9 Va. Admin. Code § 25-31-165

Current through Register Vol. 41, No. 9, December 16, 2024
Section 9VAC25-31-165 - Requirements applicable to cooling water intake structures
A. Definitions. The following definitions apply specifically to this section:

"Annual mean flow" means the average of daily flows over a calendar year.

"Closed-cycle recirculating system" means a system designed, using minimized makeup 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" means 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 new facility's intake flow that is used for cooling purposes.

"Cooling water intake structure" means the total physical structure and any associated constructed waterways used to withdraw cooling water from state waters. The cooling water intake structure extends from the point at which water is withdrawn from the surface water source up to, and including, the intake pumps.

"Design intake flow" means the value assigned (during the facility's design) to the total volume of water withdrawn from a source water body over a specific time period.

"Design intake velocity" means 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) against which organisms might be impinged or through which they might be entrained.

"Entrainment" means the incorporation of all 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" means 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" means any facility that is not a new facility.

"Freshwater river or stream" means 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 section, a flow-through reservoir with a retention time of seven days or less will be considered a freshwater river or stream.

"Hydraulic zone of influence" means that portion of the source water body hydraulically affected by the cooling water intake structure withdrawal of water.

"Impingement" means the entrapment of all 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" means 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. Flow-through reservoirs with an average hydraulic retention time of seven days or less should be considered a freshwater river or stream.

"Maximize" means to increase to the greatest amount, extent, or degree reasonably possible.

"Minimize" means to reduce to the smallest amount, extent, or degree reasonably possible.

"Natural thermal stratification" means the naturally-occurring division of a water body into horizontal layers of differing densities as a result of variations in temperature at different depths.

"New facility" means any building, structure, facility, or installation that meets the definition of a "new source" or "new discharger" and is a greenfield or stand-alone facility that commences construction after January 17, 2002, and uses either a newly constructed cooling water intake structure, or an existing cooling water intake structure whose design capacity is increased to accommodate the intake of additional cooling water. A greenfield facility is a facility that is constructed at a site at which no other source is located, or that totally replaces the process or production equipment at an existing facility. A stand-alone facility is a new, separate facility that is constructed on property where an existing facility is located and whose processes are substantially independent of the existing facility at the same site. New facility does not include new units that are added to a facility for purposes of the same general industrial operation (for example, a new peaking unit at an electrical generating station).

"Ocean" means marine open coastal waters with a salinity greater than or equal to 30 parts per thousand (by mass).

"Source water" means the water body from which the cooling water is withdrawn.

"Thermocline" means the middle layer of a thermally stratified lake or reservoir. In this layer, there is a rapid decrease in temperatures.

"Tidal excursion" means the horizontal distance along the estuary or tidal river that a particle moves during one tidal cycle of ebb and flow.

"Tidal river" means 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.

