Document 7OJzrVzezqb9rjpe5z6rwZM0j

Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Region 10 Enforcement and Compliance Assurance Division 1200 6th Avenue Seattle, WA 98101 INSPECTION REPORT Inspection Date: Time: Weather: Media: Regulatory Program: 05/25/2021 Entry: 9:00 a.m. Exit: 12:00 p.m. Periodic overcast with evidence of recent heavy precipitation Clean Water Act (CWA) CWA NPDES/Industrial Stormwater Permittee Name(s): Permittee Addresses: Permittee City, State, Zip Code: Facility Name: Facility Physical Location: City, State, Zip Code: Facility Contact(s): County: Clyde Companies (Sunroc Corporation) 501 E. 41st St, (Sunroc Corporation) Garden City, ID 83714 Notus, Boise River Rd. Facility Dixie River Rd. Latitude/Longitude 43.7206, -116.8166 Caldwell, ID 83607 Kevin Kalmbach, Pit Supervisor Phone: (208) 600-2763 Email: kkalmbach@sunroc.com Canyon County, Idaho NPDES Permit: EPA Facility Identifier: Industrial Sector Subsector Primary SIC Code(s) Facility Receiving Water(s) Facility Receiving Water(s) Description: 2015 EPA Multi-Sector General Permit (MSGP) IDR053231 Sector D: Asphalt Paving and Roofing Materials Sector J: Construction Sand and Gravel D1 and J1 D1: 2951 J1: 1442 Unnamed irrigation ditch, Upper Center Point Canal, Boise River Ditch, Canal, River Inspector(s): Anthony D'Angelo - PG Environmental Signature: Charissa Bujak - EPA Region 10 Sarah Hansen Jen Doughty U.S. EPA Contract Inspector (Lead Inspector) U.S. EPA Inspector IDEQ Compliance Officer IDEQ Compliance Officer (720) 789-8049 Date: 08/11/2021 (208) 378-5754 (208) 373-0397 (208) 799-4887 Inspection Date: May 25, 2021 1 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report EPA Region 10 Recipient: Brian Levo Signature: Digitally signed by BRIAN BRIAN LEVO Date: 2021.08.11 LEVO 08:41:31 -07'00' Date: Inspection Date: May 25, 2021 2 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Table of Contents Section I - Inspection Information...................................................... 4 Purpose and Scope of the Inspection ...................................................................................................... 4 Opening Conference................................................................................................................................. 4 Facility Description ................................................................................................................................... 5 Documents Requested During Inspection ............................................................................................... 6 Section II - Observations .................................................................... 6 Section III - Areas of Concern ............................................................. 7 Section IV - Closing Conference........................................................ 11 Attachment A - Photograph Log....................................................... 12 Attachment B - Exhibit Log .............................................................. 27 Inspection Date: May 25, 2021 3 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Section I - Inspection Information Purpose and Scope of the Inspection On May 25, 2021, I, Anthony D'Angelo, a U.S. Environmental Protection Agency (EPA) Contract Inspector, along with U.S. EPA inspector Charissa Bujak (hereafter, we or Inspection Team) conducted an industrial stormwater inspection of the Clyde Companies' (Sunroc Corporation's) Notus, Boise River Rd. Facility (previously referred to as Notus Facility; and hereafter, Permittee or Facility) in Caldwell, Idaho. We were accompanied by two compliance officers for the Idaho Department of Environmental Quality (IDEQ), Sarah Hansen and Jen Doughty. The purpose of the inspection was to determine compliance with the requirements of EPA's National Pollutant Discharge Elimination System (NPDES) 2015 MultiSector General Permit for Discharges of Stormwater Associated with Industrial Activities (hereinafter, the MSGP or Permit). The Permittee is authorized to discharge stormwater and uncontaminated groundwater under the Permit under NPDES Permit No. IDR053231. The inspection consisted of two parts: a preliminary records review and a Facility walk-through. Photographs taken by the Inspection Team during the Facility walk-through are included in Attachment A. Exhibits are included in Attachment B. The Inspection Team requested digital copies of the Facility records reviewed during the inspection and performed a more thorough review after the inspection. Opening Conference I provided a notice of inspection, via phone call, to the Facility on the morning prior to the inspection at approximately 8:00 a.m. I spoke with Christie Wood (Sunroc Corporation) who stated that she would notify the Facility's Pit Supervisor of the inspection. Upon arriving at the Facility at 9:00 a.m. on the day of the inspection, we met Kevin Kalmbach (Pit Supervisor) near the Facility batch plant and proceeded to the batch plant office trailer to begin the inspection. Charissa