40 CFR 503
Regulations for setting "Standards for the use or disposal of sewage sludge" Title 40 Code of Federal Regulations Part 503.
Aquifer
A subsurface formation that stores or transmits water in recoverable quantities and can be used as a source of well water for domestic and agricultural use.
Available water holding capacity
The capacity of soil to hold water between field capacity and the wilting point of plants. It is the pool from which growing plants obtain the water necessary for plant growth.
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.
Biochemical Oxidation Demand (B.O.D.)
A measure of the oxygen consumed in organic rich water by aerobic microorganisms for metabolic functions.
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 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.
BMP
Best Management Practices (BMP) are operating methods that ensure the proper handling of biosolids for protection of the environment.
Bulk density
The mass of dry soil per unit bulk volume (solids plus pores) expressed in g/cm3.
California Environmental Quality Act (CEQA)
Policies enacted in 1970, and subsequently amended, the intent of which is the maintenance of a quality environment for the people of California now and in the future.
Chemical Oxidation Demand (C.O.D.)
A measure of the oxygen needed to oxidize organic and inorganic compounds in water.
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
Material 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.
Composting
This is the process in which solid organic materials are decomposed in the presence of oxygen through the action of bacteria and other microorganisms. Dewatered biosolids are mixed with sawdust or wood chips that act as bulking agent by absorbing water and increasing the porosity of the mixture. This mix is then composted and cured for a minimum of six weeks. High temperatures (103 degrees to 150 degrees Fahrenheit) generated during this process pasteurize the mixture. A peat like product is the end result. Composted biosolids are easier to handle, store and use than liquid and dewatered biosolids.
Crops
Crops are plants grown for human or animal consumption and use. Crops used directly for human consumption are those eaten by humans with only superficial washing in water. Crops may be processed for human consumption by many means, most of which reduce the likelihood of contact with or ingestion of pathogens. Food chain crops are those crops ultimately used for food by humans and other animals.
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.
Disposal
Method of final disposition that does not provide any beneficial use. Disposal includes landfilling and incineration. Sludge-only lagoons where sludge remains for more than two years are also defined as disposal by regulation.
Domestic wastewater
Wastewater from restrooms and sanitary conveniences of residences, cities, mobile home parks, subdivisions, restaurants, rest homes, resorts, motels, factories, stores and other commercial businesses. It also includes industrial contributions when domestic and industrial wastewater are combined in a city sewer system.
Domestic wastewater sludge
Sludge generated from the treatment of domestic wastewater.
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).
Environmental Impact Report
Document in which the impacts of any state or local, public or private project action which may have a significant environmental effect are evaluated prior to its construction or implementation, as required by the California Environmental Quality Act.
EPA
United States Environmental Protection Agency. The federal agency assigned to administer the federal Clean Water Act and other federal environmental laws.
Exceptional Quality (EQ) Biosolids
Biosolids that meet low pollutant and Class-A pathogen reduction limits (virtual absence of disease causing organisms) and that have reduced levels of degradable compounds that attract vectors. Once the biosolids meet EQ standards (and equivalent classifications) there are very few restrictions on their use, labeling or sale.