B. Cooling water intake structures for new facilities.
1. Applicability.
a. This section applies to a new facility if it:
(1) Is a point source that uses or proposes to use a cooling water intake structure;
(2) Has at least one cooling water intake structure that uses at least 25% of the water it withdraws for cooling purposes as specified in subdivision 1 c of this subsection; and
(3) Has a design intake flow greater than two million gallons per day (MGD).
b. Use of a cooling water intake structure includes obtaining cooling water by any sort of contract or arrangement with an independent supplier (or multiple suppliers) of cooling water if the supplier or suppliers withdraw(s) water from waters of the United States. Use of cooling water does not include obtaining cooling water from a public water system or the use of treated effluent that otherwise would be discharged to state waters. This provision is intended to prevent circumvention of these requirements by creating arrangements to receive cooling water from an entity that is not itself a point source.
c. The threshold requirement that at least 25% of water withdrawn be used for cooling purposes must be measured on an average monthly basis. A new facility meets the 25% cooling water threshold if, based on the new facility's design, any monthly average over a year for the percentage of cooling water withdrawn is expected to equal or exceed 25% of the total water withdrawn.
d. This section does not apply to facilities that employ cooling water intake structures in the offshore and coastal subcategories of the oil and gas extraction point source category as defined under 40 CFR 435.10 and 40 CFR 435.40.
2. Compliance.
a. The owner or operator of a new facility must comply with either Track I in subdivision 2 b or c of this subsection or Track II in subdivision 2 d of this subsection. In addition to meeting the requirements in subdivision 2 b, c or d of this subsection, the owner or operator of a new facility may be required to comply with subdivision 2 e of this subsection.
b. Track I requirements for new facilities that withdraw equal to or greater than 10 MGD. Facilities must comply with all of the following requirements:
(1) Reduce intake flow, at a minimum, to a level commensurate with that which can be attained by a closed-cycle recirculating cooling water system;
(2) Design and construct each cooling water intake structure to a maximum through-screen design intake velocity of 0.5 ft/s;
(3) Design and construct the cooling water intake structure such that the total design intake flow from all cooling water intake structures meets the following requirements:
(a) For cooling water intake structures located in a freshwater river or stream, the total design intake flow must be no greater than 5.0% of the source water annual mean flow;
(b) For cooling water intake structures located in a lake or reservoir, the total design intake flow must not disrupt the natural thermal stratification or turnover pattern (where present) of the source water except in cases where the disruption is determined to be beneficial to the management of fisheries for fish and shellfish by any fishery management agency(ies);
(c) For cooling water intake structures located in an estuary or tidal river, the total design intake flow over one tidal cycle of ebb and flow must be no greater than 1.0% of the volume of the water column within the area centered about the opening of the intake with a diameter defined by the distance of one tidal excursion at the mean low water level;
(4) Select and implement design and construction technologies or operational measures for minimizing impingement mortality of fish and shellfish if:
(a) There are threatened or endangered or otherwise protected federal, state, or tribal species, or critical habitat for these species, within the hydraulic zone of influence of the cooling water intake structure; or
(b) Based on information submitted by any fishery management agency(ies) or other relevant information, there are migratory and/or sport or commercial species of impingement concern to the department that pass through the hydraulic zone of influence of the cooling water intake structure; or
(c) It is determined by the department, based on information submitted by any fishery management agency(ies) or other relevant information that the proposed facility, after meeting the technology-based performance requirements in subdivision 2 b (1), (2), and (3) of this subsection, would still contribute unacceptable stress to the protected species, critical habitat of those species, or species of concern;
(5) Select and implement design and construction technologies or operational measures for minimizing entrainment of entrainable life stages of fish and shellfish if:
(a) There are threatened or endangered or otherwise protected federal, state, or tribal species, or critical habitat for these species, within the hydraulic zone of influence of the cooling water intake structure; or
(b) Based on information submitted by any fishery management agency(ies) or other relevant information, there are or would be undesirable cumulative stressors affecting entrainable life stages of species of concern to the department, and the department determines that the proposed facility, after meeting the technology-based performance requirements in subdivision 2 b (1), (2), and (3) of this subsection, would contribute unacceptable stress to these species of concern;
