Cisterns: Pros & Cons

(Illustration of the hydrologic cycle by Tre` Arenz, taken from Rainwater Collection For the Mechanically Challenged.)

Very few things in life are 100% positive, cisterns included.  Way back when I first started writing about our homestead, I vowed to be upfront with the good, the bad & the ugly.  Here's what Fred and I have compiled:  the pros and cons of catching your rainwater in a cistern.

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Pros:
1.  Independence from public water supply. 
We are 100% on our own, which means that we control what's added---or not added---to our water.  When you turn on a faucet in our home, you are not greeted with the smell of chlorinated water.

2.  Cost
After installation (which is comparable to drilling a well), monthly cost to filter the water is minimal.

3.  Ability to avoid polluted groundwater.
This one is big for me.  Pennsylvania is currently going through the growing pains with drilling and fracking our Marcellus Shale layer.  There isn't much legislation in place to govern the drilling companies and mandate responsibility to the citizens of our state regarding the cleanliness of our drinking water.  And while contamination from fracking fluids isn't terribly common, groundwater is a tricky thing to keep track of, impossible to control.  I'm able to avoid having to wonder if my water is contaminated, simply because my water doesn't come from the ground.

4.  Soft water
In terms of hardness/softness, rainwater is on the softer side.  In addition, we're able to avoid common well problems such as iron or sulfur.

5.  Access
I have access to water, even if the power were to be out for quite a bit of time.  Even if I needed to collect it by hand from the tank and boil it on the stove in an emergency situation, I would still have access to water.  (As an aside, since we have a waterless toilet, we can still use our bathroom even if the power is out.)



Cons:
1.  Cost
Initial cost, depending where you live and what pieces of the system you need to purchase, can be the same as the cost for drilling a well.  In our case, we spent $7,675.00.

2.  Responsibility
No two ways about it, you need to be responsible individual if you want to harvest rain as your only supply of water.  Each job is small, but needs to be done if the system is to run properly.  Filters need to be changed monthly.  Gutters must be cleaned out, so excess gunk doesn't try to wash into the tanks.  pH needs to be monitored.  The roof washer must be emptied out in preparation for the next rainstorm.  You need to keep the weather forecast in mind---if it looks like the weekend holds the largest storm for the fall, you had better be at home to open and close the roof washer, to catch every precious drop of water. 

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There you have it---the ups and downs as we see it.  As with everything, there was a bit of a learning curve, but we are very pleased with our rainwater collection system.  Our cisterns have been a fantastic investment in a system that will work well for many years to come. 

What's it going to cost me?

Boy, that could be the title for so many posts!  I wanted to do a short post on the cost of our cistern setup.  Because let's face it---either you find catching your water appealing or not.  And if you do, one of your first questions needs to be, "What would it cost for me to set up a water catchment system?"

Keep in mind, these numbers are from two years ago.  The number one rule in construction is that prices are constantly on the rise.

Four fiberglass tanks, 1,500 gallons each---$5,700.00  ($838.00 of this was freight charges.)
Roof Washer---$875.00
Pump---$600.00
Filters/UV light---$500.00

So starting from scratch, our system cost $7,675.00.  Yes, that's a lot of money.  You have to factor in that at the time of construction, we were comparing the cost of a cistern to the cost of drilling a new well.  A few of you have mentioned having stone cisterns on your property.  Your investment cost would be a lot less, considering that you don't have to buy storage tanks.

To be continued.

Coming on Sunday:  Costs vs. Benefits of Catching Your Water in a Cistern

Thanks for visiting!
Grace

Splurge

Okay---yesterday I left with the promise that I would share our "water splurge".  Ready?

During construction, Fred and I put a Jacuzzi in our bedroom.

I know!  Totally inconsistent with the "good-for-the-environment" side of me.  Doesn't really fit with the "saving water by using a composting toilet", except maybe that it helps me justify having it.  ;)

Here's the thing:  I believe in splurging from time to time.  Before Fred and I had children, we had an overnight getaway each winter.  Sometimes it coincided with cross country skiing.  More often than not, it involved a nice hotel room, complete with a whirlpool bath.

When we were looking to build our home there were many areas where we cut costs, but we decided to allow ourselves one splurge item.  Different people choose to splurge on different things in life---travel, cars, appliances, computers, etc.  Our splurge was to purchase a Jacuzzi.

