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HomeMy WebLinkAboutNC0021849_Permit Modification_19990201State of North Carolina Department of Environment and Natural Resources Division of Water Quality James B. Hunt, Jr., Governor Wayne McDevitt, Secretary A. Preston Howard, Jr., P.E.,,Director Mr. John Christensen, Town Manager Town of Hertford P.O. Box 32 Hertford, North Carolina 27944 Dear Mr. Christensen: L Af k NCDENR, NORTH CAROLINA DER�RTMENT OF ENVIRONMENT AND NATURAL RESOURCES February 1, 1999 11�� .' ( �h e,-) �C_ -et L 0- a' '0 a Subject: NPDES Permit Modification Permit No. NCO021849 Town of Hertford WWTP Perquimans County In accordance with the application for a discharge permit received on September 2, 1998 and additional information received on'November 13, 1998, the Division is forwarding herewith the subject NPDES permit. This permit is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency dated December 6, 1983, and as subsequently amended. The following modifications, as indicated in the draft, have been finalized: Upon expansion to 0.70 MGD, BOD5 and ammonia monthly average limits are 15.0/30.0 mg/l (Summer/Winter) and 4.0/8.0 mg/l, respectively. * Upon expansion to 0.70 MGD, BOD5 weekly average limits are 22.5/45.0 mg/l (Summer/Winter). Uponexpansion. to 0.70 MGD, a total residual chlorine (TRQ limit of 28 �tg/l applies if chlorine is used for disinfection. Upon expansion to 0.70 MGD, instrearn monitoring is required for temperature, dissolved oxygen (DO), and fecal coliform. Weekly monitoring will be required in the summer, and monthly monitoring will be required in the winter. Expiration Date - Please note also that this permit modification changes the expiration date for -the subject permit to December 3 1, 2002.. The Division is beginning the second five-year cycle of river basin lanning and permit renewals. An p C' examiniition.of the basin planning schedule has revealed that the timing of permit renewals does not allow an evenly distributed workload as first envisioned. In an effort to improve customer, service, and after a review of the water quality issues in your area, the Division is changing the permit renewal schedule for NPDES permits in your sub-�basin. P.O. Box 29535, Raleigh, North Carolina ' 27626-0535 Telephone (919) 733-5083 FAX (919) 733-0719 An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumee paper Please find enclosed the amended permit cover page, supplement to cover, and effluent limitations page for outfall 001 (A(2.) only), all of which should be inserted into your permit. The old cover pages should be discarded. All other terms and conditions contained in the original permit remain unchanged and in full effect. This permit modification is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency. If any parts, measurement frequencies, or sampling requirements contained in this permit are unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty (30) days following feceipt of this letter. This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings, Post Office Drawer 27447, Raleigh, North Carolina 27611-7447. Unless such demand is made, this decision shall be final and binding. Please take note that this permit is not transferable. Part II, E. 4. addresses the requirements to be followed in case of change in ownership or control of this discharge. This permit does not affect the legal requirements to obtain other permits which may be required by the Division of Land Resources or any other Federal or Local governmental permit that may be required. If you have any questions or comments concerning this permit, please contact Bethany A. Bolt at (919) 733-5083, extension 55 1. Sincerely, Original Signed By David A. Goodrich A. Preston Howard, Jr., P.E. Enclosure cc: Washington Regional Office/Water Quality Section NPDES Unit Central Files Mr. Roosevelt Childress, EPA Point Source Compliance Enforcement Unit Permit No. NCO021849 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WATER QUALITY PERMIT TO DISCHARGE WASTEWATER UNDER THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM In compliance with the provision of North Carolina General Statute 143 -215. 