The URL can be used to link to this page

Home My WebLink About10.03.25 Board Correspondence - FW_ Environmental and Recreational Compliance Report submitted in FERC P-7242-060 by STS Hydropower, LLC,et al.From:Clerk of the Board To:Clerk of the Board; Connelly, Bill; Cook, Holly; Cook, Robin; Durfee, Peter; Jessee, Meegan; Kimmelshue, Tod; Kitts, Melissa; Krater, Sharleen; Lee, Lewis; Little, Melissa; Pickett, Andy; Ritter, Tami; Stephens, Brad J.; Sweeney, Kathleen; Teeter, Doug; Zepeda, Elizabeth Cc:Nuzum, Danielle; Loeser, Kamie Subject:Board Correspondence - FW: Environmental and Recreational Compliance Report submitted in FERC P-7242-060 by STS Hydropower, LLC,et al. Date:Friday, October 3, 2025 8:20:04 AM Please see Board Correspondence - -----Original Message----- From: 'FERC eSubscription' <eSubscription@ferc.gov> Sent: Friday, October 3, 2025 6:25 AM Subject: Environmental and Recreational Compliance Report submitted in FERC P-7242-060 by STS Hydropower, LLC,et al. .ATTENTION: This message originated from outside Butte County. Please exercise judgment before opening attachments, clicking on links, or replying.. On 10/3/2025, the following Filing was submitted to the Federal Energy Regulatory Commission (FERC), Washington D.C.: Filer: STS Hydropower, LLC Eagle Creek Renewable Energy, LLC (as Agent) Docket(s): P-7242-060 Lead Applicant: STS HydroPower, Ltd. Filing Type: Environmental and Recreational Compliance Report Description: STS Hydropower, LLC submits Dewatering and Water Quality Monitoring Plan for the removal and decommissioning of the Kanaka Hydroelectric Project under P-7242. To view the document for this Filing, click here https://urldefense.com/v3/__https://elibrary.ferc.gov/eLibrary/filelist?accession_num=20251003- 5000__;!!KNMwiTCp4spf!GYYg5o_Qq8oDzGfnZEE3cvCzBaTn8LpwpERabwnaYm_VcoD4RLkRCfzEKpO3BnvsFHCCPgwWmhAB_T6WJs3lUiYgFwBbQ_GPkNKg$ To modify your subscriptions, click here: ------------------------------------------------------------------------ Please do not respond to this email. Online help is available here: https://urldefense.com/v3/__http://www.ferc.gov/efiling-help.asp__;!!KNMwiTCp4spf!GYYg5o_Qq8oDzGfnZEE3cvCzBaTn8LpwpERabwnaYm_VcoD4RLkRCfzEKpO3BnvsFHCCPgwWmhAB_T6WJs3lUiYgFwBbQx8icW7B$ or for phone support, call 866-208-3676. STS Hydropower, LLC c/o Eagle Creek Renewable Energy, LLC 7315 Wisconsin Avenue, Suite 1100W Bethesda, Maryland 20814 240.482.2700 VIA Electronic Filing October 2, 2025 Debbie-Ann. Reese, Secretary Federal Energy Regulatory Commission 888 First Street NE, Room 1A Washington, DC 20426 Re: Kanaka Hydroelectric Project License Surrender (FERC 7242-060) Dewatering and Water Quality Monitoring Plan Dear Secretary Reese: STS Hydropower, LLC, (STS) hereby submits a Dewatering and Water Quality Monitoring Plan (“Plan”) for the Kanaka Hydroelectric Project (P-7242-060) License Surrender in compliance with section B of the Commission’s September 15, 2025, Order Approving Surrender and Removal and Condition 2 of the State Water Quality Certification. On August 20, 2025, STS submitted a draft of the Plan to the Water Resources Control Board (SWRCB) for review and comment. The SWRCB provided comments on August 22, 2025. STS revised the Plan to address the comments and resubmitted the Plan to the SWRCB on September 11, 2025. A comment matrix is attached to this filing. STS subsequently spoke with the WRCB on September 24 and October 2, 2025. During these conversations the SWRCB confirmed that the Plan is under review and stated that the approval letter will be issued soon. STS will provide the Commission with a copy of the approval letter upon receipt. Should you have any questions or require additional information, please do not hesitate to contact me at (920) 293-4628 ext. 347 or via email at melissa.rondou@eaglecreekre.com. Sincerely, Melissa Rondou Director, Licensing and Compliance STS Hydropower, LLC Attachment: Dewatering and Water Quality Monitoring Plan Comment Matrix Record of Consultation CC: Diana Shannon, OEP Division of Hydropower Administration and Compliance Nathan Fisch, California State Water Resources Control Board Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Re: Kanaka Hydroelectric Project License Surrender (FERC 7242-060) Page 2 of 2 Dewatering and Water Quality Monitoring Plan October 2, 2025 Dewatering Water Quality Monitoring Plan Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Dewatering and Water Quality Monitoring Plan STS Hydropower, LLC Removal and Decommissioning of the Kanaka Hydroelectric Project License Surrender Federal Energy Regulatory Commission Project No. 7242 Prepared For: STS Hydropower, LLC c/o Eagle Creek Renewable Energy, LLC 116 N. State Street, P.O. Box 167 Neshkoro, WI 54960 Prepared By: EcoKai Environmental, Inc. 425 15th Street, Suite 3246 Manhattan Beach, CA 90266 September 2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Contents Introduction .................................................................................................................................................. 1 Monitoring Plan Purpose .............................................................................................................................. 1 Project Summary ........................................................................................................................................... 1 Water Quality Objectives .............................................................................................................................. 2 Description of Construction Activities .......................................................................................................... 3 Sealing the Penstock and Filling the Wet Well ......................................................................................... 4 Roads and Access ...................................................................................................................................... 5 Powerhouse and Substation Removal ...................................................................................................... 6 Tailrace Abandonment .............................................................................................................................. 7 Project Area Regrading and Revegetation ................................................................................................ 7 Water Quality Monitoring ............................................................................................................................. 8 Water Quality Sampling and Analysis Methodology ................................................................................ 