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Home My WebLink About2024-03-06 IDEQ Rock Creek Lift station Inspection Report - February 13, 2024 Idaho Pollutant Discharge Elimination System Wastewater Treatment Plant Sanitary Sewer Overflow Inspection Report Twin Falls WWTP Permit Number: ID0021270 Inspection Date: February 13, 2024 Prepared by Brandi Lowe — IPDES Compliance Officer Twin Falls Regional Office 650 Addison Avenue West, Suite 110 Twin Falls, ID 83301 Report Date: March 6, 2024 Twin Falls WWTP ID0021270 Table of Contents 1 Facility Information..................................................................................................................1 1.1 Facility Details...................................................................................................................1 2 Inspection Chronology..............................................................................................................5 2.1 Phone Call Documentation................................................................................................5 2.2 Previous Inspection Report................................................................................................5 3 On-site Inspection.....................................................................................................................5 3.1 Opening Conference..........................................................................................................6 3.2 Site Inspection...................................................................................................................6 3.3 Sampling..........................................................................................................................14 4 Closing Conference ................................................................................................................14 5 Post Inspection........................................................................................................................14 5.1 Conversation Log ............................................................................................................14 5.2 24-Hour Noncompliance Report .....................................................................................15 5.3 5-Day Report...................................................................................................................15 Table of Figures Figure 1. Rock Creek Lift station, sewerage pipe from small residential community, and Rock Creek................................................................................................................................. 5 Figure 2. Rock Creek Lift Station overflow area, discharge points, and origination point............ 5 Table of Photographs Photograph 1. Rock Creek Lift Station influent comminutor......................................................... 7 Photograph 2. Wastewater pipe, red arrow indicating bowed area where wastewater exited the pipe, yellow areas indicating standing wastewater, facing northwest.............................. 8 Photograph 3. Overview of private property impacted by the SSO, yellow arrows indicating standing water, facing southwest...................................................................................... 9 Photograph 4. Southmost discharge point to Rock Creek, yellow arrow indicating flow from the property, facing northwest........................................................................................ 12 Photograph 5. Middle discharge point to Rock Creek, yellow arrows indicating erosion channel, facing northwest............................................................................................... 13 Photograph 6. Northmost discharge point to Rock Creek, yellow arrow indicating erosion channel, facing northwest............................................................................................... 13 ii Twin Falls WWTP ID0021270 1 Facility Information Facility Name: Twin Falls Wastewater Treatment Plant Permit Number: ID0021270 Permit Status: Effective November 1, 2009; Expired October 31, 2014 Administratively Continued Facility Type: Sewage Treatment Plant - Major Classification: Class IV SIC Code: 4952—Sewerage Systems NAICS Code: 221320—Sewage Treatment Facilities Overflow Location: West of the Rock Creek Lift Station 42.563337°, -114.495169° Mailing Address: PO Box 1907 Twin Falls, ID 83301 Facility Contacts: Nathan Erickson—Environmental Engineer Office: (208) 735-7272 Cell: (208) 358-5731 neickson@tfid.org Dan Black—Project Manager Office: (208) 734-9933 Cell: (208) 420-7724 dan.black@Jacobs.com 1.1 Facility Details