plant, water supply treatment plant or air pollution control facility, and other
discarded materials including solid, liquid, semisolid, or contained gaseous material resulting from industrial, commercial, mining, and agricultural operations and
from community activities Sect.6903(27). The regulatory definition is found at
40CFR261.2(a)(1). A solid waste is defined by the US regulation as any
“discarded material” not expressly excluded by the US regulations. A material is
considered “discarded” if it is “abandoned,” “recycled,” or “considered inherently
waste-like.” Accordingly, the discarded, abandoned, recycled, or waste-like materials generated from a laboratory facility are all considered to be solid wastes.
Solidification/stabilization (S/S) The process utilizes chemically reactive formulations that, together with the water and other components in sludges and other
aqueous hazardous wastes, form stable solids.
Solids retention time (SRT) The theoretical length of time, usually in days, that
solids are retained in an aeration basin, clarifier, or other structure. SRT is used to
calculate wasting rates.
Soluble BOD (SBOD) Soluble BOD is a sample that has been filtered through a
0.45μm filter. Soluble BOD includes volatile fatty acids (VFAs) and organic
material that will readily ferment to create more VFAs in an anaerobic selector.
Soluble Dissolved in a solution and more readily available for biochemical or
chemical reactions. For instance, soluble BOD or soluble COD is readily available as food to microorganisms in a biochemical reaction. Soluble BOD includes
volatile fatty acids (VFAs) and organic material that are readily available to
microorganisms in a biological process.
Solution (a) A liquid (solvent) that contains a dissolved substance (solute). (b) A
liquid mixture of dissolved substances. In a solution, it is impossible to see all the
separated parts.
Solvent A liquid used to dissolve another substance.
Spatial Analysis It is the process of modeling, examining, and interpreting model
results. Spatial analysis is useful for evaluating suitability and capability, for
estimating and predicting, and for interpreting and understanding.
SPDES permit State Pollutant Discharge Elimination System (SPDES) permit is
each State’s regulatory agency document issued by either a state agency, which is
designed to control all discharges of pollutants from all point sources and storm
water runoff into US waterways. A State’s treatment plant that discharges to a
State’s surface water will have an SPDES permit.
Spectrophotometer (a) Meter that uses a specific wavelength of light to measure
light absorption in a sample; used for phosphorus, ammonia, nitrite, and nitrate
analyses. (b) A spectrophotometer is an instrument designed for physical sample
analysis via full spectrum color measurement. By providing wavelength-bywavelength spectral analysis of a sample’s reflectance, absorbance, or transmittance properties, it produces precise data beyond that observable by the human
eye. Spectrophotometers offer a higher level of flexibility and versatility than
colorimeters due in part to the fact that they offer multiple illuminant/observer
combinations and are capable of measuring metamerism, identifying colorant
12 Glossary of Natural Resources and Environmental Pollution Control
485
discarded materials including solid, liquid, semisolid, or contained gaseous material resulting from industrial, commercial, mining, and agricultural operations and
from community activities Sect.6903(27). The regulatory definition is found at
40CFR261.2(a)(1). A solid waste is defined by the US regulation as any
“discarded material” not expressly excluded by the US regulations. A material is
considered “discarded” if it is “abandoned,” “recycled,” or “considered inherently
waste-like.” Accordingly, the discarded, abandoned, recycled, or waste-like materials generated from a laboratory facility are all considered to be solid wastes.
Solidification/stabilization (S/S) The process utilizes chemically reactive formulations that, together with the water and other components in sludges and other
aqueous hazardous wastes, form stable solids.
Solids retention time (SRT) The theoretical length of time, usually in days, that
solids are retained in an aeration basin, clarifier, or other structure. SRT is used to
calculate wasting rates.
Soluble BOD (SBOD) Soluble BOD is a sample that has been filtered through a
0.45μm filter. Soluble BOD includes volatile fatty acids (VFAs) and organic
material that will readily ferment to create more VFAs in an anaerobic selector.
Soluble Dissolved in a solution and more readily available for biochemical or
chemical reactions. For instance, soluble BOD or soluble COD is readily available as food to microorganisms in a biochemical reaction. Soluble BOD includes
volatile fatty acids (VFAs) and organic material that are readily available to
microorganisms in a biological process.
Solution (a) A liquid (solvent) that contains a dissolved substance (solute). (b) A
liquid mixture of dissolved substances. In a solution, it is impossible to see all the
separated parts.
Solvent A liquid used to dissolve another substance.
Spatial Analysis It is the process of modeling, examining, and interpreting model
results. Spatial analysis is useful for evaluating suitability and capability, for
estimating and predicting, and for interpreting and understanding.
SPDES permit State Pollutant Discharge Elimination System (SPDES) permit is
each State’s regulatory agency document issued by either a state agency, which is
designed to control all discharges of pollutants from all point sources and storm
water runoff into US waterways. A State’s treatment plant that discharges to a
State’s surface water will have an SPDES permit.
Spectrophotometer (a) Meter that uses a specific wavelength of light to measure
light absorption in a sample; used for phosphorus, ammonia, nitrite, and nitrate
analyses. (b) A spectrophotometer is an instrument designed for physical sample
analysis via full spectrum color measurement. By providing wavelength-bywavelength spectral analysis of a sample’s reflectance, absorbance, or transmittance properties, it produces precise data beyond that observable by the human
eye. Spectrophotometers offer a higher level of flexibility and versatility than
colorimeters due in part to the fact that they offer multiple illuminant/observer
combinations and are capable of measuring metamerism, identifying colorant
12 Glossary of Natural Resources and Environmental Pollution Control
485