Wisconsin Administrative Code › Department of Natural Resources › NR 100-199 - Environmental Protection - General › Chapter NR 111 - Cooling Water Intake Structures › Subchapter II - Existing Facilities › Section NR 111.12 - Impingement mortality BTA standards

Current through June 24, 2024
(1) MANDATORY
				  REQUIREMENTS.
(a)
Generally.
Except when approved by the department as provided in par. (b) and subs. (3)
				  and (4), the owner or operator of an existing facility shall comply with one of
				  the following alternatives, subject to the additional requirements specified in
				  sub. (2) or s. NR 111.16(1) if the department requires such additional
				  measures:
1. 'Closed cycle recirculating
				  system.' Operate a closed-cycle recirculating system as defined in s. NR
				  111.03(5). In addition, the owner or operator of a facility shall monitor the
				  actual intake flows at a minimum frequency of daily. The monitoring shall be
				  representative of normal operating conditions and shall include measuring
				  cooling water withdrawals, make-up water, and blowdown volume. In lieu of daily
				  intake flow monitoring, the owner or operator of a facility may monitor cycles
				  of concentration at a minimum frequency of daily.
2. '0.5 Feet per second maximum design intake
				  velocity.' Operate a cooling water intake structure that has a maximum design
				  intake velocity less than or equal to 0.5 feet per second. The owner or
				  operator of the facility shall submit information to the department that
				  demonstrates that the maximum design intake velocity does not exceed 0.5 feet
				  per second. The maximum velocity shall be achieved under all conditions,
				  including during source water surface elevations associated with Q 7,10 flows
				  and during periods of maximum head loss across the screens or other devices
				  during normal operation of the intake structure. The maximum design intake
				  velocity shall be calculated using the method specified in s. NR
				  111.03(26).
3. '0.5 Feet per second
				  actual intake velocity.' Operate a cooling water intake structure that has a
				  maximum intake velocity less than or equal to 0.5 feet per second. The owner or
				  operator of the facility shall submit information to the department that
				  demonstrates that the maximum actual intake velocity does not exceed 0.5 feet
				  per second at the point with the smallest open area between the point at which
				  water is withdrawn from a water of the state and the first screen. The maximum
				  velocity shall be achieved under all conditions, including during source water
				  surface elevations associated with Q 7,10 flows and during periods of maximum
				  head loss across the screens or other devices during normal operation of the
				  intake structure. The department may authorize the owner or operator of the
				  facility to exceed the 0.5 feet per second velocity at an intake for brief
				  periods for the purpose of maintaining the cooling water intake system, such as
				  backwashing the screen face. In addition, the owner or operator of the facility
				  shall monitor the velocity at the intake continuously and report any
				  exceedances of 0.5 feet per second. In lieu of velocity monitoring at the
				  intake, the owner or operator of the facility may calculate the actual intake
				  velocity as follows:
View
					 Image
where:
V = the actual intake velocity.
Q = the actual intake flow rate based on monitoring.
A = wetted area of the screen at the given water
					 depth.
P = screen open area percentage divided by
					 100.
4. 'Existing offshore
				  velocity cap.' Operate an existing offshore velocity cap that was installed on
				  or before October 14, 2014. Offshore velocity caps installed after October 14,
				  2014 shall make either a demonstration under subd. 6. or meet the performance
				  standard under subd. 7. In addition, the facility shall monitor total daily
				  intake flow.
5. 'Modified traveling
				  screens.' Operate a modified traveling screen that the department determines
				  meets the definition specified in s. NR 111.03(29) and that, after review of
				  the information required in the impingement technology performance optimization
				  study specified in s. NR 111.41(5), the department determines is the BTA for
				  impingement reduction at the site. As the basis for the department's
				  determination, the owner or operator of the facility shall demonstrate that the
				  technology is or will be optimized to minimize impingement mortality of all
				  species except those designated as fragile or nuisance. The permit shall
				  include verifiable and enforceable permit conditions that ensure the technology
				  will perform as demonstrated.
6.
				  'Systems of technologies as the BTA for impingement mortality.' Operate a
				  system of technologies, management practices, and operational measures that,
				  after review of the information required in the impingement technology
				  performance optimization study specified in s. NR 111.41(5), the department
				  determines is the BTA for impingement reduction at the facility's cooling water
				  intake structure. As the basis for the department's determination, the owner or
				  operator of the facility shall demonstrate that the system of technologies has
				  been optimized to minimize impingement mortality of all species except those
				  designated as fragile or nuisance. In addition, the department's decision will
				  be informed by comparing the impingement mortality performance data under s. NR
				  111.41(5) to a performance standard of no more than 24 percent impingement
				  mortality, including latent mortality and excluding fragile and nuisance
				  species. The permit shall include verifiable and enforceable permit conditions
				  that ensure the system of technologies will perform as demonstrated.
7. 'Impingement mortality performance
				  standard.' Achieve a 12-month impingement mortality performance standard of all
				  life stages of fish and shellfish of no more than 24 percent mortality,
				  including latent mortality, for all species together, except those designated
				  as fragile or nuisance, that are collected or retained in a sieve with maximum
				  opening dimension of 0.56 inches and kept for a holding period of 18 to 96
				  hours. The department may prescribe an alternative holding period. The facility
				  shall conduct biological monitoring at a minimum frequency of monthly to
				  demonstrate its impingement mortality performance. Each month, the facility
				  shall use all of the monitoring data collected during the previous 12 months to
				  calculate the 12-month survival percentage. The 12-month impingement mortality
				  survival performance standard is the total number of fish killed divided by the
				  total number of fish impinged over the course of the entire 12 months. The
				  owner or operator of the facility shall choose whether to demonstrate
				  compliance with this requirement for the entire facility, or for each
				  individual cooling water intake structure for which this subdivision is the
				  selected impingement mortality requirement.