Like I said, if you're worrying about the chemicals from the roof, shouldn't you also worry about the chemicals in the water itself, whether city, rain, or well?

Crankyoldman: Nothing says refreshing like a tall glass O' bird poo water.

With regards to asphalt roof chemicals in the water to water veggies, would these chemicals actually get inside the veggies or would it just be surface stuff that would wash off?

For bacteria/viruses could you just use a water purifier like the MSR Miox that you would use when backpacking to "zap" the water killing all organisms? This would at least eliminate the bird poop threat if not the chemical threat.

An article in the May/June 2008 issue of "livebetter" on Arsenic in drinking water should give us all pause since most of us on well water and many on municipal water systems have Arsenic levels that exceed the current 10 ppb the EPA ground water people allow. The WHO has lowered the permissible level much below that.
I'd be less concerned about what might get into the water glowing off my roof than what is already in it.

Here is a link that might be useful: livebetter

If one is not concerned about putting things like Miracle Grow and other chemical fertilizers on their veggies, as well as insecticides of every description, then I can hardly see how a little rainwater running off the roof would be a concern. Me-thinks some people worry just a little too much at times. Just my take on it.

Greg
Nevada

i read this thread because my wife wants rain barrels. it seems many people here feel that since there are potentially toxic chemicals in fertilizers, miracle grow, normal rain water, etc., that we shouldn't worry about potentially toxic chemicals that may "possibly" accumulate in the rain barrels from the roof. that simply doesn't make any sense. adding potentially toxic chemicals to our system is not OK just because we have potentially toxic chemicals coming from other things.

obviously, it is a personal decision if you want to use the rain barrels for your garden. one thing that has not been addressed here is what exactly those potentially toxic chemicals might be. without knowing that, i certainly wouldn't call it "silly" if someone decides not to use the rain barrels for their veggies.

For those suggesting metal roofs, I'd be concerned about galvanized metal more than anything. That's what most metal roof material is.

No one here even talked about just capturing some water off your roof and bringing it somewhere to have it tested. Like some other said the amount of time that the water actually sits on your roof is so limited that not much can be absorbed into it. For all you that worry about the other chemicals that are in there to kill mold and fungi do you think that it really washes off? If so then in less then a year you would have mold and fungi growing on your roof. My point is these take a glass of water that ran off your roof and a glass of tap water and have it tested. I'm sure you'll rather drink the rain water off the roof.

http://www.nrdc.org/water/drinking/uscities.asp

Rainwater is known to contain many pollutants including such things as Sulfur Dioxide and the other things that spew from coal fired power plants and manufacturering plants, bird feces, and tons of other potentially nasty stuff. However in some parts of the world, Bermuda for example, homes are required to have rainwater catchment systems so those living in that house will have water to drink and bath with. The same is true in other parts of the world. Some people in the USA have installed rainwater catchment systems and use that water as a primary source of water and just a bit of research n the interrnet will produce a ton of websites about these systems.
If a system is installed it should have a flushing system included so the first water, the most poluted, can be discharged and not stored.

There's a discussion of sorts posted at the following link about the safety of rooftop collected water.

Here is a link that might be useful: healthy or not?

Rainwater not safe. Where do you imagine the water you drink comes from????

Seems like this questioned opened up a big can of worms. Rainwater run off has been used by organic gardners for many years with no harm that I have ever heard about. After your roof has been rained on hundreds or thousands of times, I double that there is much loose residue that's gonna come off.

There is a big benefit from rainwater, especially after a thunder storm, that no one has picked up on. Nitrogen! The electricity from lightning charges the atmosphere and converts a mesurable amount of nitrogen into the rainwater. Take notice the next time you have a thunder storm, of the great sudden growth in your plants. It's free fertilizer!!

Ron
The Garden Guy
http://www.TheGardenGuy.org

g'day shax,

"shax said,
Since I've used rainwater exclusively, I've grown to 7 feet tall, 240lb of rippling muscle, my IQ has increased to 200 and beautiful women beat a path to my door!"

must be the possum poop that does it hey?? lol lol!! i only gets a bit of bird poop in mine huh chcukle?

but yes we use only tank water, though in the 'burb's we have turned of our town water, only ever feel clean after tank water shower. we have a tiled roof (not by choice or it would be corrugated)

len

Here's the link to the Texas Rainwater Harvesting Manual. Your roof shingles are leaching toxins immediately upon installation and continue to leach toxins as long as they are on your roof. We're going through this right now. I don't feel good about putting toxic shingles on my roof. The only safe roof is a metal roof. And watch out if you have lead boots. They must be painted with latex paint to keep the lead from getting into your rainwater collection.

