The installation of our rainwater harvesting system has just been completed but I have some nagging questions. Perhaps the combined wisdom of ATA members can shed som elght on them. I decided to have a 'whole of house' system which delivers us drinking water from our 5,650 lite tank with mains back up. One inlet is direct from a gutter, the other is from a charged system. I have five issue for resolution.
i) Regarding the filter placement, is a carbon filter designed to reduce sediment, turbidity taste/odour & chlorine best placed first or second from the tank when a filter which reduces sediment is also used?
ii) Is the black plastic piping used in place of copper 100% safe? I'm concerned that it may be made from chemical compounds that may leach into our drinking water. In my case, the placement of the filters will prevent them from filtering out any unwanted contaminates from the plastic pipe. What is the composition of that pipe?
iii) I have installed a Davey Rainbank system as backup and it is situated in an exposed position above the tank without any covering from the elements. I'm concerned that exposure to the rain and western sun will degrade it very quickly. Should it be covered?
iv) Whenever I read articles about wet systems the info I get is "wet rainwater collection systems (also called ‘charged’ or ‘flooded’ systems) are where the pipes from the gutter go down the wall and underground and then up into the tank. Because the pipes are underground and below the entry point to the tank, even during periods without rainfall water remains in the pipes. This water can become stagnant and should not be allowed to enter the rainwater tank". If this does occur and stagnant water is conveyed into our tank, won't the stagnant water cause health problems? How can I tell if the water in the charged system is stagnant?
v) In-ground first flush diverters are recommended by all publications I read about 'charged' systems along with "secondary insect proof screens" fitted to the downpipes as well as the need to "fit insect proof screens or Flap Valves to inlet pipes to prevent mosquitoes from breeding in the ‘wet’ system". The mesh at the entry point of the tank prevents mozzies and their larvae entering it so are these warnings a marketing exercise to get us to buy unnecessary add ons or is there a valid risk? Even though they can't get in their waste matter can. I can also imagine cockroaches enjoying a free drink in those pipes.
The installer has a lot of experience and he recommended against doing anything other than using first flush diverters and the two filters and that I monitor the water quality and make adjustments if necessary.
