(a) Compliance requirements.      
        (1) One of the vector attraction reduction requirements in subsection (b)(1) - (10) of this section shall be met when bulk biosolids are land applied to agricultural land, forest, a public contact site, or a reclamation site.       
        (2) One of the vector attraction reduction requirements in subsection (b)(1) - (8) of this section shall be met when bulk biosolids are applied to a lawn or home garden, or are sold or given away in a bag or other container.       
        (3) One of the vector attraction reduction requirements in subsection (b)(1) - (11) of this section shall be met when biosolids are placed on an active disposal unit.       
        (4) One of the vector attraction reduction requirements in subsection (b)(9), (10), or (12) of this section shall be met when domestic septage is applied to agricultural land, forest, or a reclamation site.       
        (5) One of the vector attraction reduction requirements in subsection (b)(9) - (12) of this section shall be met when domestic septage is placed on an active disposal unit.       
      (b) Compliance alternatives.      
        (1) The mass of volatile solids in the biosolids shall be reduced by a minimum of 38%.       
        (2) If anaerobically digested biosolids cannot meet the 38% volatile solids reduction requirement in paragraph (1) of this subsection, vector attraction reduction can be demonstrated by digesting a portion of the previously digested biosolids anaerobically in a laboratory in a bench-scale unit for 40 additional days at a temperature between 30 and 37 degrees Celsius. If, at the end of the 40 days, the volatile solids in the biosolids at the beginning of that period is reduced by less than 17%, vector attraction reduction is achieved.       
        (3) If aerobically digested biosolids cannot meet the 38% volatile solids reduction requirement in paragraph (1) of this subsection, vector attraction reduction can be demonstrated by digesting a portion of the previously digested biosolids that has a percent solids of 2.0% or less aerobically in a laboratory in a bench-scale unit for 30 additional days at 20 degrees Celsius. If, at the end of the 30 days, the volatile solids in the biosolids at the beginning of that period is reduced by less than 15%, vector attraction reduction is achieved.       
        (4) The specific oxygen uptake rate (SOUR) for biosolids treated in an aerobic process shall be equal to or less than 1.5 milligrams of oxygen per hour per gram of total solids (dry weight basis) at a temperature of 20 degrees Celsius.       
        (5) Biosolids shall be treated in an aerobic process for 14 days or longer. During that time, the temperature of the biosolids shall be higher than 40 degrees Celsius and the average temperature of biosolids shall be higher than 45 degrees Celsius.       
        (6) The pH of biosolids shall be raised to 12 or higher by alkali addition and, without the addition of more alkali, shall remain at 12 or higher for two hours and then remain at a pH of 11.5 or higher for an additional 22 hours.       
        (7) The percent solids of biosolids that do not contain unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 75% based on the moisture content and total solids prior to mixing with other materials.       
        (8) The percent solids of biosolids that contains unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 90% based on the moisture content and total solids prior to mixing with other materials.       
        (9) Biosolids shall be injected below the land surface. No significant amount of the biosolids shall be present on the land surface within one hour after the biosolids are injected. If the biosolids that are injected below the land surface are Class A or Class AB with respect to pathogens, as described in §312.82 of this title (relating to Pathogen Reduction), the biosolids shall be injected below the land surface within eight hours after the biosolids are discharged from the pathogen treatment process.       
        (10) Biosolids applied to the land surface or placed on a surface disposal site shall be incorporated into the soil within six hours after application or placement on the land. If the biosolids that are incorporated into the soil are Class A or Class AB with respect to pathogens, as described in §312.82 of this title, the biosolids shall be applied to or placed on the land within eight hours after the biosolids are discharged from the pathogen treatment process.       
        (11) Biosolids placed on an active disposal unit shall be covered with soil or other material at the end of each operating day.       
        (12) The pH of domestic septage shall be raised to 12 or higher by alkali addition and, without the addition of more alkali, shall remain at 12 or higher for 30 minutes.       
     Source Note:        The provisions of this §321.83 adopted to be effective October 13, 1995, 20 TexReg 7840; amended to be effective October 2, 2014, 39 TexReg 7756; amended to be effective April 23, 2020, 45 TexReg 2542