(6) Submit the application information required in 9VAC25-31-100 Q and subdivision 4 b of this subsection;
(7) Implement the monitoring requirements specified in subdivision 5 of this subsection;
(8) Implement the record-keeping requirements specified in subdivision 6 of this subsection.
c. Track I requirements for new facilities that withdraw equal to or greater than two MGD and less than 10 MGD and that choose not to comply with subdivision 2 b of this subsection. Facilities must comply with all of the following requirements:
(1) Design and construct each cooling water intake structure at the facility to a maximum through-screen design intake velocity of 0.5 ft/s;
(2) Design and construct the cooling water intake structure such that the total design intake flow from all cooling water intake structures at the facility meets the following requirements:
(a) For cooling water intake structures located in a freshwater river or stream, the total design intake flow must be no greater than 5.0% of the source water annual mean flow;
(b) For cooling water intake structures located in a lake or reservoir, the total design intake flow must not disrupt the natural thermal stratification or turnover pattern (where present) of the source water except in cases where the disruption is determined to be beneficial to the management of fisheries for fish and shellfish by any fishery management agency(ies);
(c) For cooling water intake structures located in an estuary or tidal river, the total design intake flow over one tidal cycle of ebb and flow must be no greater than 1.0% of the volume of the water column within the area centered about the opening of the intake with a diameter defined by the distance of one tidal excursion at the mean low water level;
(3) Select and implement design and construction technologies or operational measures for minimizing impingement mortality of fish and shellfish if:
(a) There are threatened or endangered or otherwise protected federal, state, or tribal species, or critical habitat for these species, within the hydraulic zone of influence of the cooling water intake structure; or
(b) Based on information submitted by any fishery management agency(ies) or other relevant information there are migratory and/or sport or commercial species of impingement concern to the department that pass through the hydraulic zone of influence of the cooling water intake structure; or
(c) It is determined by the department, based on information submitted by any fishery management agency(ies) or other relevant information that the proposed facility, after meeting the technology-based performance requirements in subdivisions 2 c (1) and (2) of this subsection, would still contribute unacceptable stress to the protected species, critical habitat of those species, or species of concern;
(4) Select and implement design and construction technologies or operational measures for minimizing entrainment of entrainable life stages of fish and shellfish;
(5) Submit the application information required in 9VAC25-31-100 Q and 9VAC25-31-165 B 4;
(6) Implement the monitoring requirements specified in 9VAC25-31-165 B 5;
(7) Implement the recordkeeping requirements specified in 9VAC25-31-165 B 6.
d. Track II. The owner or operator of a new facility that chooses to comply under Track II must comply with the following requirements:
(1) Demonstrate to the department that the technologies employed will reduce the level of adverse environmental impact from cooling water intake structures to a comparable level to that which would be achieved using the requirements of subdivision 3 b (1) and (2) of this subsection. This demonstration must include a showing that the impacts to fish and shellfish, including important forage and predator species, within the watershed will be comparable to those that would result implementing the requirements of subdivisions 3 b (1) and (2) of this subsection. This showing may include consideration of impacts other than impingement mortality and entrainment, including measures that will result in increases in fish and shellfish, but it must demonstrate comparable performance for species that the department identifies as species of concern. In identifying such species the department may consider information provided by fishery management agencies with responsibility for fisheries potentially affected by the cooling water intake structure along with data and information from other sources.
(2) Design and construct the cooling water intake structure such that the total design intake flow from all cooling water intake structures at the facility meet the following requirements:
(a) For cooling water intake structures located in a freshwater river or stream, the total design intake flow must be no greater than 5.0% of the source water annual mean flow;
(b) For cooling water intake structures located in a lake or reservoir, the total design intake flow must not disrupt the natural thermal stratification or turnover pattern (where present) of the source water except in cases where the disruption is determined to be beneficial to the management of fisheries for fish and shellfish by any fishery management agency(ies);
