City Water Hook Up? No Thanks!

by Bob Drew, Founder of Ecovie Rainwater Collection Systems

Brian and Keri Fosse of Atlanta just moved into their newly built home in the Grant Park neighborhood. Because the lot they chose had no city water (or sewer) connection, they would have had to pay a lot to have them installed, because the lot was high on a hill and other factors.  So, logically, Brian and Keri went a different route.

They installed a rainwater collection system as their fresh water supply and an Aqualoop greywater recycling system to minimize fresh water demand. Even though their new dream home is in the heart of Atlanta, their water system is totally off the grid, with no city water connection at all!

The system is designed to easily meet all water needs for the Fosse’s, both indoors and outdoors.  The family of 4 plan to have an extensive apple orchard and vegetable garden, so we’ve designed the system for comfortable living through great water management.  Some highlights of this off grid system:

•  Assures water supply for an average of 5 inhabitants for all indoor use as well as for orchard and garden watering.

•  Assures on site stormwater infiltration.•Provides clean, treated rainwater that exceeds both Atlanta City water quality and EPA drinking water standards.

•Provides treated greywater that meets NSF 350 commercial standards.

•  The system is designed to have very low maintenance requirements.

Let’s go through the details!

By the Numbers — Water Supply: 

1. The Fosse’s will be using around 20-25 gallons per day per person of fresh water indoors (i.e. clean, pristine rainwater).  That is less than half the amount an average person uses.  They achieve this through Aqualoop greywater recycling and low flow fixtures. Aqualoop recycles around 80 to 115 gallons per day depending mainly on how long their showers are! Their 1.75 GPM Hansgroe shower head puts out great flow, unlike some others with their piddly flows. The Fosse’s have budgeted their showers at 5-8 minutes long.  Longer showers mean more water for plants but more rainwater usage.The Fosse’s expect to generate only 17 gallons of greywater per day per person, far below our typical estimate of 33 GPD/person. Around 35,000 gallons of rainwater are needed per year for indoor use.  Check your own water bill and you will see how low this usage is!

2.  From the 2,400 sq. ft. roof, around 75,000 gallons of rain hit the roof each year on average.  Of this amount, some water evaporates or overflows the tanks to the rain gardens, so around 53,000 gallons on average is actually used.  In a  drought year like Atlanta had in 2007, the amount drops to around 43,000 gallons which means less rainwater is available for outdoor watering but still enough for gardens and landscaping.

3.  In a normal rainfall year around 18,000 gallons of rainwater is available for outdoor watering.  During a drought, this would be cut back to around 8,000 gallons of rainwater.

4.  Greywater captured from showers, laundry and bathroom sinks averages around 85 gallons a day from 5 people and can supply around 27,000 gallons of treated non-potable water.  Around 13,000 gallons is used in toilets and the cold water portion of laundry, both of which have very low-flow fixtures.  This leaves 14,000 gallons of reclaim water for use outdoors.

5.  During an average rainfall year, there should be over 615 gallons a week year around for outdoor watering.  During a drought such as the one in 2007, there may only be around 430 gallons available a week.  With this analysis, there should be more than enough water even during drought conditions!

How did we do it?

1. 6,000 gallons above ground rainwater tank for the 2,400 square foot roof.  It takes around 4.2 of rain to fill the tanks.  When full this would last about 2 months with no rain to top it off.

2. Ecovie installed a rainwater system which follows the City of Atlanta code for potable rainwater.

3. Aqualoop MBR greywater recycling technology with single membrane cartridge for 80-120 GPD treatment capacity in a 180 gallon bio-reactor and 300 gallon treated water tank.

4. The rainwater tank overflows to a 2,500 gallon Excess Tank.  Excess greywater is also stored here.  This water is for watering the garden.

5. The Excess Tank overflows to a rain garden, so all stormwater is kept on site.

This example of an off grid water system is certainly made easier by being located in the rainy southeast US.  Atlanta, in fact, tends to have relatively constant rain through the year with no dry and wet season.  The Fosse’s system shows how water can be managed to comfortably meet all a household’s water needs using far less fresh water regardless of location.  Imagine putting a system like this in drier regions.  The Aqualoop system will have the same effect everywhere with a 40% fresh water reduction on average.  Rainwater can be used when available to further reduce municipal and well water demand.  So, one can easily envision a 60% to 100% reduction in municipal and well water demand for residential use, be it in single family homes or in large high rises or hotels.  This type of water management would go a long way to reduce the burden growth (both economic and population) puts on traditional water supplies.

As always, I encourage you to consider taking some or all of these steps for your upcoming construction  projects, both large and small.  At Ecovie, we are solving the world’s water challenges one building at a time!