OAC 252:606-8-4
Class A biosolid production
Cite as Okla. Admin. Code § 252:606-8-4
(a) The construction of facilities to produce a Class A biosolid shall be permitted by the DEQ and
meet the requirements located in OAC 252:656-19.
(b) Compost.
(1) Composted Class A biosolids are produced by:
(A) combining the biosolids produced at a wastewater treatment plant with wood chips or other
source of carbon approved by the DEQ;
(B) the materials being heated, through the controlled biological decomposition of organic
material that has been sanitized through the generation of heat and processed to further reduce
pathogens in accordance with the requirements contained in 40 CFR, Part 503, and stabilized
to the point that the material is beneficial to plant growth through:
(i) the within-vessel composting method or the static aerated pile composting method
where the temperature of the sewage sludge is maintained at 55° Celsius (131° Fahrenheit)
or higher for three (3) or more consecutive days; or
(ii) the windrow composting method wherein the temperature of the sewage sludge is
maintained at 55° Celsius (131° Fahrenheit) or higher for fifteen (15) or more days. During
the period when the compost is maintained at 55° Celsius (131° Fahrenheit) or higher for
fifteen (15) or more days, there shall be a minimum of five (5) turnings of the windrow;
(C) the combined material being removed to a second location to complete the curing process;
and
(D) being processed or tested to demonstrate that the material meets the pathogen reduction
requirements of 40 CFR § 503.32 (a) and the vector attraction reduction requirements of 40
CFR § 503.33 prior to use.
(2) Upon completion of the process, the compost may be used as described in the sludge
management plan.
(c) Other Class A biosolid production methods.
(1) For all other Class A production methods, the following requirements must be met:
(A) The applicant shall submit to the DEQ a plan for the production of the Class A biosolids,
which must receive approval from the DEQ;
(B) The applicant shall perform a pilot study on the DEQ -approved process for at least one (1)
year to determine that the process meets the requirements of 40 CFR § 503.32 (a) and 40 CFR
§ 503.33;
(C) The Class A biosolid production method shall include a process for the biosolids to be
dewatered, unless a waiver of the dewatering requirement is granted by the DEQ;
(D) The process shall be approved by EPA; and
(E) The applicant shall receive a final approval from the DEQ before distributing the Class A
biosolid.
(2) Upon completion of the requirements at OAC 252:606-8-4(c)(1), the Class A biosolid may be
used as described in the sludge management plan.