1. (a) The permittee shall take soil samples within the same 45-day time frame each calendar year.
2. (b) Laboratory analyses of the soil samples must be submitted to the executive director by September 1 following the sampling date.

3. (c) The plant nutrient parameters shall be analyzed on a plant available basis. The permittee shall provide annual soil analyses of the dispersal zones for the following substances:

   1. (1) pH (sample consisting of two volumes of water to one volume of soil mixture), in standard units;
   2. (2) conductivity (sample consisting of two volumes of water to one volume of soil mixture), reported in millimho per centimeter;
   3. (3) total Kjeldahl nitrogen. Methods that rely on mercury as a catalyst are not acceptable;
   4. (4) nitrate-nitrogen;
   5. (5) plant-available potassium, reported on a dry-weight basis in milligrams per kilogram (mg/kg);
   6. (6) calcium, reported on a dry-weight basis in mg/kg;
   7. (7) magnesium, reported on a dry-weight basis in mg/kg;
   8. (8) sulfur, reported on a dry-weight basis in mg/kg;
   9. (9) phosphorus, analyzed according to the Mehlich III procedure (the North American Proficiency Testing Program of the Soil Science Society of America) and reported on a dry-weight basis in mg/kg;
   10. (10) sodium, reported on a dry-weight basis in mg/kg;
   11. (11) salinity; and
   12. (12) trace elements as specified in the individual permit.

4. (d) The permittee shall take samples in:

   1. (1) the zero to 12-inch zone of the soil; and
   2. (2) the 12- to 24-inch zone of soil in the disposal area.
5. (e) If soil conditions or weather preclude sampling within the time period required, the permittee may submit a request to sample at another time. The request must include justification for the schedule change and the replacement schedule.
6. (f) Alternate soil sampling depths and frequency may be approved by the executive director if the permittee demonstrates that the alternate depths and frequency sufficiently monitors nutrient levels.
7. (g) The permittee shall collect soil composite samples from each broadly defined soil characterization or texture, as defined by the United States Department of Agriculture.
8. (h) The permittee shall take at least one composite soil sample from each dispersal zone.
9. (i) The permittee must comply with any alternate sampling methods or schedules required by the executive director.

Source Note:The provisions of this §222.157 adopted to be effective July 5, 2006, 31 TexReg 5308; amended to be effective January 9, 2020, 45 TexReg 363.