In Canada we expect access to safe and reliable drinking
water, and per person, Canada has the world’s largest supply of freshwater. Newfoundland and Labrador is
no exception with an abundance of ponds, lakes, rivers and wetlands. However, when
we take a look worldwide, climate change is threatening our access to clean water.
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| The Human Right to Water (Image from UN Water Decade Programme) |
The World Health Organization (WHO) in partnership with UNICEF, reported in
2010 that 884 million people did not have access to clean drinking water. At that
time, the United Nations made access to clean water a human right. This
human right is being threatened in some surprising ways due to climate change.
First, climate change can effect our water quality. Extreme weather events
can stir up silt and increase runoff and warmer temperature can cause the over
production of biological and chemical elements. For example storm sewers can be
overwhelmed by heavy rain and flash floods, leading to untreated water entering
our drinking water supplies.
Also the
way we produce clean water impacts climate change. When water is treated in plants that use large amounts of energy, which in many cases are powered by
coal, natural gas, oil and other fossil fuels this contributes to greenhouse
gas emissions. Also,
the demand for clean water has increased the use of bottled water. As more bottles
are manufactured and shipped around the world this also contributes to greenhouse
gases emissions. Coming
at us from different angles, climate change impacts our clean water on the
global scale.
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| Bottled Water (Image from Readers Digest) |
Wetlands can help! Believe it or not, natural wetlands have
the power to clean water! They offset the production of greenhouse gases by
doing what they do naturally, purifying water in our environment. The process
begins when flowing water meets a wetland. This water can be from rivers, lakes,
sewage or agricultural runoff. Once the water meets the wetland it moves very
slowly because the thick vegetation, the absorbent peat soils, and the network
of roots are able to hold water in the wetland for an extended period of time.
This allows for physical, chemical, and biological processes to clean the water.
Physical processes in wetland habitats include the trapping
sediment and excess minerals. After a heavy rain fall or extreme weather event,
such as a hurricane or flooding, sediment can be stirred up. These heavy sediments can clog our waterways and treatment plants, kill fish, and
smother bottom feeding wildlife and plants.When these
sediment heavy waters pass through a wetland, the habitat acts like a sieve, allowing
sediment to settle at the bottom before it reaches water supplies and wildlife
habitat. According
to the Ecological Society of America, wetlands can trap and retain 80 – 90% of
sediment from runoff!
Besides silt and sediment, wetlands also help remove
potentially harmful elements. Phosphorus is a naturally occurring element that
is essential for life, but in
excess it can lead to kidney disease. Excess
phosphorous can end up in water supplies though over fertilization of
agricultural crops. In its particulate (or solid) form, it is first removed by the
wetland using the physical processes of sedimentation. Once this particulate phosphorous settles out
in the slow moving, highly vegetated water of wetlands, chemical processes
remove even more phosphorus. Dissolved phosphorus, in the form of liquids and
gases, accumulate, react with the wetland sediments, and eventually precipitates
(solidifies) into other harmless elements including aluminum, iron and calcium
phosphorus.
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| Nitrogen and phosphorus cycles in a wetland. (Image from IAN University Of Maryland) |
Wetlands also use biological processes to filter excess elements
and pollution from water. Plants, algae and bacteria uptake and transform chemical
elements that in excess, are considered pollutants. Like
phosphorus, high nitrogen levels are also present in areas where heavy
fertilizer is used. Ammonia, which is in many fertilizers, converts to nitrates
when exposed to water and high levels of nitrates can cause
many problems including methemoglobinemia (blue baby syndrome) that inhibits
the flow of oxygen in the bloodstream of infants. Nitrogen
removal in wetlands is a naturally occurring process. Microbes found on plant
roots and stems, take up
nitrogen and convert it into harmless nitrogen gas and release it into the air. Wetlands are able to eliminate 70 –90% of entering nitrogen through this process.
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| Constructed wetland in Stephenville, NL (Image from Abodoz.com) |
Wetlands have proven so effective at purifying water, companies
around the world are constructing wetlands to clean municipal waste water. Constructed wetlands are a system of wetland beds that can mimic some of the filtration
power of natural systems. Several municipalities
in Newfoundland have opted for constructed wetland systems including Marystown,
Appleton, and Stephenville. Wastewater is first passed through a screen to remove large non-organic
materials, then the water passes through several wetland beds where it is
filtered and able to return to the natural environment in lakes and rivers. Any
settled materials are collected and sent through an additional wetland beds where
the native plants re-mineralize the sediments and create compost that can be
used for landscaping.
