Sunday, January 1, 2012

The Sustainability Review – Water Storage

By Mike Forbes, Co-op Volunteer Writer

Last month we talked about calculations with the goal of obtaining realistic numbers of our water consumption.  In talking with a friend he mentioned that looking at your water bill is a simple way for those who live in a city to determine this.  On your bill you’ll see your consumption, typically in cubic feet which is easily converted to gallons by multiplying that number by 7.48.  I thought this would be good to pass on.

Now on to the most challenging aspect of rainwater use, storage. People use various methods such as plastic, wood, and concrete tanks, old dairy trucks, wooden wine barrels, and above ground swimming pools.

Our house water supply which includes drinking water consists of four, dark green 1600 gallon HDPE plastic tanks.  This is probably one of the most foolproof, proven and affordable methods of storing water.  Dark colors are important because algae will grow rapidly in a light colored tank if exposed to light.  Having more than one tank is nice on several fronts. They are easier to handle, readily available, comparably inexpensive (our tanks cost approximately $600 each delivered) and provide redundancy in the event a leak.  The HDPE plastic is the same material that milk jugs are made from and current testing shows that it doesn’t leach chemicals into the water.

Above or below ground?  Above is generally easier but not always practical as water freezes.  Our tanks are located above ground in a room with 2” of foam insulation around them.  I don’t fret about the tanks themselves freezing as it would take a really big cold spell to freeze that much water.  However, I do worry about the plumbing and watch it closely when the temperatures dip below freezing.  In 6 years we have never seen pipe temps below 37 deg F. 

If you decide to go with a below ground tank make sure it is rated for below ground use as they are structurally very different.  On the converse, below ground tanks typically rely on the surrounding dirt for stability and can collapse in on themselves if used above ground (ask me how I know this?).

For most people it’s not going to be realistic to store all the water that falls on their roof as this would take a very large tank(s).  This is where calculating usage is essential to balance what you use with having an adequate supply, even through the dry months of summer.  I analyzed the rainfall data by month and estimated when we would run low.  We go into the summer with full tanks from the spring rains and when July comes we don’t see much rain until September.  The lowest our tanks have been was 750 gallons total at which point we started hoping for rain.  An additional tank would give us a more comfortable buffer.

Many people are going to use rainwater for irrigation only.  In this case many problems are eliminated since you can have storage located outside that is seasonal and drained during the winter months.  I’ve seen many people use wine barrels at the base of their downspouts for this and others place large tanks out in the yard.  As long as you are diligent in draining your system in the fall this can be a very effective setup.  My current plan for larger scale irrigation system is to fill a 24’ above ground swimming pool providing over 13,500 gallons of water.

Water tanks can be sourced locally through Hahn Supply and occasionally craigslist.  A word of caution on used tanks. Many have been used for chemical and fuel storage.  These liquids may have absorbed into the tank and would not be a good choice for drinking water.  I see very few used tanks out there that are suitable for drinking water, not to say one might turn up tomorrow. 

If you are looking for more information, our library has the definitive resource on water storage is Water Storage by Art Ludwig.

Mike can be reached at and welcomes questions/comments.

The Sustainability Review – Rainwater Calculations

By Mike Forbes, Co-op Volunteer Writer

Break out your thinking caps, actually just your middle school math skills for this month’s article. We are going to figure out your actual water usage and see if rainwater can supply your household needs (or agricultural needs).

One realistic caveat to supplying your house with rainwater, you must be committed to using water wisely and installing efficient water using appliances in your home.  This doesn’t mean living like you are on a boat but it does mean buying low flush toilets (dual flush preferably), low flow showerheads and faucets, a modern dishwasher, and a front loading clothes washer.  It also entails using those appliances wisely. No expectation of 2 minute lather/rinse shower is being made just not the 30 minute shower experience or daily 60 gallon bath.

Our goal is to find out how much water we use per day on average (we’ll put a fudge factor in at the end to cover unexpected extra use). First we need to make a list of all the water-using devices in your home and how much water they use measured by use or time.  I created a spreadsheet for this that helped dramatically with the calculations.  Let’s look at your shower as an example.  On the showerhead there is most likely going to be a marking that shows the flow rate in gallons per minute or gpm.  Ours is 1.5 gpm.  For every minute our shower is on 1.5 gallons are coming out of it.  If I take a 10 minute shower I can conclude that 15 gallons of water were used (10 min x 1.5 gpm = 15 gallons).  Many appliances it isn’t that simple.  Let’s take the dishwasher for example.  In the owner’s manual there is probably a table that shows water consumption per load for each different cycle.  This is the number you are looking for.  Some dishwashers adjust the water based on how dirty the dishes are so I’d use the higher number to be safe.  If there isn’t a number you can test the usage by running the appliance and capturing the water in buckets and measuring the discharge.  Not the most convenient of methods but it does work and I’ve found the published numbers to be remarkably close to my tests.

