(a) Protection of fresh water. The applicant must demonstrate that both surface and subsurface fresh water will not be polluted by the application of wastewater by the subsurface area drip dispersal system.
(b) Domestic wastewater.
  (1) The permittee shall maintain the pH of the effluent within the limits of 6.0 - 9.0 standard units immediately prior to dispersal, unless a specific variance is approved by the executive director based upon site-specific conditions.
  (2) When a subsurface area drip dispersal system applies effluent on land where there is the potential for public contact with the soil, the permittee shall comply with Effluent Set 4 located in §309.4 of this title (relating to Table 1, Effluent Limitations for Domestic Wastewater Treatment Plants), or with more stringent effluent limitations prescribed by the executive director, if warranted to protect human health or the environment.
  (3) When a subsurface area drip dispersal system applies effluent on land where there is not the potential for public contact with the soil, the permittee shall comply with Effluent Set 5 located in §309.4 of this title, or with more stringent effluent limitations prescribed by the executive director, if warranted to protect human health or the environment.
  (4) Disinfection.
    (A) Permittees applying treated effluent to land where there is the potential for public contact with the soil must disinfect the effluent prior to it entering the subsurface area drip dispersal system in accordance with §309.3(g) of this title (relating to Application of Effluent Sets).
    (B) If the effluent is to be transferred to a holding pond or tank prior to dispersal, the permittee shall ensure that the effluent meets the relevant criteria of §222.87 of this title (relating to Effluent Limitations) at the time it enters the distribution system.
    (C) Permittees are allowed to use ultraviolet disinfection systems only with effluent having a daily average five-day biochemical oxygen demand concentration and total suspended solids concentration that are less than 20 milligrams per liter each.
  (5) The permittee must comply with requirements other than those specified in this section, if determined by the executive director to be necessary to protect human health.

Source Note: The provisions of this §222.85 adopted to be effective July 5, 2006, 31 TexReg 5308; amended to be effective January 9, 2020, 45 TexReg 363