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Home My WebLink AboutNC0068152_Inspection_20180716DocuSign Envelope ID: C763963A-5BDA-4A2A-801A-56E4AA6F0817 United States Environmental Protection Agency Form Approved. EPA Washington, D.C. 20460 OMB No. 2040-0057 Water Compliance Inspection Report Approval expires 8-31-98 Section A: National Data System Coding (i.e., PCS) Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type 1 IN 1 2 15 I 3 I NCO068152 111 12 I 18/06/20 I17 18 Lr,] ] 19 LG] 201 I 211111 1 1 1 1 1 111 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 111 1 1 1 1 1 166 Inspection Work Days Facility Self -Monitoring Evaluation Rating 131 QA ----------------------Reserved------------------- 67 70 I I 71 I I 72 I r l u ty 73 I I 174 751 I I I 1 1 1 I80 I I i Section B: Facility Data Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include Entry Time/Date Permit Effective Date POTW name and NPDES oermit Number) 09:30AM 18/06/20 16/08/01 Eden Glen Mobile Village WWTP 2 Gospel Way Exit Time/Date Permit Expiration Date Weaverville NC 28787 11:00AM 18/06/20 20/10/31 Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data Joedavid Matthew Hal l/0RC/828-586-5588/ Name, Address of Responsible Official/Title/Phone and Fax Number Contacted Randy Roberson, //828-779-5265/ No Section C: Areas Evaluated During Inspection (Check only those areas evaluated) Operations & Maintenance Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) (See attachment summary) Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date Linda S Wiggs ARO WQ//828-296-4500 Ext.4653/ Timothy H Heim ARO WQ//828-296-4665/ EW Signature of Management Q A ReviewerDocusigned by: Agency/Office/Phone and Fax Numbers E7/13/2018 Date 7E617A38285848C... EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete. Page# DocuSign Envelope ID: C763963A-5BDA-4A2A-801A-56E4AA6F0817 NPDES yr/mo/day Inspection Type (Cont.) NCO068152 111 121 18/06/20 1 17 18 IDI Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) This TA was performed concurrent with Linda Wiggs (ARO) and a CSI. Observations: The plant was observed to be producing high quality effluent while the blowers in the aeration basin were operating, and while not operating, however, immediately following blower shut-off, there appeared to be a hydraulic "surge" from the aeration basin through the clarifier that move a significant amount of solids into the chlorine contact chamber and subsequently the receiving stream. Effluent quality was extremely poor with visible high solids and high flow for approximately 5 minutes following this event. The ORC reported that this phenomenon occurs regularly when the blower shut down. Potential Causes: It appears that the shutdown of the blowers causes a hydraulic surge through the plant which results in high velocities/pressures in the clarifier and pushes solids into the contact chamber. The solids blanket in the clarifier was not at an acceptable level (verified with sludge judge) and the ORC reported that varying the solids depth does not improve the problem. It is possible that excess air from the blowers results in an expansion of the volume of water in the aeration basin, and when the blowers are shut off, the volume collapses resulting in the hydraulic surge. It is also possible that excessive blower volume/velocity is causing floc shear and reducing settling characteristics. A settleability test performed at the time of the inspection showed negligible settling characteristics after the blowers were operated. D.O. probe used during blower operation showed excess oxygen in the aeration basin. The sludge judge was used in several locations and did indicate excessive solids in the plant. Possible Solutions: 1. Reduce blower size and/or air volume and velocity in the aeration basin. This may be accomplished by replacing the blower, re -gearing the belt drive, or closing the valves on the blower lines in the aeration basin. The blowers should be operated at the minimal power level needed to supply D.O. to achieve BOD reduction. This will also reduce the power bill for the facility. 2. Reconfigure blower motor controls to allow a gradual shut down of blowers, instead of the "hard off" currently used. 3. Mitigate the hydraulic surge before it reaches the clarifier. This facility is very old and the structural steel that could be observed was in poor condition in many areas, especially between the aeration and clarifier. It is possible that the orifice that allows flow from the aeration basin to the clarifier is too large (or new holes have broken open) and reducing the size of this orifice would prevent the surge from entering the clarifier. Verification of this would require drawdown, cleaning, and visual observation of the plant and its components. 4. Replace the facility. Given its age, it is possible that this facility has reached the end of its useful life and repairs required to return it to compliance would exceed those of replacing the plant. Page# DocuSign Envelope ID: C763963A-5BDA-4A2A-801A-56E4AA6F0817 Permit: NCO068152 Inspection Date: 06/20/2018 Owner - Facility: Eden Glen Mobile Village WWTP Inspection Type: Technical Assistance Operations & Maintenance Is the plant generally clean with acceptable housekeeping? Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable Solids, pH, DO, Sludge Judge, and other that are applicable? Comment: This TA was performed concurrent with Linda Wiggs (ARO) and a CSI. See inspection for more info. Yes No NA NE ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ Page# 3