What issues are there with using water off the roof

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I am thinking about what to do about the water issue. If I collect rain water which comes off the roof, what do I need to worry about? Will there be chemicals which need to be removed or do I just have to worry about bacteria, etc?

-- Allan Lovett (allanl3561@aol.com), October 30, 1998


Alan: this is a great idea. There's a good book on this subject available from

http://www.amazon.com/exec/obidos/ASIN/0946688222/qid=909777608/sr=1-1 /002-2672284-1207637

If you decide to pursue this, I hope you will come back and let everyone know how you did it!


-- E. Coli (nunayo@beeswax.com), October 30, 1998.

You may also want to check out this web page I found awhile back:



-- Rick Tansun (ricktansun@hotmail.com), October 30, 1998.

Go for it! Here in Australia, one of the dryest continents on the planet, all the country people do exactly that. You ontain a closed water tank and modify the guttering and pipes to feed directly through a small sieve (filter) into the water tank. The tank will soon develop some natural algae, which is beneficial. If you test the water in the tank by dropping a small foreign body into it, the object (mouse shit, for example) the stuff will be sucked across the surface of the water and move to the edge of the tank... There is is eaten by the algae. Notwithstanding these wonders of nature, the water is perfectly drinkable. There are no chemicals, such as chlorine (mustard gas) or flouride (rat poison) in the water. There is no need to boil it. However, if you find mosquitos breeding in your tank, you can fix that by pouring in a capful of kerosine fuel. The oil forms a film on the surface of the water and this suffocates the mosquito larvae. When I did my Permaculture course aT Tyalgum, New South Wales, recently, the instructor mentioned that one enterprising chap in Melbourne obtained a contract to collect water from the roof of a sports stadium there. He just rocks up with a tanked and collects the water, which is then put straight into bottles in his "factory". It is then sold as drinking water to the public! And what's more, it has been tested, and it is extremely pure and drinkable !!! How's that for a money-making scheme? If anyone does it in the US after reading this, cut me in for 10 percent, eh? :-)

-- David Harvey (vk2dmh@hotmail.com), October 30, 1998.

Thanks David, but I like my anti-freeze recepe better. I just hope it snows a lot in quebec winter 99/2000.

-- Chris (catsy@pond.com), October 30, 1998.

A friend told me that asphalt shingles will pollute rain/collected drinking water.I know for sure that they deteriorate into fine dust.Lehmans has absolute filters for $250,$185,$85(?) This solar distiller is simple and inexspensive but I dont know if it will filter said dust. www.solardome.com/SolarDome84.html

-- Arthur Rambo (buriedtreasure@webtv.net), October 30, 1998.

A friend told me that asphalt shingles will pollute rain/collected drinking water.I know for sure that they deteriorate into fine dust.Lehmans has absolute filters for $250,$185,$85(?) This solar distiller is simple and inexspensive but I dont know if it will filter said dust. www.solardome.com/SolarDome84.html Almost forgot. Lehmans 330-857-5757 2 mos. wait. No I do not work for them, but I wish I had bought stock

-- Arthur Rambo (buriedtreasure@webtv.net), October 30, 1998.

Bought two 75-gall rain barrels from Gardener's Supply (http://gardeners.viamall.com/), blurb says:

"For thousands of years, people have harvested and saved rainwater for domestic and agricultural use. The practice makes just as much sense today, when pollution and drought threaten our country's water supplies. Rainwater is 'softer' than most tap water, and being free of the chemicals used to treat municipal water supplies, it's better for plants and soil life."

Statistics: 1" of rain will provide 625 galls of water from a 1000 sq.ft. roof.

Barrels have a built-in safety grid, insect screen, overflow pipe, and 4' hose with thumb control.

-- Aitch (jimp7@mindspring.com), October 30, 1998.

What if it doesn't rain????

-- deborah cunningham (dac@ccrtc.com), October 31, 1998.

What if it doesn't rain?

Let me rephrase that last question more accurately:

What if useful precipitation doesn't fall from the sky?

Local conditions matter exclusively - as local a condition as what is the shape of your roof! Are you Northern of southern hemisphere? Is it a mediatereaun climate like northern CA, where rain is frequent in winter, but never occurs in the summer months? A dry high desert like 29 Palms or upstate New Mexico/AZ? Wet, irregular rain with "no" or very infrequent freezing like here in upstate GA?

If snow falls, and doesn't melt, then it does you no good until it melts and could be directed down the downspout without re-freezing.

If rain falls in useable amount, an d if it can be redirected to a useful storage container, plan on using it for non-drinking purposes if you wish - bath water, flushing toilets, washing the cat (drying cat in solar-powered microwave I'm told should be optional), washing the kitchen floor after washing the cat, washing the car, washing the kids, etc.

-- Robert A. Cook, P.E. (Kennesaw, GA) (cook.r@csaatl.com), October 31, 1998.

I've found useful information on many different water collection schemes in the information published by state cooperative extension offices. A good place to start is the following URL:


It lists all the states and unfortunately I can't tell you which states to try for appropriate information. I believe I did it real scientifically - I looked at the map and picked states with low rainfall and started checking their coop sites.

