Greywater Codes across America

New Mexico
North Carolina
Graywater: Friend or Foe?Ok, if you have read through a few pages of this guide already, you might correctly assume I consider greywater to be our friend.
I am, however, focussed on sustainability rather than corporate / municipal dollars and sense. I want my kids to live well, in a prosperous and rewarding country. What makes me happy, doesn‟t necessarily make others happy.Greywater is a friend for:

  • States / cities / counties with a severe water shortage or water infrastructure issue. Heck, if customers can use less water and still be happy they can save their expensive gardens, who wouldn’t be happy – unless re-use is too successful and cuts into revenue?
  • Customers (most likely you!) You have already paid for the water once – why can‟t you use it the way you want – a perfectly logical argument. If you are charged a sewer cost based on consumption, it makes even more sense to use graywater instead of potable water on your garden.

Graywater is a foe for:

  • Health officials and engineers who view graywater as a nuisance rather than an opportunity. This is THE big one. Despite millions of people reusing graywater for at least half a century across the world, for both ornamental and consumption irrigation, without any reported incidences of health issues, the official is there to protect you from becoming sick from re-using water you have generated yourself on your property, so that if you have an illness, you can‟t re-infect yourself with an illness you already have (and no that doesn‟t make sense to me either). The critical point is how code and regulations are defined. If the regulations are too prescriptive, then the onus is on the official (a problem for the official, because possibly not enough detail was written into the code). If the codes and regulations are outcome based , then responsibility lays with the manufacturer / installer / property owner.
  • Water purveyors with treatment plants / infrastructure. As an example, Southern Nevada does have the infrastructure to capture each drop of effluent / graywater, treat it and re-supply to customers as fresh water. They have a limited allocation from the Colorado basin, which they are presently re-using (and charging for) approximately 3 times.This is logical up to the point that over 70% of residential water use is external, and of that 30% is wasted via incorrect irrigation methods. (SNWA water use facts)From their perspective, they are more efficient at re-using (treating) the water at the municipal plant, and when compared to in-efficient graywater re-use methods (branched drain = 20%, Laundry to Landscape = 30%) , they are correct. .However, when graywater re-use methods (dripperline) are at 90% efficiency or above, then on-site graywater re-use is better overall for the catchment.

    The numbers don‟t add up. For each 100 gallons consumed, (internal and external use), only 30 gallons is returned for treatment. Therefore the net use at the residence is 70 gallons.

    If a graywater irrigation system was installed, with an appropriate garden design, and 0 gallons potable water used for irrigation, the net use would be 30 gallons.

  • Water company’s business modelsMost water companies are public service monopolies that are established to provide a reliable service on a non profit basis.Reducing consumption through conservation plays havoc with their bottom line. When people conserve, rates have to rise to makeup the shortfall in revenue. I highly recommend this article by Brett Walton / Circle of Blue. It discusses the conundrum of short term cost of conservation vs. the long term benefits of water conservation.

Good code vs. Bad Code

Good Code defines the outcome, without defining how to get there.

  • On this basis, pumping stations are designed in accordance with plumbing codes.
  • Irrigation systems are designed to avoid surface pooling by irrigating an appropriately sized area based on planting requirements, rather than specifying the irrigation must occur 6” under ground (beneath the root zone for many plants).
  • Good code doesn’t make conservation expensive, by requiring expensive documentation, and official site inspections – if best management practices are followed (e.g. ETo based irrigation design)

Bad code is most commonly derived from sewer / septic regulations that focus on disposal of graywater, instead of maximizing the benefit of graywater.