Dr. John Todds' work on alternative water systems in buildings are possible at MIT:

Science has criticized contemporary conventional wastewater treatment.  The basic
reasons are as follows:

1: They generate large amounts of sludge which is often toxic and is thus environmentally
stressful if disposed of by ocean dumping, land filling, spreading or incinerating.
2: They employ environmentally damaging chemicals to precipitate out solids,
phosphorus and chlorine.
3: They fail to remove metals and synthetic organic compounds.
4: They are costly in terms of financial capital, energy and labor.
5: Engineering difficulties are still incurred with the elimination of fine suspended solids,
colloidal matter and dissolved substances.

Natural aquatic systems, including wetlands, lakes and ponds, have waste treatment
and utilization potential inherent in their dynamics and they have mechanisms for
providing alternatives to the five criticisms above. The challenge for ecological
engineering is to take the mechanisms, pathways, nutrient flows and organisms found in
all of these systems and design them into mesocosms that are the ecological
technologies of the future. What society needs is integrated waste treatment. In this
scenario a waste treatment facility is no longer a sewage treatment plant. It becomes a
nutrient and materials management system, or a water-based farm with useful products
and a viable economy as central to the design criteria.

At present, our industrial processes emphasize the moving of materials and energy from
nature through the economic system as the primary way we "create value". The main
economic activities are, therefore, producing and consuming. We might contrast this to a
mature forest or pond. In these natural systems the processes of production and the
consumption, including recycling of wastes and nutrients, are balanced processes. On
the forest floor the decomposing organic matter recycles the nutrients and nurtures the
trees. The limnology of a pond is a wonderful example of many interacting systems, with
constant changes in the ecology, but a stable overall effect on the environment. The
system balance and stability is only disturbed when we overload the pond with pollutants
or too many nutrients from human systems.

Natural ecosystems have a large number of pathways and so can be called distributed
systems. Species diversity reinforces the stability of these systems with redundancy in
function. The result is self-organization, self-repair, self-reproduction, and a great ability
to adapt to perturbations in external conditions. If industrial processes can have these
same positive attributes, they will be highly effective and often restorative.

Sim Van Der Ryn
Ecological Design

John Todd & Nancy Jack Todd
From Eco-Cities to Living Machines: Principles of Ecological Design

B. C. Mollison
PERMACULTURE: A Designers' Manual