Once you know the water usages for all devices you’ll need to make some estimates as to how often you use them.  I would recommend erring on the high side but also keep it realistic.  You could even track your usage before making this calculation on a notepad for several days or weeks.  The longer you track your usage the more accurate the number.  For example, I estimated that each person in our household will flush the toilet 4 times on the #1 flush (.8 gpm) and 2 times on the #2 flush (1.6 gpm).  Doing the math I get (4 flushes x .8 gpm) + (2 flushes x 1.6 gpm) = 3.2 gal + 3.2 gal which totals to 6.4 gal/person/day.  For the four of us our total toilet water use equals 25.6 gal/day.  This is probably high and over the years I’ve found it to be but for estimations sake it is a safe figure to use.  Do this for each device and you’ll get a total water use per day for your household. To account for waste, guests, and unexpected water use I add 10-20% to this number to get my daily household water use figure.  Hopefully you’ll find that your daily usage is much lower than the US average at 80-100 gallons per person. 

All of these calculations above refer to using rainwater for indoor domestic water use.  There is no reason why these calculations can’t be used in the garden.  Drip systems are generally rated in gpm per dripper and water meters can be purchased affordably to measure total water flow through a sprinkler system.

Once we have obtained our daily water usage we can then come together with our expected annual rainfall figure we estimated in the September article.  With these two numbers in hand we’ll start the discussion on water storage.  It however will have to wait until January.

Mike is can be reached at and would be happy to share his spreadsheet with you if you wish to start the journey to rainwater usage.

Tuesday, September 20, 2011

Responsibilities of an Aspiring Post-petroleum Citizenry

Green Transportation
by Jeanne McHale, Co-op Newsletter Volunteer

It would be nice if this month’s Green Transportation column were a laundry list of simple things you can do to reduce the environmental impact of getting around: bike, walk, carpool, etc.  But none of these healthy practices matter in the long run, if Exxon-Mobile and its Canadian subsidiary Imperial Oil are allowed to imperil the planet with their climate-killing mining practices.  The massive Kearl Tar Sands project (250 square miles mined so far, with a possible scope of 54,000 square miles), poses threats to the environment on a geological scale.  In a climate-bashing triple-whammy, this environmental obscenity wastes natural gas to fluidize  a nasty carcinogenic precursor, scrapes off the boreal forest and nullifies its capacity for absorbing CO2, and would ship the end-product to China where it will be subject to fewer regulations when it’s burned. Leaking tailings ponds are fouling the Athabasca River, causing deformed fish and ruining livelihoods.  Rare cancers are inflicting whole families of people who live near the tar sands.
               Earlier this year, Big Oil had its slimy tentacles stretched toward the scenic Clearwater and Lochsa Rivers.  Now the loads, which were earlier deemed to be “impossible to reduce in size,” have been sliced lengthwise to fit under freeway overpasses, and these stubby behemoths have the green light from the Idaho Department of Imperial Oil Transportation (I.D.I.O.T.) to pound Highway 95 on their way north to the ecological freak show. 

            The night of Aug. 25, six brave Moscow citizens were arrested and hundreds more protested the passage of a half-height Exxon-Mobile megaload. Since then, a handful of additional loads bound for Alberta have been met by robust gatherings of resistors. At least 60 more stubby megaloads are idling in Lewiston while B.O. and I.D.I.O.T. rework their travel plan to try to minimize opportunities for free speech, much of which has been expressed within blocks of our food co-op. 
            Biking and walking are small contributions made by individuals.  Massive social change to prevent dire environmental consequences, on the other hand, requires a lot of people acting together to affect policy. Come downtown and participate in peaceful demonstrations against megaload madness.   Reject Moscow’s participation in genocide and climate change.    

                Jeanne McHale thanks the members of Wild Idaho Rising Tide for their hard work and recommends friending them on Facebook to keep abreast of tar sands resistance work.   

Sunday, September 4, 2011

The Sustainability Review – Rainwater Geometry

By Mike Forbes, Co-op Volunteer Writer

I’ve written about rainwater systems for several years now, specifically about our experience with installing, filtering, and using it.  I’ve received many questions in that time regarding everything about our system.  There is one question that keeps rearing its head.  How much water can I collect off of my roof?

