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Home My WebLink About2024-05-14 IDEQ SSO Report City of Twin Falls ID0021270 Idaho Pollutant Discharge Elimination System Wastewater Treatment Plant Sanitary Sewer Overflow Inspection Report City of Twin Falls WWTP Permit Number: ID0021270 Inspection Date: May 1 , 2024, and May 6, 2024 Prepared by Brandi Lowe — IPDES Compliance Officer Twin Falls Regional Office 650 Addison Avenue West, Suite 110 Twin Falls, ID 83301 Report Date: May 14, 2024 City of Twin Falls ID0021270 Table of Contents 1 Facility Information..................................................................................................................1 1.1 Facility Details...................................................................................................................1 2 Inspection Chronology..............................................................................................................5 2.1 24-Hour Report Review ....................................................................................................5 2.2 Previous Inspection Report................................................................................................5 3 On-site Inspection.....................................................................................................................5 3.1 Opening Conference..........................................................................................................6 3.2 Site Inspection (May 1, 2024) ...........................................................................................6 3.3 Site Inspection (May 5, 2024) ...........................................................................................5 3.4 Sampling............................................................................................................................7 4 Closing Conference ..................................................................................................................8 4.1 External Agency Communications....................................................................................8 ii City of Twin Falls ID0021270 Table of Figures Figure 1. Rock Creek Lift station, sewerage pipe from small residential community, and Rock Creek................................................................................................................................. 5 Figure 2. Sampling locations from the May 1, 2024, site visit....................................................... 5 Table of Tables Table 1. Sample locations and results from May 1, 2024, sampling by DEQ................................ 8 Table of Photographs Photograph 1. Collection system pipe where wastewater exited during the SSO, red arrows indicating holes in the pipe, facing north. ........................................................................ 6 Photograph 2. Collection system pipe, red arrows indicating holes in the pipe, facing northeast. .......................................................................................................................... 7 Photograph 3. Collection system pipe, red arrows indicating holes in the pipe, facing northwest. ......................................................................................................................... 7 Photograph 4. Untreated wastewater in field prior to discharging to Rock Creek, facing southeast. .......................................................................................................................... 8 Photograph 5. SSO discharge location to Rock Creek. .................................................................. 8 Photograph 6. Rock Creek upstream sample location, facing west................................................ 9 Photograph 7. SSO discharge sampling location and Rock Creek downstream sampling location, facing northwest. ............................................................................................... 9 Photograph 8. Collection system pipe and temporary plugs, facing north..................................... 5 Photograph 9. Pipe replacement(green)to the collection line, facing northeast. .......................... 6 Photograph 10. Removed pipe and wastewater flooding the field, facing northeast...................... 6 Photograph 11. Discharge location to Rock Creek, brown plume indicated by red arrows........... 7 iii City of Twin Falls ID0021270 1 Facility Information Facility Name: Twin Falls, City of—Twin Falls WWTP 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 Facility Location: West of the Rock Creek Lift Station 42.563337°, -114.495169° Mailing Address: PO Box 1907 Twin Falls, ID 83301 Facility Contact(s): Nathan Erickson—Environmental Engineer Office: (208) 735-7272 Cell: (208) 358-5731 neickson@tfid.org 1.1 Facility Details One collection system line originates from a small residential community to the west of the Rock Creek Lift Station. The collection line slopes down from the west canyon wall, suspends across Rock Creek, before eventually descending into the ground of a privately owned field immediately to the west of the Rock Creek Lift Station(Figure 1). Details on the connection to the lift station, as well as the previous Sanitary Sewer Overflow(SSO)that occurred in this location can be found at EDMS File 2024FAU107. 