8 Monitoring Locations ................................................................................................................................ 8 Reporting and Adaptive Management Procedures ...................................................................................... 9 References .................................................................................................................................................. 11 Tables Table 1: Water Quality Monitoring Locations and Baseline Water Quality (June 21, 2025) Figures Figure 1 – Project Location Figure 2 – Project Components Figure 3a – Powerhouse Area Figure 3b – Powerhouse Area - Elevation Figure 4a – Diversion Dam Area Figure 4b – Diversion Dam Area - Elevation Figure 5 – Diversion Dam and Wet Well Dewatering Components Figure 6 – Access Road No. 1 BMPs. From Page ECP-3 of Kanaka Erosion Control Plan Figure 7 – Access Road No. 3 BMPs. From Page ECP-2 of Kanaka Erosion Control Plan Document Accession #: 20251003-5000 Filed Date: 10/03/2025 1 | P a g e Introduction In May 2025, the State Water Resources Control Board (State Water Board) prepared an Initial Study/Mitigated Negative Declaration (IS/MND) to provide an environmental analysis required by the California Environmental Quality Act for the State Water Board’s issuance of a Water Quality Certification (Certification) for the proposed Removal and Decommissioning of the Kanaka Hydroelectric Project License Surrender (Project). The Project (FERC Project No. 7242) is owned by STS Hydropower, LLC (STS). STS has applied to the State Water Board for water quality certification for the removal and decommissioning of the Project. This Dewatering and Water Quality Monitoring Plan (Monitoring Plan) addresses Condition 2 of the Certification for the Project. Monitoring Plan Purpose The purpose of this Monitoring Plan is to outline water quality monitoring procedures to protect and document water quality during Project activities. These procedures will assist in compliance with water quality standards in the Central Valley Regional Water Board’s Water Quality Control Plan for the Sacramento River Basin and the San Joaquin River Basin (Central Valley Basin Plan, Central Valley Regional Water Board 2019) and the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan, State Water Board 2018). The Central Valley Basin Plan identifies existing beneficial uses for Lake Oroville and its tributaries, which includes Sucker Run Creek, as: power; contact recreation; non-contact recreation; warm freshwater habitat; cold freshwater habitat; warm spawning habitat; cold spawning habitat; and wildlife habitat. The beneficial uses, together with the water quality objectives contained in the water quality control plans and applicable state and federal anti- degradation requirements, constitute California’s water quality standards for purposes of the Clean Water Act. Project Summary The Project is located on private property on Sucker Run Creek in Butte County, approximately 15 miles east of the City of Oroville, and three miles northwest of the census designated place of Forbestown, California (Figure 1). Sucker Run Creek is a tributary to the South Fork Feather River that flows into Lake Oroville and has a watershed area of approximately 15.5 square miles upstream of Kanaka Dam. A small tributary creek, Little Sucker Run, flows into Sucker Run Creek with the confluence just upstream of the bridge that crosses Sucker Run Creek within the Project area. Based on streamflow data collected at USGS Gage No. 11396395, located in Sucker Run Creek about one mile downstream of the Project, the average annual flow was approximately 10.4 cubic feet per second (cfs) prior to 2012 when the gage stopped logging data. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 2 | P a g e In August 2017, the Ponderosa Fire burned approximately 4,000 acres of land and severely damaged the Project’s powerhouse building and ancillary facilities. As a result of the fire, the Project ceased power generation. STS is proposing to decommission the Project and surrender its FERC license. The Project consists of: (1) Kanaka Diversion Dam (a privately owned structure of the current landowner) that is approximately 12-foot-high and 36- foot-long and equipped with a flashboard gate spillway, low-level outlet, 16-inch-diameter bypass gate, and a screened intake that, when operating, would divert up to 30 cubic feet per second (cfs) to a wet well and a 5,669-foot-long penstock that was used for power generation; (2) a 3-foot-high by 8-foot-wide monitoring weir located approximately 80 feet downstream of the diversion dam; (3) a 35-foot by 38-foot Kanaka Powerhouse with a 28-foot-long tailrace that when operating, discharged flow back to Sucker Run Creek; and (4) appurtenant facilities. When operational, Kanaka Diversion Dam entrained 0.23 acre-feet of water and the powerhouse generated up to 1.12 megawatts. STS is proposing the following construction activities to decommission the Project: (1) remove the former Kanaka Powerhouse and substation structures and regrade the site to match surrounding contours; (2) install a concrete plug in the pipe between the screened intake area of the diversion dam and the wet well, permanently inhibiting water diversions to the penstock; (3) cut and cap the lower end of the penstock and install a concrete plug to permanently disconnect the penstock from the powerhouse and abandon-in-place the penstock; (4) install a sand and gravel plug in the penstock wet well to stop water collection (5) fill and grade the tailrace with native material to abandon it in place; (6) abandon-in-place the Kanaka Diversion Dam; and (7) rehabilitate an existing unnamed access road by removing vegetation to provide access for the decommissioning of the Project. Following Project implementation, the road will remain in place. Once decommissioned, the Kanaka Diversion Dam will become the sole responsibility of the private landowner and all natural stream flows will either overtop the diversion dam or flow through the dam’s low-level outlet and bypass gate. Flows will no longer enter the penstock. Project construction is anticipated to take approximately 8 weeks and is anticipated to occur between September to October, 2025. Water Quality Objectives Water quality objectives to protect the beneficial uses of Lake Oroville and its tributaries, including Sucker Run Creek, are designated in the Central Valley Basin Plan. The current water quality objectives provided in the Certification for turbidity, pH, temperature, dissolved oxygen, and visible pollutants are presented below. