Asphalt shingle roof and drinkable water question

Hello happy permie people!

Before I knew any better I had my North Florida roof redone in white asphalt shingles. Only later did I 'woke up' did I discover that capturing rainwater for drinking purposes from an asphalt shingle roof will have too many toxins in the water, making is questionable as to whether it's safe to drink long term.

I am wondering if anyone knows whether I can cover the shingles somehow with....something, to make the rainwater I catch safe to drink. I've looked into some filtering systems but the few representatives I've spoken with say they cannot guarantee their products will filter out the carcinogens that can be imparted into water via the shingle roof.

Is there anything I can do to my roof (besides replacing it) that'll make collecting rainwater for drinking purposes safe?

Thank you everyone!



Logan

Logan, you might want to look at David Tarsi's website on slow sand filters. Slow Sand Filtration David's page is a great resource for slow sand filtration since we started looking at rain water retention and he has also posted to Rainwater Catchment here on Permies. Note his extensive research and reporting of water quality improvements through this type of filter, including almost complete reduction in hydrocarbons.

The drought cycle convinced us this was a necessity. I built a small scale filter as a prototype to play with, used the run-off from the chicken coops galvanized steel roof. Worked pretty well for the while I was playing with it, and it made it obvious to me that you have to be careful with the types of sand used in the filter, not just any sand will work. It's time consuming and you have to pay careful attention to it as it's using a living group of organisms to do the "dirty" work. Whole project was pushed one burner back since the drought is certainly over (for now), but it's still high on the list. We have an asphalt shingle roof too but time, health and budget have delayed replacing it with something else.

Good luck.

What I would be worried about is e coli contamination from bird poop. I know the birds like to do there thing on my roofs and I don't know if your proposed filter system would be able to treat this effectively.
If it was me, I would use the roof water for other purposes but not for drinking.

Logan,
Great question.

I have a couple for you though.
Is there a reason you need your roof water?
Have you looked into filtering it?
Could you just use the roof water for your plants? I saw a contraption on another site
that showed urine entering the top of a funnel full of dirt and water coming out the bottom.
Now I don't care if it was me that peed in the top of the funnel, I just don't think I will
be drinking what comes out the bottom.

Urine to Drink?

I also saw some information regarding an engineer being posed questions on filtering out
chemicals and pesticides. Ancient Filtration Process

Here is a Google of Removing Impurities

I hope some of that helps or at least keeps you from getting sick. We lived in an RV
for a long time and I had one of those water dispensers that I used bottles refilled
from one of those 25 cent a gallon places. Water Dispenser
You could also use Manual Water Pump.

Thanks everyone! I appreciate the response.

Mostly, I want to learn how to deal with water capture from an asphalt shingle roof, and learn how to make it drinkable. Currently I do use the water for my garden (when I actually water it, it which seldom) but I was hoping I could capture and clean enough water to switch my whole house to rainwater rather than the gunk filled, stinky water I get from the muni water source. I am *very* water conscious and I only use about 350 gallons per month for the two of us. Right now I have two, 275 IBC totes and another just sitting there. So I think I could capture enough to run our household.

I don't "need" to do this. I think it's a very wise skill to learn and the HUGE bonus (and bragging rights for all the right reasons) is being able to use rain water I capture rather than having to pay for sub-par water.

I did some reading and didn't find a lot of info on cleaning water well that's been caught from asphalt shingle roof. What little I did read left me with the impression that cleaning it up enough to drink safely over time, was questionable. Given this I thought maybe it's just best to cover the roof somehow and then I wouldn't have to worry as much about extreme cleaning the water and then just go the regular route for cleaning up rain water.

I will definitely check out the links and info everyone presented.

There's a part of me that wishes I could just cover the roof with a suitable and safe substance, that way I wouldn't have to worry about what's getting in the water from the shingles. I mean, the less I have to worry about going in, the better.

Hey Eric. I have not seen that site before and I'm definitely going to take a look at it. Thank you!! That looks like a GREAT site. It looks very thorough, and the fact that his system has been running 24x7 for that many years certainly helps me know that this is a dedicated individual giving out information based on a long time working system.

Re: bird poop on roof... I think there are fairly clever but simple methods to let a certain amount of water "wash" the roof, then after that it's diverted to your cistern.

I have the same issue and I’m in Palm Coast Florida. Here’s what I found out. I’m considering this. Elastomeric paints are specialty roof coatings specifically for rainwater harvesting. While the material isn't cheap and multiple coats are often required, this could be something to consider, especially for rooftops that aren't otherwise safe to collect from. The National Sanitation Foundation (NSF) provides a list of approved roof coatings for potable rainwater catchment systems.

*All water collected for potable use (e.g. human consumption) must be treated to meet drinking water standards.

If your worries are about bacterial contamination (e. coli), boiling or solar sterilization of the water should kill pathogens.  I have seen some set-ups with (filtered) rainwater going into something like a carboy situated in sun. I don't know much about the specifics, though.

Logan Therrion wrote:Thanks everyone!  I appreciate the response.

Mostly, I want to learn how to deal with water capture from an asphalt shingle roof, and learn how to make it drinkable.  Currently I do use the water for my garden (when I actually water it, it which seldom) but I was hoping I could capture and clean enough water to switch my whole house to rainwater rather than the gunk filled, stinky water I get from the muni water source.  I am *very* water conscious and I only use about 350 gallons per month for the two of us.  Right now I have two, 275 IBC totes and another just sitting there.  So I think I could capture enough to run our household.

I don't "need" to do this.  I think it's a very wise skill to learn and the HUGE bonus (and bragging rights for all the right reasons) is being able to use rain water I capture rather than having to pay for sub-par water.

I did some reading and didn't find a lot of info on cleaning water well that's been caught from asphalt shingle roof.  What little I did read left me with the impression that cleaning it up enough to drink safely over time, was questionable.  Given this I thought maybe it's just best to cover the roof somehow and then I wouldn't have to worry as much about extreme cleaning the water and then just go the regular route for cleaning up rain water.

I will definitely check out the links and info everyone presented.  

There's a part of me that wishes I could just cover the roof with a suitable and safe substance, that way I wouldn't have to worry about what's getting in the water from the shingles.  I mean, the less I have to worry about going in, the better.

I realize this post is many years old at this point. But I can't get passed the part where you say that you only use... 175 gallons of water per person, per month? I need to do my homework, of course, but that sounds nearly unbelievably low. How impressive, responsible an awesome of you.

F

The 175 gallons per person is a little tight, but perfectly reasonable if gardening and livestock is not considered.

I ran for months with a 5 gal military shower, by showering every other day ( I had super dry skin).  That is 75 gal a month.
Add another 30 gal for drinking and cooking.
That leaves 70 gal for cleaning dishes, floors, etc.

Clothes washing is the big variable.  It could be taken out of that 70 gal.  In my case, I went to the laundry mat in town.