If you're going to water your vegetables with toxic water, come on guys, even the people who manufacture these shingles say they are unsafe for watering vegetable gardens. There's so much denial in manufacturing that I really sit up and take notice if the people who make the stuff say it's bad for you.

Here is a link that might be useful: Texas Rainwater Harvesting Manual

kimmsr: could you please list several of the many municipal water systems you mentioned that are exceeding the USEPA limit for Arsenic. As an operator of a municipal water system, I find it hard to believe that they are still up and running in the state(s) they are operating in while their respective state(s) regulators are aware of the situation.

Michael

I've read a lot of opinions here and some links to "studies" but nothing that sounds like science.

The WA. State Dpt of Ecology has a website on rain harvesting. The roof types they recommend against for capturing garden water are those treated with a fungicide or algecide and metal roofs with zinc or copper. We're are looking at a rainwater system. We have almost no rain mid July into earyl Sept and at the same time have to cut back usage from our commuinty well. So a catchment system seems the way to go. For a 2500 square feet of growing beds/rows to get just 1/4" a week for two months takes 3000 gallons so I'm out searching for affordable tanks. There's a lot more to this than I expected. Tom

g'day tom,

we have a 25k/litre tank around 5k/imp/gal, for us that would be enough for all our water use through the year with our average rainfall in around the 1k/mm range. but that is because we recycle all our used water, some into the garden (only got 16sq/mts), other into potted plants and some goes to flushing solids only in the toilet, urine never gets flushed mine gets bucketed for adding to the kitchen pre-rinse water and wash water for the vege' garden.

target to use all water more than once.

no science needed in rainwater collection just some common sense(type of roofing! we over here only get coloured cement tile and corrugated colour bonded zincaluum) and the need to see that if you are in low rainfall areas there are not a lot of other options, all the rest is fear hype.

len

Here is a link that might be useful: lens garden page

I have been reading up on rain barrels and using it for vegtable and fruit plants. There is a lot of conflicting opinions. What I have read is that shingled roofs that don't have asbestos are ok to use on the plants, as long as your not watering the actual fruit or vegtable. Things like carrots, potatotes, etc, that grow under ground probably shouldn't use the water from the roof. Also, check out the study from Rhode island University about this:

http://www.uri.edu/ce/healthylandscapes/Rain%20barrel%20bro.pdf

It says not use that water on vegtables close to harvest time. and that you must wash the produce after harvesting, well. (DUH)

there is concern that roof water would place to much minerals into the garden, like zinc. but these appear to just be fears and not documented proof. For now, my plants will get what I can collect. People complain about bacteria from bird feces on the roof. Well birds crap in my garden and fertilizer is chicken crap.

Water your flowers, bushes, and grass to your hearts content with this water.

Let me chime in here. I love to throw in a little controversy into these threads by looking at it from a different point of view. For those of you on a munuciple water system: How much do you pay for a hcf (748 gallons) of water? How much will this rain barrel setup cost? How many centuries would it take to pay for the barrel? steve

My dog seems to like the rainwater I catch in buckets better than city water! Of course he also licks himself shamelessly you know where as well...

By the way, I have not heard any comments on the type of material the barrels should be made of. Are there certain types of plastic barrels that should be avoided, especially in S Texas heat that would practically cook the water and potentially cause a plastic leaching effect? I know that I can taste plastic in a water bottle left in a hot car.

I have a barrel for rainwater made of some kind of poly something or other plastic and at the time I purchased it years ago it was supposed to be the way to go for not leaching. I would like to purchase at least one more but would like to hear the lastest buzz on the best barrel.

Thanks!

Roger

Here's an idea about a reasonably priced rainwater catchement system. There are things called IBC totes that can be had for very reasonable amounts. I picked mine up for $80 from a local surplus store. They come in cage and to make them aesthetically pleasing you should probably build some kind of wooden box around them, but they are way more economical than 55 gallon barrels, or the incredibly expensive 'purty' ones from the box stores.

