Rainwater harvesting advice

In Ireland where I live it is discouraged to use rainwater for anything other than flushing toilets, washing machines and outdoor use. Drinking and showering is a big no no. I was told by one official recently that it is in the same category as sewage water which I find ridiculous. I appreciate that drinking rain water without proper filtering is potentially dangerous although I have a friend who's been drinking it for years and he's still alive and well. I'm determined to set up a low cost low tec harvesting system but I'm a bit concerned by all the negative stuff and the need to use expensive UV filters and what not. My question is this: Is it OK to use unfiltered rainwater for washing/showering and anything else apart from drinking. Obviously I'd have to filter the water to get rid of the fine grit and dirt from the roof but without all the other expensive filtering products that the "rainwater harvesting industry" are trying to push on us. Cheers, Stephen

You would only be doing what millions of people have done throughout human history.

The only real caution that applies when dealing with water is that you don't want to ingest any water-borne diseases. There are two ways that cultures have solved this potential problem: (1) drink boiled water (as in tea & coffee) and (2) put enough alcohol in the water to kill any bad bugs. When you look at all the products that are sold related to water and water consumption, remember all the marketing involved and that Evian spelled backwards is naive.

Stephen, using catchment water for everything is commonplace in my area. But there are a few precautions that you may wish to consider.

1- Gathering surface. Rooves of metal, slate, tile and coated aluminum are safe for collecting rainwater. But asphalt is not.
2- Stored water is best if the sunlight is kept out. Thus an enclosed tank or cistern, barrels with lids, or an open tank with some sort of covering. This is not a must, but it helps keeps algae from growing.
3- Stored water needs protection from mosquitoes, other insects, rodents, birds, etc. A tarp, screening, or a roof of some sort.
4- Stored water being used for human use should be sanitized in some fashion while it is being stored. Bleach works fine. So does industrial strength hydrogen peroxide, although it tends to be more difficult to get and is more expensive. The ultimate system is an ultraviolet water system. Water treated with UV is safe for drinking.
5- Many people also filter their water to protect their water pump and pipe system.

My own system is very basic, but it works. We've been using it for ten years. Rainwater is collected off our metal roof. It goes to a large holding tank via rain guttering and pipes. We have no first water diverter, but instead have a mesh box at the end of the discharge pipe to catch leaves and other debris from the roof. Our tank has a black tarp covering it. The end of the intake pipe used to draw water out of the tank sits 6 inches above the bottom of the tank in order to avoid drawing sediment off the bottom. There are other ways to avoid sediment, but this works for us. We use bleach for sanitizing. Bleach is added monthly and again after a rain. We use a swimming pool test kit to monitor the water's pH and chlorine levels. In that we have close access to excellent drinking water, I don't use our catchment for drinking and cooking. But we use it for everything else. If I were to use it for drinking, I think I'd put a small UV system on a pipe going to the kitchen dedicated for drinking/cooking use. But I'm not interested in that for the moment. Those UV lamps use quite a bit of power.

...Su Ba
www.kaufarmer.blogspot.com

I'd collect it for as many uses as you can
I think rainwater is nearly always the healthiest, tastiest, least wasteful supply option.
Plants seem to prefer it too.
I'm a big fan of the 'first flush diverter'.
Over here it's invisible pathogens in (mainly bird) faeces that's the main potential issue.
The first flush washes any fresh poo away along with the dirt, leaves etc.

maybe a bit late, but YES YES YES. we use untreated rainwater that has been pumped through a sediment filter for everything but drinking and cooking, for which we use a Berkey filter, which in my opinion is the best simple countertop gravity filter available. you just pour water in the top container, and it slowly drips thru into the bottom container free of all biological and chemical contaminants. it does not interface with plumbing systems, so you can dip water from your barrels or whatever. as with all filters, the cleaner the input the longer they last but these last 3,000 gallons per filter, 6,000 gallons if 2 are used together