| (a) An authorization from the commission is not required
for the use of graywater and alternative onsite water from a graywater
reuse system or a combined reuse system for agricultural purposes.
Treatment required by this section does not require authorization
from the commission.
(b) The graywater and alternative onsite water must
be generated and used onsite.
(c) Graywater reuse systems and combined reuse systems
are not authorized to overflow onto the ground under any circumstances.
(1) Graywater reuse systems must be designed and constructed
so that 100% of the graywater can be diverted to an organized wastewater
collection system or on-site sewage facility (OSSF), unless prohibited
by Chapter 285, Subchapter H of this title (relating to Disposal of
Graywater). The graywater must be diverted during periods of non-use
of the graywater reuse system or if the system reaches maximum capacity.
The graywater must enter the organized wastewater collection system
or OSSF through either one air gap or two backflow valves or backflow
preventers.
(2) Combined reuse systems must be designed and constructed
so that 100% of the graywater can be diverted to an organized wastewater
collection system or OSSF, unless prohibited by Chapter 285, Subchapter
H of this title prior to entering the combined reuse system. Graywater
must be diverted to the organized wastewater collection system or
OSSF during periods of non-use of the system or if the combined reuse
system reaches 80% capacity. The graywater must enter the organized
wastewater collection system or the OSSF through either one air gap
or two backflow valves or backflow preventers.
(3) Combined reuse systems that store stormwater, rainwater,
and/or foundation drain water must have an automatic shutoff system
to stop the inflow of stormwater, rainwater, and foundation drain
water into the combined reuse system. The automatic shutoff system
must activate when the combined reuse system reaches 80% capacity.
(d) Water from a graywater reuse system or a combined
reuse system may be used for the following activities.
(1) Process water. Water from a graywater reuse system
or a combined reuse system that is used for irrigation and other agricultural
purposes may be treated to a standard that allows the water to be
used in operational processes.
(2) Landscape maintenance. Water from a graywater reuse
system or a combined reuse system that is used for landscape maintenance
must meet the following limits.
(A) If the water will be applied in areas with public
access, the water must meet the following limits:
(i) Escherichia coli (E. coli), 20
most probable number (MPN) or colony-forming units (CFU) per 100 milliliters
(ml), 30-day geometric mean; or
(ii) E. coli (not to
exceed), 75 MPN or CFU per 100 ml, single grab sample.
(B) If the water will be applied in areas with restricted
access to the public, the water must meet the following limits:
(i) E. coli, 200 MPN
or CFU per 100 ml, 30-day geometric mean; or
(ii) E. coli, 800 MPN
or CFU per 100 ml, single grab sample.
(3) Dust control. Water from a graywater reuse system
or a combined reuse system that is used for dust control must meet
the E. coli limits in paragraph (2)(B)
of this subsection.
(4) Irrigation of fields. Water from a graywater reuse
system or a combined reuse system that is used to irrigate fields
where edible crops are grown or fields that are pastures for milking
animals, the water must meet the E. coli limits
in paragraph (2)(A) of this subsection. E.
coli limits do not apply to graywater and alternative onsite
water that is used to irrigate fields other than those where edible
crops are grown or fields that are pastures for milking animals.
(5) Toilet or urinal flushing. Water from a graywater
reuse system or a combined reuse system that is used for toilet or
urinal flushing must meet the following requirements.
(A) E. coli must be
less than 2.2 MPN or CFU per 100 ml for 30-day geometric mean and
less than 200 MPN or CFU per 100 ml maximum single grab sample.
(B) Total suspended solids must be less than 10.0 milligrams
per liter for 30-day geometric mean and less than 30.0 milligrams
per liter maximum single grab sample.
(C) All exposed piping and piping carrying graywater
and/or alternative onsite water within a building must be either purple
pipe or painted purple; all buried piping must be either manufactured
in purple, painted purple, taped with purple metallic tape, or bagged
in purple; and all exposed piping must be stenciled in yellow with
a warning reading "NON-POTABLE WATER."
(6) Other uses. Water from a graywater reuse system
or a combined reuse system that is used for other similar activities
must:
(A) meet the E. coli limits
in paragraph (2)(A) of this subsection if used in a way that the public
may come into contact with the water; or
(B) meet the E. coli limits
in paragraph (2)(B) of this subsection if used in a way that the public
will not come into contact with the water.
(e) Water from a graywater reuse system or a combined
reuse system that is required to meet the E.
coli limits in subsection (d) of this section must be monitored
for E. coli at least monthly. These
records must be maintained at the site and be readily available for
inspection by the commission for a minimum period of five years.
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