(c) For cooling water intake structures located in an estuary or tidal river, the total design intake flow over one tidal cycle of ebb and flow must be no greater than 1.0% of the volume of the water column within the area centered about the opening of the intake with a diameter defined by the distance of one tidal excursion at the mean low water level.
(3) Submit the application information required in 9VAC25-31-100 Q and 9VAC25-31-165 B 4 c.
(4) Implement the monitoring requirements specified in 9VAC25-31-165 B 5.
(5) Implement the record-keeping requirements specified in 9VAC25-31-165 B 6.
e. The owner or operator of a new facility must comply with any more stringent requirements relating to the location, design, construction, and capacity of a cooling water intake structure or monitoring requirements at a new facility that the department deems are reasonably necessary to comply with any provision of state law, including compliance with state water quality standards (including designated uses, criteria, and antidegradation requirements).
3. Alternative requirements.
a. Any interested person may request that alternative requirements less stringent than those specified in 9VAC25-31-165 B 2 a through e be imposed in the permit. The department may establish alternative requirements less stringent than the requirements of 9VAC25-31-165 B 2 a through e only if:
(1) There is an applicable requirement under 9VAC25-31-165 B 2 a through e;
(2) The department determines that data specific to the facility indicate that compliance with the requirement at issue would result in compliance costs wholly out of proportion to those EPA considered in establishing the requirement at issue or would result in significant adverse impacts on local air quality, significant adverse impacts on local water resources other than impingement or entrainment, or significant adverse impacts on local energy markets;
(3) The alternative requirement requested is no less stringent than justified by the wholly out of proportion cost or the significant adverse impacts on local air quality, significant adverse impacts on local water resources other than impingement or entrainment, or significant adverse impacts on local energy markets; and
(4) The alternative requirement will ensure compliance with other applicable provisions of the Clean Water Act and state law.
b. The burden is on the person requesting the alternative requirement to demonstrate that alternative requirements should be authorized.
4. Application information requirements.
a. The owner or operator of a new facility must submit to the department:
(1) A statement of intention to comply with either:
(a) The Track I requirements for new facilities that withdraw equal to or greater than 10 MGD in 9VAC25-31-165 B 2 b;
(b) The Track I requirements for new facilities that withdraw equal to or greater than 2 MGD and less than 10 MGD in 9VAC25-31-165 B 2 c or;
(c) The requirements for Track II in 9VAC25-31-165 B 2 d.
(2) The owner or operator must also submit the application information required by 9VAC25-31-100 Q and the information required in either subdivision 4 b of this subsection for Track I or subdivision 4 c of this section for Track II when application is made for a new or reissued VPDES permit.
b. Track I application requirements. To demonstrate compliance with Track I requirements in 9VAC25-31-165 B 2 b or c, collect and submit to the department the information in subdivision 4 b (1) through (4) of this subsection.
(1) Flow reduction information. To comply with the flow reduction requirements in 9VAC25-31-165 B 2 b (1), submit the following information to demonstrate reduction of flow to a level commensurate with that which can be attained by a closed-cycle recirculating cooling water system:
(a) A narrative description of the system that has been designed to reduce intake flow to a level commensurate with that which can be attained by a closed-cycle recirculating cooling water system and any engineering calculations, including documentation demonstrating that make-up and blowdown flows have been minimized; and
(b) If the flow reduction requirement is met entirely, or in part, by reusing or recycling water withdrawn for cooling purposes in subsequent industrial processes, provide documentation that the amount of cooling water that is not reused or recycled has been minimized.
(2) Velocity information. Submit the following information to demonstrate compliance with the requirement to meet a maximum through-screen design intake velocity of no more than 0.5 ft/s at each cooling water intake structure:
(a) A narrative description of the design, structure, equipment, and operation used to meet the velocity requirement; and
(b) Design calculations showing that the velocity requirement will be met at minimum ambient source water surface elevations (based on best professional judgment using available hydrological data) and maximum head loss across the screens or other device.
(3) Source water body flow information. Submit the following information to demonstrate that the cooling water intake structure meets the flow requirements in 9VAC25-31-165 B 2 b (3) and c (2):