Here is a link that might be useful: IBC totes for rain catchment

I have an asphalt shingle roof and have been using rainwater I get off my roof to water seedlings for years and they seem to grow much better in it than the chlorinated Colorado River water loaded with salt that comes out of the tap. For one thing, I no longer get salt burn that I used to get from the Colorado River water that is imported into southern California.
I can tell you one thing, rainwater off the roof tastes terrible, I drank some to test it before I was going to use it in my fish tank. If I use rainwater for my aquarium I only use water that fell directly into a plastic bucket after tasting that stuff.
Another problem is dirt and pollen in the rainwater off the roof. We never get enough rain in California to the point where I can waste it by letting the first part of the storm clean the roof. Our typical rainstorm is 1/8 of an inch for a whole day. So expect a layer of mud to accumulate at the bottom of your rain barrel, that's why I would recommend a plain 55 gallon drum where the whole top comes off so you can clean it. If you have trees around your house the rainwater will often be yellow from the pollen.
The most poisonous type of roof is an anti-mildew treated wood shake roof. My neighbors dog was poisoned and died when it drank water that dripped into its water bowl off its owners shake roof. The water off an asphalt shingle roof must not be poisonous even though it tastes bad because a neighborhood cat is always drinking out of my rainwater storage buckets and seems to be doing fine.

Here's an idea about a reasonably priced rainwater catchement system. There are things called IBC totes that can be had for very reasonable amounts. I picked mine up for $80 from a local surplus store. They come in cage and to make them aesthetically pleasing you should probably build some kind of wooden box around them, but they are way more economical than 55 gallon barrels, or the incredibly expensive 'purty' ones from the box stores.

Here is a link that might be useful: IBC totes for rain catchment

I lost track of this discussion so this information is a bit tardy. I know people that, due to unfounded fears, would not water their gardens with rainwater from their roofs, but drink bottled water from "pure mountain" streams where wild animals do things.
I was a Boy Scout back in the 1940's and we were taight then that water from a "pure mountain" stream needed to be boiled or treated with the pills we carried before being used for drinking water.
Most everything I have seen here against using water from the roof of your house is based on junk science because the water you drink every day is just as polluted.

Here is a link that might be useful: Arsenic levels in water

About the only way to discern contamination fears, I would think, is to have your water analyzed. Can be a cheap as 20 bucks to many hundreds depending on what you suspect.

I've been catching rainwater from a composition shingle roof, clean the barrel every time after using the water, and there's always a dark sludge in the bottom of the barrel from the roof. Though the water is only 13 tds, it tastes terrible from the undissolved solids, and is certaianly not fit for drinking. There is probably a plethora of toxic chemicals come from the composition shingles on the roof.

I use a reverse osmosis systen in the house, that reduces the pollution in city water by 98 percent but I still don't trust city water. I want to use the natural water from the sky. So my aim is to get a good portion of my drinking water each year from the roof. I've been looking at water purification systems, for example hooking up a 3 stage filter to the barrel, consisting of sediment, carbon block, and ceramic, the latter to replace the RO membrane as that is not needed outside. The TDS is already good.

Looking at all this I'm thinking it sure would be good to not have to remove all that black shingle crud from the water at the start! So now I'm thinking to have that 1/4 of the roof covered with metal. My understanding is that stainless steel is the best metal but expensive. For those of you who are drinking rainwater from the roof, what would you recommend in my case? I'm estimating there might be 500 square feet of roof. And how to avoid the high cost of roofers? Thanks

Kimmsr: your quote, "...many on municipal water systems have Arsenic levels that exceed the current 10 ppb the EPA ground water people allow" Really, I'd like to see the source of information from the EPA for that statement. Do you know what occurs when a municipal water system exceeds the MCL for a given substance, I do, I manage a municipal water system. Your quote appears reckless, uninformed and irresponsible. I may be wrong though.

