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Home My WebLink AboutNC0024571_Technical Assistance_20050712FWAT, July12, 2005 Mr. James H. Walters, Environmental Director City of Lumberton P.O. Box 1388 Lumberton, North Carolina 28358 SUBJECT: NPDES NO: NC0024571 Lumberton WWTP Robeson County Technical Assistance Visit Dear Mr. Walters, Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Alan W. Klimek, P.E., Director Division of Water Quality I haveresponded to a telephone call from your wastewater treatment plant Operator in Responsible Charge, Mr. Jon W. Locklear, to conduct a technical = assistance visit at your facility. I visited the facility on June 14, 2005 and was given a tour. Since this facility has shown consistent compliance, it was puzzling as to why the T.A. was needed. Jon shared with me the challenge that had been directed to him. Attached is a summary of my visit. I appreciate Jon and his staff with their cooperation in supplying technical data for my review. This is the summary of the first review of which will beupdated in the future when additional suggestions are available. If I can be of further assistance, please contact me at the Fayetteville Regional Office, at 910-486-1541. Sincerely, Don Register Wastewater Treatment Consultant Surface Water Protection Fayetteville Regional Office Cc: Belinda S. Henson, FRO Jerry Rimmer, Training and Certification NorthCarolina Naturally North Carolina Division 'of Water Quality 225 Green Street— Suite 714 Fayetteville, NC 28301-5043 Phone (910) 486-1541 Customer Service Internet h2o.enr.state.nc.us FAX (910) 486-0707 1-877-623-6748 An Equal opportunity/Affirmative Action Employer— 50% Recycled/10% Post Consumer Paper United States Environmental Protection Agency EPA Washington, D.C. 20460 Water Compliance Inspection Report Form Approved. OMB No. 2040-0057 Approval expires 8-31-98 Section A: National Data System Coding (i.e., PCS) Transaction Code NPDES yr/mo/day Inspection 1 U 2 ISI 3I NC0024571 I11 121 05/06/14 117 Type Inspector Fac Type 18 U 19ISI 20 u I I I I I I I I I I I I I I I 166 Remarks 211 I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I Inspection Work Days Facility Self -Monitoring Evaluation Rating B1 QA Reserved----------- --------- 67 I 12.0 169 70 U 71 LJ 72 I J 731 1 174 751 1 1 1 1 1 1 180 Section B: Facility Data Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include POTW name and NPDES permit Number) Lumberton WWTP 700 Lafayette St Extension Lumberton NC 28359 Entry Time/Date 09:15 AM 05/06/14 Permit Effective Date 04/09/01 Exit Time/Date 03:45 PM 05/06/14 Permit Expiration Date 09/07/31 Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) / / / Jon W Locklear/ORC/910-671-3859/ Other Facility Data Name, Address of Responsible Official/Title/Phone and Fax Number James H Walters,P0 Box 1388 Lumberton NC 28358/Environmental Contacted Director/910-671-3856/9106713953 No Section C: Areas Evaluated During Inspection (Check only those areas evaluated) Permit � Records/Reports � Sludge Handling Disposal � Facility Site Review 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 Don Register FRO WQ//910-486-1541 Ext.709/ Signature of Management A Reviewer Agency/Office/Phone and Fax Numbers Date knit . ' ono. 7 — 13 -Os EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete. NPDES 3 NC0024571 I11 12[ yr/mo/day 05/06/14" 117 Inspection Type 18i„i (cont.) 1 Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) A technical assistance visit was requestedjby ORC Jon Locklear. The T.A. was a result of "new budget" money concerns and the new Town Manager was challenging each division to cut -back on spending. The Environmental Director was concerned regarding the operation of the WWTP because of it using all of the tankage and equipment when the treatment plant is at approximately 30% capacity. The WWTP has a designed flow of 20 MGD and the current flow averages approximately 6-7 MGD. The four aeration basins are 3.5 MG each and each basin has six 75 Hp aerators and two 40 Hp mixers and the basins are followed by five final clarifiers and the associated return sludge pumps. The ORC has a concern of taking any of the basins or clarifiers off line because of the WWTP's history of I&I problems. Since this is of concern and if the goal is saving money, the first step would be to see how much could be saved by reducing unnecessary aerators and or mixers. Three aerators were turned off in each basin (saving a total of 900 Hp). The D.O.and activated sludge characteristics were closely monitored along with the daily lab results, which showed no negative effects. The reduction in Hp will continue until the limit is determined. Wasting of sludge has '"resumed with the MLSS currently above 7,000 mg/1. The MLSS will need to be reduced before any consideration is given to removing any tankage from service. The aerobic digester was looked at next to determine how the three 800,000 gallon digestion tanks would be operated. It was determined that"wasting would occur to each digester until the tank was thickened to as near to 2% dry solids as possible and then aerated until the sour test was met. After the sour test is met then the fecal coliform would be collected and analyzed from a composite "of seven samples of the digested sludge. When all of the test are successfully completed, the sludge will then be transfered to a holding tank and further thickened if possible before land application. Land application of the WWTP's digested sludge has just begun again after several months of inactivity. The digested sludge must be aerated only as much as needed to prevent odors from occuring. Downsizing "if possible" this WWTP and optimizing it's power usage will be a lengthly process. It has been determined by studying the piping schematics (as builts aren't available) that the design is not very versatile in how it can be routed in regard to the aeration basin/clarifier utilization. It may be possible with some minor piping modifications that it may be more.fexible and usable in different configerations. I would highly recommend that monies be budgeted to hire an engineer to study the piping and recommend what modifications can be made and at what estimated cost to yield more fexibility with the system. During the next several months power costs will be monitored along with the plant process to determine the success of the technical assistance. Permit Yes No NA NF (If the present permit expires in 6 months or less). Has the permittee submitted a new application? I 0 ❑ 0 Is the facility as described in the permit? 0 0 0 Are there any special conditions forthe permit? 0 • 0 0 Is access to the plant site restricted to the general public? ❑ ❑ ❑ Is the inspector granted access to all areas for inspection? •❑ ❑ ❑ Comment: There are several pieces of equipment that listed in the permit that are inoperative and not used, such as; effluent filters, lime stabilization system for biosolids. Aerobic Digester Yes No NA NF Is the capacity adequate? 0.00 Is the mixing adequate? •❑ ❑ ❑ Is the site free of excessive foaming in the tank? • 0 0 0 Is the odor acceptable? . . • ❑ ❑ ❑ Is tankage available for properly waste sludge? 11000 Comment: The digesters are too small to be able to digest and thicken effectively. The associated piping for the digesters are also ill arranged: supernant drawoffs, waste sludge pipelines, sludge loading pipelines