I remember doing the calculations years ago and quickly realized that in our circumstance that we would have more water falling on our roof than we could easily store.  Storage became our issue but for you it might not be since our roof is rather large.  My point in writing this is that it’s important to know what your water capture potential is and design your storage and useage accordingly.  I’m not going to go through any of the techniques or roof materials of rainwater collection as I’ve done that in the past, this article is purely theoretical.  Previous articles can be found on the Co-op website or from me directly.

Let’s walk through the math with an imaginary 20’ x 20’ small house.  Time to put on your high school geometry thinking cap. The most important thing here is to visualize the roof area that the rain is falling on, not the length of the roof line. The slope of the roof isn’t important here. The dimensions we are looking for are the lengths of the walls plus any overhang, ultimately the total roof area that the rain will see.  With our house we have a 20’ x 20’ roof giving us an area of 400 sq. ft.

Next we need to know how much rain comes out of the sky.  Where do you find this data?  There are various sites out there with specific data for a location but this one is a simple to use and easy to decipher.  Many other sources require you to dig a bit and don’t give a good overview.  Simply input your zip code and scroll down to Average Precipitation.  For Moscow, Idaho this is 23.7 inches. 

Imagine a roof of 400 square feet with 23.7 inches (1.97 feet) of water sitting on top of it.  This is our potential rain resource.  In order to get to something we understand better we must convert to gallons.  To do this, we must convert those numbers to a volume like cubic feet by multiplying our area by the depth of water.  Everything must be in feet to do this so the equation looks like this:  Area (in square feet) x depth (in feet) = cubic feet.  Our example: 400 square feet x 1.97 feet = 788 cubic feet.

Now we can convert this cubic foot measurement to gallons.  Looking this up we find that there are 7.48 gallons per cubic foot.  Multiplying we get a grand total of 5,894 gallons falling on our roof. This is a lot more than most people can easily store and this is for a small roof.   

What do we do with this number? We start the design process of storage and useage.  In our next article we’ll talk about the design process and walk through the steps.  I’ve created a spreadsheet that looks at monthly rainfall and useage to assist in this process.
I think it is common to think we live in a dry area and that rainfall isn’t a significant source of water for us on the Palouse.  The math doesn’t lie and it will become quite apparent after doing the math that we do have a good resource by which we can offset our use of precious groundwater.

Mike enjoyed the cool summer and can be reached at

Tuesday, August 2, 2011

Has been hot Green Transportation: Jim LaFortune and the MAMBA Challenge

By Jeanne McHale, Co-op Volunteer Writer
This column is written with a divided heart.  It features a man who left a wonderful legacy of trails enjoyed by hikers, bikers and skiers on Moscow Mountain.  In his 51 years, Jim LaFortune had more fun outdoors than three normal people. I am obliged to tell you about his generosity and the continuation of his trail-building work, and yet I want you to keep it secret. A web of well-maintained trails laces Moscow Mountain, accessible from Foothill or Moscow Mt. Rd. and roughly centered at Four Corners.   The trails are the work of Moscow Area Mountain Bike Association, with co-operation from Bennett Lumber and private landowners. Moscow cyclists love these trails and drive their cars to use them. How do I work that into a column about Green Transportation?

In the early 90s Jim and Kathie LaFortune were new to the area. Jim and his dog Bones began to explore Moscow Mountain looking for trails. In those days, the land was littered with shotgun shells and beer cans. The first trail Jim and friends cleared was North Contour in 1991, now a 1 mile “beginner” run. Soon he was collecting money for trail-building tools and developing a partnership with Bennett. Thanks to this groundwork, cyclists are now seen as good stewards of the mountain, and so is Bennett lumber.  But Kathie says Jim’s devotion to carving these trails was really a selfish act.  “He realized that Moscow was going to be his home for quite a while and needed a place to ride.”

The popular Headwaters Trail makes a roly-poly loop above Pond 9 on the west side. Its meandering switchbacks suggest a trail built for entertainment rather than transportation. Some of the trails are obscenely difficult to bike. The ridge road, which I used to climb on my road bike, is tame compared to Deep Vee.  I wonder if I could ever be as good a biker as Jim was, even in the last few months of his too-short life. I can’t handle the black diamonds on MAMBA trails, but I’m not scared of a little gravel and regularly cycle-commute from our home near the west parking area to town.  

I would like to thank the 500 or so MAMBA members who maintain the trails for all to enjoy.  

If you’d like to help, meet at Rosauers at 8:45 am on Aug. 6 or 27, bringing water, snacks, and gloves.   I would also like to issue this Green Transportation challenge.  Consider designating Foothill Road one of the official trails, call it “Washboard,” and letting your Moscow Mountain adventure begin right in your driveway.

Jeanne McHale looks forward to circumnavigating the wild Weitas Roadless area by bicycle on her upcoming vacation.

