Water Contamination

Below: a drainage pipe is clogged.

Sources of water contamination

The sources of pollution responsible for contributing to water contamination are not easily identified even when they are likely coming from industrial, municipal or agricultural activities. Data from the 1980s has identified greater amounts of water contamination occurring in areas of intensive agricultural production. Responsibility has even been placed directly on certain types of agricultural practices, with the determination that they contribute up to 40% of the pollution discharged into watercourses in Quebec. (Bilan des pratiques agroenvironnementales, 1997) Contaminants are mostly sediment, chemical residues, as well as bacteria.

Factors affecting water contamination

• Soil characteristics
• Drainage
• Compaction
• Slope
• Level of nitrates in root zone
• Extent of cover crops
• Expected spring run-off

Phosphorus

Excessive phosphorus in the environment can lead to the destruction of fish and wildlife habitat. As surface waters become enriched with phosphorus, the growth of aquatic plants increases. Excessive vegetation (often algae) leads to low oxygen levels in the water, which suffocates most water life. This process is known as eutrophication.

Potential sources of phosphorus contamination are:

• Excessive use of fertilizers
• Soil erosion from fields or streambanks
• Surface water run-off carrying soil particles
• Manure storage sites and barnyard run-off
• Livestock entering watercourses
• Milkhouse washwater containing phosphate-based detergents
• Household septic systems
• Untreated municipal sewage

Prevention of phosphorus pollution from agricultural practices

• Reduce soil erosion
• Apply phosphates as a crop nutrient only as required
• Place phosphates in the soil and work in immediately
• Use commercial fertilizers efficiently, i.e. banding applications