The Rock Creek Lift Station is maintained and operated by Jacobs, a company contracted by the City of Twin Falls. The City of Twin Falls maintains and operates collection systems leading to and from the lift stations. All influent sewage that enters the Rock Creek Lift station flows via gravity and is diverted to a comminutor that breaks down large debris before being pumped to a force main to the wastewater treatment plant. One sewer line from a small residential community enters Rock Creek Lift Station from the west of the property. That line is suspended over Rock Creek and slopes down before eventually contacting the ground and becoming buried. The line that is suspended intersects a privately owned property currently used for livestock(Figure 1). 1 Rock Creek Lift Station • _ od n1 Rock Creek Lift Station iq Suspended pipe ♦ + 1 Z' ; 1 p , �♦ �'dff.Lift Station influent ` 1 ,` # • , ; , and comminutor . Coo Earth N h.g-Lends opsrni— - - L 200 tt 2 Inspection Chronology 2.1 Phone Call Documentation At approximately 10:20 a.m. Nathan Erickson called me and reported that the Rock Creek Lift Station had experienced an overflow event. Mr. Erickson explained that he was on site and there were crews working on the suspected issue and informed me that wastewater was discharged to Rock Creek. He further explained that the suspected cause was due to the failure of the influent comminutor. I informed Mr. Erickson that I would meet him at the site shortly to document the sewerage overflow. 2.2 Previous Inspection Report During the previous IPDES Collection System Survey on October 24, 2023, DEQ identified an area of concern with the operation and maintenance at the Rock Creek Lift Station. During the inspection, the following was noted: • Head gates were rusted • [Comminutor] was making considerable noise • Grease buildup in the wet wells A record of resolution for the area of concern is due March 6, 2024. 3 On-site Inspection Date and Time: February 13, 2024, at 10:40 a.m. Inspectors: Brandi Lowe—IPDES Compliance Officer, DEQ Twin Falls Regional Office Sean Woodhead— Surface Water Manager, DEQ Twin Falls Regional Office Facility Representative: Nathan Erickson—Environmental Engineer Office: (208) 735-7272 Cell: (208) 358-5731 nerickson@tfid.org Elmer Freeman—Wastewater Collection Supervisor Cell: (208) 308-7393 efreeman@tfid.org Weather: Sunny, —42°F 5 Twin Falls WWTP ID0021270 Purpose: To investigate the SSO and determine compliance with the facility's IPDES Permit ID0021270 and IDAPA 58.01.25, "Rules Regulating the Idaho Pollutant Discharge Elimination System Program." 3.1 Opening Conference This was an announced inspection. When Sean Woodhead and I, Brandi Lowe, arrived on-site we were met by Nathan Erickson and Elmer Freeman. After introductions, I informed Mr. Erickson that we were on site to document the SSO including obtaining information about the event, taking pictures of the site, and assessing the discharge points to Rock Creek. We were not denied access to any areas within the vicinity of the SSO, the Rock Creek lift station, or discharge points along Rock Creek. 3.2 Site Inspection Mr. Erickson, Mr. Woodhead, and I inspected the Rock Creek Lift Station influent channel and comminutor. Mr. Erickson explained that the event started due to the failure of the in-line comminutor when wastewater was not able to flow through to the lift station sufficiently as the channel's flow was constricted. Wastewater was not able to enter the Rock Creek Lift Station and was backed up in the collection system. Before arriving at the site, the comminutor was brought back online but failed a second time. During the inspection, the comminutor was offline (Photograph 1). There were many Twin Falls City employees present that were standing by to remove large debris that entered the lift station as the Jacobs team troubleshooted the comminutor. 6 Twin Falls WWTP ID0021270 r �l %f \e. 1 h Photograph 1. Rock Creek Lift Station influent comminutor. Due to the position of the wet wells relative to the nearby manholes and pipe, wastewater was backed up and exited the pipe to the west of the facility. Upon entry to the overflow area on the private property to the west of the lift station, Mr. Erickson, Mr. Woodhead, and I were greeted by Elmer Freeman, who walked us around the property. Mr. Freeman and Mr. Erickson explained that the pipe spanning the private property where the leak occurred was originally thought to be privately owned until recently, when it was discovered that the City was responsible for its maintenance. The pipe transports wastewater from a trailer subdivision west of Rock Creek to the Rock Creek Lift station via gravity flow. It was discussed on site that the collection line needed maintenance. In the middle of the property, a pipe was present and partially covered by surrounding dirt. Mr. Erickson explained that the bowed part of the pipe was where the overflow exited and began collecting on the private property (Photograph 2). 