Wednesday, June 22, 2011

Green Transportation- The Thermodynamics of Bicycle Commuting

Jeanne McHale, Newsletter Volunteer

            Bicycling is an extremely efficient form of transportation.  A typical cyclist burns about 400 calories per hour, less than is required for swimming, jogging, or cross-country skiing.  Those calories must be replenished, or cyclists would literally vanish into the sunset.  In this column, I consider the energy cost of bicycle transportation as opposed to driving a personal vehicle.  You may find some of this data rather shocking, but please read on before you make out your shopping list.

             Food calories as a unit of energy are actually kilocalories (kcal). When converted to units of kilojoules (kJ), they must be multiplied by 4,184.  So the apple I just munched, nominally 80 calories, provided me with 335 kJ of energy.  But the apple didn’t grow in my yard, it had to be transported.  Agriculture accounts for a considerable portion of our fossil fuel consumption.  According to Barbara Kingsolver, author of “Animal, Vegetable, Miracle,” a typical food item travels 1,500 miles to reach your dinner plate, and the average American’s food consumption accounts for about 400 gallons of oil per year.  My husband and I rack up about 3,000 mile per year on our Toyota, which translates to about 100 gallons of gas per year.  Yikes, could we be burning more oil by eating then by driving?

            Let’s look at this more closely.  As often as I can, I commute to work on my bicycle, a 32 mile round trip.  This takes me about two and half hours, consuming about 1,000 food calories or 4,200 kJ. The same trip in my car would burn a gallon of gas, which provides about 125,000 kJ, based on the heat of combustion of isooctane. This is 30 times as much energy as that required to fuel the engine of my bike, which burns “fat” instead of “oil.”   Sounds better to bike, right? But according to Kingsolver, each food calorie consumed requires dozens or even hundreds of calories from fossil fuel to raise, market, and transport it.  So unless I make local food choices, replenishing those food calories spent cycling could actually increase rather than decrease my fossil fuel consumption!

            The solution to the problem is to cycle and eat locally.  The Co-op, the Growers Market, and the Moscow Farmer’s Market provide many tasty alternatives to petroleum-intensive food products.  Food tastes so much better when it’s been raised locally and even better after an appetite-stimulating bike ride.  See you on the trail.

Green Transportation is written by Jeanne McHale, who notes that her own efforts to grow food this Spring have required petroleum input in the form of polyethylene sheets to protect seedlings from frost.  

Wednesday, April 20, 2011

The Sustainability Review - The Hay Box

By Mike Forbes, Co-op Volunteer Writer

When you cook food much of the heat energy from your stove is used to overcome heat loss from your food to it’s surroundings.  Couldn’t we insulate our food so heat isn’t lost as rapidly thereby using less energy to cook it? Definitely.

Rice. Theoretically, once the rice boils the heat energy needed to complete cooking is present.  The heat leaves the rice because the food is insulated poorly. We overcome this loss by turning the burner down low and simmering it for 30-40 minutes, wasting electricity or fuel. 

What if we boiled the rice and then quickly put it in an insulated box where the heat energy couldn’t escape and the rice would then finish cooking? 

The catch is building a box that heat can’t escape from. What I’ve done successfully for years is build various insulated boxes from commonly available items.

I use them primarily for keeping food hot for a LONG period of time and cooking beans, millet and quinoa.  I’ve also been known to use it for steeping grains and preparing yeast in the beer making process…  If I put a hot food into the box I can pull it out 2-4 hours later still piping hot.

The trick to maximizing efficiency is to build a box that has as little air in it as possible with the largest pot you expect to use. My boxes are built from rigid foam insulation with a radiant barrier (shiny aluminum coating toward the inside).  I glue them together with hobby glue or foam adhesive (Natural Abode and MBS both carry non-toxic, low VOC glues that work well).  I put little strips of wood on the inside bottom to keep the hot pots directly off the insulation.  The door is just a rectangle of foam that wedge fits into the box. It is critical to make the door tight fitting, if you put a slight bevel to the door it will create a much better seal.  Using a table saw to make your cuts makes the process very easy and accurate.  Options for dressing up your box cosmetically are endless.  I typically wrap them in wood to make them more visually appealing but for years had a silver box wrapped in duct tape sitting on top my refrigerator.

If you build the box to your largest pot you can still use smaller pots with good success if you add more thermal mass to the box.  I found that filling small jars with hot water works well to eliminate these air spaces.

Currently we are planning on converting one of our kitchen cabinets into a haybox.  We’ll incorporate insulation into the door with the taper fit foam as mentioned earlier.   It is my understanding that this concept is old and that traditionally hay was used in the boxes as insulation, hence the name hay box.

Mike welcomes questions.  He can be reached at