Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. of
Sub-Agency 0011 - Water Quality
Chapter 15 - USE OF SURFACE DISPOSAL OF BIOSOLIDS, APP. A-C
Part C - SURFACE DISPOSAL
Section 32 - Vector attraction reduction
Current through September 21, 2024
(a) One of the vector attraction reduction requirements in Section 32(f) through (p) shall be met when bulk biosolids are applied to agricultural land, forest, a public contact site, or a reclamation site.
(b) One of the vector attraction reduction requirements in Section 32(f) through (m) shall be met when bulk biosolids are applied to a lawn or a home garden.
(c) One of the vector attraction reduction requirements in Section 32(f) through (m) shall be met when biosolids are sold or given away in a bag or other container for application to the land.
(d) One of the vector attraction reduction requirements in Section 32(f) through (q) shall be met when biosolids (other than domestic septage) are placed on an active biosolids unit.
(e) One of the vector attraction reduction requirements in Section 32(n), (o) and (p), or (r) shall be met when domestic septage is applied to agricultural land, forest, or a reclamation site and one of the vector attraction reduction requirements in Section 32(n) through (r) shall be met when domestic septage is placed on an active biosolids unit. Compliance with the conditions of a General Statewide Permit for Land Application of Domestic Sewage In Remote Areas satisfies the requirements of this section.
(f) The mass of volatile solids in the biosolids shall be reduced by a minimum of 38%.
(g) When the 38% volatile solids reduction requirement in Section 32(f) cannot be met for an anaerobically digested biosolids, vector attraction reduction can be demonstrated by digesting a portion of the previously digested biosolids anaerobically in the laboratory in a bench-scale unit for 40 additional days at a temperature between 30 and 37 degrees Celsius. When at the end of the 40 days, the volatile solids in the biosolids at the beginning of that period is reduced by less than 17%, vector attraction reduction is achieved.
(h) When the 38% volatile solids reduction requirement in Section 32(f) cannot be met for an aerobically digested biosolids, vector attraction reduction can be demonstrated by digesting a portion of the previously digested biosolids that has a percent solids of two percent (2%) or less aerobically in the laboratory in a bench-scale unit for 30 additional days at 20 degrees Celsius. When at the end of the 30 days, the volatile solids in the biosolids at the beginning of that period is reduced by less than 15%, vector attraction reduction is achieved.
(i) The specific oxygen uptake rate (SOUR) for biosolids 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 degrees Celsius.
(j) Biosolids shall be treated in an aerobic process for 14 days or longer. During that time, the temperature of the biosolids shall be higher than 40 degrees Celsius and the average temperature of the biosolids shall be higher than 45 degrees Celsius.
(k) The pH of biosolids 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.
(l) The percent solids of biosolids that does not contain unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 75 % based on the moisture content and total solids prior to mixing with other materials.
(m) The percent solids of biosolids that contains unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 90% based on the moisture content and total solids prior to mixing with other materials.
(n) Biosolids shall be injected below the surface of the land.
(o) Biosolids applied to the land surface or placed on a surface disposal site shall be incorporated into the soil within six hours after application to or placement on the land.
(p) When biosolids that are incorporated into the soil are Class A with respect to pathogens, the biosolids shall be applied to or placed on the land within eight hours after being discharged from the pathogen treatment process.
(q) Biosolids placed on an active biosolids unit shall be covered with soil or other material at the end of each operating day.
(r) The pH of domestic septage shall be raised to 12 or higher by alkali addition and, without the addition of more alkali, shall remain at 12 or higher for 30 minutes.
(s) Compliance with the conditions of a General Statewide Permit for Land Application In Remote Areas, see Appendix C, is considered equivalent to these vector attraction reduction requirements.
