Systems

Water

Introduction

Canada ranks a dismal 28th among the 29 nations of the Organization for Economic Cooperation and Development (OECD) in terms of per capita water consumption. Only Americans use more water than Canadians.

Canada uses 1,600 cubic metres of water per person per year. This is more than twice the average in France, three times as much as the average German, almost four times as much as the average Swede and more than eight times as much as the average Dane. The average Canadian uses about 340 litres of water per day. A family of four may use up to 1360 litres per day, even more in the summer months. That's a small swimming pool each day that is largely going down the drain. Drinking water is but a miniscule part of the overall water consumption habits. Not even 1% is used as drinking water.

The strain over this over-consumption is being felt on streams and lakes, but mostly on the ground water supply. Certainly, part of the problem is the consuming habits. Part of it is also the source.

Home Alive goes to the source. HomeAlive takes advantage of its non-toxic, inert steel roof to capture rainwater and snow melt and stores it in a 10,000 litre underground cistern for later use by the residents.

But before even considering using simple precipitation for household and drinking uses, Home Alive incorporates water conservation techniques including water-efficient appliances such as front loading clothes washer and Energy Star tm rated dish washer. It also uses composting (also known as dry toilets) instead of traditional flush toilets. This saves an estimated 200 litres of water per day or a staggering 73,000 litres per year!

The combination of these strategies enables residents to use captured rainwater instead of having a drilled well or a hook up to city water.

How it Works - Water from the Sky

Rain that lands on the roof is directed toward the cistern by inert steel eavestroughs. On its way there, the first 20 litres of each rainfall is diverted and dumped, having washed the roof of things such as small organic matter (dust, dirt, bird droppings). There are also catchers for larger matter such as leaves and twigs. The fresh clean water that continues thereafter is permitted to splash into the buried cistern.

Inside Home Alive there are a pair of tanks in the attic, totaling about 450 litres of storage or about half the estimated needs of four residents in this house. These tanks simply drain by gravity into the domestic water plumbing system.

When Attic Tanks become low, a pump is triggered to draw water from an Intermediate Storage Tank located on the main floor of Home Alive The Intermediate Tank holds another 450 litres that, together with the Attic Tanks, ensures that at any given time there is a full day's supply of clean water inside the house.

When the Intermediate Tank has a low water level, a pump submerged in the buried Cistern sends water to Home Alive's purification systems. This water is passed first over the schmutzdecke or biofilm of a sand biofilter. The Biosand Filter is a natural environment that traps and digests pathogens that may have been contained in the Cistern water. After draining through this Biosand Filter, the water seeps through a large Granulated Activated Carbon (GAC) Filter, essentially like a whole-home Brita (TM). This further removes impurities, in particular things that may affect taste like minerals and possibly heavy metals or other pollutants. Finally, as a last defense, the water then passes through a Ultraviolet Disinfector. Practically speaking this is a self-contained UV light that sterilizes and kills any harmful organisms that may have managed to survive to this point.

This clean, crisp, safe and delicious water then refills the Intermediate Tank, ensuring a constant supply to the residents.

Easy Maintenance

One of the biggest concerns of people unfamiliar with this sort of system is maintenance. One might think that the sand filter would start to become quite unhygenic after a period. Certainly, regular maintenance is important, but it is not complex. Once a month, the sand filter gets a backflush cleaning. It takes about five to ten minutes to execute. In fact, a base level of bacteria in the sand filter is important as it provides the biologically active component that cleans the water. The two other filters in the system, the GAC and the UV filters require no cleaning.

* Statistics are from the OECD Environmental Data Compendium, 1999.

For More on Water Catchment and Storage Systems

• Learn about the HomeAlive systems hands-on. Everdale offers seasonal workshops on different aspects of the systems. You can also take part in guided Saturday Tours of HomeAlive. Visit www.everdale.org
• Check out the HomeAlive Buyer's Guide for suppliers and equipment of these systems.

> Back to Top