The Lord’s gift and we flush it down the sewer

NYC’s typical town home owner literally flushes 66 million gallons of rainwater a year down the sewer.  That’s the amount of water that is collected on your roof on an average year in NYC!  If you only know how catching this water could improve your life you would be running to do it.

A couple of notes before we begin:

  1. on an average year a typical 25-foot townhouse in NYC will be able to collect approx.65,945 gallons of rainwater! That’s right, 65,945 gallons!
  2. The average person goes to the bathroom four times a day for “number one” and once for “number two” and most modern toilets in NYC flush 1.6 gallons per flush (old-fashioned toilets use 3 gallons per flush).  So assuming a family of 4, that means this family consumes 32 gallons per day or 11,690 gallons per year!
  1. Outdoor watering of the lawn and sidewalk cleaning are big consumers and utilize at 2 gallons per minute.  To clean a 25 foot sidewalk in NYC would require approx. 15 minutes which translates into approx. 11,000 gallons per year.

This water is what many in the industry call “grey water”: not clean enough to drink but good enough to water our lawns, clean sidewalks, flush our toilets and replenish our pools and commercial air conditioning systems.

So what’s the alternative to flushing free water into the city sewer system that the City then needs to treat with noxious chemicals before dumping these into our beaches and rivers?  Incentives and good old American Enterprise.

The United States Green Building Council awards Buildings with the coveted LEED designation which is commonly referred to as a “Green Building”.  Some of the many qualifications a building will need to incorporate to gain this certification includes efficient lighting, windows, air conditioning, ecological materials, and water conservation. LEED candidates tend to be buildings with greater than 50,000 SF and can amortize the cost of this certification (starts at $50,000).

Moreover, NYC currently processes “household” sewer together with water collected from rain falling on streets and roofs.  On heavy rain days NYC’s sewer treatment plants cannot handle all the effluent and simply disposes untreated water into rivers and streams.  This raises the risk of e-coli infection to such levels that after heavy rains the Parks Department mandates public beach closures for danger to humans.


Jamaica Sewer Treatment Plant

And, for this very reason, NYC is under a federal mandate to Upgrade its sewer to deal with this runoff issue. Sewer treatment plants are EXPENSIVE to build, difficult to find a suitable location for, undesirable, smelly, etc, etc, etc.  Runoff water, which is fairly clean, UNNECESSARILY treated with chemicals, filtered and processed before being sent to a river or stream-chemicals that flow into the maritime food chain.


Outflow of UNTREATED Overcapacity from Tallman Treatment Plant 

Cities should find practical, economic and effective solutions for smaller buildings to do their part in easing the runoff problem.  And City Government should implement a Water/Sewer fee reduction plan for buildings that use gray water for sidewalk cleaning and lawn irrigation (and maybe toilet use!).

Enterprising companies such as the RainWater Pillow provide a perfect solution for the vast majority of City buildings to be able to do this in their unused basement space. A pillow is connected to the roof drain and inflates as rain water collects.  A spout connected to a pump uses gray water.  The company estimates that a 10,000 gallon “pillow kit” measuring 20” Wide, 20” Long and 5” tall will cost approx. $8,950 and “exceed potable water standards” (although I personally wouldn’t drink from it and limit the use for grey water!).  Something well worth the cost.

rainwater pillow

Typical design of the Rainwater System for a NYC Townhome


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