7 Twin Falls WWTP ID0021270 —; M Photograph 2.Wastewater pipe, red arrow indicating bowed area where wastewater exited the pipe,yellow areas indicating standing wastewater, facing northwest. During the inspection of the private property near the pipe, we observed many puddles of wastewater(Photograph 3). Mr. Erickson explained that he was unsure when the overflow started but that a City employee was driving by the site earlier that morning and noticed that there was puddling on the private property. Mr. Freeman explained that the response to the incident included the inspection of the lift station influent and subsequently involved the inspection of manholes that appeared to be overflown. After looking in the manholes the broken pipe was found causing the flooding of the property. 8 Twin Falls WWTP ID0021270 Feb Rock Creek , Pipe overflow N .�� - point Emppr ti Photograph 3. Overview of private property impacted by the SSO, yellow arrows indicating standing water, facing southwest. Upon inspecting the southwest border of the private property near Rock Creek, Mr. Erickson explained that there were three points of discharge where the wastewater overflowed the property and entered Rock Creek(Figure 2). Upon the initial discovery of the SSO, Jacobs took a sample of the southmost discharge point for temperature, pH, and E. coli. 9 Rock Creek Lift Station • _�•�� Dischar •- • 1 overflow point ♦ �p ♦ ~ -'may � _•� w• - •.-►,•". '•' •� � y._ oo Earth R mage Candy Fr 200 ft The sU§motdishag point was actively discharging wastewater through aa0rindrainpipe (Photograph 4. Mr. Erickson clarified that the current discharge was less than it was during the initial overflow period as the field was no longer being actively flooded from the SSO. ^ } < 2< #~ ^«« _ #\� Photograph 4 Souhmot discharge point to Rock Cree yellow arrow indicating flow from the property,facing northwest. Two more discharge points, both north o the first discharge point from the storm drainpipe were also inspected. Atthe time oft einspection, neither loc Son was actively discharging, but both locations had pudding and evidence of erosion from runoff(Photograph 5 an d 6. 12 Twin Falls WWTP ID0021270 Photograph 5. Middle discharge point to Rock Creek,yellow arrows indicating erosion channel, facing northwest. r` Y f 17 9 q s ¢ate Photograph 6. Northmost discharge point to Rock Creek,yellow arrow indicating erosion channel, facing northwest. 13 Twin Falls WWTP ID0021270 During the inspection of the private property, Rock Creek was observed for discoloration, fish kills, and overall appearance. Turbidity was noted at the southmost discharge point,but otherwise there was no evidence of a fish kill or sedimentation at the location. Mr. Erickson offered to walk the Creek periodically throughout the day from the private property to look for fish mortality and expressed that he would report his observations if he observed anything unusual. Both Mr. Freeman and Mr. Erickson agreed that they would not be sanitizing the private property until the water percolated as to reduce the risk of contaminating discharged wastewater with chemicals to Rock Creek. Before leaving the site, Mr. Erickson stated that Dan Black with Jacobs would be filing both the 24-hour noncompliance report and the 5-day report on the SSO. Immediately after leaving the site Mr. Woodhead and I went to Rock Creek Park, an access point to Rock Creek less than one mile downstream from the discharge site and observed the stream conditions. At Rock Creek Park, there was no evidence of a fish kill or sedimentation deposits. 3.3 Sampling Samples were not collected by DEQ during this inspection. Jacobs staff took one sample from the southmost discharge point during the overflow. The day after the discharge event had stopped, Jacobs took two additional samples, one sample upstream and one sample downstream of the discharge to Rock Creek. Results of all samples were included with the 5-day report (EDMS 2024FAP745). 