Kinark Sustainable Living Centre

Water and Waste System

The quality of a civilization can often be determined by the ways in which it gathers its water and disposes of its waste water. Our water is seemingly abundant and safe, and our waste seems to be dealt with. But is the invisibility of the process hiding problems?

Design Intent

1. To use a minimal amount of fresh water
2. To collect the required fresh water from rainfall on the roof of the building
3. To dispose of waste water with minimal environmental impact
4. To heat water using only the sun’s energy

Materials and Methods

Since this building site was not serviced by a municipal water system or an existing well, we decided to avoid tapping into the ground water. This is an expensive procedure, and one which is having an unknown effect on important aquifers under our feet. For a building with minimal water needs, the amount of water that can be harvested from the roof is more than sufficient. We put up guarded eaves trough on the east side of the north roof to collect water but exclude leaves and other debris that would otherwise be collected. The water collected is piped through the wall and into a large storage tank inside the building. From here, the water is moved to the various fixtures by a small electric pump, after passing through a double-chambered filter. The toilet and sinks are all water-saving models.

Hot water is provided by a homemade solar thermal collector, placed on the south side of the building. This collector is charged with a non-toxic anti-freeze liquid. When the collector is warmed by the sun the fluid in the collector heats up, becoming less dense and rising as a result. The heated fluid rises to the top of the panel and up into the building where it enters a flat plate heat exchanger. Here, it gives its heat to the water in the hot water storage tank. This water similarly rises at it warms, creating a convection loop from the bottom of the tank to the top. From the top of the tank it is delivered to the hot water taps when they are turned on.

Effluent leaving the building first enters a conventional septic tank, where solids settle to the bottom and where anaerobic bacteria go to work breaking down wastes. Liquid effluent leaves the septic tank and enters the Ecoflo treatment tank buried outside the building. Within the Ecoflo unit, effluent is moved through a series of peat filters, which strain the water and which contain microbes and bacteria that treat the water. By the time effluent leaves the bottom of the tank to rejoin the groundwater, it is largely cleaned of toxins that might otherwise contaminate the groundwater.

Questions

Why collect rainwater?

Rainwater collection is free, delivering good quality, largely mineral-free water without need for power or for disturbing aquifers.

Why is the rainwater tank inside the building?

Typically, rainwater collection tanks are buried outside or underneath the building. We thought it would be valuable for people in the building to see the quantity of water available to them, and to be able to monitor their usage accordingly. We also thought it would be interesting for people to see how much water comes off the roof during a rainfall.

Why can’t we drink the rainwater?

New legislation concerning water in public buildings makes it too difficult and expensive to monitor the quality of the water thoroughly enough. However, similar systems are used in households in various parts of North America where groundwater simply isn’t available. Many of these systems incorporate UV filters to kill bacteria, and the water is safe to drink.

Why is the water brownish?

The water coming off the roof has been in contact with the cedar shingles, and the tannins in the wood are taken up into the water, giving it this colour. You may notice a cedar-y smell to the water too.

What happens if there’s no rain for a long time?

The tank inside the building holds approximately 2000 liters (500 gallons) of water. This is enough for around 3-4 months of regular use of this building. It is very rare to go more than 1/3 of a year without any precipitation. If the tank appears to be running low, the buildings users must adjust their usage accordingly.

What’s the clear blue tank for?

When rain first washes down the roof, it can carry a lot of dirt and other impurities that have settled on the roof since the last rainfall. This tank holds the first rush of water that carries these impurities, and prevents them from entering the main holding tank. The valve at the bottom of the flush tank is set to drip slowly, so that it will empty itself before the next rain.

Why does the thermal solar system have no pumps or switches?

We chose a thermo-siphoning system for its simplicity and low cost. Once pressure tested and filled with fluid, this system requires no maintenance and has no moving parts to break down, nor does it consume any electricity. It simply relies on basic physics to ensure that the hottest fluid always moves to the top of the system, forcing the coolest liquid to enter the system at the bottom.

Why use the Ecoflo waste treatment system?

Conventional septic systems count on the soil around the weeping tiles to treat the effluent that flows through the system. Many times, the soil is not capable of filtering all the impurities, and contaminated water enters the groundwater system. The Ecoflo system treats the effluent more thoroughly, using the natural communities of microbes and bacteria in its peat moss beds to ensure that much purer water enters the water table. The Ecoflo is one of many systems that can more thoroughly treat waste water before it is released into the ground.