1 • �11 I 1 Rock Creek Lift Station • - —--_,_ _ - - od ti mil'"`• T♦ —�i` :i�+► _ .� ,` �__•rt `. eta ' • ck Creek Lift Station iq Suspended pipe •�Y. 1 •r Lift Station influent and comminutor ♦ + 1 Z' �♦ ,ram r•'��• ` 5u u Goo arth N• h.g-Lends opsrni— - I 200 tt City of Twin Falls ID0021270 2 Inspection Chronology 2.1 24-Hour Report Review Two 24-Hour Noncompliance Reports were recorded on the IPDES Noncompliance Hotline by Nathan Erickson for the occurrences of the SSOs. Both SSOs were caused due to a blockage and wastewater exited the collection system through open holes present in the conveyance pipe. At the time of the first noncompliance report for the SSO that occurred on April 30, 2024, no wastewater was reported to have entered Rock Creek(EDMS File 2024FAP 1248). The second noncompliance report for the SSO that occurred on May 5, 2024, indicated that the operators were unsure if wastewater entered Rock Creek (EDMS File 2024FAP 1283). 2.2 Previous Inspection Report During the previous IPDES Sanitary Sewer Overflow Inspection on February 13, 2024, DEQ identified two violations. One violation was identified for discharging untreated wastewater to WOTUS and the other violation was identified for improper operation and maintenance of equipment at the Rock Creek Lift Station and the collection system line to the west of Rock Creek Lift Station. 3 On-site Inspection Date and Time: May 1, 2024, at 1:00 p.m. and May 5, 2024, at 1:30 p.m. Inspectors: Brandi Lowe—IPDES Compliance Officer, DEQ, Twin Falls Regional Office Sean Woodhead—Surface Water Manager, DEQ Twin Falls Regional Office Facility Representative (May 1, 2024): Nathan Erickson—Environmental Engineer Office: (208) 735-7272 Cell: (208) 358-5731 nerickson@tfid.org Facility Representative (May 5, 2024): Elmer Freeman—Wastewater Collection Supervisor Cell: (208) 308-7393 efreeman@tfid.org Weather (May 1, 2024): Windy, cloudy, —50°F Weather (May 5, 2024): Windy, cloudy, —55°F 5 City of Twin Falls ID0021270 Purpose: To follow up on the noncompliance report for each SSO that occurred and to 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 Both site visits were announced inspections. When Sean Woodhead and I, Brandi Lowe arrived on-site on May 1, 2024, we were met by Nathan Erickson. When Mr. Woodhead and I arrived on site on May 5, 2024, we were met by Elmer Freeman. During each site visit, we were not denied access to any areas of the property. A phone call conversation was conducted with Mr. Erickson after each reported SSO to coordinate the site visits. 3.2 Site Inspection (May 1, 2024) Mr. Erickson, Mr. Woodhead, and I inspected the field to the west of the Rock Creek Lift Station from the fence bordering the lift station to Rock Creek. We walked along the collection line and along the west border of the private property along Rock Creek. During the site visit, wastewater was not actively exiting the collection system as the line had been cleared prior to our arrival. Much of the collection conveyance line had holes and the ground surrounding the line was saturated(Photograph 1, 2, and 3). ", il � dg^ s� Photograph 1. Collection system pipe where wastewater exited during the SSO, red arrows indicating holes in the pipe, facing north. 6 City of Twin Falls ID0021270 l _ Photograph 2. Collection system pipe, red arrows indicating holes in the pipe, facing northeast. V W�'G7ns . �yy Y Photograph 3. Collection system pipe, red arrows indicating holes in the pipe,facing northwest. Along Rock Creek, no fish kills or sediment deposits were observed. Along the border of the property to Rock Creek, a dirt berm was present. Much of the wastewater collected along the berm and was not observed to be moving during the site visit. On the northwest corner of the property the berm flattens, and the standing wastewater connected to a discharge location into Rock Creek(Photograph 4 and 5). Mr. Erickson explained that the property owner also flood irrigates the pasture, so it was unknown if all the standing water was due to the SSO or if some of the irrigation water was combined with the wastewater. 