Current through Reg. 49, No. 52; December 27, 2024
(a) For the
purposes of this section, alternative onsite water does not include reverse
osmosis reject water, as this source of water is regulated by Subchapter E of
this chapter (relating to Special Requirements for Use of Industrial Reclaimed
Water).
(b) 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 at an industrial
facility, commercial facility, or institution. Treatment required by this
section does not require authorization from the commission.
(c) The graywater and alternative onsite
water must be generated and used onsite.
(d) 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, on-site sewage facility (OSSF),
authorized outfall in a wastewater discharge permit, or authorized disposal
area in a Texas Land Application Permit (TLAP). The graywater must be diverted
to the organized wastewater collection system, OSSF, authorized outfall in a
wastewater discharge permit, or authorized disposal area in a TLAP during
periods of non-use of the graywater reuse system or if the system reaches
maximum capacity. The graywater must enter the organized wastewater 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, OSSF, authorized outfall
in a wastewater discharge permit, or authorized disposal area in a TLAP prior
to entering the combined reuse system. Graywater must be diverted to the
organized wastewater collection system, OSSF, authorized outfall in a
wastewater discharge permit, or authorized disposal area in a TLAP 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.
(e) Water from
a graywater reuse system or a combined reuse system may be used onsite for the
following activities.
(1) Process water. Water
from a graywater reuse system or a combined reuse system that is used for
process water must 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 (not to
exceed), 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) 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 installed after January 6,
2005, 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."
(5) 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.
(f) Water from a graywater reuse system or a
combined reuse system that is required to meet the E. coli
limits in subsection (e) 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 of five
years.