1, other lawful standards and regulations promulgated and adopted by the North Carolina Enviror.unental Management Commission, and the Federal Water Pollution Control Act, as amended, Town of Her�fbrd is hereby authorized to discharge wastewater from a facility located at Hertford Wastewater Treatment Plant NCSR 1108 north of Hertford Perquirnans County to receiving waters designated as Perquimans River in the Pasquotank River Basin in accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts I, II, III, and IV hereof. This permit shall become effective March 1, 1999. This permit and authorization to discharge shall expire at midnight on December 31, 2002. Signed this day February 1, 1999. Original Signed By Pavid A. Goodrich A. Preston Howard, Jr., P.E., Director Division of Water Quality By Authority of the Environmental Management Commission SUPPLEMENT TO PERMIT COVER SHEET Town of Hertford is hereby authorized to: Permit No. NCO021849 1. Continue to operate an existing 0.4 MGD wastewater treatment plant consisting of a grit removal chamber, aeration basin, clarifier, chlorine contact chamber, sludge digester, and drying beds, located at Hertford VPNTP, on NCSR 1108, north of Hertford, Perquimans County, and 2. After receiving an Authorization to Construct for expansion above 0.4 MGD, operate a 0.70 MGD wastewater treatment plant consisting of a mechanical bar screen and grit removal system, sludge holding tank, oxidation ditch, dual clarifiers, post aeration, ultra -violet disinfection, sludge digester, and drying beds, located at Hertford WWTP, on NC SR I 10 8, north of Hertford, Perquimans County, and 3. Discharge from said treatment works at the location specified on the attached map into the Perquimans River, which is classified as C-Swamp waters in the Pasquotank River Basin. ion's P, —2, J 7 7 . ( I - - J/ 44 "4 W K, 4 J :Lj! --7 r o C�enty S h 0 I F--:j 0', a 30 L —6- T% )kk r7: _j . 4. A Y 31 4-1 -7 1007 We, e r U. T *1 r "' rai e e an' Pary * iL Bear Garden Point 3 Ak� �06 2 IN i-N- <1 S. IT. ert o r :.-a I h P, /w Nuo. Crow Point I TU Z L mi h S Latitude: 36012'19" Longitude: 76128'34" Quad# C33NW Receiving Stream: Perquimans River Stream Class: C-Swamp Subbasin: 30152 NCO021849 Town of Hertford WWTp Facility ", WM Location SCALE 1:24000 ,t4]F A (2). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS Permit No. NCO021849 During the period beginning upon expansion above 0.4 MGD and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial number 001. Such discharges shall be limited and monitored by the Permittee as specified below: tF "UEN V'd 'CTERISTICS',*',"'1�?`� OW E I NJI g "HARA VR OR ­MONITO :�.Dai Measuremefi V0 t y�,-Maximum ,;!SampW, 'Locationt' Flow 0.70 MGD Continuous Recording I or E BOD, 5-day, 200 C2 (April I —October 31) 15.0 mg/L 22.5 mg/L Weekly Composite 1, E BOD, 5-day, 20OC2 (November 1 — March 31) 30.0 mg/L 45.0 mg/L Weekly Composite 1, E Total Suspended SolidS2 30.0 mg/L 45.0 mg/L Weekly Composite 1. E NH3-N (April 1 — October 31) 4.0 mg/L Weekly Composite E NH3-N (November . 1 — March 31) 8.0 mg/L Weekly Composite E PH 3 Weekly Grab E Total Residual Chlorine 4 28 pg/L 2NVeek Grab E Temperature OC Daily Grab E Temperature OC Weekly Grab U, D Dissolved Oxygen Weekly Grab U, D Fecal Coliform (geometric mean) 200/100 ml 400/100 ml Weekly Grab E, U, D Total Nitrogen (NO2+NO3+TKN) Quarterly Composite E Total Phosphorus Quarterly Composite E Notes: 1 Sample Locations: E - Effluent, I — Influent, U — Upstream about 0.75 miles of effluent channel/Perquimans River confluence (near terminus of dirt road in this vicinity), D — Downstream about 0.33 miles of effluent channel/Perquimans River conflu6nce (at railroad bridge). Instream monitoring shall be grab samples taken weekly (Jun -Sep) and monthly (Oct -May). 2 The monthly average effluent BOD, and Total Suspended Solids concentrations shall not exceed 15% of the respective influent value (85% removal required). 3 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 4 Monitoring requirement applies only if chlorine is used for disinfection. There shall be no discharge of floating solids or visible foam in other than trace amounts. FEBRUARY 1, 1999 MODIFICATION The Perquimans Weekly P.O. Box 277 Hertford, NC 27944 Telephone (919) 426-572�,'p CLIPPING OF LEGAL ADVERTISEMENT NORTH CAROLINA ATTACHED HERE PERQUINIANS COUNTY 4 PUBLIC NOTICE STATE OF NORTH CAROLINA .1 ENVIRONMENTAL AFFIDAVIT OF PUBLICATION '4.MANAGEMENT COMMISSION PO�T OFFICE BOX 29535 Before the undersigned, a Notary Public of said RALEIGH, N.C. 27626-0535 County and State, duly commissioned, qualified, and NOTIFICATION OF INTENT ISSUE A STATE authorized by law to administer oaths, personally :kT0 NPDES PERMIT appeared On 'the basis' of thorough SUSAN HARRIS stag review and applica- who, being first duly sworn, deposes and says that she is tlon,of Article 21 of Chap- ter,*143, General Statutes the Editor of The Perquimans Weekly, engaged in the of Aorth Carolina, Public publication of a newspaper known as The Perquimans LavA#'92-500 and other low- I ful'standards and regula- Weekly, published, issued, and entered as second class tIon§, the North Carolina Environmental Manage - mail in the City of I lertford, in said County and State; that mew Commission propos- she is authorized to make this affidavit and sworn es to issue a' permit to dis- I chalge to the persons'list- I statement; that the notice or other legal advertisement, a ed,below effective 2/l/99, and subject to special true copy of which is attached hereto, was published in conditions. .4 . The Cfer)quimans Weeky on the following dates: 