Section 327IAC6.1-4-14. Pathogen treatment processes

   (a) For purposes of section 13(c)(2) of this rule, the processes to significantly reduce pathogens (PSRP) include the following:

(1) Aerobic digestion, including the following:

(A) A biosolid must be agitated with air or oxygen to maintain aerobic conditions for a specific mean cell residence time at a specific temperature.

(B) Values for the mean cell residence time and temperature must be between:

(i) forty (40) days at twenty degrees Celsius (20°C); and

(ii) sixty (60) days at fifteen degrees Celsius (15°C).

(2) Air drying, including the following:

(A) A biosolid must be dried on:

(i) sand beds; or

(ii) paved basins.

(B) The biosolid must dry for a minimum of ninety (90) days.

(C) For at least sixty (60) consecutive days, the ambient average daily temperature must be above zero degrees Celsius (0°C).

(3) Anaerobic digestion, including the following:

(A) Biosolid must be treated in the absence of oxygen for a specific mean cell residence time at a specific temperature.

(B) Values for the mean cell residence time and temperature must be between:

(i) fifteen (15) days at thirty-five degrees Celsius (35°C) to fifty-five degrees Celsius (55°C); and

(ii) sixty (60) days at twenty degrees Celsius (20°C).

(4) Composting, including the following:

(A) Using either the within-vessel, static aerated pile, or windrow composting methods*, the temperature of the biosolid must:

(i) be raised to forty degrees Celsius (40°C) or higher; and

(ii) remain at forty degrees Celsius (40°C) or higher for five (5) days.

(B) For four (4) hours during the five (5) days, the temperature in the compost pile must exceed fifty-five degrees Celsius (55°C).

(5) Lime stabilization in which sufficient lime is added to the biosolid to raise the pH of the biosolid to 12 after two (2) hours of contact.

  (b) For purposes of section 13(b)(2)(E)(ii) of this rule, the processes to further reduce pathogens (PFRP) include the following:

(1) Composting, including the following:

(A) Using either the within-vessel composting method* or the static aerated pile composting method*, the temperature of the biosolid must be maintained at fifty-five degrees Celsius (55°C) or higher for three (3) days.

(B) Using the windrow composting method*:

(i) the temperature of the biosolid must be maintained at fifty-five degrees Celsius (55°C) or higher for fifteen (15) days or longer; and

(ii) during the period when the compost is maintained at fifty-five degrees Celsius (55°C) or higher, there must be a minimum of five (5) turnings of the windrow.

(2) Heat drying, including the following:

(A) A biosolid must be dried by direct or indirect contact with hot gases to increase the percent total solids of the biosolid to ninety percent (90%) or greater.

(B) Either:

(i) the temperature of the biosolid particles must exceed eighty degrees Celsius (80°C); or

(ii) the wet bulb temperature of the gas in contact with the biosolid as the biosolid leaves the dryer must exceed eighty degrees Celsius (80°C).

(3) Liquid biosolid must be heated to a temperature of one hundred eighty degrees Celsius (180°C) or higher for thirty (30) minutes.

(4) Thermophilic aerobic digestion, including the following:

(A) Liquid biosolid must be agitated with air or oxygen to maintain aerobic conditions.

(B) The mean cell residence time of the biosolid must be for ten (10) days at fifty-five degrees Celsius (55°C) to sixty degrees Celsius (60°C).

(5) Biosolid must be irradiated with beta rays from an accelerator at dosages of at least one (1.0) megarad at room temperature, which is approximately twenty degrees Celsius (20°C).

(6) Biosolid must be irradiated with gamma rays from certain isotopes, such as Cobalt 60 and Cesium 137, at dosages of at least one (1.0) megarad at room temperature, which is approximately twenty degrees Celsius (20°C).

(7) For pasteurization, the temperature of the biosolid must be maintained at seventy degrees Celsius (70°C) or higher for thirty (30) minutes or longer.

  (c) For purposes of subsection (a)(5), the pH of biosolid must be measured at twenty-five degrees Celsius (25°C) or measured at another temperature and then converted to an equivalent value at twenty-five degrees Celsius (25°C).

  *Methods for within-vessel, static aerated pile, or windrow composting methods may be found in "Environmental Regulations and Technology─Control of Pathogens and Vectors in Sewage Sludge", EPA-625/R-92/013, available from U.S. Environmental Protection Agency, Cincinnati, Ohio, 1992. This method is also available for copying at the Indiana Department of Environmental Management, Office of Land Quality, 100 North Senate Avenue, Room N1154, Indianapolis, Indiana 46204. (Water Pollution Control Division; 327 IAC 6.1-4-14; filed May 15, 1998, 10:20 a.m.: 21 IR 3798; readopted filed Jan 10, 2001, 3:23 p.m.: 24 IR 1518; errata filed Feb 6, 2006, 11:15 a.m.: 29 IR 1937; readopted filed Nov 21, 2007, 1:16 p.m.: 20071219-IR-327070553BFA; readopted filed Jul 29, 2013, 9:21 a.m.: 20130828-IR-327130176BFA)