Florida Administrative Code › 62 - DEPARTMENT OF ENVIRONMENTAL PROTECTION › 62 - Departmental › Chapter 62-672 - MINIMUM REQUIREMENTS FOR EARTHEN DAMS USED IN PHOSPHATE MINING AND BENEFICIATION OPERATIONS AND FOR DIKES USED IN PHOSPHOGYPSUM STACK SYSTEM IMPOUNDMENTS › Section 62-672.200 - Definitions

Current through Reg. 50, No. 138; July 16, 2024
(1) 100-Year Rainfall Event - A rainfall
				event which is characterized by a mean return period of one hundred years,
				i.e., a rainfall event which has a 99% probability for not being exceeded
				during any given year.
(2) 100-Year
				Annual Rainfall - The 100-Year rainfall event representing total annual
				rainfall of 76 inches.
(3)
				Abandoned dam - An abandoned dam is one associated with a settling area from
				which sufficient water has been removed to make the residue no longer a
				pollutional threat to surface waters or a hazard of any type to land
				areas.
(4) Above-Grade Perimeter
				Earthen Dike - A perimeter earthen dike that has its design freeboard above the
				adjacent ground surface.
(5) Active
				dam - An active dam is one associated with a settling area into which
				wastewater is being introduced for purposes of clarification or in which free
				water remains in contact with the dam.
(6) Auxiliary holding pond (AHP) - a lined
				storage pond, designated by the operator and approved by the department in
				accordance with Rule  62-673.320, F.A.C., typically
				used to hold untreated process water. AHPs are intended to increase system
				storage above that otherwise provided by cooling/surge ponds and are typically
				located within the footprint of a phosphogypsum stack system. An existing AHP
				may be unlined where it was authorized by a permit issued in accordance with
				Rule  62-673.320, F.A.C., to be in use
				as of July 19, 2006, or was otherwise subject to a demonstration provided in
				accordance with subsection
				 62-673.650(2),
				F.A.C.
(7) Backup power - A
				secondary source of power not likely to fail simultaneously with the primary
				source.
(8) Beach or Delta - A
				gently sloping area of gypsum deposited within the settling compartment, above
				the process water level.
(9)
				Beneficiation - The processing of phosphate ore to separate the phosphate rock
				from the associated sand and clays.
(10) Berm - A shelf that breaks the
				continuity of the slope of an embankment in order to arrest the velocity of
				storm water flowing down the face and/or to enhance the stability of the
				embankment.
(11) Cast dam - A cast
				dam is one constructed of fill which was put in place by a dragline or other
				machine capable of free dumping, and is not mechanically compacted in
				progressive layers.
(12)
				Cooling/surge pond - impounded areas within the phosphogypsum stack system,
				excluding settling compartments atop the phosphogypsum stack, that provide
				cooling capacity, surge capacity, or any combination thereof, for the
				phosphoric acid process water recirculation system including phosphogypsum
				stack transport, runoff, and leachate water from the process
				watershed.
(13) Core - A zone of
				relatively impervious material within the dam to resist the flow of water
				through the dam.
(14)
				Cut-off-trench - An excavation into the foundation material to accept an
				extension of the core.
(15)
				Department - The Florida Department of Environmental Protection.
(16) Dike - A barrier to the flow of
				phosphogypsum and process water which is constructed of naturally occurring
				soil (earthen dike) or of phosphogypsum and which is a component of a
				phosphogypsum stack system.
(17)
				Drain - A material more pervious than the surrounding fill which allows seepage
				water to drain freely while preventing piping or internal erosion of the fill
				material.
(a) Blanket drain is a continuous
				horizontal drain layer within or beneath the downstream portion of the
				dam.
(b) Chimney drain is a
				continuous sloping drain layer within the downstream portion of the
				dam.
(c) Toe drain is a
				wedge-shaped drain supporting the downstream toe of the
				dam.