| Secondary standards | (Environmental Engineering) Recommended drinking water quality standards which relate to aesthetics and/or health. These standards are recommended, not required. See primary standards. |
| Secondary treatment | (Environmental Engineering) In wastewater treatment, the conversion of the suspended, colloidal and dissolved organics remaining after primary treatment into a microbial mass with is then removed in a second sedimentation process. Secondary treatment included both the biological process and the associated sedimentation process. |
| Suspended growth reactor | (Environmental Engineering) A reactor in which the microorganisms are suspended in the wastewater. Examples of suspended growth reactors are activated sludge reactors and anaerobic digesters. See attached growth reactor. |
| Total suspended solids | (Environmental Engineering) (TSS) is the amount of suspended (filterable) matter in a water. |
| Ultimate biochemical oxygen demand (BODu) | (Environmental Engineering) The total amount of oxygen required to oxidize any organic matter present in a water, i.e. after an extended period, such as 20 or 30 days. |
| Volatile solids | (Environmental Engineering) (VS) is the amount of matter which volatilizes (or burns) when a water sample is heated to 550EC.Volatile suspended solids |
| Wastewater | (Environmental Engineering) Consumed or used water from a municipality or industry that contains dissolved and/or suspended matter. |
| Data warehouse - | (Software Engineering) a large, independent database that has access to databases that serve many different applications that are required by a business |
| Defect removal efficiency (DRE) - | (Software Engineering) a nondimension ratio (between 0 and 1) that provides an indication of the degree to which errors are removed from software before it is released to end-users |
| Grammatical parse - | (Software Engineering) a technique that is used during analysis and intended to help isolate basic data objects and functions |