Bujak and I presented our inspector credentials to Mr. Kalmbach. Mr. Kalmbach explained that he is primarily responsible for pit operations. He also explained that NPDES compliance activities at the Facility such as inspections, monitoring, and reporting NPDES compliance data to EPA are conducted by a consultant: Syman Group. Representatives from Syman Group were not present during the inspection. During the opening conference, we held brief discussions with Mr. Kalmbach regarding the Facility's operations, industrial activities, stormwater inspections and monitoring, employee training program, corrective actions, and recordkeeping. We briefly reviewed Permit-required records that were sent to the Facility electronically by Syman Group. We then proceeded to a separate office trailer near the gravel crushing and washing operations to review additional records, including the Facility's Stormwater Pollution Prevention Plan (SWPPP). Following the inspection, both hardcopy and electronic documentation reviewed onsite were provided to the Inspection Team electronically for additional review. The onsite copy of the Facility's SWPPP was dated August 9, 2018 (amended April 30, 2020). Mr. Kalmbach confirmed with Syman Group during the inspection that the Permittee would be submitting a Notice of Intent (NOI) to EPA for coverage under the 2021 MSGP on May 30, 2021. Following the opening conference, we proceeded outdoors with Mr. Kalmbach to conduct the Facility walk-through. Inspection Date: May 25, 2021 4 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Facility Description The Facility is a sand and gravel mining operation along the Boise River in Canyon County, Idaho (refer to Photograph 1, and Exhibits 1, 2, and 3). The Facility is located approximately 1 mile southwest of Notus, Idaho and approximately 9.2 miles west-northwest of Caldwell, Idaho. Industrial operations conducted at the Facility include sand and gravel mining; aggregate washing, crushing, and stockpiling; and hot mix asphalt batching. A tributary of the Upper Center Point Canal and an unnamed irrigation ditch run east to west through the Facility. These waterways eventually discharge to the Boise River northwest of the Facility. The Facility's SWPPP and NOI identify one stormwater outfall from the Facility: Outfall 001, located at 43.7206, -116.8166. These coordinates align with Outfall 001 noted on the SWPPP site map; it appears to be the point where the unnamed irrigation ditch leaves the Facility to the west (refer to Exhibit 3). Mr. Kalmbach stated that groundwater and stormwater from the Facility do not discharge to the tributary of the Center Point Canal. Groundwater exposed in the mining pit is pumped into an onsite groundwater retention basin, referred to as the Ground Water Sediment Pond, located in the northern area of the Facility (refer to Exhibit 3, and Photographs 2 through 9). Under normal conditions, the groundwater is then pumped from the Ground Water Sediment Pond and conveyed by pipe over the tributary of Center Point Canal and discharged continuously (year-round) into the unnamed irrigation ditch (refer to Photographs 10 through 13). Mr. Kalmbach identified the point where the pipe discharges into the unnamed irrigation ditch as the Facility's compliance point, referred to as the main discharge point. During the wet season, groundwater exposed in the mining pit increases, and a second dewatering pump is needed to pump groundwater into the retention basin. In addition, a second pump and discharge pipe are needed to pump groundwater from the retention basin over the tributary of Center Point Canal and into the unnamed irrigation ditch. The second pipe discharges into the unnamed irrigation ditch upstream from the main discharge point (refer to Photographs 14 and 15). Year round, a portion of the groundwater from the retention basin is pumped to the aggregate wash plant where it is used to wash aggregate (refer to Photograph 16). Effluent from the wash plant water is retained on site and treated through six settling ponds arranged in series (refer to Photographs 17 through 21). Mr. Kalmbach stated during the inspection that this wash water is not discharged offsite and does not contact other groundwater or stormwater sources except for the stormwater that falls into it. A series of berms along the perimeters and receiving water boundaries prevent stormwater discharges from the leaving the Facility. Stormwater runoff that flows into the retention basin is commingled with groundwater and discharged into the unnamed irrigation ditch or is used at the aggregate wash plant. Mr. Kalmbach stated that stormwater runoff from the batch plant operations area is contained by berms and is infiltrated into the surrounding ground surface, rather than commingling with groundwater or discharge offsite. Groundwater and stormwater discharged from the Facility subsequently flow into the lower section of the Boise River that is designated as impaired for sediment, phosphorous, and fecal coliform bacteria. As