Attachment C
List of Key Terms
Alternative daily cover (ADC): ADC means cover material other than earthen material placed on the surface of the active face of a municipal solid waste landfill at the end of each operating day to control vectors, fires, odors, blowing litter, and scavenging. Federal regulations require landfill operators to use six inches of earth material as daily cover unless other materials are allowed as alternatives. CalRecycle has approved 11 ADC material types. Generally, th ese materials must be processed so that they do not allow gaps in the exposed landfill face.
Anaerobic digestion: Anaerobic digestion is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen.
Beneficial use: Use of a product with a defined benefit, such as biosolids used as soil amendment. Disposal, such as landfilling or incineration, is not beneficial use.
Biogas: A mixture of different gases produced by the breakdown of organic matter in the absence of oxygen to produce a renewable energy source when combusted.
Biosolids: Organic fertilizer or soil amendments produced by the treatment of domestic wastewater. Biosolids consist primarily of dead microbes and other organic matter. Untreated sludge or sludge that does not conform to regulated pollutants and pathogen treatment requirements are not considered biosolids. Biosolids are regulated through the Environmental Protection Agency Title 40 Code of Federal Regulations Part 503 Rule (often referred to as the “503 Biosolids Rule”).
Biosolids land -application facility: A facility where biosolids are spread onto the land at agronomic rates for production of food or fiber. The facility includes any structures necessary to store the biosolids until the soil, weather , and crop conditions are favorable for land application.
Class A biosolids: Material that has met the Class A pathogen reduction requirements or equivalent treatment by a process to further reduce pathogens (PFRP) in accordance with 40 CFR 503. Processes include composting, heat drying, heat treatment, thermophilic aerobic digestion, beta or gamma ray irradiation, and pasteurization.
Class B biosolids: Mater ial that has met the Class B pathogen reduction requirements or equivalent treatment by a process to significantly reduce pathogens (PSRP) in accordance with 40 CFR 503. Processes include aerobic digestion, composting, anaerobic digestion, lime stabilization, and air drying.
Dewatering; dewatered biosolids: A process used to remove water from biosolids producing dewatered biosolids that contain equal to or greater than 20 percent dry solids.
Dry weight basis: Calculated on the basis of having been dried at 105 degrees Celsius until reaching a constant mass (i.e., essentially 100 percent solids).
40 CFR 503: Regulations for setting "Standards for the use or disposal of sewage sludge," Title 40 Code of Federal Regulations Part 503.
Gasification: Thermal process to convert carbon -based material into a synthesis gas.
Gasification is different from incineration, which uses large amounts of air for combustion to make carbon dioxide and heat. Gasification is in a typical temperature range of 900°F to 3000°F with a limited supply of air or oxygen, only a fraction of what is used in incineration. The synthesis gas can be used as a fuel to make electricity. There are no known sewage sludge gasification systems operating in the US solely on sewage sludge.
Land application: The beneficial use of biosolids applied to land based upon crop needs and the composition of biosolids.
Pathogen: An organism capable of causing a susceptible host to develop a disease or infection.
Pyrolysis: Thermal process to convert carbon -based material into a synthesis gas. Pyrolysis is different from incineration, which uses large amounts of air for combustion to make carbon dioxide and heat. Pyrolysis uses an indirect source of heat to thermally decomp ose organic materials, in a typical temperature range of 400°F to 1400°F, and in the absence of air or oxygen. The unreacted fixed carbon component of the material, along with any inorganic materials, forms a char/ash mixture that remains as a residual. The synthesis gas can be used as a fuel to make electricity and/or as heat used in a biodryer (as in the patented BioForceTech system) to offset external fuel sources for drying the sludge.
Sludge: The solid, semi-solid, or liquid residue removed during the treatment of wastewater.
Thermal hydrolysis process (THP) (Lystek Technology): Lystek’s THP is a low temperature and pressure process that disintegrates microbial cell w alls and hydrolyzes complex macromolecules into simpler components. It uses digested or undigested sludge as a feedstock, breaks the feedstock down in a reactor using high speed shearing, uses alkali treatment to increase pH, and is completed with injection of low temperature and low-pressure steam.
Lystek’s THP differs from the CAMBI process evaluated in the Biosolids Facilities Plan; the CAMBI THP operated at a higher temperature and pressure, utilized pretreatment screening and pre-thickening, and did not use alkali treatment.
Thermophilic digester: A type of anaerobic digester that operates at temperatures above 50°C and produces biogas.
Vectors: Rodents, flies, mosquitoes , or other organisms capable of transporting infectious agents.