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 3 | P a g e  Turbidity: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Increases in turbidity attributable to controllable water quality factors shall not exceed the following limits: o Where natural turbidity is less than 1 Nephelometric Turbidity Unit (NTU), controllable factors shall not cause downstream turbidity to exceed 2. o Where natural turbidity is between 1 and 5 NTUs, increases shall not exceed 1 NTU. o Where natural turbidity is between 5 and 50 NTUs, increases shall not exceed 20 percent. o Where natural turbidity is between 50 and 100 NTUs, increases shall not exceed 10 NTUs. o Where natural turbidity is greater than 100 NTUs, increases shall not exceed 10 percent. In determining compliance with the above limits, an appropriate averaging period, not to exceed 24 hours, may be applied, provided that beneficial uses will be fully protected.  pH: pH shall not be depressed below 6.5 nor raised above 8.5.  Dissolved Oxygen: The Licensee shall not decrease dissolved oxygen below 7.0 milligrams per liter.  Temperature: The Licensee shall not allow temperature to rise more than 5 degrees Fahrenheit above the natural receiving water temperature. Description of Construction Activities Construction activities outlined in the Project Summary are described below with additional detail. Construction will occur generally in two phases. The first phase includes sealing the pipe between the diversion dam and the wet well and sealing and filling the wet well. The second phase will occur after the first phase is complete and includes powerhouse and substation removal and tailrace backfilling and abandonment. Best management practices (BMPs) will be employed for erosion and sediment control at project work sites during each phase of construction activities. The Kanaka Project Stormwater Pollution Prevention Plan (SWPPP) (EcoKai 2025) provides additional details of construction BMPs to be employed during construction. Erosion Control Plan figures from the SWPPP are included in this Monitoring Plan as Figures 6 & 7 showing BMPs in the wet well area and powerhouse area, respectively. Exact locations and types of BMPs will be determined in the field by the Project QSD based on site conditions. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 4 | P a g e Sealing the Penstock and Filling the Wet Well STS proposes to remove the sediment accumulated inside the wet well and decommission the penstock sequentially. If at the time of work, the creek is flowing over the top of the dam and into the intake screens, STS proposes temporary flow impediment measures on the serviceable structure of the diversion to reduce flow into the wet well through the intake screens. STS will position a series of sand bags1 or gravel bags2 secured with a steel bar along the crest of the dam above the intake screens to temporarily slow water flowing over the dam, and then drape an impermeable fabric membrane overtop of the intake screens with the goal of stopping or substantially reducing flow through the screens and into the wet well (Photos 1-3; Figure 5). Once water entering the wet well from the creek is stopped or reduced enough to be manageable, a pump or vacuum truck will be used to suck the water and sediment out of the wet well to the point where the flap gate to the penstock can be completely closed. If the vacuum truck is unable to remove sediment sufficiently to close the gate, workers will enter the wet well and begin removing the sediment by hand, either with buckets or bags, shovels and other handheld tools. The water and sediment removed from the wet well will be placed in a relatively flat upland area at least 100 feet from the creek to allow the water to infiltrate into the ground. Appropriate BMPs (e.g., silt fence3, fiber rolls4, sand bags etc.) will be implemented, as needed, to ensure the sediment does not enter the creek. After the sediment has dewatered, STS proposes to beneficially reuse the sediment in areas where fill is needed for decommissioning activities (i.e. road maintenance). Once sealed, the wet well will be back filled with sand and gravel sourced from a suitable upland area on site. The pipe between the diversion dam and the wet well will be sealed with a concrete plug to ensure no potential future water diversion. The new concrete plug shall be a minimum of 60 inches long and fill the diameter of the pipe. Once the concrete has set in place separating the screen intakes from the wet well, the fabric membrane over the intake screens and the sandbags along the crest of the dam above the screens will be removed. This will allow creek water to once again flow over the crest of the dam and into the screens. Water will be prevented from entering the wet well by the concrete plug and the water will flow over the dam and into the creek below. The outlet (downstream end) of the penstock, which is located in the remains of the powerhouse, will be cut and capped at the downstream end using a steel cap plate and a 1 Sand bags will be woven polypropylene, polyethylene, polyamide or similar fabric filled with non-cohesive, Class 3 or similar permeable material free from clay and deleterious material, such as recycled concrete or asphalt. Bag dimensions may vary based on locally available material. 2 Gravel bags will be will be woven polypropylene, polyethylene, or polyamide fabric or burlap filled with crushed rock, clean and free of clay, organic matter, and other deleterious material, or with other suitable non-cohesive, porous gravel. 3 Silt fencing will be woven geotextile material with a minimum width of 36 in. 4 Fiber rolls will be prefabricated, made from weed-free rice straw, flax, curled wood fiber, coir or similar and bound into tight tubular rolls by netting or wrap. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 5 | P a g e concrete plug that would be a minimum of 60 inches long that would be installed behind the cap, permanently discontinuing the connection from the diversion dam to the downstream powerhouse. Sealing the flap gate in the wet well and sealing the downstream end of the penstock will permanently discontinue the connection from the diversion dam to the downstream powerhouse. Following the work, all flow would be released at the dam, primarily through the drain gate. The 30-inch diameter, 5,669-foot long penstock would be left in place once it is permanently sealed to prevent water entry, as described above. During eight (8) site inspections in 2024 and early 2025, STS inspected the penstock between the wet well and the powerhouse for signs of leakage, erosion, and structural failure. No signs of leakage, deterioration, or distress were observed and no erosion was observed that was attributed to the penstock. Details of these inspections were reported to