required by Part 6.2.4 of the MSGP, Discharges to Impaired Waters Monitoring, the Facility is required to conduct quarterly benchmark monitoring for total suspended solids (TSS), total phosphorus (TP), and E. coli to meet target values identified in a written notice from EPA Region 10 to the Permittee in Inspection Date: May 25, 2021 5 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report December 2015. The Facility is subject to additional quarterly benchmark monitoring for TSS and nitrate plus nitrite nitrogen as well as annual Effluent Limitations Guidelines and Standards (ELG) monitoring for TSS, pH, and oil and grease. Mr. Kalmbach explained that all NPDES compliance sampling and inspections are conducted by Syman Group. Documents Requested During Inspection Due to the ongoing COVID-19 pandemic, the Inspection Team confirmed that Facility documentation was available at the time of the inspection, but we did not review the documentation in detail while on site. The Inspection Team noted that minimal documentation was maintained at the Facility and that Facility staff needed to request documentation from Syman Group. The Inspection Team obtained electronic copies of the following documents from Ms. Wood during the inspection and from Kamren Garfield (Sunroc Corporation) shortly after the inspection. Documents used to support observations presented in Section II of this report are included in Appendix B, Exhibit Log and are referenced where applicable. Stormwater Pollution Prevention Plan (SWPPP), August 9, 2018 (amended April 30, 2020) SWPPP Inspection Reports, 2017-2021 MSGP Quarterly Visual Assessment Reports, 2018-2021 Analytical laboratory results for all compliance sampling, 2017-2021 Section II - Observations Following the opening conference, the Inspection Team and IDEQ compliance officers, accompanied by Mr. Kalmbach, began the Facility walk-through at the north-central perimeter. At the time of the inspection, the weather was overcast with temperatures in the 60s. Heavy precipitation fell at the Facility on the morning before the inspection. Here we observed dewatering pumps in the northeast corner the mining pit. Mr. Kalmbach explained that groundwater that accumulates on the surface of the mining pit is ultimately conveyed to this location. We observed two dewatering pumps that were actively pumping the groundwater from this collection point into an adjacent retention basin, referred to in the SWPPP as the Ground Water Sediment Pond (refer to Photograph 6). We then observed the Ground Water Sediment Pond and associated pumping, the tributary of Center Point Canal, the unnamed irrigation ditch, and the Facility's two discharge points into the unnamed irrigation ditch (refer to Photographs 7 through 15). At the time of the inspection, the Permittee was actively discharging water from the Ground Water Sediment Pond through both outfalls. Scouring was occurring on the embankment of the unnamed irrigation near the upstream, secondary seasonal outfall. Next, we observed the aggregate wash plant and the series of settling basins (refer to Photographs 16 through 21). We followed the series of settling basins and observed the final settling basin west of the wash plant area which was contained by a berm on the downgradient side. There appeared to be sufficient freeboard in the final settling basin and the berm was intact and vegetated. If the final settling basin overtopped the downgradient containment berm, it would appear likely that the contents of the basin would discharge into the adjacent tributary of the Center Point Canal. We then observed the Facility's fuel storage area near the aggregate wash plant (refer to Photographs 25). Following this, we drove down into the mining pit to observe groundwater levels and conveyances. Inspection Date: May 25, 2021 6 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Mr. Kalmbach explained that groundwater collects in a low point in the central portion of the excavated pit area, referred to on the SWPPP site map as Sediment Pond (Exhibit 3). He added that mining operations are occurring on the far western pit wall and that stormwater runoff from that area is typically contained. This area was unable to be viewed due to active mining operations occurring. An earthen berm was constructed along the western edge of the groundwater accumulated in this low point (refer to Photographs 2, 3, and 4). Mr. Kalmbach further explained that from this low point, groundwater is piped north, under the pit access road and aggregate conveyer belt, into a channel that flows to the surface water collection point in the northeastern portion of the pit. This channel was inaccessible due to the operating aggregate conveyer belt that spans the pit from west to east along the main pit access road (refer to Photographs 4 and 5). This channel flows to the dewatering pumps in the northeastern portion of the mining pit which pump to the Ground Water Sediment Pond (refer to Photograph 6). We concluded the Facility walk-through at the mining pit. For a list of areas of concern identified from the Inspection Team's review of Permit-required documents and onsite Facility walk-through, refer to Section III, Areas of Concern. Section III - Areas of Concern The presentation of areas of concern in this report does not constitute a formal compliance determination or Permit violation. An area of concern is an observation about Facility protocols or conditions that may be inconsistent with the requirements of the Permit. The Inspection Team noted areas of concern in both the records review performed post-inspection and the onsite Facility walkthrough. 