21 January 2008

Rain Harvester Part 2 of 4

The most challenging part of putting our rain harvester together was deciding what to use as the storage receptacle. Below are some links to sites I went to while in the shopping/research phase of the project. The last one, Waterhog, is actually a new link that I picked up recently and decided to add to the list for Future House consideration. What all of the links have in common is that they provide products specifically designed for the storage of liquids. I noticed immediately that anything designed to perform a singular duty will most likely cost far more than what you can do with a little inventiveness. If you click on the links, you will see that some of these receptacles can cost thousands of dollars. However, these large-scale tanks should not hastily be written off of anyone's list when designing a rain collector just because they're pricey. I'll get into these reasons why in a bit, but first I want to cover how we came to our decisions and then I'll venture into some alternatives and their benefits later.

When we began calculating the volume of water we wanted to collect, we tried to negotiate all factors that would help promote sustainability and eco-mindedness. Our sustainable interests were pretty much focused on the garden. I assume that this is the desire for a fair percent of folks who harvest rain. In southeast Pennsylvania we get a good amount of rain, but it comes in large amounts at distant intervals.

Sometimes we can go over a month without any kind of significant precipitation. Another kicker to our infrequent downpours is that we are on the peak of a very rocky foothill. This terrain lends itself to counterproductive drainage; so the rain we do get doesn't soak and stay in the soil as much as we'd care for. After Meg did some calculations, we realized that we would need at least 500 gallons. We would have actually needed more, because 500 gallons would give our 1,200 square foot garden a good watering only once a day for about a week. But, you know those light rains that last maybe half an hour and only get the surface a little wet while an inch down is still bone dry? Well, if the system utilizes enough roof space, those little spit rains can replenish a significant amount of water to your harvester.

Our eco-minded approach to harvesting rain is that the water collected doesn't just have to be for gardening. It is not necessary to use potable water for all household needs. In the United States we are feeling the effects of population increases with poor water management. (I know the same is happening elsewhere on the planet and I hope that those of you living in those countries could perhaps give your input on the significance of rainwater in your area.) Meg and I have three more rain harvesting projects that are in the design phase and will hopefully be up and running by late spring. Two of them will utilize more of the house's roof: one to help fill the pool in order to combat evaporation, and one to offer water for general washing like for cars and the porch. The third will hopefully feed off of the shed by the garden and we will use it for additional plant watering and to clean vegetables and garden tools.

After we decided on the water volume we wanted to collect, we then went to price. As I said earlier, containers designed specifically for rain collection can be very pricey (even a 55 gallon "rain barrel" can cost $100), so we opted for alternative materials. I found that the best way to do this is to brain storm the different kind of containers you'd like. Remember to account for space and aesthetics. The different containers we considered were:

  • Plastic drums
  • Steel drums
  • Tank from old fire truck
  • Discarded water heaters
  • Dig a pond
After you have a list of possibilities, hit the internet. The best options came from Ebay and Craigslist. I don't know if Craigslist is worldwide, but it is all over the U.S. and I highly recommend it to everyone searching for anything from a screwdriver to a job.

Digging a pond quickly became out of the question, because we didn't have the equipment or people power, it's too permanent for a rental property, and we had no desire to deal with the possibility of mosquitoes. Also, chickens can't swim. The tank from an old fire truck was impossible to find and transporting it would have been equally so. Discarded water heaters would have become more hazardous than what they are worth. Steel or plastic drums turned out to be the cheapest and most obtainable resource. We also had to find someone who could give us ten barrels at once, because at that time we had two little cars that couldn't fit any drums and needed to rent a truck from the Home Depot to pick up the barrels.

**If you have your own truck, I suggest going for plastic barrels, because they are easy to find for free. The places to ask for them are drug companies, breweries (that's what hops comes in), or any major food importer. Once these places receive their goods in these barrels, by law they can't reuse them. Since it costs them money to get rid of them, they are usually happy to have someone else haul them away. If this is available to you and all you need is 55 gallons of water, then you can seriously build your harvester for under $7.50 (hose not included).**

We found our barrels on Ebay for $9.00 a pop. For the price of ten plus the truck rental, we were able to get 500 gallons for the proce some companies charge for 55.

If you desire as much water as we did and if price and people power is not a concern and/or you are building a home from the ground up, I would highly suggest burying a large cistern. If it is a new home, you can easily incorporate the rain water into your gray water system for toilet flushing, laundry, and all the other things discussed above. If tying the cistern into your home is not idealistic, burying it is still beneficial for reducing algae growth, and eliminating the need for winterizing.

Link to Part 1 of the rain harvester series.

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Anonymous said...

Thanks for the details and links, I am looking forward to larger cisterns in the future.

I have seen good tanks at TSC for reasonable rates (though much more than your custom job), if you have a trailer to transport.

Also, if you are near rural areas, Craigslist or auctions turn up some sweet deals.



Kelly said...

Hello Rob, When Meg and I buy our own land we plan to invest in a large cistern. If you're building from scratch it just makes too much sense.

It's good to hear that you are a fellow Craigslist shopper. You can get some great deals on some crazy stuff. We haven't ventured into auctions yet, but we'll be sure to ask you and Mia for advice before we do. Cheers.

Anonymous said...

http://www.tank-depot.com usually has the best price on water tanks and they have a rain-water collection adapter for large plastic storage tanks.

Anonymous said...

Ditto the tank-depot.com kudos; was able to get a 250 gallon vertical tank with their rainwater collection adapter; ordered online and received the tank 4 days later!