the Water Board in a Supplement Field Assessment and Proposed Recommendations document dated March 1, 2025. Roads and Access During STS’s 2024 site inspections, two culverts along the access trail between the damaged bridge over Sucker Run Creek and the diversion dam were observed to be plugged with native soil and rock. In January 2025, STS cleared both culverts which returned them to a functional drainage system. Details of the culvert inspections and actions were reported to the Water Board in a Supplement Field Assessment and Proposed Recommendations document dated March 1, 2025. An existing earthen access road from Sucker Run Road to the diversion dam (Access Road No. 1) will provide access to deliver materials or equipment to and from the diversion dam (Figure 2). Construction staging areas for equipment and materials will be located as shown on Figure 2. In some instances, equipment may be temporarily staged along Access Roads 1 & 3. Grading is not anticipated to be needed for Access Road No. 1. Fiber rolls and sand bags will be installed at the end of the road to prevent sediment transport into the creek from the road (Figure 6). Prior to forecasted rain, sand bag water bars will be installed every 50 feet along the access road as shown in Figure 6. Additional details regarding stormwater erosion control measures are presented in the Kanaka SWPPP (EcoKai 2025). The powerhouse access road (Access Road No. 3 on Figure 2) from Utility Road 3 to the parking pad is approximately 0.5 miles long and is accessible but contains areas of erosional ruts caused by stormwater runoff along the road. Ruts in the road occur primarily along stepper sections of the road closer to the powerhouse area and may be filled with material such as #2 limestone gravel. Minimal grading will be performed along the road as needed and in a manner that prevents erosion and the discharge of sediments to Sucker Run Creek. Graded soils will not be pushed down slope but will be distributed along the roadway and the upslope edge of the road. BMPs such as silt fencing, sand bags, and fiber rolls will be placed along the access road as shown in Figure 7 to prevent discharge of sediment from the road moving downslope into the Document Accession #: 20251003-5000 Filed Date: 10/03/2025 6 | P a g e creek. Prior to forecasted rain, sand bag check dams will be installed along the access road as shown in Figure 7. Existing vegetation downslope of the road toward the creek will be preserved in place. Blocked existing culverts along the powerhouse access road (Access Road No. 3) will be cleared of sediment and reburied. Culverts will be exposed to the extent necessary to clear them of material and will be reburied as needed. Material in the culverts will be removed in a manner to prevent any discharge of the material downslope of the roadway. The material removed may be utilized during road improvement activities. Areas along the uphill slope side of the access road adjacent to the culverts will be cleared, as needed, to facilitate the flow of any stormwater into the culverts. The cleared culverts will direct any stormwater under the roadway and discharge into Sucker Run Creek as designed. Powerhouse and Substation Removal The Project powerhouse and substation are located within a flat area adjacent to Sucker Run Creek. The powerhouse is a 35-foot by 38-foot structure that housed the turbine and power generation materials. Approximately 50 feet northeast of the powerhouse, a 10-foot by 10-foot concrete slab holds transmission equipment associated with the substation. Transmission lines and poles were removed in May 2022. The plant was designed to require very little oil and had no hydraulic or lubricant oil systems. Actuators were either electrically or pneumatically operated, and bearings were greased. The 2018 fire consumed any small amount of oil products that would have been exposed to the fire, leaving behind only oil contained within oil-containing equipment. Following the fire, all oil containing equipment remaining in the powerhouse was drained of oils. The transformer, located outside of the powerhouse, is the only oil containing equipment left on site. STS intends to haul the transformer offsite. All above-ground materials associated with the powerhouse will be demolished, including the foundation and walls. In addition, a portion of the underground penstock and the turbine and power generation materials that are located within the powerhouse will be removed. This material and equipment would be hauled offsite to Neal Road Landfill. Anchor bolts would be ground off, and interior pits within the powerhouse structure would be filled with a native mix of rocks and soils sourced from borrow pits located in an area to be determined upland on the same property. Parts of the foundation associated with the powerhouse that are currently buried would be abandoned in place. The substation structure will be removed and hauled offsite, including any oils or hazardous materials, in compliance with safe handling requirements for hazardous materials. Similar to the powerhouse, the above-ground foundation would be demolished, and anchor bolts ground down and removed. Parts of the foundation that are currently buried would be abandoned in place. All mechanical and electrical equipment will be removed. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 7 | P a g e In total, approximately 60 cubic yards of rocks and soils will be needed to fill the powerhouse interior pits. Once all of the equipment and material has been removed, the area will be regraded. Demolition of the powerhouse and substation will be conducted in a manner that avoids discharge of material to the creek. A work area boundary will be delineated that will limit the work area to the access road and the flat terrain area around the powerhouse and substation and will restrict work on the slope above the creek to the greatest extent possible. STS will implement BMPs including fiber rolls, sand or gravel bags, and silt fencing during work in the powerhouse area, as presented in Figure 7, to prevent any sediment, oil and/or grease from being released into the creek or the surrounding area. Sand or gravel bags and silt fencing will be installed along the top of the slope above the creek in the Project work area to prevent material from moving downslope into the creek. A sandbag berm will be installed along the downstream end of the tailrace to prevent fill material from entering the creek. Fiber rolls and sand or gravel bags will be installed along the northern border of the work area under the hillside slope to prevent any potential run-on of stormwater and sediment from the hillsides into the construction work area (Figure 7). Once a borrow pit location is chosen, sand or gravel bags and/or fiber rolls will be implemented, as needed, to prevent sediment transport from the borrow site during any precipitation events. Further details of construction erosion control measures are detailed in the Project SWPPP (EcoKai 2025). The water quality monitoring locations shown in Figures 2 through 4 will be measured for turbidity, pH, temperature, and dissolved oxygen every hour during any construction activities in the powerhouse area that could potentially lead to discharges to the creek. Tailrace Abandonment The 28-foot tailrace channel (total area approx. 