
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low
