Stabilization. (1) In lime-soda water softening, any process that will minimize or
eliminate scale-forming tendencies. (2) In corrosion control, pH adjustment of water to
maintain carbonate equilibrium at the saturation point.
Standpipe. (1) A pipe or tank connected to a closed conduit and extending above the
hydraulic grade of the conduit, installed to afford relief from surges in pressure in
pipelines. (2) A tank resting on ground, with its height greater than its diameter, used
to store water in distribution systems. (3) A fixed vertical pipe for furnishing water to
the upper part of buildings in case of fire.
State. The agency of the state government which has jurisdiction over public waster
systems. During any period when a state does not have primary enforcement
responsibility pursuant to section 1413 of the Safe Drinking Water Act (Public Law 95-
523), the term "state" means the Regional Administrator, US Environmental Protection
Sterilization. Destruction of all living organisms, usually by a chemical compound or
Stratum. A geological term used to designate a single bed or layer of rock which is
more or less homogeneous in character.
Streamflow. The water that is flowing in a stream channel. Commonly used
interchangeably with stream discharge to designate the rate of flow.
Superchlorination. The application of chlorine to water to provide free residual
chlorination, in which the residual is usually so large as to require dechlorination.
Supplier of Water. Any person who owns or operates a public system.
Surge. A monetary increase in flow (in an open conduit) or pressure (in a closed
conduit) which passes longitudinally along the conduit, due usually to sudden changes
Survey, Hydrographic. An instrumental survey to measure and determine
characteristics of streams and other bodies of water within an area, including such
things as location, area extent, and depth of water in lakes or the ocean; the width,
depth, and course of streams; position and elevation of high water marks; location and
depth of well, etc.
Suspended Solids. All visible material in water which at the time of sampling is not
dissolved, and which can be removed by filtration.
Suspension. A system consisting of small particles kept dispersed by agitation or by
molecular motion in the surrounding water. The permanency of suspension is