Recycling Blackwater
By Steven Eggleston, SCE Studio
Part 3 of a 3 part series
These articles are designed to provide a gradual, in-depth, hands-on approach to evolving concepts in sustainability. This article is the final part of a three part series addressing water conservation in our built environment; the three main techniques include greywater management (see HomeLink summer 2008 issue), rain/snow collection (see HomeLink winter 2008 issue) and blackwater treatment.
Freshwater supplies are shrinking around the globe due to rising temperatures and droughts, increasing sprawl, population and inefficient resource usage. In the Southwestern United States, the Colorado River is shared by many states before it trickles into Mexico. Water is diverted for irrigation and urban uses all along its route, with Arizona and California as the biggest users. Mexico then uses all that dribbles its way, with very little water ever reaching the once fertile delta on the Sea of Cortez. The Colorado River is completely allocated, yet growth in the southwest continues; five of the ten fastest-growing cities are in the river's drainage. A part of the answer maybe found in using this natural commodity in a more efficient manner.
Blackwater (sewage) is generated by residences, institutions and commercial structures. It includes waste liquids from toilets, baths, showers, dish washers, sinks, and washers and is disposed of through your wastewater treatment system. In most cities the sewage from residences, commercial buildings and industries is treated by a municipal wastewater treatment facility. In the rural areas you will find a private wastewater treatment system. In both the urban and rural wastewater treatment systems, the wastewater is treated and usually discharged back into the environment. The blackwater and the greywater are discharged with no water reclamation, although recently the separation of greywater from blackwater is becoming more popular in the developed world, with the use of greywater being permitted for watering plants and recycled for flushing toilets.
In the early days of Routt County it was not uncommon to find an outhouse as the option for your bathroom needs. This evolved to indoor plumbing with the development of wastewater treatment systems. Most urban and rural wastewater treatment systems discharge the effluent into the environment. An evolving option is the treatment of blackwater through the use of a "living system," which allows reuse of water for flushing toilets, watering plants, washing the dishes, brushing teeth and drinking. This is possible and it has been done before.
In 1976, Dr John Todd and his colleagues developed "An ARK for P.E.I." at Spry Point on Prince Edward Island in Canada. The ARK project generated many of the principles that became "living machines".
"In principle, a living machine is an ecologically engineered technology developed to restore, conserve, or remediate sewage or other polluted water by replicating and accelerating the natural purification process of streams, ponds, and marshes. In practical application, a living machine is a self-contained treatment system designed to treat a specific waste stream using the principles of ecological engineering. It does this by using the diverse communities of bacteria and other microorganisms, algae, plants, trees, snails, fish and other living creatures." John Todd (www.toddecological.com)
TODD ECOLOGICAL DESIGN
The "living machine" starts in an attached or detached greenhouse. The systems often include an anaerobic pre-treatment component, activated carbon filter (for odor control), flow equalization, and aerobic tanks as the primary treatment. The final stage uses either an Ecological Fluidized Bed and/or a small wetland, a holding pond/cistern and a ultraviolet disinfection with the output being potable water. The design and size requirement of the system is dependant on the waste flow.
Two examples of Dr. John Todd's work include:
Cape Cod, Mass. Greenhouse Waste Treatment Plant
"Bacteria consume the organic sewage and turn ammonia into nitrates. The nitrates are used as food for algae and fertilizer for duckweed. Zooplankton and snails consume the algae. Fish eat the zooplankton. Floating plants soak up the leftovers. Bulrushes, cattails, and hyacinths render toxins harmless. Trees absorb heavy metals. The by-products are decorative plants and minnows, both of which are sold. Todd's "living machine" system makes it possible to do all this in the cooler northern climates. The town of Harwich, Mass. began using Todd's system in 1990." (Dr. John Todd. @wikipedia.org)
Kona, Hawaii. Punawai Lake Restores, The Four Seasons Resort
“This EPA award-winning 3.5 million gallon pond was designed by Dr. John Todd and Jonathan Todd. The Project was initiated by the caretakers of the Resort wanting to keep the pond free of algae without resorting to high flushing rates that would use valuable water on the dry side of the island of Hawaii. Two Restorers were installed during the construction of the pond along with six airlifts and a subsurface filtration system. Pond water is pulled through the bottom gravel filtration and up to the center of the Restorers at a turnover rate of thirty-two hours. As a biological platform, each Restorer provides a growing medium for over twenty-six species of native Hawaiian fauna and several species of Hawaiian fish and shrimp. The diversity of plant life provides a thriving habitat for much wildlife.” (www.toddecological.com)
Blackwater restoration may be ideal for some areas of Routt County where water is scarce or a concrete sewer storage vault is the only current option. Check with the Colorado Division of Water Resources and your local building, zoning and environmental departments for any requirements, local restrictions, subdivision regulations or guidelines that may apply to your project. 
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