A lot of the information is in either .html or PDF files, so you can grab it and go, reading later.


-- jd (hemwat@bellsouth.net), October 31, 1998.

"Rainwater Harvesting" is the newest buzzword in the sustainable development eco-friendly EPA crowd. For more information than you will probably ever need to successfully implement a rainwater harvesting program for DRINKING WATER simply plug "rainwater harvesting" into your YAHOO or other search engine and pursue the many many sources of information available.

-- Ann Fisher (zyax55b@prodigy.com), November 02, 1998.

Here's a link that I found informative and useful. They are selling a book, but if the information in the book is as good as that on the website, it will be well worth the price. (Rainwater Link)

-- Hardliner (searcher@internet.com), November 02, 1998.

Issues: bird droppings, material leached out of roof.

In many ways roof runoff is of better quality than most metropolitan water supplies. Bleach treatment can almost certainly deal with any bacterial pollution from bird droppings.

If you have an asphalt roof there may be carcinogens leached out of the asphalt into the water. It's unlikely to be any more unsafe than real coffee. If you think it's a problem, filter the water through an activated charcoal filter; these are extremely effective at removing this sort of pollution.

-- Nigel Arnot (nra@maxwell.ph.kcl.ac.uk), November 02, 1998.

Roofs should be checked for lead in weatherproofing finishes. Older style linseed oil paints often had lead oxide in the paint.

Any pharmacist/chemist should be able to tell you from a small sample of the finish.

If a roof is finished (painted) with a lead based paint avoid harvesting water from it at all costs.

Otherwise rainwater is fine.

Check out http://www.naturalmom.com/leadsour.htm for information about lead sources in the home.

-- Bob Barbour (r.barbour@waikato.ac.nz), November 02, 1998.


Rain Water & Snow are not pure as many people mistakenly believe, but are contaminated with Dust, Smoke Particles, Chemicals, Bacteria, Minerals and Radioactive Fallout such as Strontium 90.

In falling through the air, Snow picks up as much contamination as does Rain  and freezing does not kill bacteria.

While the Tried & Proven Rural America Method of catching Rain Water Run-Off from the roof of a house or other building, collecting it in roof rain gutters and diverting it via a downspout into a Cistern or Other Water Reservoir System is an excellent method of obtaining Free Water, the water is not pure and must be treated before use for Cooking & Drinking.

In addition to the pollutants in the atmosphere, further contamination results from fiberglass and other materials in the shingles themselves, dust and other impurities on the surface of the roof, rotting leaves, insects, dead birds and other debris in the rain gutters  and in the Cistern or Other Storage Reservoir itself, which is far from being sterile.

In the Good Old Days, anyone who has ever removed the cover to a Cistern and looked in, has seen dead rats, mice, other dead animals, bugs, other filth, slime and debris that had fallen into the cistern. These sorts of contamination can easily be avoided with todays technology in constructing water storage reservoirs and tanks that are well sealed  but contamination will still enter the Cistern or Other Water Storage Reservoir via pollutants in the rain water, roof surface and roof rain gutters.

For a full dissertation about Rain Water & Other Types of Water, Drinking Water Treatment and Purification Methods [Filtration. Reverse Osmosis (RO). De-Ionization. Chemical Treatment and Steam Distillation], go to Internet URL Site http://www.conquestinc.com.

Also available at the same Internet Site is a listing of the various types of Water Testing that are available, with sources of Commercial Companies who do such testing.

Conquest International Corporation is an Authorized Marketing & Sales Agent for the Leading U.S. Manufacturer of Water Distillation Equipment and Small Water Bottling Plants.

Conquest provides Full Spectrum Planning & Design of Residential & Commercial Water Filtration, Treatment and Purification Systems  including Water Well Hook-Up, Operation & Maintenance.

A lucrative opportunity exists in becoming a Dealer or Distributor for Water Distillation Equipment and Small Water Bottling Plants  either as an addition to the Product Line of an existing business, or for individuals interested in Self-Employment. Interested parties are requested to contact Ned Colburn, Conquest International Corporation, 1109 SW 8th Street, Plainville, Kansas 67663. Tel [785] 434 2483. Fax [785] 434 2736. E-Mail: cicks@ruraltelnet.com

-- Conquest International Corporation (cicks@ruraltel.net), November 03, 1998.

Thanks for the info, Conglomerate Inc. But I'm wondering, can't any of you guys just answer a question without a plug for your bid'ness?

Uncle Deedah.

PS, Ask me about our "Survive Y2K" home remodeling plans, including our "Evade and Escape" basement add ons, and remember, there are only two weeks left in our "Bulletproof Bidet" bathroom special!

-- Uncle Deedah (oncebitten@twiceshy.com), November 03, 1998.

Not an answer - another question. Does anyone know of a website that has regional rainwater composition information on? I can get tap water info for almost anywhere from the local water company.

-- sarah c. (s.cornell@uea.ac.uk), September 01, 1999.

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