Earthwise goes greener

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From overhanging trees to the wrong LEDs, there was plenty to learn retrofitting this Perth community centre, write Graeme Worth and Lucy Simnett.

Earthwise Community Association is located on the site of an old church in the inner-city suburb of Subiaco in Perth. The site, leased from the Uniting Church, is home to an op shop, food centre, community lunches and music sessions, with much of the focus on the extensive permaculture gardens established over many years.

The team at the volunteer-run organisation decided to install equipment and infrastructure for better water and energy use, and with a prime city location, show visitors what is possible in retrofitting an existing building. Educational activities and resources have been developed around the environmental installations including an open day, workshops, information fliers, signage and tours.

The grant application

The project would be expensive and initially time consuming, so the only viable option was to apply for a grant. The grant was submitted to Lotterywest WA and, somewhat to our surprise, funded in its entirety.
We received funding for:

  • Two 1.5kW grid-connect solar arrays for electricity generation
  • A 38,000 litre rainwater tank for sub-surface reticulation in the garden and toilet flushing
  • A heat pump hot water system
  • An education package including signage and funding to run workshops
  • A part-time education officer for 12 months

A number of smaller activities were also funded such as window insulation, an energy efficient fridge and freezer, PowerMate energy meters and LED lighting.

The first step was to employ the Education Officer, whose initial responsibilities were to liaise with and oversee installation contractors and manage the grant finances. We had allowed two days a week, however, for phase two, which involved signage and preparation of educational and workshop material, we should have increased the time to at least three days a week. You live and learn!

The nitty-gritty of equipment installation, performance and problems can be conveniently divided into  water and energy, and tie in well with existing efficient waste management.

Water smart tank

There are a lot of options when it comes to rainwater tanks, so do your homework before you buy. The tank we selected has the following features:

  • 38,572L Highline steel tank with plastic bladder
  • 2.56m high, 4.38m diameter, area 15m²
  • Collects off 148.5m² of roof
  • Wet system (buried pipes) with over 118 metres of stormwater pipe, 40 metres of blueline and seven metres of copper pipe used.

The tank cost $14,680 ($13,000 installed, plus $500 for paving, $600 for gutter cleaning, $300 for first-flush system, $200 for the sand base, $80 aggregate).

The rainwater tank comes with a 70 litre first-flush diverter. We were originally going to collect water from half the roof area, but when installation commenced we figured we’d be mugs not to use the whole roof. This was a great idea, except the first-flush diverter was too small and we had to spend an extra $300 installing three downpipe diverters. While it was obvious to use the collected water on the gardens, we decided to also connect the tank water to the toilets for flushing, thus reducing our mains water use during winter when the tank would fill but the water not used. This, of course, necessitated a lot of additional plumbing. We were caught by imperfect quotations; in this case the quotation was not from a plumber so make sure you are aware of the expertise of people submitting quotes. The original plan to run the plumbing connections beneath the building turned out to be impossible and we had to find at least another $500 to remove and replace 45 metres of brick paving, as well as additional piping.

The subsurface reticulation includes five stations covering approximately 90m² of garden on the west side of the building. Last summer the system was set to run twice a week for 30 minutes on each station, or five hours a week. With these settings water use is 3612 litres per week. One tank of water could run the reticulation for 10 weeks or if rainfall is good, for 26 weeks. Whenever the tank is empty, water supply automatically switches back to mains water.

Retrofitting an old church raised extra complications as it was difficult to access high gutters, there was no floor trapdoor to access the parts of the building that were raised and few detailed building plans could be found.
The final component was a diverter—supplied at cost by the manufacturer Redwater Australia together with a second unit donated and raffled—to send cold water back to the rainwater tank instead of down the sink when the hot water taps are turned on. This unit has worked really well, with just one small hitch when the tank installer accidentally connected the water back to the first-flush system, and not the tank.

Read the full article in ReNew 116
Find out more about Earthwise Community Subiaco

EOFY ReNew 2017

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