Zone of Initial Dilution definition

Zone of Initial Dilution means the region surrounding or adjacent to the end of an outfall pipe or diffuser ports whose boundaries are defined through calculation of a plume model verified by the State Water Board.

Zone of Initial Dilution or "ZID" means the area of the receiving water directly after the end of the pipe where an instantaneous volume of water gives up to a one-to-one (1:1) dilution of the discharge.

Zone of Initial Dilution means a delineated portion of a mixing zone in which wastewater discharges will be allowed to rapidly combine and begin dispersing into the water body. The acute criteria of 567—subrule 61.3(3) will apply at the boundary of this zone.

Examples of Zone of Initial Dilution in a sentence

• ZID Zone of Initial Dilution means the region of initial mixing surrounding or adjacent to the end of the outfall pipe or diffuser ports.

• Both permits also establish limits to apply at and beyond the Zone of Initial Dilution based on the American Samoa water quality standards, which differ for Utulei into Pago Pago Harbor and Tafuna into Vai Cove.

• The Zone of Initial Dilution is defined as the area immediately surrounding the outfall where rapid and irreversible turbulent mixing of the wastewater with the receiving water is achieved.

• The cumulative significant impacts to marine resources would be reduced to less than significant with the implementation of Mitigation Measure HS-C/MR-C: Implement Measures to Avoid Exceedances over Water Quality Objectives at the Edge of the Zone of Initial Dilution.

• Elevations in ocean salinities above ambient salinity levels due to the discharge of brine from the proposed project were evaluated using several models that predicted salinity at the edge of the Zone of Initial Dilution (ZID) and at the Brine Mixing Zone (BMZ) during three oceanographic seasons (Davidson, upwelling and oceanic) under generally prevailing water temperatures and salinities.

More Definitions of Zone of Initial Dilution

Zone of Initial Dilution or "ZID" means that area extending from the port openings of a high rate diffuser to the initial edge of the mixing zone where due to great turbulence a constant instream waste concentration (IWC) cannot be determined. For purposes of this definition a high rate diffuser is a submerged outfall in the form of a single pipe outlet or of multiport design giving rise to one or several submerged discharge jets designed to induce mixing between the effluent and receiving stream. The diffuser will protect against surface impingement and bottom attachment of the submerged jet(s) and in general a minimum exit velocity of ten feet per second shall be provided. The length of the ZID and thereby the distance to the initial edge of the mixing zone shall not exceed the more stringent of the following requirements:

Zone of Initial Dilution means a small area in the immediate vicinity of an outfall structure in which turbulence is high and causes rapid mixing with the surrounding water.

Zone of Initial Dilution means the region of initial mixing surrounding or adjacent to the outfall pipe or diffuser port, in which dilution is caused by the momentum and buoyancy of the discharge.

Zone of Initial Dilution or "ZID" means the area of the receiving water directly after the end of the

Zone of Initial Dilution means the limited area permitted by the cabinet surrounding or downstream from a discharge location where rapid, first-stage mixing occurs. The zone of ini- tial dilution is the domain where wastewater and receiving water initially mix. (35 Ky.R. 208; Am. 856; 1452; eff. 1-5-2009; 39 Ky.R. 561; eff. 4-5-2013; 46 Ky.R. 154, 1186; eff. 1-3-2020.)

Zone of Initial Dilution or “ZID” means an area within a Department-authorized mixing zone where acute criteria may be exceeded. This area shall be no larger than necessary and shall be sized to prevent lethality to swimming or drifting organisms by ensuring that organisms are not exposed to concentrations exceeding acute criteria for more than one (1) hour more frequently than once every three (3) years. The actual size of the ZID will be determined by the Department for a discharge on a case-by-case basis, taking into consideration mixing zone modeling and associated size recommendations and any other pertinent chemical, physical, and biological data available.‌

Zone of Initial Dilution. (ZID) means the region of initial mixing surrounding or adjacent to the end of the outfall pipe or diffuser ports.