Louisiana Administrative Code › Title 33 - ENVIRONMENTAL QUALITY › Part IX - Water Quality › Subpart 2 - The Louisiana Pollutant Discharge Elimination System (LPDES) Program › Chapter 47 - Criteria Applicable to Cooling Water Intake Structures under Section 316(b) of the Clean Water Act › Subchapter B - Requirements Applicable to Cooling Water Intake Structures for Phase II Existing Facilities under Section 316(b) of the Clean Water Act › Section IX-4735 - What special definitions apply to this Subchapter?

Current through Register Vol. 50, No. 6, June 20, 2024
A. In addition to the definitions provided in
					 LAC 33:IX.2313, the following special definitions apply to this Subchapter.
Adaptive Management Method
- a type of
						project management method where a facility chooses an approach to meeting the
						project goal, monitors the effectiveness of that approach, and then based on
						monitoring and any other relevant information, makes any adjustments necessary
						to ensure continued progress toward the project's goal. This cycle of activity
						is repeated as necessary to reach the project's goal.
Annual Mean Flow
- the average of daily
						flows over a calendar year.
All Life Stages
- eggs, larvae,
						juveniles, and adults.
Calculation Baseline
- an estimate of
						impingement mortality and entrainment that would occur at your site assuming
						that the cooling water system has been designed as a once-through system; the
						opening of the cooling water intake structure is located at, and the face of
						the standard 3/8-inch mesh traveling screen is oriented parallel to, the
						shoreline near the surface of the source water body; and the baseline
						practices, procedures, and structural configuration are those that your
						facility would maintain in the absence of any structural or operational
						controls, including flow or velocity reductions, implemented in whole or in
						part for the purposes of reducing impingement mortality and entrainment. You
						may also choose to use the current level of impingement mortality and
						entrainment as the calculation baseline. The calculation baseline may be
						estimated using historical impingement mortality and entrainment data from your
						facility or from another facility with comparable design, operational, and
						environmental conditions; current biological data collected in the water body
						in the vicinity of your cooling water intake structure; or current impingement
						mortality and entrainment data collected at your facility. You may request that
						the calculation baseline be modified to be based on a location of the opening
						of the cooling water intake structure at a depth other than at or near the
						surface if you can demonstrate to the state administrative authority that the
						other depth would correspond to a higher baseline level of impingement
						mortality and/or entrainment.
Capacity Utilization Rate
- the ratio
						between the average annual net generation of power by the facility (in MWh) and
						the total net capability of the facility to generate power (in MW) multiplied
						by the number of hours during a year. In cases where a facility has more than
						one intake structure, and each intake structure provides cooling water
						exclusively to one or more generating units, the capacity utilization rate may
						be calculated separately for each intake structure, based on the capacity
						utilization of the units it services. Applicable requirements under this
						Subpart would then be determined separately for each intake structure. The
						average annual net generation should be measured over a five-year period, if
						available, of representative operating conditions, unless the facility makes a
						binding commitment to maintain capacity utilization below 15 percent for the
						life of the permit, in which case the rate may be based on this commitment. For
						purposes of this Subchapter, the capacity utilization rate applies to only that
						portion of the facility that generates electricity for transmission or sale
						using a thermal cycle employing the steam water system as the thermodynamic
						medium.
Closed-Cycle Recirculating System
- a
						system designed, using minimized make-up and blowdown flows, to withdraw water
						from a natural or other water source to support contact and/or noncontact
						cooling uses within a facility. The water is usually sent to a cooling canal or
						channel, lake, pond, or tower to allow waste heat to be dissipated to the
						atmosphere and then is returned to the system. (Some facilities divert the
						waste heat to other process operations.) New source water (make-up water) is
						added to the system to replenish losses that have occurred due to blowdown,
						drift, and evaporation.
Cooling Water
- water used for contact
						or noncontact cooling, including water used for equipment cooling, evaporative
						cooling tower makeup, and dilution of effluent heat content. The intended use
						of the cooling water is to absorb waste heat rejected from the process or
						processes used, or from auxiliary operations on the facility's premises.
						Cooling water that is used in a manufacturing process either before or after it
						is used for cooling is considered process water for the purposes of calculating
						the percentage of a facility's intake flow that is used for cooling purposes in
						LAC 33:IX.4733.A.4.
Cooling Water Intake Structure
- the
						total physical structure and any associated constructed waterways used to
						withdraw cooling water from waters of the state. The cooling water intake
						structure extends from the point at which water is withdrawn from the surface
						water source up to, and including, the intake pumps.