(a) If the cooling water intake structure is located in a freshwater river or stream, provide the annual mean flow and any supporting documentation and engineering calculations to show that the cooling water intake structure meets the flow requirements;
(b) If the cooling water intake structure is located in an estuary or tidal river, provide the mean low water tidal excursion distance and any supporting documentation and engineering calculations to show that the cooling water intake structure facility meets the flow requirements; and
(c) If the cooling water intake structure is located in a lake or reservoir, provide a narrative description of the water body thermal stratification, and any supporting documentation and engineering calculations to show that the natural thermal stratification and turnover pattern will not be disrupted by the total design intake flow. In cases where the disruption is determined to be beneficial to the management of fisheries for fish and shellfish provide supporting documentation and include a written concurrence from any fisheries management agency(ies) with responsibility for fisheries potentially affected by the cooling water intake structure(s).
(4) Design and Construction Technology Plan. To comply with 9VAC25-31-165 B 2 b (4) and (5), or 9VAC25-31-165 B 2 c (3) and (4), submit the following information in a Design and Construction Technology Plan:
(a) Information to demonstrate whether or not the criteria in 9VAC25-31-165 B 2 b (4) and b (5), or 9VAC25-31-165 B 2 c (3) and c (4) are met;
(b) Delineation of the hydraulic zone of influence for the cooling water intake structure;
(c) New facilities required to install design and construction technologies and/or operational measures must develop a plan explaining the technologies and measures selected based on information collected for the Source Water Biological Baseline Characterization required by 9VAC25-31-100 Q. (Examples of appropriate technologies include, but are not limited to, wedgewire screens, fine mesh screens, fish handling and return systems, barrier nets, aquatic filter barrier systems, etc. Examples of appropriate operational measures include, but are not limited to, seasonal shutdowns or reductions in flow, continuous operations of screens, etc.) The plan must contain the following information:
(i) A narrative description of the design and operation of the design and construction technologies, including fish-handling and return systems, that will be used to maximize the survival of those species expected to be most susceptible to impingement. Provide species-specific information that demonstrates the efficacy of the technology;
(ii) A narrative description of the design and operation of the design and construction technologies that will be used to minimize entrainment of those species expected to be the most susceptible to entrainment. Provide species-specific information that demonstrates the efficacy of the technology; and
(iii) Design calculations, drawings, and estimates to support the descriptions provided in 9VAC25-31-165 B 4 b (4) (c) (i) and (ii).
c. Application requirements for Track II. In order to with the requirements of Track II in 9VAC25-31-165 B 2 d collect and submit the following information:
(1) Source water body flow information. Submit to the department the following information to demonstrate that the cooling water intake structure meets the source water body requirements in 9VAC25-31-165 B 2 d (2):
(a) If the cooling water intake structure is located in a freshwater river or stream, provide the annual mean flow and any supporting documentation and engineering calculations to show that the cooling water intake structure meets the flow requirements;
(b) If the cooling water intake structure is located in an estuary or tidal river, provide the mean low water tidal excursion distance and any supporting documentation and engineering calculations to show that the cooling water intake structure facility meets the flow requirements; and
(c) If the cooling water intake structure is located in a lake or reservoir, provide a narrative description of the water body thermal stratification, and any supporting documentation and engineering calculations to show that the natural thermal stratification and thermal or turnover pattern will not be disrupted by the total design intake flow. In cases where the disruption is determined to be beneficial to the management of fisheries for fish and shellfish provide supporting documentation and include a written concurrence from any fisheries management agency(ies) with responsibility for fisheries potentially affected by the cooling water intake structure(s).
(2) Track II Comprehensive Demonstration Study. Perform and submit the results of a Comprehensive Demonstration Study (study). This information is required to characterize the source water baseline in the vicinity of the cooling water intake structure(s), characterize operation of the cooling water intake(s), and to confirm that the technology(ies) proposed and/or implemented at the cooling water intake structure reduce the impacts to fish and shellfish to levels comparable to those achieved by implementation of the requirements in 9VAC25-31-165 B 2 b (1) and (2) of Track I. To demonstrate the "comparable level" requirement, include information showing that:
(a) Both impingement mortality and entrainment of all life stages of fish and shellfish are reduced by 90% or greater of the reduction that would be achieved through 9VAC25-31-165 B 2 b (1) and (2); or
(b) If the demonstration includes consideration of impacts other than impingement mortality and entrainment, that the measures taken will maintain the fish and shellfish in the water body at a substantially similar level to that which would be achieved through 9VAC25-31-165 B 2 b (1) and (2); and
(c) Develop and submit a plan to the department containing a proposal for how information will be collected to support the study. The plan must include:
(i) A description of the proposed and/or implemented technology(ies) to be evaluated in the study;
(ii) A list and description of any historical studies characterizing the physical and biological conditions in the vicinity of the proposed or actual intakes and their relevancy to the proposed study. If existing source water body data is used, it must be no more than five years old, demonstrated sufficient to develop a scientifically valid estimate of potential impingement and entrainment impacts, and include documentation that the data were collected using appropriate quality assurance/quality control procedures;
(iii) Any public participation or consultation with federal or state agencies undertaken in developing the plan; and
(iv) A sampling plan for data that will be collected using actual field studies in the source water body. The sampling plan must document all methods and quality assurance procedures for sampling, and data analysis. The sampling and data analysis methods proposed must be appropriate for a quantitative survey and based on consideration of methods used in other studies performed in the source water body. The sampling plan must include a description of the study area (including the area of influence of the cooling water intake structure and at least 100 meters beyond); taxonomic identification of the sampled or evaluated biological assemblages (including all life stages of fish and shellfish); and sampling and data analysis methods; and
(d) Submit documentation of the results of the study to the director. Documentation of the results of the study must include:
(i) Source Water Biological Study. The Source Water Biological Study must include a taxonomic identification and characterization of aquatic biological resources including a summary of historical and contemporary aquatic biological resources; determination and description of the target populations of concern (those species of fish and shellfish and all life stages that are most susceptible to impingement and entrainment); and a description of the abundance and temporal/spatial characterization of the target populations based on the collection of multiple years of data to capture the seasonal and daily activities (e.g., spawning, feeding and water column migration) of all life stages of fish and shellfish found in the vicinity of the cooling water intake structure; an identification of all threatened or endangered species that might be susceptible to impingement and entrainment by the proposed cooling water intake structure(s); and a description of additional chemical, water quality, and other anthropogenic stresses on the source water body.
(ii) Evaluation of potential cooling water intake structure effects. This evaluation will include calculations of the reduction in impingement mortality and entrainment of all life stages of fish and shellfish that would need to be achieved by the technologies selected to implement requirements under Track II and an engineering estimate of efficacy for the proposed and/or implemented technologies used to minimize impingement mortality and entrainment of all life stages of fish and shellfish and maximize survival of impinged life stages of fish and shellfish, demonstrating that the technologies reduce impingement mortality and entrainment of all life stages of fish and shellfish to a comparable level to that which would be achieved implementing the requirements in 9VAC25-31-165 B 2 b (1) and (2) of Track I. The efficacy projection must include a site-specific evaluation of technology(ies) suitability for reducing impingement mortality and entrainment based on the results of the Source Water Biological Study. Efficacy estimates may be determined based on case studies that have been conducted in the vicinity of the cooling water intake structure and/or site-specific technology prototype studies.
(iii) Evaluation of proposed restoration measures. If restoration measures are proposed to maintain the fish and shellfish provide information and data to show coordination with the appropriate fishery management agency(ies) and a plan that provides a list of the measures to implement to demonstrate and continue to ensure that restoration measures will maintain the fish and shellfish in the water body to a substantially similar level to that which would be achieved through 9VAC25-31-165 B 2 b (1) and (2).
