Graywater is the water that goes down the drains in the kitchen and bathroom sinks, shower and washing machines. There are many unwanted particles in this effluent: hair, dirt, oils and cleaning products. While most of the time it is too dirty for untreated reuse in the household or for direct drainage into freshwater river systems it is a valuable quenching and fertilizing liquid for gardens.
The vast majority of the drainage from any household is gray-water but this is mixed with “black water” from toilets. Black water is considered hazardous as it may contain biological agents like ecoli and other organisms that can cause sickness to humans. However, by separating the two drainage systems the gray-water can be used for non-potable water uses thus both saving municipalities water and sewage treatment costs.
Popular in the Western States
The practice of reusing gray-water for irrigation is becoming popular in the western states especially with residences. The drainage water goes into a root watering system for trees, shrubs and even vegetable gardens. Not only does this save a huge water bill the homeowner is saved the cost of fertilizers especially the chemical kind that does harm to the aquifer.
Swamps and Wetlands are Nature’s Sewage Disposal Units
Another use for gray-water is to have it collected from a subdivision and have it flow into a wetland area. In the long-term implementing a gray-water wetland is both an inexpensive and practical method for the recondition of water either for reuse or for sustaining a parkland area. This includes mimicking the natural swamp systems where different species of plants break down organic compounds, including toxic chemicals, into simple compounds that are no longer harmful to living organisms.
Bio-film and Plant Action
In a natural wetland the various species of algae, earth humus, decaying vegetation and living plant root systems promote the growth of “bio-films.” These are large swarms of complex bacteria and microorganisms that can change even toxic wastes into simple compounds. Each type of organism and bacteria within the biofilm has its own specialty in breaking down compounds into smaller units which can then be metabolized by other species. In other words one bacteria’s excrement becomes another’s food.
Plant life that is broken down into its simple materials by bacteria then becomes food for the plant life in the wetland. This is a type of underwater compost. Plant roots absorb the simple compounds that are then evaporated into the air or, as in the case of wild rice, are harvested by other species. So between the bacteria and plants there is a symbiotic relationship for removing.
Gray-water Urban Wetlands
Up until recently wetlands were considered wasted land full of mosquitoes. Many were situated along the flood plains of major rivers and people who wanted river access had them drained and filled in. Not only did this end delicate ecosystems the destruction of the wetlands meant that many animals, birds and fish lost breeding grounds. In addition, the wetlands acted as filters for the river whose bio-films took out harmful agents and sediments entering the rivers. In effect they were “nature’s kidneys.” By taking out the wetlands sediments and harmful compounds took their toll on life further downstream.
The reintroduction of urban wetlands could be a salvation, not only restoring the eco-systems but also by making life better for the human inhabitants.
Kim Kinrade invites you to to his website and blog on the many wonders of Nova Scotia, Canada’s Atlantic Playground. http://www.traveltonovascotia.com There is so much to see and do in Nova Scotia within a small area that it has become an optimum destination for many travelers.