A little common sense will keep your pipes gunge free.

If you live in a rural area – and let’s face it, if you’re reading this paper chances are pretty high that you do and if you don’t, hopefully we will convert you – there’s a good chance you rely on tank-water and/or you collect rainwater for drinking and household use.

Rainwater does get a bit of bad press though what with pollution worries and acid rain fears – so we have had a dig around to find out just how safe it is to rely on the stuff that comes out of the sky, off the roof, into the tank, and finally out of the tap. 

Rainwater is pretty safe to drink as long as you are careful about how you collect and store it.  As mind bogglingly obvious as this may sound, you must make sure there is absolutely no way for animal or human waste to enter the source of supply. 

It’s also a good idea to make sure the tank is covered so no bird droppings go in and to discourage rats and mice from doing the breast stroke in your shower water. 

 If you are collecting rainwater from your roof, check there are no lead flashings or lead-based paint products causing elevated lead levels in collected water. It is probably a good idea to keep trees around the area to a minimum – leaves in the water can cause taste and odour issues that make chlorine seem like a good idea.

If you live somewhere where a lot of spraying is carried out for crops or orchards, be aware of spraying times and remember spray drift can land on the roof and be flushed into tanks with first rains. If spray drift is likely to be a problem, consider professional advice about installing a first flush diverter. Despite its name, this has nothing to do with your toilet but will  flush the first couple of hundred litres of water collected in your tank to avoid possible contamination. 

If you have the space, a two tank system is better than one large tank.  The first tank can be used primarily as a settling tank with the second tank being the draw off.

Try to avoid having sections of pipe that will contain standing water before the tank. During hot dry spells all kinds of things can collect in that water, decompose and quickly turn from ‘leaves’ to ‘gunge’.  That gunge is then forced into the tank following the next rain, causing all sorts of issues – from bad taste to illness.

Clean and disinfect your system every 6-12 months including the guttering.   It’s a good idea at this point to open the scour valve to remove any accumulated – well – gunge.  Disinfection can be achieved by calculating 167ml of household bleach per 1000 litres of water (167ml= 2/3 cup). Leave it in the tank for a few hours before flushing to waste.

It does pay to be sensible when it comes to drinking water – after all the trip from cloud to glass can meet with more than a few possible contaminants.  That said you don’t need to plan to clean your teeth in champagne just yet.  Instead be sure your  drinking water is collected from  non-toxic surfaces – so check for lead, chromium or cadmium in its paint, nails, flashings or soldering. Paints used for roofs should be labelled “suitable for potable water supply,” as should pre-finished roofing materials.

The same applies to pipe and storage materials.  Because rainwater is slightly acidic it can react with and leach uncoated metallic roofs – if you have a roof of this style make sure it has been  pre-coated or painted. 

Self cleaning rainwater strainers to all downpipes can be connected to the tank or at the inlet of the tank – which will help keep organic contamination to a minimum. Just remember to check them periodically to avoid a build up of that ‘g’ word (gunge).