341 square feet) will be abandoned in place and filled with native materials (mix of rocks and soil) from a location upland on the same property and graded to match the outside slope. Riprap will be added at a 2H:1V scale at the end of the channel for slope protection. Work will be conducted during the dry season, above the ordinary high water mark to prevent the need for dewatering and reduce the potential for impacts on water quality. Sand or gravel bags will be placed around the outlet of the tailrace during construction to protect the creek from any discharge during backfilling or during a rain event. No work is planned for the streambank. Project Area Regrading and Revegetation Following the completion of powerhouse removal and associated tasks, STS will conduct minor grading of the flat area around the powerhouse to create a stabilized soil condition to reduce the potential for long term erosion or soil loss. The graded Project area around the powerhouse will be replanted with native vegetation and/or seed. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 8 | P a g e Water Quality Monitoring Project activities that may impact water quality in Sucker Run Creek include: (1) removal of the Kanaka Powerhouse; (2) backfilling and abandonment of the tailrace; (3) re-grading the access road to the powerhouse and parking pad; (4) sealing the penstock and backfilling the wet well; and (5) culvert work that includes removing any accumulated soil and rock to prevent future blockage until site decommissioning is complete. Water quality monitoring will be performed as described in Condition 2 of the Certification during any dewatering, in-water, and water-adjacent Project activities with the potential to discharge to Sucker Run Creek. Monitoring will be performed for the parameters and at the sampling locations and frequency described below. Water Quality Sampling and Analysis Methodology Monitoring water quality parameters within Sucker Run upstream and downstream of Project construction activities will consist of measuring temperature, pH, dissolved oxygen, turbidity, as well as monitoring for visual pollutants such as oils, greases, fuels, turbidity, and plumes. Within approximately one week prior to start of Project activities, these water quality parameters will be measured to establish baseline water quality conditions. Monitoring for temperature, pH, dissolved oxygen, and turbidity will be conducted hourly and monitoring for visual pollutants will be conducted continuously during any Project activities with the potential to discharge to Sucker Run Creek. Water quality parameters will be measured using multi-sensor instruments, such as In-Situ ® or equivalent, that are programmed to record and report multiple water quality parameters from a single unit. Prior to and during monitoring, all field instruments will be calibrated per manufacturer standards and frequency. Measurements will be logged daily and entered into a Project database for analysis and reporting. Per Condition 3 of the Certification, if more than 0.25 inch of rain is forecast during Project activities, work in and around Sucker Run Creek with the potential to result in a discharge will cease and the site will be secured to avoid discharges until the forecast rainfall event is over. Monitoring Locations Construction will occur in two phases, the first at the wet well and the second at the powerhouse area. During each phase of work, water quality will be monitored upstream and downstream of the Project activities (Figures 2 through 4). During construction at the wet well, the upstream monitoring location (ML-1US) will be approximately 50 feet upstream of the diversion dam where the stream is flowing freely and not yet pooled behind the structure (Photo 4). This location represents natural (background) stream conditions unaffected by the Project components or any Project activities. The downstream monitoring location (ML-1DS) (exact location TBD in the field) will be located approximately within 100 feet downstream of Document Accession #: 20251003-5000 Filed Date: 10/03/2025 9 | P a g e the diversion dam and represents changes in stream conditions, if any, compared to natural conditions due to Project activities during this phase of work (Figure 4a). During the second phase of construction at the powerhouse area, the upstream monitoring location (ML-2US) (exact location TBD in the field) will be approximately 100 feet upstream of any anticipated road and culvert work within Access Road No. 3 (Figure 2). The downstream monitoring location (ML-2DS) will be approximately 100 feet downstream of the power plant tailrace (Photo 5). This location represents changes in stream conditions, if any, compared to natural conditions due to the influence of Project activities during this phase of work. Water samples were collected at ML-1US and at ML-2DS on June 21, 2025, and measured for temperature, pH, dissolved oxygen, and turbidity to document baseline conditions of the water quality upstream and downstream of the Project at the time of the samples. As stated above, another baseline water sample will be collected at all four monitoring locations in Table 1 within approximately one week prior to start of construction activities to establish baseline conditions just prior Project activities. Table 1 summarizes these monitoring locations and the June 2025 water quality parameters measured. Table 1: Water Quality Monitoring Locations and Baseline Water Quality (June 21, 2025) Monitoring Location Description GPS Coordinates (WGS84) Temp (C) pH DO (mg/L) Turbidity (NTUs) ML-1US Approx. 50 ft upstream of diversion structure. 39.562001 -121.280323 13.3 7.36 9.83 1.1 ML-1DS Approx. 100 ft downstream of diversion structure. 39.562282 -121.280558 - - - - ML-2US Approx. 100 ft upstream of access road work. 39.558466 -121.292804 - - - - ML-2DS Approx. 100 ft downstream of powerhouse. 