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| An illustration of a constructed wetland system (Image from Abydoz.com) |
Constructed wetlands can be appropriate for small
communities, but do not replace natural wetlands and do not always provide the
many other services provided by natural wetlands such as flood control, carbon
sequestration and wildlife habitat.
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| Wetland in Carmanville, NL (Image from SAM NL) |
We are learning more about wetlands, their power as natural
water filters, and the many other ecosystems services they provide in the face of
climate change. Unfortunately, in Canada
we lose 80 acres (32 hectares) of wetland per day.
Conserving wetlands, and better understanding their functions, can assist us in
keeping water clean by mitigating the effects of climate change.
What can YOU do to conserve wetlands that purify our water?
1) Use natural fertilizers on our home gardens
2) Take your fertilizers, pesticides, oil and other toxic wastes to the Household Hazardous Waste disposal station nearest you
3) Plant native vegetation on your property and in wetland restoration projects (Click to find our link on how to enhance your backyard habitat)
4) Volunteer to monitor and clean municipal and urban waterways – organizations like NA ACAP, Municipalities, and WWF regularly host cleanups where you can do your part!
5) Conserve and protect natural wetlands in our municipalities by supporting parks and organizations committed to protecting wetlands and natural areas
6) Support proper municipal planning that considers impacts on waterways as part of all urban, industry and agricultural development. Attend your local public consultations whenever your municipality asks, and share your concerns about wetlands and waterways being conserved for the future
Resources:
Ducks
Unlimited Canada. “How wetlands take care of Canada’s Water” http://www.ducks.ca/stories/water/how-wetlands-take-care-of-canadas-water/ . Website.
Ducks Unlimited Canada.
“Making a Dam Difference at The Etang Stater Wetland “ http://www.ducks.ca/stories/volunteers/making-a-dam-difference/ .
Website.
Ecological Society of America “Reveling secrets about…
natural water purification” PDF. https://www.esa.org/ecoservices/WaterPurificationFactSheet.pdf
Grace Communications Foundation, Water Program “The Impact
of Climate Change on Water Resources” http://www.gracelinks.org/2380/the-impact-of-climate-change-on-water-resources Website.
Livestrong “Too Much
Phosphorus in the Body” https://www.livestrong.com/article/496979-too-much-phosphorus-in-the-body/ Website.
Michigan Environmental
Education Curriculum, Wetland Ecosystems “How to wetlands filter harmful
substances” http://techalive.mtu.edu/meec/module12/Chemicalfunctionsofwetlands.htm . Website.
National Park Service. “Water Filtering of Wetlands” https://www.nps.gov/keaq/learn/education/water-filtering-of-wetlands.htm
. Website.
Nature “Cool
Green Science: Building wetlands for clean drinking water” https://blog.nature.org/science/2013/01/30/feature-building-wetlands-for-clean-water/ Website.
(Perma)Culture
and Sanity “Wastewater Treatment and Constructed Wetland part I” http://permaculture-and-sanity.com/pcarticles/constructed-wetland-wastewater-treatment-part1.php Website.
Ramsar. Factsheet, “Wetlands: Why Should I care?” https://www.ramsar.org/sites/default/files/documents/library/factsheet1_why_should_i_care_0.pdf
. PDF.
Ramsar. “Wetlands; a sustainable solution for water
purification and security” https://www.ramsar.org/news/wetlands-a-sustainable-solution-for-water-purification-and-security-0
. Website.
Sciencing. “How do wetlands purify water?” https://sciencing.com/do-wetlands-purify-water-7585568.html
. Website.
The
Wetlands Initiative. “Value of Wetlands: Cleaner Water” http://www.wetlands-initiative.org/cleaner-water . Website.
The
Wetlands initiative. “Ask a Scientist: Nutrient Removal” http://www.wetlands-initiative.org/nutrient-removal/ . Website.
UN Decade programme on advocacy and communication (UNW-DPAC)
“The Human Right to Water” PDF. http://www.un.org/waterforlifedecade/pdf/facts_and_figures_human_right_to_water_eng.pdf
UN Water “International Decade for Action ‘Water for life’
2005 – 2015” http://www.un.org/waterforlifedecade/human_right_to_water.shtml Website.
United States Environmental Protection Agency. “Climate
Impacts Water Resources” https://19january2017snapshot.epa.gov/climate-impacts/climate-impacts-water-resources_.html#Quality
. Website.
