Current through Register Vol. 47, No. 17, September 10, 2024
A. Control
measures are operational requirements representing best management practices
that graywater treatment works must follow when operating a graywater treatment
works.
B. Control measures that
apply to all graywater uses:
All graywater treatment works must be operated in accordance
with the following control measures:
1. Graywater must be collected in a manner
that minimizes the presence or introduction of:
a. hazardous or toxic chemicals in the
graywater to the greatest extent possible;
b. human excreta in the graywater to the
greatest extent possible;
c.
household wastes;
d. animal or
vegetable matter, and
e. for
Laundry to Landscape systems (Graywater Use Category A1), this includes control
over the type of clothing in the washing machine (e.g. no reusable diapers; not
using graywater when someone in the household is sick).
2. Use of graywater is limited to the
confines of the facility that generates the graywater.
3. The graywater treatment works must be
operated and maintained in accordance with the O&M manual, including all
manufacturer recommended maintenance activities. The O&M manual must remain
with the graywater treatment works throughout the system's life and be updated
based on each modification and approval made to the system. The O&M manual
must be transferred, upon change of ownership or occupancy, to the new owner or
tenant.
a. For Category C2 graywater
treatment works that have a capacity to receive greater than 2,000 gallons per
day (gpd), operational and maintenance records must be maintained for a minimum
of the past five (5) years.
4. The owner or operator of a graywater
treatment works must minimize exposure of graywater to humans, domestic pets,
and other animals.
5. Graywater use
and graywater treatment works must not create a public nuisance.
6. Graywater must not be stored for more than
24 hours unless the graywater has been treated by a graywater treatment works
that meets the design requirements of section 86.12. All graywater must be
stored inside a tank(s) that meets the design requirements of section
86.12(A)(5).
7. Temporary or
semi-temporary connections from the potable water system or public water system
to the graywater treatment works are prohibited. Permanent connections from the
potable water system or public water system to the graywater treatment works
must meet the design requirements of 86.12(A)(6).
C. Control measures that apply to subsurface
irrigation graywater use, including mulch basins (Graywater Use Categories: A1,
B1, and B2)
Subsurface irrigation graywater treatment works must be
operated in accordance with the following additional control measures:
1. Edible crop irrigation is prohibited for
non-single family subsurface irrigation (Graywater Use Category: B2).
2. Edible crops irrigated with graywater
treatment works must be washed with potable water prior to consumption.
3. Edible crops irrigated with
graywater treatment works must be for personal consumption only and not for
sale.
4. Single family units that
allow for short term rentals (e.g. Airbnb, VRBO, etc.) are prohibited from
using graywater for edible crop irrigation and Laundry to Landscape graywater
treatment works.
5. Irrigation of
sprouts, leafy greens and root crops is prohibited.
6. Irrigation is prohibited when the ground
is frozen, plants are dormant, during rainfall events, or the ground is
saturated.
7. Irrigation scheduling
must be adjusted so that application rates are closely matched with soil and
weather conditions.
8. Graywater
must be applied in a manner that does not result in ponding, runoff, or
unauthorized discharge to state waters. For dispersed subsurface irrigation
systems, the graywater must be applied at an agronomic rate. For mulch basins
systems, the graywater must not be applied in excess of the soil adsorption
rate.
9. For mulch basin systems,
mulch must be replenished and undergo periodic maintenance as needed to reshape
or remove material to maintain surge capacity and to prevent ponding and
runoff.
D. Control
measures that apply to indoor toilet and urinal flushing graywater use
(Graywater Use Categories: C1 and C2)
Indoor toilet and urinal flushing graywater treatment works
(Categories C1 and C2) must be operated in accordance with the following
additional control measures.
1.
Graywater for toilet and urinal flushing use must be disinfected.
a. Graywater treatment works that utilize
chlorine for disinfection must have a minimum of 0.2 mg/L and a maximum of 4.0
mg/L of free chlorine residual throughout the indoor graywater plumbing system,
including fixtures.
b. Single
family graywater treatment works that utilize non-chemical methods, such as UV,
for disinfection must have a chlorine puck present in each toilet or urinal
tank.
2. Graywater for
toilet and urinal flushing must be dyed with either blue or green food grade
vegetable dye and be visibly distinct from potable water.
E. Control measures that apply to rural fire
protection graywater use (Graywater Use Categories: D1 and D2)
Rural fire protection graywater treatment works (Categories
D1 and D2) must be operated in accordance with the following additional control
measures.
1. Graywater for rural fire
protection use must be stored in a watertight storage cistern consistent with
86.10(F)(3) for single family graywater treatment works and 86.10(G)(3) for
non-single family graywater treatment works.
2. Graywater for rural fire protection use
must be disinfected prior to graywater entering the storage cistern.
a. Graywater treatment works that utilize
chlorine for disinfection must have a minimum of 0.2 mg/L and a maximum of 4.0
mg/L of free chlorine residual throughout the indoor graywater plumbing system,
prior to being pumped to the storage cistern; or
b. UV disinfection prior to being pumped to
the storage cistern.
3.
The local fire district/authority must be notified and agree to graywater use
for fire protection prior to its adoption and use in a local city, city and
county or county.