We have a gray water system installed in our Brooklyn green show house. Unfortunately we were using the Brac system, which sucks. We were having so many problems with it that we took it out and made the house conventional until we design our own system.

Until then all waste water goes down the drain and fresh water feeds the toilets.

This was a very interesting experiment to see how our sewer and water bill would change. With the gray water system installed we have had consistent bills for about $450 per quarter, which is still really high in my opinion considering we used less water and we passed less water into the sewer than most.

But now that we are not using gray water our bill went up to $650 per quarter.

That is an extra $200 every three months in water bills. That is $800 per year more for a household with two adults and two children.

Our last gray water installation cost the client $8,000. All things being equal it will take them ten years to pay off their system if they save $800 a year. Considering a gray water system could last as long as any plumbing system – 40 years or more – it makes a lot of financial sense to do gray water in New York.

This is a big turning point for me since most of Eco Brooklyn’s clients have installed gray water systems most for ecological reasons, and there are many: reduce storm sewer loads, river overflow, water consumption etc.

In a state where water is not really scarce like it is in California for example, there is not such a huge push for conserving water in New York. Although most educated ecologists would agree that water does need to be conserved in New York.

Most of the interest in gray water systems for Eco Brooklyn’s clients has been the green novelty of it as well as the very large benefit of a gray water system on NY sewers. New York sewers overflow every time it rains. That overflow is a torrent of feces and other toxic substances that flow into and contaminates the rivers and canals of NY.

Like green roofs that reduce the flow of rain water from a building into the sewer, gray water has a powerful impact on making NY and Brooklyn a healthier and greener place via cleaners waters and subsequently cleaner air.

But seeing these start numbers in the water bill of the green show house puts a whole new light on the tangible value of gray water systems in Brooklyn brownstones – this value is not the ethical or ecological value of being green but the very easily quantifiable and universally understood value of money.

Looking at the savings of a water bill makes it pretty clear that a gray water system is a good financial investment.

Lets say your plumbing lasts 40 years, which is a conservative number. If you have a gray water system you will save $800 per year (in the show house at least). If it costs $8,000 to install, then your savings after 40 years is $32,000 minus the investment of $8,000 for a net savings of $24,000.

That means you would be $24,000 richer than somebody without a gray water system. And where is the sacrifice? Apart from the up front cost I really don’t see any.

And yet the effortless contribution to society and the planet is huge. This household in question produces about 500 gallons a week in gray water that stays on site for the garden and green roof. Over forty years that is over a million gallons of water NOT going to the sewer. And this is a household with high efficiency faucets. It would be a lot more water for a typical home.

Likewise that same household uses about 200 gallons of water to flush toilets each week. That is over 400,000 gallons of fresh water over 40 years that was NOT used to flush toilets because they used the recycled house water via the gray water system instead. Again they use high efficiency toilets and don’t flush for the first pee so it would be double or triple that in a typical house.

These benefits are huge. And at the same type the homeowner is actually saving money while producing these benefits.

Why doesn’t every Brownstone in Brooklyn have a gray water system? It should be mandatory. I bet if every home in Brooklyn and Manhattan had gray water our waters would be so much cleaner. I wonder if we could swim in them and eat the fish from them. What a great dream.

Bottom line, gray water in New York homes makes a lot of sense.