I am on my 4th year of testing/studying roof water harvesting. I could write pages on this. A slow sand water filter added to your rain barrel system will remove nearly all hydrocarbon pollutants from roof water along with 99.999 percent of harmful biological contamination. I have had 60 separate tests done on water from slow sand filters/roof/surface water sources. A first flush diverter will remove most of the hydrocarbon pollution from roof water. (by the way, public water supply reservoirs are sealed with tar - it does not dissolve in cold water) In the winter, here in Washington state, the temperature of the roof is not high enough to allow much hydrocarbon pollution from the composition roof to get into the water. To make a very long story short: Unless you have a roof with asbestos (pre 1980), or herbicide in it (moss killers), or a cedar shake roof (most of them contain copper and arsenic as a wood preservative and they all contain tannins from the cedar) you are safe watering vegetables from a rain barrel - just be sure to wash them before eating - the vegetables; that is! The website listed here has 4 years of info on roof water harvesting. Don't give up on rain barrels, they work in all but the most toxic situations. A simple slow sand water filter and first flush diverter will make most roof water safe for a vegetable garden.

Here is a link that might be useful: biological sand water filter

I have a rain barrel system that is pretty detailed. It is now a total of 12 55-gallon drums all connected in series using 2" PVC pipe. The downspout comes into one barrel with a filter over it. Then because with the way water finds it's own level, the water level in all 12 barrels rise at the same time.

I put a large 2" PVC ball valve in place to separate nine barrels from the other three. This will allow me to have the valve open when it is raining to fill all 12 barrels. Then I can shut the valve and drain the three barrels into another set of three just below those. One of them is filled with compost and dead plant material. By the time the water trickles through this, it is then distributed amongst the four barrels. I can then use a pump and pump the compost tea back into the three barrels above, open the ball valve, and then when I water my garden with the PVC irrigation system, it has a 3-part water to 1-part compost tea mixture - instant fertilizer!

Definitely was a lot of work but am happy with it. I had a nine-barrel system up until this fall and then added the other three with the ball valve - so I'll begin using that this year.

Here are some videos I've made. I still will need to make another video when the spring comes around to show how the new compost tea system works.

Rain Barrel Water Collection System
PVC Irrigation System & Rain Barrel Integration

Here is a link that might be useful: BsnTech Gardening Blog

I have two rain barrels and have used the water for 4 years now. They really saved my butt during the drought we had here in Georgia a few years ago. My plants respond much better to rain water than the hose water. I have a screen on the top of my barrels that catches any pebbles from the shingles and other debris. I've never seen any debris in the barrels (I do have algae, but I think it is beneficial to the plants I water). I have used it for watering potted tomato plants, but I don't do a lot of veggie growing.

To be clear, this is NOT drinking water and it says it right on the barrel. Any rain water that is collected for drinking would have to be filtered several times I would think.

And another ga. person here...I have 5 rain barrels & a metal roof! I've used it for 3 yrs. now without any problems!
Metal roofs are great for collecting the water...so good we had had to put 2 (TWO) overflows on a couple of the barrels. When we get a downpour (1/2" in 10 min.)it can really fill them up FAST!

Just a quick FYI, the URL to our popular rain barrel site, posted earlier in the thread, has changed...

Here is a link that might be useful: Rain Barrels - Build your own instructions, Safety, Calculator, and more!

Just a quick FYI, the URL to our popular rain barrel site, posted earlier in the thread, has changed:

Here is a link that might be useful: Rain Barrels - Build your own instructions, Safety, Calculator, and more!

Those that are worried about pollutants in runoff water should think about this. I'm not disagreeing with you just saying collecting from your roof isn't bad.

Unless you are growing in a greenhouse that same water with the same pollutants fell on your garden. The pollutants you mentioned are found in the air around cities not in roof tiles. Whatever chemicals there are contained in your roof tiles make little difference in the grand scheme.

Your tap water has all sorts of nasty chemicals to. Arsenic, chlorine etc...

I�ve used rain barrel water for 10 years and have a growing concern about it�s safety. I�ve never been tempted to drink it, yuck.

From a MN Dept. of Health Environmental Toxicologist April 2006: "other contaminants that may deposit onto roofs from air. It appears that contaminants that rainwater washes off of shingles may be a significant source of surface water contamination. The contaminants that are washing off of roofs include zinc, lead, chromium, arsenic, and polyaromatic hydrocarbons. It is similar to what you might collect off of a parking lot."

This raises all kinds of issues for me. I think Testing needs to be done recognizing that some of the science is unclear and standards and acceptable limit in parts per million maybe inaccurate. It would be nice if certain common pollutants could be identified and a public service lab function to test samples for concerned citizens much like soil samples have been tested in the past for nitrogen, phosphorus, potassium and ph. Levels.

