Water

Part I – Storm Water

There is plenty of water for the planet.  Unfortunately it is not distributed equitably.  In some areas draught is causing crop failures, population displacement, starvation, strife and disease costing millions of lives.  In the United States the problem is not as severe, but the indicators make it evident that we must get serious about conserving water.

We must take advantage of the rain water and snow melt available to us.  In most developments little attention is paid to controlling storm water so we do not take advantage of the water that falls on our properties.  Too much of it runs off impervious surfaces such as roofs and driveways and flows into sewers that conduct it to streams and rivers, or worse, into combination sewers where the storm water is mixed with sewage and conducted to treatment plants.  In heavy rains the excess water causes flooding and often overburdens water reclamation plants to the point where untreated sewage is release into our water ways.

Storm Water Runoff Being Wasted

One of Greening Neighborhoods objectives is to restore natural, predevelopment levels of storm water evaporation, infiltration and runoff.

What we can do

Storm water utilization ideas that cost very little

Collect storm water runoff from your roof and use to irrigate plants

Create diversion swales within your yard to divert storm water, direct it to plants and keep it from running directly off your property.

Storm water utilization ideas that are more costly but will have good payback

Collect storm water in rain barrels nd use it to water lawns, plants and gardens.

Landscape with drought tolerant native plants.

In hardscape areas, use pervious pavements so storm water percolates back into the soil.

How much can I save by utilizing storm water

Example 1

Most homes direct the storm water that falls on the roof directly to the street, where it is conducted to streams or sewage treatment plants.  This water can be collected in rain barrels and utilized to water the lawn and irrigate plants and gardens.  The savings are twofold.  First, by keeping the storm water on site, streams will be less likely to flood during storms, storm water will be kept from being conducted to waste water treatment plants, and our aquifers will be recharged.  Costs to municipalities and our taxes will be reduced.

Second by using storm water instead of municipally treated water, our monthly water bill will be reduced.  If your roof area is 1,000 square feet, and it rains 4 inches per month, and all your storm water is utilized, you can save 2,400 gallons of water each month.  That is a potential monthly savings¹ of $40.00.

Example 2

By using native draught tolerant plants, we can have a landscaped yard that will survive in periods where rainfall is below normal.  During such periods municipalities enforce lawn watering bans and our investment in yard plants is jeopardized.  Hundreds of dollars can be saved by not having to replace landscaping.

Example 3

By using pervious paving, storm water is allowed to percolate into the ground and recharge aquifers rather than run off.  While there is no direct savings, there are deferred costs to the public sector.  Flooding and associated tax payer costs are reduced, erosion is mitigated, silting is reduced, and, if you live in an area where there are combination sewers, the amount of waste water to be treated is reduced.

Example 4

By using storm water to flush toilets instead of municipal treated water, our monthly water bills are reduced.  Again, as in example 1, the potential monthly savings would be $40.00.

The cost of installing such a system in an existing home would mean buying large rain collection cisterns, filters, pumps and new plumbing pipes directing water from the cistern to the toilets.  This system could cost over $3,000, which would mean a six year payback.  Some municipalities require that the captured storm water be purified to drinking water standards before it can be used to flush toilets.  If this is the case, a series of ultraviolet purification lamps would have to be installed in the cistern.  This would add additional cost to the system and require periodic maintenance.

In practice collecting rain water to flush toilets in a retrofitted home is not very cost effective.  A less expensive approach is to install a dual flush toilet, or one of the many devices on the market that convert standard toilets to dual flush.  (See Part II – Treated Municipal Water).

How savings were calculated

Example 1

The amount of storm water that can be captured from our roof tops depends on the roof area and the rainfall.  In our example we assumed a roof area of 1,000 square feet.

• To find your roof area measure the footprint of your home in square feet – since roof slope doesn’t matter in this calculation, the home footprint will equal the effective roof area.
• Then look up monthly rainfall in your area at http://countrystudies.us/united-states/weather/ for rainfall in inches per month.
• Multiply your roof area times rainfall in your city times 0.60.  (The 0.60 constant converts inches of rain water to gallons and takes into account water not captured.)
• This gives you the number of gallons of rainwater that can be collected.
• This example is base on municipal water rates of %0.0167 per gallon.  Most cities calculate our water bills in CCF (100 cubic feet).  To convert gallons to 100 cubic feet (CCF) divide gallons collected by 748.  In our example we collected 2400 gallons or 3.21 CCF.  (2,400 / 748 = 3.21).
• So the price of municipally treated water in our example is $40 / 3.21 or $!2.46 per 1CCF.

Depending of the lay of our property, a simple gravity supplied drip irrigation system might be appropriate.  If the home is low on the property a pump in the catch container can be installed to pump irrigation water to a supply basin at the highest elevation.

Example 2

Normally, plants native to an area are draught tolerant.  By following some simple procedures your plants will survive:

• It is important to plant in the late fall or spring (check with your local nursery for the best times to plant specific varieties).
• Amend the soil around plants.
• Add a layer of organic mulch to the planting site, being careful not to pile mulch around the stem or trunk of the plant.
• Water by drip irrigation rather than sprinkling

These guidelines will help guard your investment.

