Biosolids can attract “vectors,” which are basically any living carrier that transmits an infectious agent (think ticks, mosquitoes, fleas, some kinds of flies, etc.). Meeting EPA Part 503 standards for Class A or B biosolids of various types requires that the biosolid meets at least one (sometimes more) of the ten vector attraction reduction options listed below:
Option 1. Reduce the mass of volatile solids by a minimum of 38%.
Option 2. Demonstrate vector attraction reduction with additional anaerobic digestion in a bench-scale unit.
Option 3. Demonstrate vector attraction reduction with additional aerobic digestion in a bench-scale unit.
Option 4. Meet a specific oxygen uptake rate for aerobically treated biosolids.
Option 5. Use aerobic processes at greater than 104°F (average temperatures 113°F) for 14 days or longer (e.g., during biosolids composting).
Option 6. Add alkaline materials to raise the pH under specified conditions.
Option 7. Reduce moisture content of biosolids that do not contain unstabilized solids from other than primary treatment to at least 75% solids.
Option 8. Reduce moisture content of biosolids with unstabilized solids to at least 90%.
Option 9. Inject biosolids beneath the soil surface within a specified time, depending on the level of pathogen treatment.
Option 10. Incorporate biosolids applied to or placed on the land surface within specified time periods after application to or placement on the land surface.
The Bioset process can help you achieve these options for your wastewater treatment. Contact Schwing Bioset for more information. For a more detailed explanation of these vector attraction reduction options, refer to the EPA’s Part 503 Rule, Chapter 5 [PDF].