Here are some of my concerns:
� Manufacture of roofing materials need to be regulated to insure environmentally safe products are used and environmental impact information available on product labeling at a minimum.
� If water that is coming off the roof is not safe to use on food plants because of chemicals in the materials the implications for our streams and lakes ought not to be ignored.
� If contaminants from the air are deposited on our roofs I can only conclude they are also deposited on our gardens and plants in our yards.
� I recall seeing studies of lead take up in plants in urban settings along the boulevard strips from lead in gas, and around houses and garages from lead paint.
� Many lakes in MN have mercury advisories due to fallout from coal burning power plants emissions washed out in rain water. Is the organic material in our soils acting like a fish in a lake collecting the pollution?
� Plastic rain barrels leaching estrogen mimicking chemicals into the container water.
� The list goes on.

It is best to avoid using the water from your rain barrel on plants grown for consumption until you receive results from taking a sample of water collected from your rain barrel and having it analyzed by your local water testing laboratory. If you decide to have this water sample analyzed, have it analyzed for contaminants such as zinc, lead, chromium, arsenic, polyaromatic hydrocarbons, fecal coliform, and E. coli. - http://water.rutgers.edu/Stormwater_Management/rainbarrels.html

A sensible recommendation from the University of Rhode Island extension service:
But Can I Use the Water In My
Vegetable Garden?
Yes, but only in the same way that other nonpotable water is used. Avoid using overhead
irrigation.It is best to use this water for drip or
trickle irrigation This prevents contamination of
edible above the ground plant parts that are
hard to clean, especially leafy greens. However,
the vegetable is not safe to eat unless it is
thoroughly washed using "drinkable" water first.
Rain barrel water should not be used close to
harvest time to water the vegetable garden and
should NEVER be used to wash fruits or
vegetables from the garden or orchard prior to
consumption. - http://www.uri.edu/ce/healthylandscapes/Rain%20barrel%20bro.pdf

wow GR,

that is a lot of researching others theories, we've lived from drinking rainwater from cement tiled rooves and corrugated rooves, like many in rural here and no doubt over there, we are all very much alive and fit as, and well, we had at one stage been collecting rain water in drums/barrels to wash clothes with and again no concerns. there is no anecdotal evidence to support the negative science, bit of fear mongering me thinks for the purpose of manipulation.

more danger in drinking town water running through old lead pipes and with heaps of added chlorine and fluoride.

anyhow we still drink and live off rain water. the plants will thrive on it, and the food you grow won't be contaminated with spray poisons residuals. plus it will be super fresh.

len

Here is a link that might be useful: lens garden page

One thing I haven't really seen commented on is whether folks are directly applying the rain barrel water over the vegetables or not. I usually water at the base of the plant into the soil 100% of the time, wouldn't that mitigate a fair amount of the concerns of contaminants?

we drink our rain water and use it for cooking and all our needs.

not an advocate of overhead irrigation type water of plants, like you we water the root zone only. for no other reason to get the water to where it is needed.

we also use rainwater tanks to save substantial water ours are generally 22.5 kilo' litre size. have used drums as well but capturing around 220 litres not really enough.

len

Here is a link that might be useful: lens garden page

I go away during May/June so using a rain barrel seamed like a good idea for my garden. I plant Earthboxes so using a Rain barrel hooked to the auto watering system for the Earthbox will keep them growing while I'm gone. I was wondering about using roof water so decided to hook a house to the barrel so I could fill 55 gal barrel with hose water before leaving since the boxes only fill when needed. I read the ground filters the water and I guess can add Tlb of bleach to keep barrel safe.

We are now, on our 7th year of rainwater harvesting using rain barrels in conjunction with slow sand filters. We have been watering our vegetable garden with filtered water from the rain barrels for the past 4 years. The water comes from a composition roof. The slow sand filters take out the petroleum residue and 99.999 percent of the biological contamination. The water is perfectly fine for watering a vegetable garden. The filters may even be a bit of overkill. A first flow diverter may be all that is needed in the best of situations. There are lots of critters here with access to the roof, so we need our water filtered. We have thousands of hours of study documented on 3 websites and a blog. The link below is to the blog. The "About" page on the blog has links to all the websites. Rain water / roof water harvesting is not against the law in the U.S., contrary to popular belief. The blog link below has a post with links to sites that explain, and link to each state's laws. There are only 4 states that severely limit roof water / rain water harvesting, and laws there are changing in favor of individual roof water harvesting systems, not against, as some might think.

