Packaged plants are very economical to operate, but produce a large amount of sludge and have poor ammonia removal. Piping allows conveyance of a fluid from one point to another. Precision refers to the consistency in grouping of results in measurement. The amount of rain, snow, hail, etc., that has fallen at a given place within a given period, usually expressed in inches or centimeters of water. Pumps are mechanical devices that change pressure at a given flow.
Pumps are most efficient at only one pressure and flow and are rated accordingly.
Standards and procedures set by the administrative branch of the government to enforce laws and treaties that protect the environment. For example, the Environmental Protection Agency and the Clean Water Act establishes limits on pollution from private and public sources. A Roots blower is a positive air blower, which was first designed in 1859, based on the forward motion of fixed quantities of air from an intake, through the housing, and expulsion through an outlet. Roots blowers are used in pneumatic conveying systems to handle dry bulk materials such as grain or cement. In sewage treatment plants, centrifugal blowers are replacing roots blowers.