(iv) Verification monitoring plan. Include in the study a plan to conduct, at a minimum, two years of monitoring to verify the full-scale performance of the proposed or implemented technologies or operational measures. The verification study must begin at the start of operations of the cooling water intake structure and continue for a sufficient period of time to demonstrate that the facility is reducing the level of impingement and entrainment to the level documented in 9VAC25-31-165 B 4 c (2) (d) (ii). The plan must describe the frequency of monitoring and the parameters to be monitored. The department will use the verification monitoring to confirm that the level of impingement mortality and entrainment reduction required in is met and that the operation of the technology has been optimized. Include a plan to conduct monitoring to verify that restoration measures will maintain the fish and shellfish in the water body to a substantially similar level as that which would be achieved through 9VAC25-31-165 B 2 b (1) and (2).
5. Monitoring. The owner or operator of a new facility will be required to perform monitoring to demonstrate compliance with the requirements specified in 9VAC25-31-165 B 2.
a. Biological monitoring. Monitor both impingement and entrainment of the commercial, recreational, and forage base fish and shellfish species identified in either the Source Water Baseline Biological Characterization data or the Comprehensive Demonstration Study, depending on whether compliance with Track I or Track II was chosen. The monitoring methods used must be consistent with those used for the Source Water Baseline Biological Characterization or the Comprehensive Demonstration Study. Follow the monitoring frequencies identified below for at least two years after the initial permit issuance.
(1) Impingement sampling. Collect samples to monitor impingement rates (simple enumeration) for each species over a 24-hour period and no less than once per month when the cooling water intake structure is in operation.
(2) Entrainment sampling. Collect samples to monitor entrainment rates (simple enumeration) for each species over a 24-hour period and no less than biweekly during the primary period of reproduction, larval recruitment, and peak abundance identified during the Source Water Baseline Biological Characterization or the Comprehensive Demonstration Study. Collect samples only when the cooling water intake structure is in operation.
b. Velocity monitoring. If the facility uses surface intake screen systems, monitor head loss across the screens and correlate the measured value with the design intake velocity. The head loss across the intake screen must be measured at the minimum ambient source water surface elevation (best professional judgment based on available hydrological data). The maximum head loss across the screen for each cooling water intake structure must be used to determine compliance with the velocity requirement in 9VAC25-31-165 B 2 b (2) or c (1). If the facility uses devices other than surface intake screens, monitor velocity at the point of entry through the device. Monitor head loss or velocity during initial facility startup, and thereafter, at the frequency specified in the VPDES permit.
c. Visual or remote inspections. Conduct visual inspections or employ remote monitoring devices during the period the cooling water intake structure is in operation. Conduct visual inspections at least weekly to ensure that any design and construction technologies are maintained and operated to ensure that they will continue to function as designed. Alternatively, inspect via remote monitoring devices to ensure that the impingement and entrainment technologies are functioning as designed.
6. Records and reporting. The owner or operator of a new facility is required to keep records and report information and data to the department as follows:
a. Keep records of all the data used to complete the permit application and show compliance with the requirements, any supplemental information developed under 9VAC25-31-165 B 4, and any compliance monitoring data submitted under 9VAC25-31-165 B 5, for a period of at least three years from the date of permit issuance. The department may require that these records be kept for a longer period.
b. Provide the following to the department in a yearly status report:
(1) Biological monitoring records for each cooling water intake structure as required by 9VAC25-31-165 B 5 a;
(2) Velocity and head loss monitoring records for each cooling water intake structure as required by 9VAC25-31-165 B 5 b; and
(3) Records of visual or remote inspections as required in 9VAC25-31-165 B 5 c.
C. Cooling water intake structures for existing facilities.

Existing facilities that are not subject to requirements under this section must meet requirements under section 316(b) of the Clean Water Act determined by the department on a case-by-case, best professional judgment (BPJ) basis.

9 Va. Admin. Code § 25-31-165

Derived from Virginia Register Volume 22, Issue 24, eff. September 6, 2006; amended, Virginia Register Volume 24, Issue 3, eff. November 14, 2007; Amended, Virginia Register Volume 39, Issue 4, eff. 11/9/2022.

Statutory Authority: § 62.1-44.15 of the Code of Virginia; § 402 of the federal Clean Water Act; 40 CFR Parts 122, 123, 124, 403, and 503.