39.558542 -121.296457 17.7 7.52 8.44 3.6 Reporting and Adaptive Management Procedures STS will notify State Water Board staff of the Project schedule at least five days prior to start of Project activities. If any major changes to the Project schedule are anticipated, STS will notify the State Water Board within five days of the schedule change. In the event of an exceedance in a water quality objective attributable to Project-related controllable water quality factors, adaptive management will be implemented with additional measures to remedy the impact. Measures will include 1) stopping the Project activity that is causing the water quality exceedance, 2) inspection of the source area of any discharges into Document Accession #: 20251003-5000 Filed Date: 10/03/2025 10 | P a g e the creek, 3) installation of additional BMPs to eliminate or further reduce any discharges, and 4) potentially rescheduling a Project activity to a time when site conditions are more favorable to avoid a discharge. Project activities associated with any exceedance will cease immediately upon detection. The Deputy Director of the Division of Water Rights and the Central Valley Regional Water Board Executive Officer will be notified in no more than 24 hours following any exceedance of a water quality objective. Work will not resume until corrective actions have been implemented, water quality once again meets objectives, and the Deputy Director has provided approval to proceed. Water quality monitoring activities and observations, any observed discharges, and associated corrective actions will be documented each work day on designated field sheets. Site photos will be collected each work day and cataloged in a Project database. Water quality monitoring activities and results will be submitted by STS along with other Project information in a Project Completion Report, as described in Condition 5 of the Certification. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 11 | P a g e References California Regional Water Quality Control Board Central Valley Region. 2019. The Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board Central Valley Region, Fifth Edition. The Sacramento River Basin and the San Joaquin River Basin (Revised February 2019). EcoKai Environmental, Inc. 2025. Stormwater Pollution Prevention Plan. Removal and Decommissioning of Kanaka Powerhouse for Kanaka Hydroelectric Project License Surrender. August 2025. State Water Resources Control Board. 2018. Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan). December 12, 2018. State Water Resources Control Board. 2025. Initial Study/Mitigated Negative Declaration. Removal and Decommissioning of the Kanaka Powerhouse for the Kanaka Hydroelectric Project License Surrender. May 2025. State Water Resources Control Board. 2025. Draft Water Quality Certification for Federal Permit or License. STS Hydropower, LLC’s Removal and Decommissioning of the Kanaka Powerhouse for the Kanaka Hydroelectric Project License Surrender. Federal Energy Regulatory Commission Project No. 7242. June 2025. STS Hydropower, LLC. 2025. Kanaka Hydroelectric Project License Surrender (FERC 7242-062), Revised Water Quality Certification Application Supplement Field Assessment and Proposed Recommendations. March 1, 2025. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Photo 1: Top of dam above fish screens through which water currently enters the wet well. Looking northeast across the dam from left creek bank. Fabric membrane draped over intake screens Row of sand or gravel bags along crest of dam above screens Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Photo 2: Top of wet well in the left of photo (field personnel standing on top) and top of dam above fish screens in lower right of photo. Looking north and downstream from left creek bank. Photo 3: View standing on top of wet well looking at top of dam and fish screens. Looking east/northeast from left creek bank. Fabric membrane draped over intake screens Row of sand or gravel bags along crest of dam above screens Fabric membrane draped over intake screens Row of sand or gravel bags along crest of dam above screens Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Photo 4: Water quality monitoring location ML-1US, upstream of the diversion dam Approximate monitoring location ML- 1US Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Photo 5: Water quality monitoring location ML-2DS, approx. 100ft downstream of powerhouse tailrace Approximate monitoring location ML- 2DS Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Figure 5: Diversion Dam and Wet Well Dewatering Components rolls along top over intake screens of dam above screens Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Figure 6: Access Road No. 1 BMPs. From Page ECP-3 of Kanaka Erosion Control Plan Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Figure 7: Access Road No. 3 BMPs. From Page ECP-2 of Kanaka Erosion Control Plan Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Re: Kanaka Hydroelectric Project License Surrender (FERC 7242-060) Page 2 of 2 Dewatering and Water Quality Monitoring Plan October 2, 2025 Comment Matrix Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Dewatering and Water Quality Monitoring Plan Comment # Comment Page # Comment Response GH-1 1 This station has not logged any data since 2012 Revised text to: "Based on streamflow data collected at USGS Gage No. 11396395, located in Sucker Run Creek about one mile downstream of the Project, the average annual flow was approximately 10.4 cubic feet per second (cfs) prior to 2012 when the gage stopped logging data." GH-2 3 What kind of sandbags will be used to dewater the area? Added footnotes with descriptions of materials for sand bags, gravel bags, and fiber rolls. GH-2 3 Please see Condition 2 for guidance of the type and amount of information that the dewatering plan should contain. •Descriptions of all construction-related activities that involve dewatering, water diversions, and in-water or water adjacent work. For dewatering or temporary water diversion activities, the description shall include: •Equipment and methods that will be used for dewatering and temporary water diversion, including descriptions of procedures that will be used for installation, operation, maintenance, removal, and rewatering (e.g., inspection and follow-up actions, if applicable). •Type(s) of barriers that will be installed to isolate work areas from surface waters. •List of materials that will be used in or adjacent to the watercourse. •Site plan map(s), drawings, and/or photo(s) showing areas that may be dewatered and discharge locations, as well as areas where Project work will be completed in-water or adjacent to water. •Schedule for each stage of dewatering and water diversion activities (i.e., equipment installation, dewatering, barrier installation, temporary