1. Part 2.1.2.5 Erosion and Sediment Controls. You must minimize erosion by stabilizing exposed soils at your facility in order to minimize pollutant discharges and placing flow velocity dissipation devices at discharge locations to minimize channel and streambank erosion and scour in the immediate vicinity of discharge points. Area of Concern 1 The Inspection Team observed scouring on the embankment of the unnamed irrigation ditch adjacent to the secondary, seasonal discharge pipe from the groundwater retention basin (refer to Photographs 14 and 15). It appeared that the velocity of discharge from the discharge pipe was causing the scouring in the embankment. 2. Part 2.1.2.1 Minimize Exposure. You must minimize the exposure of manufacturing, processing, and material storage areas (including loading and unloading, storage, disposal, cleaning, maintenance, and fueling operations) to rain, snow, snowmelt, and runoff in order to minimize pollutant discharges by either locating these industrial materials and activities inside or protecting them with storm resistant coverings. Inspection Date: May 25, 2021 7 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Area of Concern 2 The Inspection Team observed large, unconsolidated and unstabilized slopes and berms of sand and soil immediately adjacent to the tributary of the Upper Center Pointe Canal that runs from east to west through the Facility. One slope of sand had eroded into the ditch (refer to Photographs 11, 22, 23, and 24). Section 3.1.1, Minimize Exposure, of the SWPPP states, "Overburden generated during the initial phases of mining will be used to construct topsoil berms along the perimeters of immediately adjacent properties, canals and irrigation diches." Additionally, BMP #1 of Section 3.1.1 of the SWPPP states, "If berms are created in fine grained soil (topsoil) they should be re-vegetated to stabilize the berm from eroding." 3. Part 2.1.2.4 Spill Prevention and Response. Implement procedures for material storage and handling, including the use of secondary containment and barriers between material storage and traffic areas, or a similarly effective means designed to prevent the discharge of pollutants from these areas. Area of Concern 3 The Inspection Team observed four 55-gallon drums of gear oil stored outside of the designated petroleum product storage area, with secondary containment, near the aggregate wash plant (refer to Photograph 25). Two of the drums contained product and two were empty. Section 2.2, Spills and Leaks, of the SWPPP states, "Fueling Island: Bulk fuel tanks will be inside secondary containment and fueling area will be graded to contain stormwater on site." It should be noted that stormwater runoff from this area appeared to flow into the aggregate wash water settling ponds and may remain onsite. 4. Part 5.2.7 Signature Requirements. You must sign and date your SWPPP in accordance with Appendix B, Subsection 11. Area of Concern 4 The Inspection Team noted that the onsite copy of the SWPPP was not signed or certified at the time of the inspection (refer to Photograph 26). 5. Part 8.J.7 Additional Inspection Requirements. Sites which discharge to waters which are designated as Tier 2 or 2.5 or waters which are impaired for sediment or nitrogen must be inspected monthly. Area of Concern 5 The Inspection Team noted that the Permittee was conducting Facility inspections quarterly. However, because the Facility is subject to impaired water monitoring in response to the siltation TMDL for the Boise River, the Permittee may be required to conduct Facility inspections monthly per Section 8.J.7 of the 2015 MSGP. Section 4.6.2, Routine Facility Inspections, of the SWPPP states, "Routine Facility Inspections of the sites will be performed quarterly, unless otherwise directed by IDEQ or EPA Region 10." Inspection Date: May 25, 2021 8 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report 6. Part 2.1.2.8 Employee Training. You must train all employees who work in areas where industrial materials or activities are exposed to stormwater, or who are responsible for implementing activities necessary to meet the conditions of this permit (e.g., inspectors, maintenance personnel), including all members of your stormwater pollution prevention team. Area of Concern 6 Employee training documentation was not available for review at the time of the inspection. During the inspection, Mr. Kalmbach stated that he was unaware whether stormwater training had been provided for the six Sunroc employees that operate the Facility. Section 4.5 of the SWPPP states, "Training Activities will be recorded and kept as part of the SWPPP in Appendix I. All training logs will include the date of the training, number and names of attendees, subjects covered, and length of training." At the time of the inspection, Appendix I of the onsite SWPPP was blank. 