Nature Clear GWS10 provides a simple and cost effective means of disposal of dark grey water. Not only is the equipment low cost, but also, if your site is suitable, the only significant excavation work required to install the system will be the trenching.
Nature Clear GWS10 is, as of 2011, only approved in Queensland and only as a primary treatment system. In addition to most Queensland councils, some councils in NSW, NT and Tasmania have also allowed the installation of Nature Clear.
The ongoing costs will be similar to those of a standard septic system .
The filtration tank, which is less than 1 cubic meter in size, consists of a pine bark coarse filter on top of different grades of sand and gravel. The filter cloth is provided but due to freight costs the sand and gravel should be sourced locally. Sample bags of these are provided with the system to assist with your selection of the correct grade materials.
The pine bark traps large particles not caught in the grease trap plus lint from the washing machine. The sand filter catches still finer materials, polishes the water and reduces the organic content of the water. The pine bark is separated from the sand by filter cloth. The filtered material and bark will compost over time and should be removed every twelve months and replaced with fresh bark, available from your local garden nursery. If your distribution area is down hill from the filtration tank your engineer should be able to design a distribution system without the use of a pump. If this is not the case you will need a pump and pump well.
The treated water must be distributed into trenches as specified by your engineer. Make sure his/her calculations of size do not include an allowance for toilet water (black water), which would make them unnecessarily large and expensive.
NOTE: In order for the filtration tank to work most effectively, food scraps and grease should be removed from the kitchen waste water via a grease trap (see available GWS10 and grease trap packages).
Grease Trap Options:
A 45 litre grease trap is supplied as standard to remove food scraps and grease from kitchen waste water. A 300 litre grease trap is also available for larger households. Some councils also insist on large grease traps to extend the life of the trenches. The 45 L trap is self-cleaned by retrieving a washable filter every 6 weeks or so, the 300 L trap needs cleaning every 1-2 years.