Life-Threatening Contaminants

Freshwater is critical for life and in limited supply. It follows that we should protect it at all costs. And yet, this resource is regularly subject to contamination from many sources, causing challenges that have destructive impacts. Here are just a few of the top threats to freshwater health.

Nutrients

While nutrients such as phosphorus and nitrogen are part of a healthy ecosystem, an excess or oversupply can have serious consequences for freshwater health. Intensive agriculture is contributing to this excess. When it rains, or when crops are overwatered, nutrient-rich fertilizers runoff into watersheds, contributing to rapid algae growth – and sometimes, large algal blooms – in freshwater sources. Through a process called eutrophication, these blooms can deplete the water’s oxygen levels, killing fish and other aquatic species. There can also be direct impacts for humans – in 2014, a summer bloom in Lake Erie caused a three-day drinking water crisis for residents of Toledo, Ohio.
 

Microplastics
 

You’ve probably heard of the Great Pacific Garbage Patch, but did you know that freshwater has a plastics problem, too? The tiny microplastics that enter waterways come from a variety of sources, including the microfibres from our clothing, microbeads used in cosmetic products, and the breakdown of larger plastic productions, such as water bottles and plastic bags. According to a 2017 study by Orb Media, tap water samples from major metropolitan areas on five continents showed that more than 83% were contaminated with plastic fibres. Microplastics have been linked to several serious health concerns for humans and aquatic species.
 

Sewage
 

While North American cities have advanced wastewater treatment facilities, some 80% of the world’s wastewater is dumped—largely untreated—back into the environment. What does this mean? Whatever we use and consume, including chemicals and pharmaceuticals, could end up in freshwater sources.