7 City of Twin Falls ID0021270 6 f a rTM . Photograph 4. Untreated wastewater in field prior to discharging to Rock Creek, facing southeast. G Photograph 5. SSO discharge location to Rock Creek. Due to the location of the standing wastewater in the field, its connection to Rock Creek, and the unknown amount of wastewater that was discharged, the group discussed the probability that the wastewater was discharged to Rock Creek. Due to these findings, DEQ conducted an E. coli 8 City of Twin Falls ID0021270 sample upstream, downstream, and at the suspected discharge location to Rock Creek (Photograph 6 and 7, Figure 2). fi I Upstream Sampling Location z o- i .ly. �S y•y, INK Zv.MY9 ,F i- Photograph 6. Rock Creek upstream sample location, facing west. l - j Downstream Sampling Location 'k All kip Y b11W u} Ri Discharge Sampling G Location Photograph 7. SSO discharge sampling location and Rock Creek downstream sampling location, facing northwest. 9 • �11 I 1 Rock Creek Lift Station SSO - -- - - - - un - - ■00 i - - - - - - - - - - o. 1� Downstream sampling location Discharget� sampling location a samplingUpstream location ►• At,` f 'y .4 i Goo) Earth - N; 200ff City of Twin Falls ID0021270 3.3 Site Inspection (May 5, 2024) Mr. Woodhead and I inspected the field to the west of the Rock Creek Lift Station from the fence bordering the lift station to Rock Creek. We were greeted by Mr. Freeman at the collection line halfway between Rock Creek and the Rock Creek Lift Station. At the time of the site visit, Mr. Freeman was working on repairing and replacing portions of the collection line as a temporary fix before the City Council is presented with the Cured in Place Pipe (CIPP)project (Photograph 8 and 9). Mr. Freeman explained that the pipe with the holes was installed in 1958 and that the temporary fixes they are making should help until the City is able to secure funding for the CIPP project. j Photograph 8. Collection system pipe and temporary plugs, facing north. 1 1 / 1 ® i�g.. .'"��Aec Wf• Sf `�{ka +iF� ,� Sss/'.+, A a'�. yq�"Ir.„ +"�"�:. �si.t,,�,W+rr r 5 City of Twin Falls ID0021270 Photograph 9. Pipe replacement(green)to the collection line,facing northeast. During the site visit, Mr. Woodhead and I walked along the private property's border to Rock Creek. Again, there were no signs of a fish kill or sediment deposits but there was standing wastewater along the berm. Additionally, the field under the line being replaced was saturated and held standing wastewater(Photograph 10). Photograph 10. Removed pipe and wastewater flooding the field, facing northeast. At the sampling location from the May 1, 2024, visit, Mr. Woodhead and I again observed standing water from the field and a connection to Rock Creek. At the location, a brown plume prior to the Creek was evident and the surrounding water appeared turbid(Photograph 11). 6 City of Twin Falls ID0021270 s� • 1 �lit�; �4� � 4�A®,,� F6:' c• .r h Photograph 11. Discharge location to Rock Creek, brown plume indicated by red arrows. 3.4 Sampling Samples were collected by DEQ during the site visit on May 1, 2024. Jake Barnes, Water Quality Analyst, collected three grab samples for E. coli upstream and downstream of the discharge location, and directly at the discharge location. Each bottle was 7 City of Twin Falls ID0021270 labeled with the date, time, and location of the sample, and all samples were placed in a cooler with ice for transport. A blank was collected by Brandi Lowe at the Twin Falls Regional Office using deionized water and all samples were transported to Magic Valley Labs (210 Addison Ave. Twin Falls, ID). A copy of the sample results and Chain of Custody are included in EDMS File 2024FAU415. Samples were analyzed according to EPA approved method SM 9223, following DEQ Water Quality Sample QAPP (EDMS File 2019AJY1). Table 1. Sample locations and results from May 1, 2024, sampling by DEQ. Label ID: Description: Result: RC Down Downstream from the discharge location 184 MPN/100mL RC Up Upstream from the discharge location 179 MPN/100mL RC DL Discharge Location 291 MPN/100mL BLANK DI Water from the TFRO WQ Laboratory <1 MPN/100mL 4 Closing Conference During the May 1, 2024, site visit I informed Mr. Erickson that I would follow up with him regarding the SSO. I also told Mr. Erickson I would look into whether the property owner could deny sanitization of the field that the SSO occurred on. The site visit was concluded at 2:15 p.m. During the May 5, 2024, site visit I thanked Mr. Freeman for his time. The site visit was concluded at 1:45 p.m. 4.1 External Agency Communications On May 8, 2024, I emailed Josh Jensen with the South Central Public Health District and informed him that the property owner was not allowing the land to be sanitized where the SSOs occurred. 8 City of Twin Falls ID0021270 Summary Violations 1. SSO Discharge to WOTUS Part LA 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 an unknown amount of untreated wastewater to Rock Creek on the following dates: • April 30, 2024 • May 5, 2024 9 City of Twin Falls ID0021270 Prepared by: ;C-,W, Date: May 8, 2024 B ndi Lowe IPDES Compliance Officer Department of Environmental Quality Reviewed by: 3� IcznL Date: May 9, 2024 Tim Beach IPDES Compliance Officer Department of Environmental Quality 12