diversion, equipment removal, and rewatering). •Description of best management practices (BMPs) that will be implemented to avoid potential water quality and aquatic resource impacts during dewatering, in-water, and water adjacent work. BMPs shall ensure discharges associated with dewatering and water diversion will not exceed water quality objectives, as defined in the Water Quality Control Plan for the Sacramento River Basin and the San Joaquin River Basin (Central Valley Basin Plan) (Central Valley Regional Water Board 2019 and any amendments thereto). BMPs may reference erosion and sediment control measures and biological resource protections required by Conditions 3 and 4, respectively. Revised text for clarification, and added reference to new Photos and new Figure 5: "STS proposes to remove the sediment accumulated inside the wet well and decommission the penstock sequentially. If at the time of work, the creek is flowing over the top of the dam and into the intake screens, STS proposes temporary flow impediment measures on the serviceable structure of the diversion to reduce flow into the wet well through the intake screens. STS will position a series of sand bags or gravel bags secured with a steel bar along the crest of the dam above the intake screens to temporarily slow water flowing over the dam, and then drape an impermeable fabric membrane overtop of the intake screens with the goal of stopping or substantially reducing flow through the screens and into the wet well (Photos 1-3; Figure 5)." GH-3 4 Due to the steep terrain I think the minimum should be at least 100 feet from the creek. If the upland area is too close to he creek on a steep slope the sediments may transport into the creek increasing turbidity. Revised text from 50 feet to 100 feet. GH-4 4 After the concrete has set within the pipe and there is no longer a water quality concern how will the area be rewatered? See Condition 2 for the level of information that is required in the rewatering plan. The paragraph was revised for additional detail and clarity to: "The pipe between the diversion dam and the wet well will be sealed with a concrete plug to ensure no potential future water diversion. The new concrete plug shall be a minimum of 60 inches long and fill the diameter of the pipe. Once the concrete has set in place separating the screen intakes from the wet well, the fabric membrane over the intake screens and the sandbags along the crest of the dam above the screens will be removed. This will allow creek water to once again flow over the crest of the dam and into the screens. Water will be prevented from entering the wet well by the concrete plug and the water will flow over the dam and into the creek below. " Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Comment # Comment Page # Comment Response GH-5 5 Please show the approximate location for where BMP’s will be deployed. Two paragraphs regarding access roads No. 1 and 3 were revised as follows with additional details and references to new Figures 6 & 7: "An existing earthen access road from Sucker Run Road to the diversion dam (Access Road No. 1) will provide access to deliver materials or equipment to and from the diversion dam (Figure 2). Construction staging areas for equipment and materials will be located as shown on Figure 2. In some instances, equipment may be temporarily staged along Access Roads 1 & 3. Grading is not anticipated to be needed for Access Road No. 1. Fiber rolls and sand bags will be installed at the end of the road to prevent sediment transport into the creek from the road (Figure 6). Prior to forecasted rain, sand bag water bars will be installed every 50 feet along the access road as shown in Figure 6. Additional details regarding stormwater erosion control measures are presented in the Kanaka SWPPP (EcoKai 2025). The powerhouse access road (Access Road No. 3 on Figure 2) from Utility Road 3 to the parking pad is approximately 0.5 miles long and is accessible but contains areas of erosional ruts caused by stormwater runoff along the road. Ruts in the road occur primarily along stepper sections of the road closer to the powerhouse area and may be filled with material such as #2 limestone gravel. Minimal grading will be performed along the road as needed and in a manner that prevents erosion and the discharge of sediments to Sucker Run Creek. Graded soils will not be pushed down slope but will be distributed along the roadway and the upslope edge of the road. BMPs such as silt fencing, sand bags, and fiber rolls will be placed along the access road as shown in Figure 7 to prevent discharge of sediment from the road moving downslope into the creek. Prior to forecasted rain, sand bag check dams will be installed along the access road as shown in Figure 7. Existing vegetation downslope of the road toward the creek will be preserved in place. ." GH-6 5 Please show the approximate location for where BMP’s will be deployed. Will the drain ditches on the uphill side of the roads be cleared to allow for drainage to the culverts? Text revised with general language regarding clearing near culverts along upslope side of road: "Blocked existing culverts along the powerhouse access road (Access Road No. 3) will be cleared of sediment and reburied. Culverts will be exposed to the extent necessary to clear them of material and will be reburied as needed. Material in the culverts will be removed in a manner to prevent any discharge of the material downslope of the roadway. The material removed may be utilized during road improvement activities. Areas along the uphill slope side of the access road adjacent to the culverts will be cleared, as needed, to facilitate the flow of any stormwater into the culverts. The cleared culverts will direct any stormwater under the roadway and discharge into Sucker Run Creek as designed." GH-7 5 Please show the approximate location for where BMP’s will be deployed. The section titled "Powerhouse and Substation Removal" was revised to clarify and consolodate discussion of BMPs and added reference to Figure 7. GH-8 6 Please show the approximate location for where BMP’s will be deployed, along with any BMP’s that will be deployed at the borrow pit sites. Text was added to clarify borrow pit BMPs: "Once a borrow pit location is chosen, sand or gravel bags and/or fiber rolls will be implemented, as needed, to prevent sediment transport from the borrow site during any precipitation events." GH-9 6 Please show the approximate location for where BMP’s will be deployed. The section titled "Powerhouse and Substation Removal" was revised to clarify and consolodate discussion of BMPs and added reference to Figure 7. GH-10 8 This monitoring location is