7. Part 5.2.2 Site Description. Provide a map showing: Locations of all stormwater monitoring points. Area of Concern 7a The SWPPP site map did not identify all stormwater discharge and monitoring points at the Facility. The Inspection Team noted that the SWPPP site map identifies two discharge points: `Outfall 001' where the unnamed ditch leaves the property and `Discharge 2' (refer to Exhibit 3). These points were indicated by an arrow pointing near where the two pipes from the groundwater retention basin discharge into the unnamed irrigation ditch, which was observed during the Facility walk-through. While it was unclear which discharge point was indicated by `Discharge 2', the Inspection Team noted that at least one of the two discharge points was not identified on the site map. The site map also does not indicate whether Outfall 001 or Discharge 2 is a stormwater monitoring point. As stated above, the Permittee conducts sampling at the downstream discharge pipe (main discharge point) into the unnamed ditch (refer to Photographs 12 and 13). Area of Concern 7b The SWPPP site map did not clearly identify groundwater conveyances in the pit area. Since the SWPPP was developed, the pit has expanded within its limits of disturbance (refer to Exhibit 2). As such, flow paths and conveyance locations had changed slightly. Of note, the conveyance of groundwater from the groundwater low point identified by Mr. Kalmbach (referred to as Sediment Pond on SWPPP Site Map), through a pipe, and into the channel that flows to the northeastern dewatering pumps shown in Photograph 6 is not clearly identified (refer to Exhibit 3). The SWPPP Site Map also does not identify any structural controls (berm) used by the Facility to segregate stormwater and groundwater. Inspection Date: May 25, 2021 9 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report 8. Part 5.2.5.3 Pertaining to Monitoring. For each type of monitoring, your SWPPP must document: Locations where samples are collected, including any determination that two or more outfalls are substantially identical. Area of Concern 8 The Inspection Team noted that the Facility's NOI and SWPPP identify one outfall: Outfall 001, located at 43.7206, -116.8166. These coordinates align with Outfall 001 noted on the SWPPP site map and appear to be the point where the unnamed irrigation ditch leaves the Facility property to the west. During the inspection, we reviewed a quarterly routine inspection report from May 15, 2020 that denotes a second discharge point 200 yards upstream of "discharge #1" (refer to Exhibit 4). The report identifies a corrective action to add this discharge point to the SWPPP. It remained unclear if this was the second, seasonal discharge pipe from the retention basin to the unnamed irrigation ditch, identified by Mr. Kalmbach during the inspection, and whether this was "Discharge 2" on the SWPPP site map (refer to Photographs 14 and 15, and Exhibit 3). The Permittee should ensure that the NOI and SWPPP identify all stormwater discharge points from the Facility to a receiving water, including any determination of substantially identical outfalls. Inspection Date: May 25, 2021 10 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Section IV - Closing Conference Due to time constraints, a closing conference was not held at the conclusion of the inspection. However, many of the areas of concern were discussed with Mr. Kalmbach during the inspection. Additionally, following the inspection, I held a brief call with Kamren Garfield (Sunroc Environmental Compliance) to discuss some of the observations and additional records. I explained to Mr. Garfield that the summary of observations (i.e., areas of concern) was "preliminary" and subject to addition, deletion, and/or modification. Area of Concern 1 - The Inspection Team observed that the discharge velocity from the upstream, seasonal discharge pipe from the groundwater retention basin to the unnamed ditch was causing scouring on the embankment of ditch. Area of Concern 2 - The Inspection Team observed large, unconsolidated and unstabilized slopes of sand and soil immediately adjacent to the unnamed irrigation ditch that receives discharges from the groundwater retention basin. Area of Concern 3 - The Inspection Team observed four 55-gallon drums of gear oil (two with product, two empty) stored outside of the designated petroleum product secondary containment storage area near the aggregate wash plant. Area of Concern 4 - The Inspection Team noted that the onsite copy of the SWPPP was not signed or certified at the time of the inspection. Area of Concern 5 - The Inspection