A non-partisan, neutral perspective supporting diversity in the color of water

Saturday, April 3, 2010

Greywater Grifting - The Series

While the scope of the March Graywater Advisory Committee meeting did not permit the various subcommittees to present their work, the question regarding whether greywater could be used for groundwater recharge emerged during the discussion.  The nexus between greywater and groundwater was the topic that the subcommittee that I volunteered to assist.  While I was not permitted to present my research, I did offer the following observations from others working on this issue.

I shared information from a recent newspaper article in the Santa Cruz Sentinel which described how greywater could be beneficial on many fronts. "For those rural homes using septic systems, the reasons to install a graywater diversion system are especially compelling. Graywater puts an immense strain on leach fields, and helps to max out your septic tank. Diverting your graywater into your landscape helps alleviate this problem and actually leads to less contamination of groundwater....In fact, the ecosystem of a mulch basin around a plant makes for a very effective wastewater treatment system. and wastewater is filtered more effectively when released on the surface of the ground rather than under....The microbes in the soil convert organic impurities in the wastewater into nutrients, which are then available for uptake by the roots of the plants. The result is water that is purer than what is discharged from a sewage treatment plant" (emphasis added).

I was particularly interested in hearing the response of the many wastewater treatment experts serving on the committee regarding this last statement.   I suspect that much of this information in the article was derived from greywater expert Laura Allen of Bay Area Greywater Action (see greywater goodies on this blog for more information).

I continued my answer with a quote from the greywater guru Art Ludwig in his book, Create an Oasis with Greywater, 5th edition, where he discussed the contamination of groundwater or well: "It is all but impossible to contaminate groundwater with a greywater system, as the treatment capacity of the topsoil is so enormous (emphasis added). Over 90% of plant roots and beneficial microorganisms are in the top few feet of soil, above most septic leachfields. However, if you have a poorly sealed well, greywater running over the surface could potentially pour into it. Solution: The CPC/UPC [California] greywater codes, which are just crude adaptations of septic tank codes, call for 50' of separation between location of greywater application and a well, same as a septic. Probably half of this is sufficient".

The response from many in the committee - laughter that the information came from a newspaper.  I can only assume they thought I was part of a larger confidence game with Laura Allen and Art Ludwig.

I was surprised by the committee's response given that MIT Urban Planning Professor and conflict resolution expert Lawrence Susskind indicates that newspaper articles and letters to the editor are important in the discourse on resource planning because the United States is a representative democracy where “...we can count on the media to help citizens educate themselves about the issues being deliberated by their elected representatives". (see Susskind, L. 2005. Resource Planning, Dispute Resolution, and Adaptive Governance. In Adaptive Governance and Water Conflict: New Institutions for Collaborative Planning, J.T. Scholz and B. Stiftel, editors. Washington, DC: Resources for the Future, pp. 141- 149).

But let's look at the bigger picture.  In an editorial published in a recent edition of the Journal of Water Resources Planning and Management by former longtime World Bank consultant and Harvard Professor John Briscoe titled "The practice and teaching of American water management in a changing world", Briscoe indicates that: "The new generation of partnerships must involve, inter alia:
  • A focus on the real world, and thus an emphasis on partnerships (a) between practitioners-who-think, and researchers-who-understand-practice...and (b) to engage with the progressive private sector which is likely to be the source of much innovation in the water domain"(emphasis added).
It sounds like Dr. Briscoe thinks there is room for practitioners like Laura Allen and Art Ludwig in the rational discourse on water resources planning rather than relying strictly on the peer-reviewed literature that according to Bernard Amadai, Professor of Civil Engineering at the University of Colorado and founder of Engineers Without Borders "...people don't read".

I think some of the confusion regarding the greywater-groundwater nexus focused on the fact that many of the committee members work directly, or indirectly, in the wastewater business. As a consequence, their perception of greywater may be "tainted" by this bias. In a recent lecture on greywater vs. septic tank effluent, Oasis Design greywater expert Art Ludwig, indicates the following:
  • "Experience with groundwater contamination from septics does not translate to greywater"; and
  • "In over 20 years of working in the greywater field, I have never heard of groundwater contamination from any of the 8 million greywater systems in the US. It is not likely that this has ever, or will ever occur" (emphasis added). 
Portland State University Professor of Urban Studies and Planning Connie Ozawa suggests that any system developed for folding science and other sorts of information into decisionmaking must be able to make space for silent voices and multiple ways of knowing.

In the next series of postings, I will explore some of these additional ways of knowing as we enter the Site Testing Trap.


  1. Your comments proove your own point - you should read and read widely. If you had read more widely you would not make such an all encompassing statement. Grey water has the same pathogens as black water and on occasions a wider range yet you are not recommending the pumping of raw sewage onto the ground. Take a scientific look at the problem and consider all aspects then you would find a generalised comment like yours is irrisponsible and totally uninformed. Soil type, gradients, depth of the water table, proximity to an active water way, local rain paterns, ambient temperature and many more inputs will determine whether your comments have credence at a particular location. To generalise as you have is dangerous to the health of people and the environment.

  2. Thanks for your comment Michael. As the post heading indicates, this is a continuing series. I anticipate addressing your comments in the next posting. I think you will be surprised at the new research. Please share the sources of your "science". I will gladly read it. But the information I have cited in this and previous postings in the Rainbow Water Coalition do not support your generalizations - that greywater is dangerous to the health of people and the environment. Thanks for reading.