- Although the Texas code is less easy to read than other codes, such as New Mexico and Arizona, it does not prohibit the use of graywater for irrigating produce.
- No authorization is required for the domestic use of less than 400 gallons of graywater each day.
- It is interesting that substantial focus is placed on using graywater to maintain moisture levels around building foundations to prevent movement / cracking. This is also common practice in Australia.
The following is an excerpt relevant to residential graywater re-use.
SUBCHAPTER F: USE OF GRAYWATER SYSTEMS
§§210.81 – 210.85
Effective January 6, 2005
Adopted December 15, 2004 Effective January 6, 2005
§210.82. General Requirements.
(a)
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Graywater is defined as wastewater from:
- showers;
- bathtubs;
- hand washing lavatories;
- sinks that are not used for disposal of hazardous or toxic ingredients;
- sinks not used for food preparation or disposal; and
- clothes-washing machines.
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(b)
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Graywater does not include wastewater from the washing of material, including diapers, soiled with human excreta or wastewater that has come into contact with toilet waste.
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(c)
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Construction of a graywater system, including storage and disposal systems, must comply with this chapter and any requirements of the local permitting authority.
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§210.83. Criteria for the Domestic Use of Graywater.
(a)
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An authorization is not required for the domestic use of less than 400 gallons of graywater each day if:
- the graywater originates from a private residence;
- the graywater system is designed so that 100% of the graywater can be diverted to an organized wastewater collection system during periods of non-use of the graywater system and the discharge from the graywater system must enter the organized wastewater system through two backwater valves or backwater preventers;
- the graywater is stored in tanks and the tanks:
(A) are clearly labelled as nonpotable water;
(B) must restrict access, especially to children;
(C) eliminate habitat for mosquitoes and other vectors;
(D) are able to be cleaned; and
(E) meet the structural requirements of §210.25(i) of this title (relating to Special Design Criteria for Reclaimed Water Systems);
- the graywater system uses piping that meets the piping requirement of §210.25 of this title;
- the graywater is applied at a rate that:
(A) will not result in ponding or pooling; or
(B) will not cause runoff across the property lines or onto any paved surface; and
- the graywater is not disposed of using a spray distribution system.
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(b)
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Builders of private residences are encouraged to:
- install plumbing in new housing to collect graywater from all allowable sources; and
- design and install a subsurface graywater system around the foundation of new housing to minimize foundation movement or cracking.
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(c)
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A graywater system as described in subsection (a) of this section may only be used:
- around the foundation of new housing to minimize foundation movement or cracking;
- for gardening;
- for composting; or
- for landscaping at the private residence.
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(d)
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The graywater system must not create a nuisance or damage the quality of surface water or groundwater.
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(e)
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Homeowners who have been disposing wastewater from residential clothes-washing machines, otherwise known as laundry graywater, directly onto the ground before the effective date of this rule may continue disposing under the following conditions.
- The disposal area must not create a public health nuisance.
- Surface ponding must not occur in the disposal area.
- The disposal area must support plant growth or be sodded with vegetative cover.
- The disposal area must have limited access and use by residents and pets.
- Laundry graywater that has been in contact with human or animal waste must not be disposed onto the ground surface.
- Laundry graywater must not be disposed to an area where the soil is wet.
- A lint trap must be affixed to the end of the discharge line.
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(f)
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Graywater systems that are altered, create a nuisance, or discharge graywater from any source other than clothes-washing machines are not authorized to discharge graywater under subsection (e) of this section.
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