Section NR 111.12 - Impingement mortality BTA standards(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does not exceed 0.5 feet per second at the point with the smallest open area between the point at which water is withdrawn from a water of the state and the first screen.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.(b)Exceptions.1. 'De minimis rate of impingement.' In limited circumstances, rates of impingement may be so low at a facility that additional impingement controls may not be justified. The department, based on review of site-specific data submitted under subch. V, may conclude that the documented rate of impingement at the cooling water intake is so low that no additional controls are warranted. Notice of a determination that no additional impingement controls are warranted shall be included in the draft or proposed permit and the department's response to all comments on this determination shall be included in the record for the final permit.2. 'Low capacity utilization power generating units.' If an existing facility has a cooling water intake structure used for one or more existing electric generating units, each with an annual average capacity utilization rate of less than 8 percent averaged over a 24-month contiguous period, the department may, based on review of site-specific data concerning cooling water system data under s. NR 111.41(4), establish the BTA standards for impingement mortality for that cooling water intake structure that are less stringent than par. (a) 1. to 7.(c)Reuse of other water for cooling purposes.The impingement mortality standard under this section does not apply to the portion of cooling water that is process water, gray water, reclaimed water, or other waters reused as cooling water in lieu of water obtained by surface water intakes.(2) ADDITIONAL MEASURES FOR OTHER SPECIES. The department may require the owner or operator of the facility to comply with additional monitoring, technologies, or measures, such as seasonal deployment of barrier nets, to protect shellfish or fragile species.(3) BEST PROFESSIONAL JUDGMENT-BASED BTA REQUIREMENTS. The owner or operator of the facility may be subject to interim, best professional judgment-based BTA requirements established by the department in the permit on a site-specific basis if an alternative schedule is granted under s. NR 111.11(2) (b) or if a complete permit application was received by the department before October 14, 2014.(4) NUCLEAR FACILITIES. If the owner or operator of a nuclear facility demonstrates to the department, upon the department's consultation with the U.S. nuclear regulatory commission, the U.S. department of energy, or the naval nuclear propulsion program, that compliance with this subchapter would result in a conflict with a safety requirement established by the U.S. nuclear regulatory commission, U.S. department of energy, or naval nuclear propulsion program, the department shall make a site-specific determination of BTA for minimizing adverse environmental impact that would not result in a conflict with the safety requirement of the U.S. nuclear regulatory commission, U.S. department of energy, or naval nuclear propulsion program.Wis. Admin. Code Department of Natural Resources NR 111.12
Adopted by, CR 19-105: cr. Register May 2020 No. 773, eff. 6-1-20; correction in (1) (a) 5., 7. made under s. 35.17, Stats., Register May 2020 No. 773, eff. 6/1/2020