Example 3

Pervious pavement comes in three basic forms; pea gravel set in a plastic matrix, grass infill within a concrete matrix, and concrete formed so air gaps exist between the aggregate.  All systems cost about the same, so the decision to use one system over the other is based on aesthetics and ease of maintenance.

In both cases a percolation test will be required to see if the ground will allow the storm water to percolate.  Some soils may be too dense for percolation to be meaningful.

http://www.concretethinker.com/applications/Pervious-Paving.sapx#

Pervious pavement is designed to allow percolation or infiltration of stormwater through the surface into the soil below where the water is naturally filtered and pollutants are removed. In contrast, normal pavement is an impervious surface that sheds rainfall and associated surface pollutants forcing the water to run off paved surfaces directly into nearby storm drains and then into streams and lakes.

http://www.lakesuperiorstreams.org/stormwater/toolkit/images/modularBlock-fig29a.gif

Example 4

The storm water collected from your roof can be used to flush toilets.  The savings could be considerable depending on the type of toilet you have.

The storm water must be filtered, stored, pumped and piped directly to the toilet.  Since it is non-potable the storm water can not be mixed with the rest of the domestic water system.  In some jurisdictions it is not allowed to use storm water to flush toilets.

Part II – Treated Municipal Water

Saving Treated Municipal Water

The United States has excellent sources of treated drinking water.  For the most part the water supple is so reliable and of such high quality that it is taken for granted – and wasted.  Problems arise when the sources of water are disrupted because of draught caused by shifting weather patterns as has been the case in southeastern states where rainfall has been only 70% of normal in recent years.  Under such circumstances the public is asked to conserve water and moratoriums on watering lawns are enacted to conserve the municipal water supply.  It has already been recommended, as a matter of general practice, that we collect rainwater from impervious surfaces, and redirect it to use for irrigation.   This practice allows the water to percolate back into the soil to recharge our aquifers.

The greatest way to conserve our municipal water and save money can come from installing a number of inexpensive water saving devices and by making a few changes in the ways we use our water.  In most homes municipal water consumption can be cut in half thereby conserving our water supply and drastically reducing our water bills.

Water saving ideas that cost $0.00

Repair faucet leaks

Wash dishes only when there is a full load

Wash clothes only when there is a full load

Turn off water when brushing teeth

Add filled water jugs in toilets to displace flush water.

Water saving ideas that cost less than $20.00

For lavatories replace aerators with 0.5 gallons per minute (gpm) aerators.

For showers replace heads with 1.8 gpm shower heads.

For kitchens replace sink aerator w/ 1.8 gpm aerator.

Install shower head cut off valves and learn to wet down, soap up and rinse off.

For landscape watering use rainwater from storage tanks

Insulate hot water supply pipes saving water wasted while getting warm.

Money saving ideas that cost <$400

For bathrooms install new dual-flush 1.1 – .8 gallons per flush toilets.

For Landscaping use drought tolerant plants and ground cover.

Install a water recirculator or on demand water heaters if your present system takes too long to deliver hot water.

How much can I save for less than a $20.00 investment?

Example 1

By changing your existing faucet aerators from 2 gallon per minute (gpm) flow rates to 1 gpm aerators, you will automatically cut your water consumption in half for tasks like hand washing, vegetable cleaning or dish rinsing.

The estimated monthly savings for a family of three = 472.5 gallons¹

The estimated reduction in your monthly water bill = $7.58²

The cost of two aerators <$7.50³

That’s a one month payback!!

Over a year the savings would be $90.96, that’s 5,670 gallons of water, which is equal to 7.58 hundred cubic feet (CCF) of water.  For many families that would be a one months saving in water consumption.

Note: Water bills are based on hundreds of cubic feet (CCF) of water consumed.  There are 748 gallons in a CCF.

Example 2

Exchange your 2.5 gpm shower head for a low flow 1.8 gpm head saving 0.7 gpm every time you take a shower.  Also, add a shower head cut-off valve between your shower head and the pipe.  This will mean a change in your shower taking habit.  Rather than leave the shower run the entire time, wet down, soap up and rinse off.

The estimated monthly savings for a family of three = 720 gallons¹

The estimated monthly saving for a family of three = $11.47

Example 3

Older toilets can be turned into “low flush” toilets by displacing some of the water in the tank.  This can be done by filling plastic water bottles with water and placing them in the tank.  An old 6 gallons per flush (gpf) toilet can be turned into a 5 gpf toilet by adding four one-quart water bottles to the tank.

For our family of three, the monthly savings would = 450 gallons

The monthly water bill would be reduced by $7.17

How much can I save for a $400.00 investment?

Example 4

By installing a new duel flush toilet that uses either 1.6 or 0.8 gpf depending if solids or just liquids are being flushed a very significant savings can be realized.