Team noted that the Permittee was conducting Facility inspections quarterly. However, because the Facility is subject to impaired water monitoring in response to the siltation TMDL for the Boise River, the Facility may be required to conduct site inspections monthly per Section 8.J.7 of the 2015 MSGP. Area of Concern 6 - Employee training documentation was not available for review at the time of the inspection. Area of Concern 7a - The SWPPP site map did not identify all stormwater discharge and monitoring points at the Facility. Area of Concern 7b - The SWPPP site map did not clearly identify groundwater conveyances or structural controls in the mining pit area. Area of Concern 8 - The Facility's NOI and SWPPP only identify one outfall; however, the Inspection observed two discharge points from the Facility into the unnamed irrigation ditch. The inspection concluded at approximately 12:00 p.m. Inspection Date: May 25, 2021 11 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Attachment A - Photograph Log The photographs below were taken during the inspection by Mr. Anthony D'Angelo, PG Environmental, U.S. EPA Contractor, using a Panasonic Lumix DMC-TS6 digital camera. Original copies of the photos are on file. Note: Photo time stamps shown are Eastern Daylight Time (EDT). Inspection Date: May 25, 2021 12 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 1. View of the Facility sign next to Dixie River Rd. Photograph 2. View, facing southeast, of the low point in the pit area which Mr. Kalmbach identified as a groundwater accumulation area and which the SWPPP site map identifies as Sediment Pond (refer to Exhibit 3). Inspection Date: May 25, 2021 13 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 3. View, facing southwest, of the low point in the pit area which Mr. Kalmbach identified as a groundwater accumulation area and which the SWPPP site map identifies as Sediment Pond (refer to Exhibit 3). Outlet pipe Photograph 4. Additional view, facing southwest, of the Sediment Pond and exposed groundwater shown in Photographs 2 and 3. Note the outlet pipe which conveys groundwater north, into a channel, and ultimately to the dewatering pumps shown in Photograph 5 and 6. Inspection Date: May 25, 2021 14 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Groundwater channel to dewatering pumps Photograph 5. View, facing north, of the approximate location where groundwater from the Sediment Pond is piped north under the main pit access road and aggregate conveyer into the channel that flows east to the dewatering pumps shown in Photograph 5. Dewatering pumps to Ground Water Sediment Pond Groundwater channel from pit Photograph 6. View, facing south, of the groundwater dewatering pumps in the northeast corner of the mining pit area. Groundwater is pumped via one permanent pump and one secondary pump (only used during wet season) to the Ground Water Sediment Pond shown in Photographs 7, 8, and 9. Inspection Date: May 25, 2021 15 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Primary groundwater inlet pipe into Ground Water Sediment Pond Photograph 7. View of the primary (year-round) inlet pipe that conveys groundwater into the Ground Water Sediment Pond. Secondary groundwater inlet pipe into Ground Water Sediment Pond Photograph 8. View of the secondary inlet pipe (during wet season) into the Ground Water Sediment Pond. Inspection Date: May 25, 2021 16 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 9. Additional view of the Ground Water Sediment Pond. Photograph 10. View, facing east (upstream), of the tributary of the Center Point Canal that flows from east to west through the Facility. The Facility does not have outfalls that discharge into this waterbody. Inspection Date: May 25, 2021 17 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Unconsolidated berm Photograph 11. View, facing west (downstream), of the tributary of the Center Point Canal that flows from east to west through the Facility. The Facility does not have outfalls that discharge into this waterbody. Note the unconsolidated soil berm adjacent to the canal. Main discharge point to ditch Photograph 12. View, facing west, of the Facility's main discharge point from the Ground Water Sediment Pond into the unnamed irrigation ditch. The stairs provide access for NPDES compliance sampling. Inspection Date: May 25, 2021 18 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 13. Additional view of the Facility's main discharge point from the Ground Water Sediment Pond into the unnamed irrigation ditch. The stairs provide access for NPDES compliance sampling. Secondary, seasonal discharge point Scouring Photograph 14. View, facing east, of the Facility's secondary, seasonal discharge point from the Ground Water Sediment Pond into the unnamed irrigation ditch. Note the scouring on the embankment of the ditch adjacent to the discharge pipe. Inspection Date: May 25, 2021 19 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Secondary, seasonal discharge point Scouring Photograph 15. Additional