Design and Construction Technology
- any
						physical configuration of the cooling water intake structure, or a technology
						that is placed in the water body in front of the cooling water intake
						structure, to reduce impingement mortality and/or entrainment. Design and
						construction technologies include, but are not limited to, location of the
						intake structure, intake screen systems, passive intake systems, fish diversion
						and/or avoidance systems, and fish handling and return systems. Restoration
						measures are not design and construction technologies for purposes of this
						definition.
Design Intake Flow
- the value assigned,
						during the cooling water intake structure design, to the total volume of water
						withdrawn from a source water body over a specific time period.
Design Intake Velocity
- the value
						assigned, during the design of a cooling water intake structure, to the average
						speed at which intake water passes through the open area of the intake screen,
						or other device, upon which organisms might impinge or through which they might
						be entrained.
Diel
- daily and refers to variation in
						organism abundance and density over a 24-hour period due to the influence of
						water movement, physical or chemical changes, and changes in light
						intensity.
Entrainment
- the incorporation of any
						life stages of fish and shellfish with intake water flow entering and passing
						through a cooling water intake structure and into a cooling water
						system.
Estuary
- a semi-enclosed body of water
						that has a free connection with open seas and within which the seawater is
						measurably diluted with fresh water derived from land drainage. The salinity of
						an estuary exceeds 0.5 parts per thousand (by mass) but is typically less than
						30 parts per thousand (by mass).
Existing Facility
- any facility that
						commenced construction as described in
						40 CFR
						122.29(b)(4) on or before
						January 17, 2002 (or July 17, 2006, for an offshore oil and gas extraction
						facility), and any modification of, or any addition of, a unit at such a
						facility that does not meet the definition of a
new facility
in LAC 33:IX.4707.
Freshwater
River
or Stream
- a lotic (free-flowing) system that does not receive
						significant inflows of water from oceans or bays due to tidal action. For the
						purposes of this regulation, a flow-through reservoir with a retention time of
						seven days or less shall be considered a freshwater river or stream.
Impingement
- the entrapment of any life
						stages of fish and shellfish on the outer part of an intake structure or
						against a screening device during periods of intake water withdrawal.
Lake
or Reservoir
- any
						inland body of open water with some minimum surface area free of rooted
						vegetation and with an average hydraulic retention time of more than seven
						days. Lakes or reservoirs might be natural water bodies or impounded streams,
						usually fresh, surrounded by land or by land and a man-made retainer (e.g., a
						dam). Lakes or reservoirs might be fed by rivers, streams, springs, and/or
						local precipitation.
Moribund
- dying; close to death.
Natural Thermal Stratification
- the
						naturally occurring and/or existing division of a water body into horizontal
						layers of differing densities as a result of variations in temperature at
						different depths.
Ocean
- marine open coastal waters with
						a salinity greater than or equal to 30 parts per thousand (by mass).
Once-Through Cooling Water System
- a
						system designed to withdraw water from a natural or other water source, use it
						at the facility to support contact and/or noncontact cooling uses, and then
						discharge it to a water body without recirculation. Once-through cooling
						systems sometimes employ canals/channels, ponds, or non-recirculating cooling
						towers to dissipate waste heat from the water before it is discharged.
Operational Measure
- a modification to
						any operation at a facility that serves to minimize impact to fish and
						shellfish from the cooling water intake structure. Examples of operational
						measures include, but are not limited to, reductions in cooling water intake
						flow through the use of variable speed pumps and seasonal flow reductions or
						shutdowns, and more frequent rotation of traveling screens.
Phase II Existing Facility
- any
						existing facility that meets the criteria specified in LAC 33:IX.4733.
Source Water
- the waters of the U.S.
						from which the cooling water is withdrawn.
Supplier
- an entity, other than the
						regulated facility, that owns and operates its own cooling water intake
						structure and directly withdraws water from waters of the state. The supplier
						sells the cooling water to other facilities for their use, but may also use a
						portion of the water itself. An entity that provides potable water to
						residential populations (e.g., public water system) is not a supplier for
						purposes of this Subchapter.
Thermocline
- the middle layer of a
						thermally stratified lake or a reservoir. In this layer, there is a rapid
						change in temperatures between the top and bottom of the layer.
Tidal River
- the most seaward reach of
						a river or stream where the salinity is typically less than or equal to 0.5
						parts per thousand (by mass) at a time of annual low flow and whose surface
						elevation responds to the effects of coastal lunar tides.
AUTHORITY NOTE:
						Promulgated in accordance with
						R.S.
						30:2001 et seq., and in particular Section
						2074(B)(3) and (B)(4)