GRASSROOTS GREYWATER:
low tech ~ low cost ~ benign
Christina Bertea
Greywater Action
Greywater Alliance
April 9, 2010
presenting
~
demystifying
TWO “LANDSCAPE DIRECT” SYSTEMS
greywater flows directly to the landscape with:
NO tanks
NO filters
NO added pumps
NO connection to the potable water supply
NO PROBLEMS!
LITTLE MAINTENANCE
EASY TO LEARN ~ INSTALL
AFFORDABLE ($100 - $300 for materials)
goal: widespread implementation resulting in significant conservation
GREYWATER CODE BASICS
(RELEVANT TO THESE TWO SYSTEMS)
* able to divert flow back to sewer/septic (3-way valve)
* direction of flow clearly labeled
* no spray irrigation, ponding or runoff/must stay on property where generated
* minimize contact with humans/domestic pets
* irrigation or disposal field may be a “mulch basin”
* discharge point covered by 2” of mulch/rock/soil or a solid shield
* an operation/maintenance manual stays with the house
* no root crops; greywater must not contact edible portion of food crops
mulch basin
greywater discharges
inside “mulch shield”
to mulch basin
“Mulch.
Organic waste material....permeable enough to allow rapid infiltration of graywater.”
“Mulch Basin.
A type of irrigation or disposal field filled with mulch...of sufficient depth, length and width
to prevent ponding or runoff.”
image from “Create and Oasis with Greywater” by Art Ludwig
since “landscape direct” systems discharge greywater
into mulch basins
they are most suited to watering:
trees
shrubs
large plants
not appropriate for:
lawns
groundcovers
beds with many small plants
“CLOTHES WASHER SYSTEM”
“...utilizing only a single domestic clothes washing machine in a one- or two-family
dwelling.”
“A clothes washer system in compliance with... (12 guidelines) is exempt from a
construction permit...”
* water from washing diapers, infectious garments, or anything soiled with
hazardous chemicals (oily rags) must be diverted back to sewer/septic
* does not alter the plumbing or impact other building systems or safety
* no added pump or potable water connection
“LAUNDRY TO LANDSCAPE” SYSTEM
features:
* easy to use diverter valve
* washer pump pushes greywater to garden
* uses 1” PVC to 1” HDPE with 1/2” outlets into mulch basins
* design flexibility--can go slightly uphill or across flat yard
* can have multiple zones/ regulate amount to different plants
* easy to change
* must choose “bio-compatible” laundry soaps
LAUNDRY TO LANDSCAPE
mulch basins
1” three-way
valve
auto-vent to
break siphon
1” HDPE main, 1/2” branches
1” zone
valve
1/2” outlets
1” HDPE main
drawing by Christina Bertea
1” three-way valve installation
code requires labeling
to indicate direction of flow
through diverter valve
auto-vent/
studor vent/
air admittance
valve-installed at
high point,
ideally
outdoors
prevents siphoning of refill water
once pump has stopped
1” ball valves can direct flow
through 1” HDPE mains
to different areas of garden
a 1” three-way valve
can be used outdoors
to create two zones:
(no danger of both zones
being closed
at the same time)
1”x1/2” barbed tees
direct greywater
through 1/2” HDPE to
outlets in mulch
1/2” ball valves can be
used to “balance” flows
HDPE tubing will be buried and mulch shield will be placed
around outlet and covered with tile, paver, or stone
from “Create an Oasis with Greywater” by Art Ludwig
“MULCH SHIELD” outlet chamber:
by inverting a one or two gallon plastic pot
and cutting around the bottom,
the “lid” can be flipped open to look inside
or perforated pipe can be used
(tops are covered with tiles, pavers, or stones)
outlets no smaller than 1/2”
allow lint to flow through
one end of a 1” main is left open as
failsafe
Homemade “Mulch Shields”:
--cheaper than valve boxes
--maintain a void that prevents
mulch or roots from clogging outlet
--mark outlet location, allow inspection
to monitor flow
--protected with paver, stone or tile
Santa Rosa’s first rebated
greywater system:
completed during a
two-day installer training
Happy homeowner with Laura Allen,
instructor and co-founder of the
Greywater Guerrillas
(now Greywater Action)
“BRANCHED DRAIN” SYSTEM
features:
* “simple system” PERMIT REQUIRED if under 250 gpd outflow
* for TUBS, SHOWERS, SINKS (except kitchen sink/dishwasher)
* three way DIVERTER VALVE IS CUT INTO DRAIN LINE
* GRAVITY FLOW through 1-1/2” ABS to garden
* piping installed with 1/4” per foot CONTINUOUS SLOPE to garden
* must be able to clear foundation
* no limit to distance other than depth of trench (given slope)
* flow is distributed by DOUBLE ELL “splitters”
* discharges greywater inside mulch shield to mulch basin
“The design of simple systems
shall be acceptable to the Enforcing Agency
and shall meet
generally accepted graywater system design criteria.”
SINKS typically have traps above the floor
a three-way diverter valve can be cut into the drain pipe
in the wall for easy access
drains for TUBS and SHOWERS are
under floor in crawlspace or basement
the drain line must be cut to install the
three-way diverter valve
slabs make this greywater inaccessible
electronic “actuators”
can operate
difficult to access valves:
the switch is mounted
in a convenient location
requires electricity
must be labeled
plywood “access panel”
in downstairs art studio
has handle position labeling drawn on it
to select “zones” for greywatering:
a three-way valve or ball valves
can be used
“flow splitters” or “double ells”:
if
perfectly level
with 2’ of straight pipe
leading into them
will split the flow evenly
best if supported by
brick or stone
“Create an Oasis with Greywater” by Art Ludwig
1” tapped plugs can be removed
to monitor flow through double ells
provide access in case of clogs
a tile/paver/stone marks location
solid shield
“Mulch Shield”
“the discharge point....
shall be covered by at least 2 inches of mulch, rock, or soil, or a solid shield
to minimize the possibility of human contact”
images from “Create an Oasis with Greywater” by Art Ludwig
homemade mulch shield
or purchased valve box
maintains open space around outlet
protects outlet from clogging
with mulch or roots
greywater freefalls onto mulch at bottom
Two LANDSCAPE DIRECT Systems
LAUNDRY TO LANDSCAPE
BRANCHED DRAIN
Permit?
No, if follow guidelines
Yes, simple system (?)
Distributed by
Washing machine pump
Gravity
Through
1” PVC to 1” HDPE
1-1/2” ABS
Slope of line
can go slightly uphill
consistent 1/4” per foot
Discharged into
mulch shield
mulch shield
Irrigation field
mulch basin
mulch basin
greywateraction.org
greywateralliance.org
“towards a sustainable water culture”