view, facing northeast, of the Facility's secondary, seasonal discharge point shown in Photograph 14. Note the scouring on the embankment of the ditch adjacent to the discharge pipe. Photograph 16. View of the aggregate wash plant, which was operating at the time of the inspection. Inspection Date: May 25, 2021 20 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Wash plant effluent into the first settling basin Photograph 17. View, facing southeast, of the aggregate wash water discharge point into the first of six onsite wash water settling ponds. Photograph 18. View, facing east, of the second wash water settling pond. Inspection Date: May 25, 2021 21 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 19. View of the third and fourth wash water settling ponds. Photograph 20. View of the fifth and largest wash water settling pond. Inspection Date: May 25, 2021 22 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 21. View of the sixth and final wash water settling pond. Mr. Kalmbach stated that this pond does not discharge offsite. Freeboard in this basin appeared sufficient and the downgradient berm was intact and vegetated. Unconsolidated slope Photograph 22. View of unconsolidated and unstabilized sand and soil slopes immediately adjacent to the tributary of Center Point Canal. Inspection Date: May 25, 2021 23 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Unconsolidated slope Photograph 23. View of an unconsolidated and unstabilized sand and soil slopes immediately adjacent to the tributary of Center Point Canal. Unconsolidated slope Sediment in canal Photograph 24. View of an unconsolidated and unstabilized sand and soil slopes immediately adjacent to the tributary of Center Point Canal. Note that the sand slope had eroded into the canal. Inspection Date: May 25, 2021 24 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Drums of gear oil Photograph 25. View of the secondary containment structure for petroleum product storage near the aggregate wash plant. Four drums of gear oil, two empty drums and two containing product, were stored outside of the containment structure. Inspection Date: May 25, 2021 25 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Photograph 26. View of the blank signature page of the onsite SWPPP. Inspection Date: May 25, 2021 26 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Attachment B - Exhibit Log Inspection Date: May 25, 2021 27 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Groundwater dewatering pumps Active mining area Main discharge point Outfall 001 Ground Water Sediment Pond Secondary, seasonal discharge point Wash water settling ponds 6 (final) Wash water settling ponds 3, 4, and 5 Wash water settling ponds 1&2 Exhibit 1. Google Earth Pro image of the Facility (imagery date: 7/19/2018). Facility features and boundaries are approximated for reference. The green dotted arrow approximates the tributary of Center Pointe Canal, and the yellow dotted arrow approximates the unnamed irrigation ditch. Inspection Date: May 25, 2021 28 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report g Channel to dewatering pumps Dewatering pumps Ground Water Sediment Pond Sediment Pond Final wash water settling pond Exhibit 2. Bing Map of the Facility (imagery undated). This aerial imagery shows the expansion of the mining pit, the Sediment Pond, as well as the groundwater conveyance channel that leads to the dewatering pumps which pump to the Ground Water Sediment Pond. Inspection Date: May 25, 2021 29 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Exhibit 3. General View: SWPPP Site Map. Red box indicates the close-up shown on next page. 30 Inspection Date: May 25, 2021 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Exhibit 3. Close-up: SWPPP Site Map (denoted by red box on previous page). Yellow boxes highlight the two discharge points identified on the site map: "Outfall 001" and "Discharge 2". Inspection Date: May 25, 2021 31 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Exhibit 4 Page 1 of 4. May 15, 2020 Stormwater Industrial Routine Facility Inspection Report (Quarterly). Note that a new discharge point was identified 200 yards above "discharge #1". Inspection Date: May 25, 2021 32 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Exhibit 4. Page 2 of 4. May 15, 2020 Stormwater Industrial Routine Facility Inspection Report (Quarterly). Inspection Date: May 25, 2021 33 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Exhibit 4. Page 3 of 4. May 15, 2020 Stormwater Industrial Routine Facility Inspection Report (Quarterly). Inspection Date: May 25, 2021 34 Notus, Boise River Rd. Facility Industrial Stormwater Inspection Report Exhibit 4. Page 4 of 4. May 15, 2020 Stormwater Industrial Routine Facility Inspection Report (Quarterly). Inspection report notes that the newly identified discharge point above "dis. #1" needed to be added to the SWPPP; however, it was clear if "Discharge 2" identified on the SWPPP site map (refer to Exhibit 3) was this discharge point. Inspection Date: May 25, 2021 35