Graywater  and  Groundwater:  Site  Tes2ng  Considera2ons  

Todd  Jarvis,  Ph.D.  Cer2fied  Engineering  Geologist  Cer2fied  Water  Rights  Examiner    

What  others  are  saying..    Graywater  puts  an  immense  strain  on  leach  fields  ,  and  helps  to  max  out  

your  sep7c  tank.  Diver&ng  your  graywater  into  your  landscape  helps  alleviate  this  problem  and  actually  leads  to  less  contamina&on  of  groundwater.  

  In  fact,  the  ecosystem  of  a  mulch  basin  around  a  plant  makes  for  a  very  effec7ve  wastewater  treatment  system…and  wastewater  is  filtered  more  effec&vely  when  released  on  the  surface  of  the  ground  rather  than  under.  

  The  microbes  in  the  soil  convert  organic  impuri7es  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.  

  “Graywater  irriga2on  systems  save  water  and  money”  

  -­‐  Dave  Walzer  Santa  Cruz  Sen&nel  interviewing  Laura  Allen  of  Graywater  Ac&on-­‐  02/27/2010  

What  others  are  saying..    Contamina2on  of  surface  water.  If  grey  water  does  not  percolate  through  

the  soil,  it  can  flow  into  creeks  or  other  waterways  untreated.  Solu7on:  discharge  grey  water  underground  or  into  a  mulch-­‐filled  basin.  Don't  apply  grey  water  to  saturated  soils.  Apply  grey  water  intermiHently  so  that  it  soaks  in  and  soil  can  aerate  between  waterings.  In  general,  contained  grey  water  applica&on  at  least  50  feet  from  a  creek  or  lake  is  not  a  problem.    

  Contamina2on  of  groundwater.  It  is  all  but  impossible  to  contaminate  groundwater  with  a  grey  water  system.  However,  property  owners  with  wells  should  not  irrigate  with  grey  water  any  closer  to  the  well  than  county  regula7ons  allow  for  a  sep7c  tank  leachfield.    

   

  Oasis  Design  aka  Art  Ludwig  

Why  do  we  need  to  heed  what  others  are  saying?  

  MIT  Urban  Planning  Professor  and  conflict  resolu7on  expert  Lawrence  Susskind  indicates  that  newspaper  ar7cles  and  leHers  to  the  editor  are  important  in  the  discourse  on  resource  planning  because  the  United  States  is  a  representa7ve  democracy  where  “...we  can  count  on  the  media  to  help  ci&zens  educate  themselves  about  the  issues  being  deliberated  by  their  elected  representa&ves".  

   Journal  of  Water  Resources  Planning  and  Management  editorial  by  former  long7me  World  Bank  consultant  and  Harvard  Professor  John  Briscoe  7tled  "The  prac)ce  and  teaching  of  American  water  management  in  a  changing  world",  Briscoe  indicates  that:  "The  new  genera&on  of  partnerships  must  involve,  inter  alia:  

  “A  focus  on  the  real  world,  and  thus  an  emphasis  on  partnerships  (a)  between  prac&&oners-­‐who-­‐think,  and  researchers-­‐who-­‐understand-­‐prac&ce...and  (b)  to  engage  with  the  progressive  private  sector  which  is  likely  to  be  the  source  of  much  innova&on  in  the  water  domain.”  

State  DHS  Guidelines  

  Graywater  is  not  listed  as  a  “Poten2al  Contaminant  Source”  

  According  to  Tom  PaUee  of  Groundwater  Sec2on  of  DHS,  unofficial  concern  about  graywater  rests  with  poten2al  viral  contaminants  within  the  “Two-­‐year  Time  of  Travel  Zones”  in  Public  Water  Supply  Wells.  

