Pennsylvania Code › Title 25 - ENVIRONMENTAL PROTECTION › Part I - Department of Environmental Protection › Subpart D - Environmental Health and Safety › Article VIII - Municipal Waste › Chapter 271 - MUNICIPAL WASTE MANAGEMENT-GENERAL PROVISIONS › Subchapter J - BENEFICIAL USE OF SEWAGE SLUDGE BY LAND APPLICATION › PATHOGENS AND VECTOR ATTRACTION REDUCTION › Appendix A - PATHOGEN TREATMENT PROCESSES

Current through Register Vol. 54, No. 28, July 13, 2024
A. Processes to significantly reduce pathogens
							 (PSRP)
1.
Aerobic Digestion
-Sewage sludge
							 is agitated with air or oxygen to maintain aerobic conditions for a specific
							 mean cell residence time at a specific temperature. Values for the mean cell
							 residence time and temperature shall be between 40 days at 68°F (or
							 20°C) and 60 days at 59°F (or 15°C).
2.
Air Drying
-Sewage sludge is dried
							 on sand beds or on paved or unpaved basins. The sewage sludge dries for a
							 minimum of 3 months. During 2 of the 3 months, the ambient average daily
							 temperature is above 32°F (or 0°C).
3.
Anaerobic Digestion
-Sewage sludge
							 is treated in the absence of air for a specific mean cell residence time at a
							 specific temperature. Values for the mean cell residence time and temperature
							 shall be between 15 days at 95° to 131°F (or 35° to 55°C) and
							 60 days at 68°F (or 20°C).
4.
Composting
-Using either the
							 within-vessel, static aerated pile, or windrow composting methods, the
							 temperature of the sewage sludge is raised to 104°F (or 40°C) or higher
							 and remains at 104°F (or 40°C) or higher for 5 days. For 4 hours during
							 the 5 days, the temperature in the compost pile exceeds 131°F (or
							 55°C).
5.
Lime Stabilization
-Sufficient
							 lime is added to the sewage sludge to raise the pH of the sewage sludge to 12
							 after 2 hours of contact.
B. Processes to further reduce pathogens
							 (PFRP)
1.
Composting
-Using either the
							 within-vessel composting method or the static aerated pile composting method,
							 the temperature of the sewage sludge is maintained at 131°F (or 55°C)
							 or higher for 3 days.
Using the windrow composting method, the temperature
							 of the sewage sludge is maintained at 131°F (or 55°C) or higher for 15
							 days or longer. During the period when the compost is maintained at 131°F
							 (or 55°C) or higher, there shall be a minimum of five turnings of the
							 windrow.
2.
Heat Drying
-Sewage sludge is
							 dried by direct or indirect contact with hot gases to reduce the moisture
							 content of the sewage sludge to 10% or lower. Either the temperature of the
							 sewage sludge particles exceeds 176°F (or 80°C) or the wet bulb
							 temperature of the gas in contact with the sewage sludge as the sewage sludge
							 leaves the dryer exceeds 176°F (or 80°C).
3.
Heat Treatment
-Liquid sewage
							 sludge is heated to a temperature of 356°F (or 180°C) or higher for 30
							 minutes.
4.
Thermophilic Aerobic
							 Digestion
-Liquid sewage sludge is agitated with air or oxygen to
							 maintain aerobic conditions and the mean cell residence time of the sewage
							 sludge is 10 days at 131° to 140°F (or 55° to 60°C).
5.
Beta Ray Irradiation
-Sewage
							 sludge is irradiated with beta rays from an accelerator at dosages of at least
							 1.0 megarad at room temperature (CA. 68°F or 20°C).
6.
Gamma Ray Irradiation
-Sewage
							 sludge is irradiated with gamma rays from certain isotopes, such as Cobalt 60
							 and Cesium 137, at room temperature (CA. 68°F or 20°C).
7.
Pasteurization
-The temperature of
							 the sewage sludge is maintained at 158°F (or 70°C) or higher for 30
							 minutes or longer.
This appendix cited in 25 Pa. Code §
															273.513 (relating to sewage
								sludge).