4 Closing Conference In the closing conference I discussed my inspection observations and answered any remaining questions that Mr. Erickson had for DEQ. I informed Mr. Erickson that my observations would be outlined in an inspection report and that a copy would be provided to them. The inspection report would be reviewed at DEQ for potential follow up and determination of violations. I thanked Mr. Freeman and Mr. Erickson for their time and assistance during the inspection process. The inspection was concluded at 11:00 a.m. and the site visit of Rock Creek Park was concluded at 11:10 a.m. 5 Post Inspection 5.1 Conversation Log On February 13, 2024, I logged the following conversations regarding the discharge event: At 11:45 a.m. I called Nathan Erickson and discussed the starting time of the SSO. I asked him if it was possible for the overflow to have started sooner than the beginning of the day, and he confirmed that another employee saw the flood yesterday. 14 Twin Falls WWTP ID0021270 At 1:10 p.m. Dan Black called me to discuss the event. Mr. Black was going to go through the Emergency Response plan and notify agencies that would be interested in the discharge event. Mr. Black explained that the SCADA system operator was onsite shortly after the overflow was reported and that they were working on receiving all the data that failed to get called out. We discussed that the 5-day report would include analytical results, the SCADA system log, and updates regarding the overflow. Mr. Black confirmed that he would call me and let me know if the overflow occurred again or if there were any pertinent new facts. At 4:10 p.m. Josh Johnson, South Central Public Health District, visited DEQ's office and met with Raphael Erickson, Tim Beach, and me. He informed us that the City of Twin Falls had called him and let him know there was an overflow. During this conversation he informed us that the original starting date that was given to him for the incident was the previous Friday, February 8, 2023. This conversation concluded that the Health District had no follow-up action to the discharge as DEQ was following up with the situation. On February 14, 2024, I emailed Dan Black and Nathan Erickson and informed them that I had received the 24-hour report and that the 5-Day Report was due February 19, 2024. On February 20, 2024, Dan Black emailed me that the new SCADA system was not fully online yet at the Rock Creek Lift Station, so they are unable to get all of the logs until the system is completely updated. He also included that the analytical results from the overflow location into Rock Creek were as follows: E. coli: >2419 colonies/100mL pH: 8.09 Temperature: 19.4°C On February 20, 2024, I reached back out to Dan Black and inquired about the pipe replacement material. Mr. Black responded that the materials to fix the pipe as well as the new comminutor are on hand and will be installed as soon as a crane is available for replacement. 5.2 24-Hour Noncompliance Report The 24-Hour Noncompliance Report was made by Dan Black on February 13, 2024 (EDMS 2024FAP691). This report included that the original start of the incident was now expected to have started Friday, February 8, 2024, with an estimation of 15,000 gallons of wastewater discharged to Rock Creek. At the time of the report, the Programmable Logic Controller was back online and operating as expected. 5.3 5-Day Report The 5-Day Report was submitted, on time, via E-Permitting on February 19, 2024 (EDMS 2024FAP745). The final estimate of gallons discharged to Rock Creek was 12,000 since the start of the event and, after further investigation, the start time was said to have been Friday, February 9, 2024. 15 Summary Violations 1. SSO Discharge to WOTUS Part I.A of the Permit states: "During the effective period of this permit, the permittee is authorized to discharge pollutants from the outfall specified herein to the Snake River... " It is a violation of the Permit that a sanitary sewer overflow discharged approximately 12,000 gallons of untreated wastewater to Rock Creek from February 9, 2024, to February 13, 2024. 2. Improper Operation and Maintenance Part IV.E of the Permit states: "The permittee must at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the permittee to achieve compliance with the conditions of this permit...This provision requires the operation of back-up or auxiliary facilities or similar systems, which are installed by the permittee only when the operation is necessary to achieve compliance with the conditions of the permit. " It is a violation of the Permit that the following were not properly operated and maintained: • Call-out alarm system • Comminutor • Collection system line to the west of Rock Creek Lift Station 12 Prepared by: Date: February 15, 2024 Bra Lowe IMES Compliance Officer Department of Environmental Quality Reviewed by: G Date: February 28, 2024 oy S Ath WW Compliance Bureau Chief Department of Environmental Quality—State Office 12