This nook of our room is still under construction.  At some point, the concrete board in the picture will be tiled.  We have the tile.  Now we just need the time!  Another note:  just because you want to splurge on an item doesn't mean you need to pay full price.  We only paid 1/2 the retail cost by purchasing the Jacuzzi at our local Builder's Surplus.

Because we depend on a cistern system for water, we are judicious about our water use.  Jacuzzi use is somewhat seasonal, more readily available in the spring and falling-into-winter months.  

It's why you won't ever catch me complaining about rain.

Water is a blessing.

-Grace

Water, water everywhere

It's absolutely ironic that I opened my mailbox to see the title story of On Earth, "Running Dry:  From Lima to Los Angeles, the survival of great cities around the world depends on sources of water that are dwindling at an alarming rate."

Ironic, because for two days, we have had nothing but rain.  Until it began snowing.  You get the idea---lots of precipitation!

Water is among our most basic needs as humans.  From the earliest cultures who toted water from a nearby river or stream---to today, where many in our country rely on the convenience of a faucet and a public water supply, water is the one resource we simply cannot do without.

When Fred and I were in the planning stages for Haven, we played around with many ideas for reducing our daily impact on the environment.  One idea that stuck was the idea of using a cistern, a way to catch the water from our roof and store it for future use.  We had seen cisterns during our trip to Bermuda, where catching your rainwater is the norm, but we knew nothing about the logistics---or legal issues---surrounding cisterns.  (Here in Pennsylvania, no one cares if you harvest your rainwater.  In some western states, where water is a very precious commodity, laws have been on the books for the past hundred years addressing water rights and prohibiting rainwater harvesting.)

Our biggest hurdle was learning about the ins and outs of rainwater collection.  What type of roof would we need?  How much water would we need to store?  Where would we store the water?  And in what?  How would we treat the water for safety?

Most of our answers came in the form of wisdom from Suzy Banks and Richard Heinichen, from their book titled Rainwater Collection For the Mechanically Challenged.  That was us!

Suzy and Richard's book walked us through building our system from start to finish.  They explain how to plan for storing an adequate amount of water and help you decide which type of tank to install.  Suggestions are offered for the site (location) of your collection tanks, and overviews are given for different pumps and filtering systems. 

How does our cistern actually work?
When it begins to rain at a conventional home the water is collected into gutters, travels through the downspout, and is funneled away from the foundation of the home.  Here at Haven, it is the opposite.  Our water collects into gutters, travels through the downspout, and is funneled into holding tanks in our basement.

At the start of a rain shower, the water is funneled first into a tank called the roof washer.  (Any pollen, caterpillar poop, etc, gets washed in there too.) This gets all the crud off the roof before we begin to catch the water we'll be drinking. Once the roof washer is filled, the water begins to collect in the four tanks. Each tank holds a maximum of 1,500 gallons, where it is stored until we need water somewhere in the house.  (After the rain is over, the roof washer is drained by turning a valve, making it ready for the next shower.)

(Roof Washer)

When we turn on a faucet, the pump kicks on and starts pulling water from the tanks. First, the water is drawn through a cotton filter to eliminate any particulates. Next, it is pulled through a carbon filter for taste. Last, it passes through a UV filter, where bacteria and viruses are killed instantly.

(Filter/UV light battery)

Quick Answers to Big Questions:

What kind of roofing material works best for collecting rainwater?
Hands-down, a metal roof is your best bet if you're collecting drinking water.  If you collect off asphalt shingles, you need to filter out small particles that break down as your roof ages.  If you have real wood shingles on your roof, the chemicals used to treat those shingles are a huge problem for drinking water.

How much water does a person use in a day?  How does that translate to knowing how much water you need to store?
Consider all that you use water for each day:  drinking, cooking, brushing teeth, showers, washing clothes, etc.  In a conserving household (where you turn water off when you brush your teeth), the average person will use between 25-50 gallons a day.  We estimated that each person in our family would use an average of 25 gallons per day, taking into account our composting toilet.
25 gallons/person/day x 4 = 100 gallons/household/day.

Looking at weather patterns over the past hundred years, we realized that we wanted to be able to store enough water to last our family for a two-month stretch at a time.  (Two months was the longest western PA had gone without a good-size rain.)