approximately ¾ miles run of river upstream of the powerhouse? Why is it so far from the work area? Consider moving the monitoring station closer to the impact area to ensure that any differences in the second monitoring station readings can be attributed to project activities. The location of ML-2US was relocated closer to, and upstream of, the powerhouse and any anticipated adjacent road work along Access Road No. 3. The "Monitoring Locations" section was revised to describe the new location and to include new photos of ML-1US and ML-2DS taken during the latest site visit. Photos of ML-1DS and ML-2US are not available as STS agreed to add these locations during a call with the Water Board after the latest site visit. GH-11 8 Please provide a photo of each monitoring location per condition 2 of the water quality certification. Photos of ML-1US and ML-2DS taken during the latest site visit are included as Photos 4 & 5, respectively. Photos of ML-1DS and ML-2US are not available as STS agreed to add these locations during a call with the Water Board after the latest site visit. GH-12 8 The change in temperature is greater than 5 degrees Fahrenheit. Hopefully having additional monitoring stations will put the project back into compliance with the basin plan. Moving monitoring location ML-2US closer to ML-2DS will also reduce the change in temperature between locations. STS agrees that additional monitoring locations, as discussed in our August 19, 2025, call will likely reduce the difference in temperature between monitoring locations shown in Table 1 of the Monitoring Plan . The field temperature measurements presented in Table 1 are most likely different because they were collected a couple of hours apart, more than a mile of stream distance apart, and in different creek habitats. Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Re: Kanaka Hydroelectric Project License Surrender (FERC 7242-060) Page 2 of 2 Dewatering and Water Quality Monitoring Plan October 2, 2025 Record of Consultation Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Outlook Kanaka Decommissioning Water Quality Monitoring Plan From Melissa Rondou <melissa.rondou@eaglecreekre.com> Date Wed 8/20/2025 8:35 PM To Hoffmann, Glenn@Waterboards <glenn.hoffmann@waterboards.ca.gov>; Fisch, Nathan@Waterboards <nathan.fisch@waterboards.ca.gov>; Erin.Ragazzi@waterboards.ca.gov <Erin.Ragazzi@waterboards.ca.gov> Cc 'Todd Bear' <tbear@ecokai.com> 1 attachment (9 MB) WQ Monitoring Plan_Kanaka_DraftFinal_rev1.pdf; Dear Glenn, Nathan, and Assistant Deputy Director Erin Ragazzi, Attached please ﬁnd the draft Dewatering and Water Quality Monitoring Plan prepared for the removal and decommissioning of the Kanaka Powerhouse under the Kanaka Hydroelectric Project License Surrender. The plan has been developed consistent with Mitigation Measure Water Quality (WQ)-1 and Condition 2: Dewatering and Water Quality Protection and is provided for your review and consideration at least 30 days prior to commencement of project work. Please let us know if you have any comments or requested revisions. Best Regards, __________________________________________________________________ Melissa Rondou |Director, Licensing and Compliance Aﬃliates of Eagle Creek Renewable Energy Desk: 920-293-4628 ext. 347 Mobile: 920-279-4804 Email: melissa.rondou@eaglecreekre.com Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Outlook Kanaka Plans From Hoffmann, Glenn@Waterboards <Glenn.Hoffmann@Waterboards.ca.gov> Date Fri 8/22/2025 6:17 PM To Melissa Rondou <melissa.rondou@eaglecreekre.com>; tbear@ecokai.com <tbear@ecokai.com>; ccarreon@ecokai.com <ccarreon@ecokai.com>; jburton@ecokai.com <jburton@ecokai.com> Cc Fisch, Nathan@Waterboards <Nathan.Fisch@Waterboards.ca.gov> 2 attachments (19 MB) EcoKai WQ Monitoring Plan_Kanaka_DraftFinal_rev1.pdf; EcoKai Erosion Measures_Kanaka_DraftFinal_rev1_red.pdf; [This email originated OUTSIDE of Eagle Creek . Exercise caution. DO NOT open attachments or click links from unknown senders or unexpected email.] Hey Melissa, Here are the Dewatering and Erosion Plans and my comments for the plans. I will be out of the office for the next two weeks returning 9/8/2025. Please CC Nathan with your responses. Best Regards, Glenn Hoffmann Engineering Geologist DIVISION OF WATER RIGHTS Water Quality Certification Unit 2 Email: Glenn.Hoffmann@Waterboards.ca.gov Phone: +1 (916) 319-9943 State Water Resources Control Boards 1001 I Street, Sacramento CA 95814 Website: www.waterboards.ca.gov Follow: X | YouTube | Facebook | LinkedIn Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Outlook Re: Kanaka Plans From Melissa Rondou <melissa.rondou@eaglecreekre.com> Date Thu 9/11/2025 3:20 PM To Fisch, Nathan@Waterboards <Nathan.Fisch@Waterboards.ca.gov>; Hoffmann, Glenn@Waterboards <Glenn.Hoffmann@Waterboards.ca.gov>; tbear@ecokai.com <tbear@ecokai.com>; ccarreon@ecokai.com <ccarreon@ecokai.com>; jburton@ecokai.com <jburton@ecokai.com> 2 attachments (11 MB) WQ Monitoring Plan_Kanaka_DraftFinal_rev2.pdf; Water Board Comment Matrix_090425.xlsx; Hello Nathan and Glenn: Attached are the revised Water Quality Monitoring Plan and the comment matrix. Please conﬁrm receipt. The revised Erosion Measures Plan will be sent separately due to ﬁle size. Thanks, __________________________________________________________________ Melissa Rondou |Director, Licensing and Compliance Aﬃliates of Eagle Creek Renewable Energy Desk: 920-293-4628 ext. 347 Mobile: 920-279-4804 Email: melissa.rondou@eaglecreekre.com Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Outlook RE: Kanaka Plans From Hoffmann, Glenn@Waterboards <Glenn.Hoffmann@Waterboards.ca.gov> Date Thu 9/11/2025 3:31 PM To Melissa Rondou <melissa.rondou@eaglecreekre.com>; Fisch, Nathan@Waterboards <Nathan.Fisch@Waterboards.ca.gov>; tbear@ecokai.com <tbear@ecokai.com>; ccarreon@ecokai.com <ccarreon@ecokai.com>; jburton@ecokai.com <jburton@ecokai.com> [This email originated OUTSIDE of Eagle Creek. Exercise caution. DO NOT open attachments or click links from unknown senders or unexpected email.] Hey Melissa, Thank you for these updated plans, I received all the attachments. I will review and let you know if I have any questions. Best, Glenn Hoffmann Engineering Geologist DIVISION OF WATER RIGHTS Water Quality Certification Unit 2 Email: Glenn.Hoffmann@Waterboards.ca.gov Phone: +1 (916) 319-9943 State Water Resources Control Boards 1001 I Street, Sacramento CA 95814 Website: www.waterboards.ca.gov Follow: X | YouTube | Facebook | LinkedIn Document Accession #: 20251003-5000 Filed Date: 10/03/2025 Document Content(s) 2025-10-02_KNKA_Dewatering and Water Quality Monitoring Plan to DHAC.pdf .1 Document Accession #: 20251003-5000 Filed Date: 10/03/2025