Compared to a 6 gpm toilet, in one year a dual flush toilet will save 26,640 gallons of water.

The yearly water bill savings will be $424.48.  That should pay for the new toilet.

Example 5

Another water saving device is the water recirculator.  This device should be installed if water is wasted at the shower or lavatory waiting for hot water to get to the tap.  The amount of water wasted can be quickly determined by measuring the water collected until it is hot enough to use for washing and bathing.  The recirculator keeps a constant flow of

hot water circulating through your pipes by a valve and pump system that uses the cold water pipe to keep hot water continuously recirculating.  Most units have a timer device that will shut off the recirculation pump in the evening and then turn it on a few minutes before you are ready for your morning shower.

The amount of savings depends on how much water is wasted before hot water gets to the tap.  If it takes ten gallons of wasted water before the tap water is hot, the recirculator will save those ten gallons.  In a year 3,650 gallons of water would be saved.

The yearly savings in your water bill would be about $58.56.

The units cost around $250.00 so that would be less than a five year payback.

How the savings were calculated

Example 1

1. Daily water savings are based on the United States Green Building Council (USGBC) research for a family of three.

Fixture	Flow gal/min Savings	Duration Minutes per Use	Number of Daily Usages	Family Members	Daily Usage in Gallons	Monthly Usage in CCF
Standard Lav	2	0.25	5	3	7.5	0.30
Lavatory	1	0.25	5	3	3.75	0.15
Savings	1	0	0	0	3.75	0.15
Standard Kitchen Sink	2	1	4	3	24	0.96
Kitchen Sink	1	1	4	3	12	0.48
Savings	1	0	0	0	12	0.48
Total Savings	2	0	0	0	15.75	0.63

Data based on USGBC Standards

In our example we have changed 2 gpm aerators for 1 gpm aerators and realized a savings of 1 gpm at our lavatory and a 1 gpm at our kitchen sink.  The table above reflects this savings.

1. The savings to our monthly water bill is based on a water rate of $12.00 per one hundred cubic feet (CCF) of water used.  That  would come to nearly $8.00 per month for this example.

Example 2

In this example we changed a 2.5 gpm shower head for a 1.8 gpm aerator for a savings of 0.7 gpm.  We also suggested adding a cut-off valve so the shower water could be shut off while soaping up, thus cutting shower time in half from 5 minutes per person to 2.5 minutes per person.  Admittedly it will take supreme dedication to shut your shower off while soaping up on a cold winter’s day – but if you do…

Fixture	Flow gal/min	Duration Minutes per Use	Number of Daily Usages	Family Members	Daily Usage in Gallons	Monthly Usage in CCF
2.5 gpm Shower	2.5	5	1	3	37.5	1.50
1.8 gpm Shower	1.8	5	1	3	27	1.08
Savings	0.7				10.5	0.42
1.8 gpm Shower	1.8	5	1	3	27	1.08
1.8 gpm Shower w/ Cut-off	1.8	2.5	1	3	13.5	0.54
Savings					13.5	0.54
Total Savings	0.7	2.5			24	0.96

Data based on USGBC Standards

The savings from just changing to a low flow shower head would be 10.5 gallons per day.

The savings from both the low flow aerator and reducing shower time would be 24 gallons per day or .96 CCF per month.

At $12.00 per CCF the cost savings would amount to $11.52 off your monthly water bill.

Example 3

Old model 6 gpf toilets use a great deal of treated municipal water.  The efficiency can be increased by simply displacing some of the water in the tank by adding filled water bottles.  In this example by adding one gallon of water to the tank, each flush uses 5 gallons instead of 6 gallons of water.

Fixture	Flow gal/flush	Number of Daily Usages	Family Members	Daily Usage in Gallons	Monthly Usage in CCF
6 gpf Toilet	6	5	3	90	3.61
5 gpf Toilet*	5	5	3	75	3.01
Savings	1	0	0	15	0.60

Data based on USGBC Standards

The monthly savings would be $7.20

The amount of water saved would be 450 gallons, but the water used is still a very high 2,250 gallons per month.  Replacing your old toilet with a new dual flush model would result in significant savings.

Example 4

The dual flush toilet will save 74 gallons of water every day for a family of three.

Fixture	Flow gal/flush	Number of Daily Usages	Family Members	Daily Usage in Gallons	Monthly Usage in CCF
6 gpf Toilet	6	5	3	90	3.61
Dual Flush – Liquid	0.8	3.33	3	7.99	0.32
Dual Flush – Solid	1.6	1.67	3	8.02	0.32
Savings over 6gpf	4.9	0.00	0	74	0.64

Data based on USGBC Standards

When the monthly water bill comes the savings will be significant.

You will save 2,220 gallons of water each month, or 2.97 CCF.  At $12.00 per CCF the monthly savings would be $35.61.

Over a year that would be $427.32 and 26,640 gallons of municipal water.

The cost of a dual flush toilet plus installation would be around $500.00 or a little more than a fifteen month payback – - a good investment.