Rhode Island Code of Regulations › Title 250 - Department of Environmental Management › Chapter 150 - Water Resources › Subchapter 10 - Wastewater And Storm Water › Part 3 - Rules and Regulations for Sewage Sludge Management (250-RICR-150-10-3) › Section 250-RICR-150-10-3.30 - Appendix 3 - Vector Attraction Reduction Requirements

Current through June 14, 2024
A.
				  Reduction in Volatile Solids Content. The mass of volatile solids in the sewage
				  sludge shall be reduced by a minimum of 38 percent (see calculation procedures
				  in "Environmental Regulations and Technology, Control of Pathogens and Vector
				  Attraction in Sewage Sludge", EPA/625/R-92/013, July 2003, U.S. Environmental
				  Protection Agency, Cincinnati, Ohio 45268).
B. Additional Digestion of Anaerobically
				  Digested Biosolids. When the 38 percent volatile solids reduction requirement
				  in option A cannot be met for an anaerobically digested sewage sludge, vector
				  attraction reduction can be demonstrated by digest-ing a portion of the
				  previously digested sewage sludge anaerobically in the laboratory in a
				  bench-scale unit for 40 additional days at a temperature between 30°C and
				  37°C. When at the end of the 40 days, the volatile solids in the sewage
				  sludge at the beginning of that period is reduced by less than 17 percent,
				  vector attraction reduction is achieved.
C. Additional Digestion of Aerobically
				  Digested Biosolids. When the 38 percent volatile solids reduction requirement
				  in option A cannot be met for an aerobically digested sewage sludge, vector
				  attraction reduction can be demonstrated by digesting a portion of the
				  previously digested sewage sludge that has a percent solids of 2 percent or
				  less aerobically in the laboratory in a bench-scale unit for 30 additional days
				  at 20°C. When at the end of the 30 days, the volatile solids in the sewage
				  sludge at the beginning of that period is reduced by less than 15 percent,
				  vector attraction reduction is achieved.
D. Specific Oxygen Uptake Rate (SOUR) for
				  Aerobically Digested Biosolids. The specific oxygen uptake rate (SOUR) for
				  sewage sludge 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°C.
E. Aerobic
				  Processes at Greater Than 40°C. Sewage sludge shall be treated in an
				  aerobic process for 14 days or longer. During that time, the temperature of the
				  sewage sludge shall be higher than 40°C and the average temperature of the
				  sewage sludge shall be higher than 45°C.
F. Addition of Alkaline Material. The pH of
				  sewage sludge 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 at 11.5 or higher for an additional 22 hours. PH measurements shall be
				  performed at 25°C or corrected to 25°C.
G. Moisture Reduction of Biosolids Containing
				  No Unstabilized Solids. Sewage sludge shall not contain unstabilized solids
				  generated during primary treatment and the solids content of the sewage sludge
				  shall be at least 75 percent before the sewage sludge is mixed with other
				  materials. The solids content of the sewage sludge shall be achieved by
				  removing water, not by adding inert materials.
H. Moisture Reduction of Biosolids Containing
				  Unstabilized Solids. Solids content of the sewage sludge shall be at least 90
				  percent, regardless of whether the sewage sludge is from primary treatment. The
				  solids content of the sewage sludge shall be achieved by removing water, not by
				  adding inert materials. The sewage sludge shall not be exposed to high humidity
				  prior to use or disposal to prevent the outer surface of the sewage sludge from
				  gaining moisture content.
I.
				  Biosolids Injection:
1. Sewage sludge shall
				  be injected below the surface of the land, and,
2. No significant amount of the sewage sludge
				  shall be present on the land surface within 1 hour after the sewage sludge is
				  injected, and,
3. When the sewage
				  sludge that is injected below the surface of the land meets the pathogen limits
				  in Appendix 5, §
											3.32 of this Part, the
				  sewage sludge shall be injected below the land surface within 8 hours after
				  being discharged from the pathogen reduction process.