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INTRODUCTION
Understanding sewage water
- Pollution of water resources by improperly or inadequately treated wastewater (sewage) contaminates drinking water supplies and is a leading cause of human disease worldwide (some 3.5 million people, mostly children under 5 die every year, about 9,000 people every day, from diseases caused by sewage pollution such as diarrhea, cholera and typhoid - in addition to causing ecosystem degradation.
- Yet, this is not the fault of what is called "sewage" water but rather by the way we handle some of its components, in particular feces, one of the richest and most productive substances. Excrement (which when mixed with water is commonly called "black water") is very rich in nutrients: 5-7% nitrogen and 3-5% phosphorus, two of the most valuable of nutrients, often called limiting factors to plant growth because of their relative scarcity and irreplaceable value. These nutrients are the main components of most chemical fertilizers. Life promoting, both to microbes and plants, feces greatly facilitate the formation of rich organic topsoils.
- Used for centuries as a very potent fertilizer, today it is being treated as a waste, disregarded and mixed with precious water (it takes 1000 to 2000 tons of water to move 1 ton of excrement), which, in addition to wasting a precious resource, spreads the pathogens (disease causing organisms). Sewage water especially becomes a problem when it is released in great quantities. When a small quantity of organic sewage water coming from a few humans is released to the environment, it often breaks down and biodegrades without being a dangerous source of contamination, but when population increases, what is otherwise rich and life bearing, becomes dangerous and disease causing. Directly sent to natural groundwater, rivers or oceans, this mixture of water with the feces rapidly becomes a toxic pollution as an increasing quantity of these elements eventually exceeds ecosystems' natural capacity of digestion and causes eutrophication: excessive nutrients.
- Today, in addition to urgent health issues, we know that untreated sewage is a leading cause of global coral reef decline, oxygen depletion, fish kill and ecological degradation of rivers and lakes - with the increasing pollution of already limited underground water tables and surface waters around the world, which provide us with our drinking water.
What is a Constructed Wetland?
- Wastewater Gardens® ecotechnology belongs to the family of artificial/constructed wetlands. What a WWG does is reproduce the conditions of natural wetlands, called the "kidneys of the Earth" for their high capacity for sewage treatment and pollution removal via the intensive plant and microbial activity that this ecosystem enables. Unlike many natural wetlands however, WWG belongs to the family of subsurface flow designs, which means that at no moment is the sewage water in contact with the air, thus preventing all bad smells, mosquito breeding or accidental human contact.
- A variety of natural mechanisms effectively treat effluent and purify all water which passes through a wetland, in this case through your Wastewater Gardens® unit. These mechanisms are biological, chemical and physical. One of the principal factors of purification are plants which are able to live in water saturated soils directly assimilating nutrients (especially nitrogen and phosphorus) and metals, removing these "pollutant" elements from the water and incorporating them into their plant tissue. The top part of the plants above the gravel brings down oxygen to the roots, which in turns enables microorganisms to live. A kind of symbiosis develops whereby the plants are consistently nourished via the water and its nutrients, among which some of the breakdown material produced by the microbes which can live through the oxygen the same plants generate.
- Highly efficient at removing potentially harmful compounds before they reach rivers, lakes and the ocean, wetlands also support diverse vegetation and provide important habitat for many animals which are essential to the overall health of the Earth's ecosystem. In addition to their purifying capacity, constructed wetlands literally create life. Plants are our "3rd lung" as they create the oxygen which we need to breathe, and metabolize carbon dioxide which we exhale.
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