So...100 gallons/household/day x 60 days = 6,000 gallons

Each of our four tanks holds 1,500 gallons of water, so we are able to store 6,000 gallons at full capacity.

(1,500 gallons in this tank as of this morning!)

What are options for water storage?
People have created cisterns out of many materials.  Historically, stone cisterns have been very popular.  Today, that is a very expensive option.  More affordable, cement tanks often have an aftertaste.  Ready-made tanks of metal, polypropylene and fiberglass are more affordable and easier to transport.  We chose tanks of fiberglass because I happen to be very picky about the taste of my water, and fiberglass was the best option for fresh-tasting water.

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Thanks for visiting!  Tomorrow:  our water-related splurge!

Grace

For further reading:

American Rainwater Catchment Systems Association

http://www.arcsa-usa.org/

Suzy Banks and Richard Heinichen, Rainwater Collection For the Mechanically Challenged  (Texas:  Tank Town, 2004)  ISBN#:  0-9664170-6-2

Pushing the Envelope

(In order to appreciate the events from this past weekend, the reader will want to remember that our straw bale home is currently heated by our backup system, a radiant floor fueled by propane. It's a great incentive to complete our Finnish masonry heater this summer for use in Winter 2010-2011.)

It was inadvertent that we were able to test the passive solar and insulative values of our home last weekend. We really meant to order the propane last week. Really. But it's getting to be good maple weather, which means busy times at home and work.

So we called for propane on Saturday. Sure, they'd be willing to deliver, for an extra $150.00.

Ah. Okay then.

So Saturday began with a feeling of regret that quickly turned into opportunity. As I've mentioned before, the insulation value of the walls of our home is quite high compared to conventional construction. We've created an efficient "envelope" (highly insulated walls, floors, ceilings, windows & doors.) We have a nice amount of passive solar gain through our south-facing windows and a decent amount of thermal mass in the floor. (In layman's terms, thermal mass refers to the ability of a material to absorb heat, to be radiated out over time.) But here's the thing---even though we theoretically knew the insulative value of our home, we had never tested it directly by turning our heat off---until this weekend.

By Saturday morning, we knew we needed to get through two days without using much propane, so we turned the radiant floor system off. (The radiant system works through a thermostat that measures the floor temperature and uses hot water---heated by propane---to keep the floor a constant temperature. The heat from the floor radiates upward and heats everything in its path.) The nice thing is, we can adjust the thermostat to decrease the temperature of the floor, but it also has a switch by which we can simply turn it off.

Looking back, I wish I had treated this weekend more scientifically and taken air and floor temperatures each hour. But anecdotally, here's what happened: we had typical maple weather all weekend, so outdoor temperatures climbed to around 45 degrees F during the day and dipped below freezing at night for both Saturday and Sunday. Each day, the passive solar energy raised Haven's interior temperature to around 69 degrees. Overnight, the air temperature in our home came down to around 64 degrees.

Overall, we were extremely pleased with how we fared at Haven this weekend. There were a lot of variables at play, such as the fairly pleasant March weather with sunshine. (Certainly, if we hadn't had sun, the house wouldn't have been as warm each day.)

So what are the potential implications of our inadvertent experiment? My conclusion is that since I am home during the day, I'll be able to monitor the outside weather and adjust the thermostat on our radiant system accordingly to greatly reduce our demand for propane on sunny days. It makes me think back to a Cape Cod we used to own, to times when we considered ourselves lucky to be able to turn the furnace off toward the end of April. What a great opportunity to be able to reduce our fuel use a month and a half earlier! It also brought me back to our time at Terra Dei, learning to build smaller fires each day as Spring progressed, so as not to waste wood and overheat the house.  It reminded me that life it built on a learning curve.

The owner of the propane company personally made our delivery yesterday. Having helped Fred choose the size and site of the tank for our proposed radiant heating system, he was curious as to how we made out this winter. I described how pleasant the floor was to walk on, then related our "experiment" from turning the system off this past weekend. He smiled ruefully, saying, "Well that's great for you, but not good news for me!" Though I kept quiet, I was dying to say, "Just wait until our masonry heater is in place next year!"

Instead, I chose to smile and wish him a good day.

Thanks for joining me along our journey!
Grace
xxoo