State  DHS  Guidelines    Summary  of  Oregon's  Suscep2bility  (Sensi2vity)  Analysis  Procedures  

  Matrix  Evalua2on    

  A  series  of  matrices  is  used  to  evaluate  the  poten2al  of  [1]  water  migra2ng  from  the  surface  to  the  aquifer  and  [2]  a  given  contaminant  persis2ng  and  moving  with  the  water.  In  each  matrix,  two  parameters  are  ploUed.  Their  intersec2on  within  the  matrix  yields  a  score  from  1  to  10.  The  higher  the  score,  the  greater  the  poten2al  that  these  parameters  will  contribute  to  aquifer  suscep2bility.  

      1.  Traverse  Poten2al.    

      2.  Infiltra2on  Poten2al.    

      3.  Mobility  Poten2al.    

      4.  Leach  Poten2al.    

      5.  Suscep2bility.    

State  UIC  Guidelines  340-­‐044-­‐0018  Authoriza2on  of  Underground  Injec2on  by  Rule  

  Basic  requirements  for  all  storm  water  injec&on  systems  authorized  by  rule  –  

(E)  The  injec&on  system  is  not  located  within  the  2  year  2me-­‐of-­‐travel  zone  as  delineated  by  the  Oregon  Health  Division  or  closer  than  500  feet  to  a  public  water  supply  well,  whichever  is  more  protec2ve.  

(G)  The  injec&on  system  does  not  exceed  a  depth  of  100  feet  and  does  not  discharge  directly  into  groundwater  or  below  the  highest  seasonal  groundwater  level.  

(H)  A  confinement  barrier  or  a  natural  or  engineered  filtra&on  medium  is  present  between  the  base  of  the  injec2on  system  and  the  highest  seasonal  groundwater  level  and  prevents  contaminants  from  reaching  groundwater,  or  the  owner  or  operator  implements  best  management  prac2ces  that  prevent  or  treat  storm  water  contamina2on  before  injec2on.  

State  On-­‐Site  Guidelines  

•  340-­‐071-­‐0150  Site  Evalua2on  Procedures  for  On  Site  Sep2c  Systems.      

  For  the  Site  Evalua7on  Report,  the  standards  include,  among  other  things  "...applicants  must  provide  at  least  two  test  pits,  with  dimensions  and  configura7on  as  directed  by  the  agent,  located  approximately  75  feet  apart  and  within  the  area  of  the  proposed  system,  including  the  repair/replacement  area",  where  "Soil  profiles  determined  from  test  pits  provided  by  applicant"  and  "Water  table  levels  (as  indicated  by  condi&ons  associated  with  satura&on  or  water  table  observa&ons)".  

Site  tes&ng  using  On-­‐site  or  UIC  methods  require  holes  which  can  serve  as  conduits  for  greywater  to  reach  

groundwater  without  treatment  

Unintended  Consequences  of  using  On-­‐site  or  UIC  si2ng  standards  -­‐  “Guerilla  Well-­‐fare”  or    

Dueling  Expert  Situa2ons  

From Jarvis (2010) Water Wars, War of the Well, and Guerilla Well-fare, Journal of Ground Water

Site  Evalua2on  and  Permijng  Situa2on  “Invasive  versus  Self  Evalua2on”  

Oregon On-site or UIC standards applied to a graywater?

"Ludwig's Law"- "Experience with groundwater contamination from septics [and UIC] does not translate to greywater".

“OOSU corollary to Ludwig's Law” - "Experience with groundwater contamination from greywater does translate to septics".

Paul Stanton, Duckboy® Cards Inc.

Recommenda2on?    The  Shovel  Test  and  Common  Sense  

The  Conflict  over  Graywater  “Green  versus  Black  &  White”  

AWWA – White Paper on Graywater (2010)

"Graywater reuse is viewed by the green-leaning layperson as the panacea for water shortages, groundwater depletion, surface water contamination, and climate change"; and

"Graywater is seen by society's public health guardians (including the water utilities) as a threat to health and safety of the users themselves and their neighbors”.

"Neither of these caricatures of graywater is accurate, although an element of truth resides in each".

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.

Mul2ple  Ways  of  Knowing  

Thank  you  for  your  aUen2on.