Here is a link that might be useful: slow sand filter blog

The Montgomery County, MD Extension Service agent told a gardening group I sat with recently that they don't recommend vegetable gardeners use rain barrel water because of...

risk of Bird Flu (from roof droppings).

I'm nearly certain this is total nonsense, but I could be wrong. It could just be embarrassingly ridiculous. I see a lot more birds fertilizing (and robbing) my garden than ever perch on my roof.

There hasn't been bird flu concerns in MD since the huge DE/MD outbreak in the mid-2000s...and that was mostly confined to bird farming operations.

At the very most, try not to make too much contact with with the water, wash your hands afterwards...meh...not a big deal.

I'd be a lot more worried about breeding mosquitoes for those that don't use BT dunks in their tanks.

If you are worried about pathogens, just add kvass to your rain barrels and the beneficial microbes will work their wonders. I added kvass to a rain barrel in the past which had developed a bad smell. The smell of the water cleared up and never a problem again. An added benefit is that the kvass water is good for the plants.

Is there not some way to filter water for drinking? and testing would likely be the way to go.

I have question regarding all of this. Today, my father and I cleaned 20 years worth of built-up sediment runoff from my house gutters. The roof is asphalt shingle, from 1996 and I don't believe the gutters have ever been cleaned until today. We had buckets of tarry black sludge, water and rocks that had unlodged from the shingles. When I wasn't looking, my dad decided to empty a few buckets worth of the liquid portion to reduce the weight. He didn't strain the liquid, he just poured off the top, so it was black nasty tar-water. And guess where he dumped it? In his septuagenarian wisdom he dumped that black water into my veggie garden because it wouldn't be as visible, since the soil was also dark.

I am pretty upset about it and felt he basically turned the center of my garden into a contaminated brownfield site.

I stopped him from pouring the final bucket in there once I noticed what he was doing, but already several had gone in. I appreciate that he wants to help out, but I never wanted him here to do this job; he imposed on me, sort of telling me it needed to be done. Now I'm thinking about dismantling the garden, raking it out and seeding with grass and giving up entirely on the idea. I don't want to eat from it anymore. I'm also upset that I had just planted some things in there not too long ago. The smell was foul from the sludge and I had to wash my hands 5 times with various soaps and pummus to get the odour out. Surely the tar-sediment which built up from sitting for 20 years in gutters is carcinogenic and awful for anyone to ingest.

Are my fears reasonable? Will that stuff wash away by summer, or will it be absorbed by the plants and maybe give me a tumour some 15 years down the road? I'll always look back to this episode if that does happen and I kept eating from that garden...

I'm not sure exactly which chemicals are in the tar/asphalt, but I did come across this bit:

"It is also worth mentioning that fiberglass used in asphalt shingles is bonded with urea-formaldehyde resin, a highly adhesive but toxic material that emits formaldehyde into the air, which can cause respiratory irritation and more serious effects on health (especially after prolonged exposures and high air concentrations in excess of 3.0-5.0 ppm)."

"Formaldehyde is highly toxic to all animals, regardless of method of intake. Ingestion of 30 mL (1 oz.) of a solution containing 37% formaldehyde has been reported to cause death in an adult human.[36]Water solution of formaldehyde is very corrosive and its ingestion can cause severe injury to the upper gastrointestinal tract."

Hello, we have bought two barrels today which we planned to use as water butts, however there is a label on one of them which reads that they originally contained Formaldehyde - the seller assured us that they had been rinsed three times. Do you think they will be safe to use for water to be used on our allotment??

I would address that question to your county or state health department. Some barrels that contained some chemicals cannot be cleaned well enough to be safe. There was a discussion amongst the health departments some time back about banning the sale and reuse of these barrels for that reason.

Rinsing the barrel 3 times with just water may not be enough and it may require a solution to clean any residue from the barrels. There was a barrel cleaning company, locally, that was shut down due to the environmental hazards they produced and tests of some barrels and some products found even then there was residue of the chemical in the barrels.

kimmq is kimmsr

Thank you ever so much, we will contact Environmental Health on Monday