Rhode Island Code of Regulations › Title 250 - Department of Environmental Management › Chapter 140 - Waste and Materials Management › Subchapter 05 - Solid Waste › Part 8 - Solid Waste Regulation No.8, Rhode Island Organic Waste Recycling Facilities (Composting Regulations) › Section 250-RICR-140-05-8.12 - Compost Product Requirements and Distribution

Current through June 14, 2024
A. Compost
				  Quality Standards
1. This rule applies to
				  compost produced in all types of composting facilities subject to §§
											8.5,
				  8.8, or
				  8.10 of this Part, as well
				  as those composting operations in §§
											8.3 and
				  8.4 of this Part that are
				  offering finished compost for sale or free distribution. The parameter limits
				  for three classes of compost, Class "A", Class "B" and Class "C", are
				  established in this section. [The allowed uses of these three classes of
				  compost are provided in §
											8.12(C) 
				  of this Part]. Any finished compost which does not meet the limits established
				  for Class "A" or Class "B" compost shall be considered Class "C" where specific
				  Class "C" limits for heavy metals are omitted.
2. Heavy Metal Limits - mg/kg (dry weight) -
				  maximum allowed
Parameter
Class "A"
Class "B"
Arsenic
41
75
Cadmium
39
85
Chromium (total)
1200
3000
Copper
1500
4300
Lead
300
840
Mercury
17
57
Molybdenum
75
75
Nickel
420
420
Selenium
36
100
Zinc
2800
7500
3.
				  Toxic Organics - mg/kg - maximum allowed
Parameter
Class "A"
Class "B"
Class "C"
PCB (total)
1.0
1.0
10
4.
				  Pathogens - Pathogens include bacteria, viruses, protozoa, helminth and fungi.
				  All classes of compost shall be produced from a process to further reduce
				  pathogens (PFRP). Acceptable composting measures to result in PFRP conditions
				  are provided in §
											8.11(N)(5)
				  of this Part. Additionally, all classes of compost produced from mixed solid
				  waste shall have a fecal conform density less than 1,000 Most Probable Number
				  per gram of total solids (dry weight) (1,000 MPN/gTS) OR a Salmonella density
				  less than 3 Most Probable Number per 4 grams of total solids (3
				  MPNMgTS).
5. Foreign Matter - % dry
				  weight - All classes of compost shall not contain glass, metal, etc. (i.e.:
				  foreign materials) that exceed the limits below. The weight fraction of all
				  foreign matter may be no greater than the limits as follows:
Parameter
Class "A"
Class "B"
Class "C"
Foreign matter
1%
2%
4%
6.
				  Particle Size Distribution
a. Class "A"
				  limit: 100% < 10mm (0.39") particle size
b. Class "B" limit: 100% < 10mm (0.39")
				  particle size
c. Class "C" limit:
				  100% < 25mm (0.98") particle size
7. Electrical Conductivity (maximum soluble
				  salts) - The optimal range for growing media, i.e., compost amended soil, is
				  0.5-4.5 mmhos/cm. Acceptable levels will vary according to end user
				  application. Compost producers shall provide electrical conductivity
				  information on labels or in other product literature, for the intended end-user
				  application and comply with user industry standards.
8. pH - The acceptable pH level will vary
				  according to end user application and will generally be in the 5.5-8.5 range.
				  Compost producers shall provide pH information on labels or in other product
				  literature, for the end-user application and comply with user industry
				  standards.
9. Maturity and
				  Stability
a. Class "A" compost and Class "B"
				  compost shall be brown to black in color and shall have a reduction in organic
				  matter, via the composting process, of at least 60% as measured by reduction in
				  volatile solids. It shall be sufficiently stable, such that it does not reheat,
				  upon standing, to greater than 20 degrees C above ambient temperatures. Other
				  techniques or measures, subject to the approval by the Department may be
				  substituted for the above to demonstrate an equivalent maturity and
				  stability.
b. Class "C" compost
				  shall be light to dark brown or brown to black in color and shall have a
				  reduction in organic matter, via the composting process, of at least 40%, as
				  measured by reduction in volatile solids. It may reheat, upon standing, to
				  greater than 20 degrees C above ambient temperature. Although it may not be a
				  very stable compost, it shall at least be of a state which does not create a
				  nuisance (odor or vector) problem, during storage or when applied by the
				  end-user. Other techniques or measures, subject to the approval by the
				  Department, may be substituted for the above to demonstrate an equivalent
				  maturity and/or stability.
c.
				  Relative to compost pile stability, temperature measurements, to determine
				  reheat characteristics, shall be at a point two feet into the pile from its
				  outside surface.
d. Additionally,
				  all classes of compost produced from waste that included sewage sludge and/or
				  septage as a co-composting material shall be produced from a composting
				  process, whereby the temperature of the composting waste is kept at 40 degrees
				  C for at least 14 days and the average temperature of the composting waste
				  during this 14 day period is greater than 45 degrees C.