(a) An authorization from the commission is not required for the residential use of graywater and alternative onsite water from a graywater reuse system or a combined reuse system when the total combined average is less than 400 gallons per day and the water is used in accordance with this subchapter. Unless directed by the executive director, an authorization from the commission is not required for the residential use of graywater and alternative onsite water from a graywater reuse system or a combined reuse system when the total combined average is greater than or equal to 400 gallons per day and the water is used in accordance with this subchapter.
(b) The graywater and alternative onsite water must originate from a private residence.
(c) Water from a graywater reuse system or a combined reuse system may only be used at the private residence for the following purposes:
  (1) to minimize foundation movement and cracking;
  (2) for gardening;
  (3) for composting;
  (4) for landscaping; or
  (5) for toilet or urinal flushing.
(d) Graywater reuse systems and combined reuse systems are not authorized to overflow onto the ground under any circumstance.
  (1) Graywater reuse systems must be designed and constructed so that the storage tank required by subsection (e) of this section overflows to an organized wastewater collection system or an on-site sewage facility (OSSF) unless prohibited by Chapter 285, Subchapter H of this title (relating to Disposal of Graywater). 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 an OSSF, unless prohibited by Chapter 285, Subchapter H of this title, prior to entering the storage tank required by subsection (e) of this section. Graywater must be diverted to the organized wastewater collection system or OSSF during periods of non-use of the system or if the storage tank required by subsection (e) of this section 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 storage tank required by subsection (e) of this section reaches 80% capacity.
(e) Except as authorized by subsection (j) of this section, graywater reuse systems and combined reuse systems must store the water in tanks and the tanks must:
  (1) be clearly labeled as non-potable water;
  (2) restrict access, especially to children;
  (3) eliminate habitat for mosquitoes and other vectors;
  (4) be able to be cleaned; and
  (5) meet the structural requirements of §210.25(i) of this title (relating to Special Design Criteria for Reclaimed Water Systems).
(f) Graywater reuse systems and combined reuse systems must use piping that meets the piping requirement of §210.25 of this title.
(g) Water from a graywater reuse system or a combined reuse system shall not be applied using a spray distribution system except in accordance with the following conditions.
  (1) Water from the spray distribution system must meet the following limits: Escherichia coli (E. coli) must be less than 14 most probable number (MPN) or colony-forming units (CFU) per 100 milliliters for 30-day geometric mean and less than 240 MPN or CFU per 100 milliliters maximum single grab sample.
  (2) Water from the spray distribution system must be applied at times when people and pets are not actively using the distribution area.
  (3) Water from the spray distribution system must not be applied during rainfall events, when the ground is frozen, or within 24 hours after one-half inch or more of rain.
  (4) Water from the spray distribution system must be applied at a rate to prevent ponding, puddling, or runoff.
  (5) Water from the spray distribution system must not be sprayed or allowed to drift off property.
  (6) The spray distribution system must not be connected to a potable or raw water irrigation system unless suitable backflow prevention is provided to protect the potable or raw water system.
  (7) The spray distribution system must be inspected and repaired as needed to prevent discharges to water in the state or off property.
(h) The property owner is responsible for ensuring that the graywater reuse system or combined reuse system is properly operated and maintained to achieve the following requirements. Monitoring and recordkeeping for E. coli and total suspended solids is not required. Property owners may refer to the regulatory guidance document that is required by the Texas Health and Safety Code, §341.039, for assistance in complying with these requirements.
  (1) Graywater and alternative onsite water shall be treated to remove debris such as lint, leaves, twigs, and branches prior to entering the storage tank by use of a 50 mesh screen.
  (2) Swimming pool backwash and drain water cannot be used within five days after adding chemicals for shock or acid treatment.
  (3) 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 14 MPN or CFU per 100 milliliters for 30-day geometric mean and less than 240 MPN or CFU per 100 milliliters 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."
(i) Builders of private residences are encouraged to:
  (1) install plumbing in new housing to collect graywater and alternative onsite water from all allowable sources, taking into consideration end-use requirements and maintaining sufficient blackwater waste flow; and
  (2) design and install a subsurface distribution system around the foundation of new housing to minimize foundation movement or cracking.
(j) Property owners who have been disposing of wastewater from residential clothes-washing machines, otherwise known as laundry graywater, directly onto the ground prior to January 6, 2005, may continue disposing of laundry graywater under the following conditions.
  (1) The disposal area must not create a nuisance or threaten human health.
  (2) Surface ponding must not occur in the disposal area.
  (3) The disposal area must support plant growth or be sodded with vegetative cover.
  (4) The disposal area must have limited access and use by residents and pets.
  (5) Laundry graywater that has been in contact with human or animal waste must not be disposed onto the ground surface.
  (6) Laundry graywater must not be disposed onto an area where the soil is wet.
  (7) A lint trap must be affixed to the end of the discharge line.
  (8) The system has not been altered after January 6, 2005, has not created a nuisance, and does not discharge graywater from any source other than clothes-washing machines.

Source Note: The provisions of this §210.83 adopted to be effective January 6, 2005, 29 TexReg 12195; amended to be effective December 29, 2016, 41 TexReg 10364