1. NPDEX No. NCO021849. ToWn of Hertford, P.O. Box 32_ Hertford, NC 27944 has app)led for a permit modi- ficWion for a facility locat- ed*-at Hertford WWTP on and that the said newspaper in which guch notice, NCSR 1108, north of Hert- paper, document, or legal advertisement was published ford Perquimans County, Thd.facility is permitted to was, at the time of each and every such publication, a discharge 0.70 MGD of newspaper meeting all of the requirements and treated domestic waste - water from one ouffall into qualifications Of Section 1-597 of the General Statutes th4-Perquimans Riveu: a ofNorth Carolina and was a qualified newspaper within Class C-Swamp stream'In the Pasquotank River Basin the meaning of Section 1-597 of the General Statutes of with tidal flow. BOD5, North Carolina. ammonia, and total resid- ud.chlorine are water quality limited. For sQme (Signature ofperson making affidavit) pc�ameters, the available lodO capacity'of the Immediate Sworn to and subscribed before me, this :ZiZi receiving", wctter will be consumed; ThisImay affect future allo- day of catipns In this pRrtlm of th4.watershed, )o Pe4ns wishing to��60'm_­ mJ9t uponlor object, 0 MY COmmeiiSSiioltNqERODIMSfP(6hk�iibcer 11, 2001 y determina- My Commission expires: ..thq4proposed tlon� are invited to submit 4e in writir sar igOo the aqove address no later thgh 1/18/99. All com- m4l�ts received prior to th(JJ date will 'be consid- or+d in the formulation of f '011 de'ter minatlons re9prding the proposed pqNnit. A public meeting m held where the DI, t�?ro f the Division of ;.X E nt, onmental ManaQ197 ment finds slanificonti NCO021849 I -ME NOTES FOR HERTFORD WWTP MAJOR MODIFICATION Summary: Major modification request to increase permitted capacity from 0.4 to 0.7 MGD. A speculative limits letter was sent out July 16, 1998 that detailed most major changes to the permit upon expansion. The facility discharges to the Perquimans River (Pasquotank River Basin, 3-01-52), which is classified C-Swamp waters. Recommended limits for BOD5/ammonia that originated from a swamp waters study that established 15/4 mg/1 (summer) based on reasonably achievable technology and waste assimilating capacity of swampy systems that do not maintain advective flow. DO readings at an ambient monitoring station located about I mile downstream of the discharge indicated levels below 5 mg/1 standard during periods of warmer weather; however, could not conclude that Hertford's discharge was contributing to those low levels. Instream monitoring included for DO, Fecal, and Temp. Class rating from 1997 staff report indicated Hertford was a Class II facility. With upgrades (additional flow, UV, no chlorine disinfection), total points should still place WWTP in Class II category. Should be checked at renewal, however. Basin Plan Water quality in this sub -basin generally fair (benthic macroinvertebrate data); in the Perquimans R., duckweed growth is problematic, attributed to non -point source run-off. Hertford is the largest discharger. The Perquimans River is rated as support - threatened, and its quality will continue to be monitored. No specific point -source permitting strategies are noted. Modification similar to spec limits, with the following exceptions: • Policy is to set weekly ave. (municipalities) limits for BOD5 by multiplying monthly average by 1. 5. Therefore, summer BOD5 weekly ave. is 22. 5 mg/ 1 instead of 3 Z 5. • Per Dave, 12/8/98: policy is NOT to apply weekly average limits for ammonia, even when the limit is set for oxygen consuming concerns. For some reason, daily max. limits in the spec. letter were calculated using a factor of 2.5. Only monthly average ammonia limits apply. • Chronic toxicity footnote omitted (previous typo). • Monitoring frequencies changed. Consistent with 213 .0500s for Class 11 facilities. • Conductivity monitoring omitted. (Not in current permit) This facility discharges 100% domestic waste, so monitoring shouldn't be necessary. WaRO (Al Hodge, 10/9/98): Recommends going for at least no net increase in pollutants discharged. Al expects this modification to go to Public Hearing. BOD Loading BODu—WLA in 1992 noted an ultimate BOD of 135 mg/l. Original model assumed a multiplier (CBODu/BOD5) of 1.5; typically 2 is assumed. I took a look at total BOD loading after expansion using both multipliers to compare. In both cases, net annual loading should decrease with proposed modified limits. 12/08/98 NCO021849 BAB Region Staff Report (10/12/98): No EAA submitted for this expansion; Add. info. request sent to facility on 10/ 14/98. Region concurs with modification as long as EAA approved and spec. limits are used. Confirmed that project does not fall under SEPA. Per Jason Doll, 7QlO would not be valid in this case since waters are tidal, so IWC > 33% is not an applicable criterion. EAA (received 11/ 13/98) Spray irrigation capital costs cited as double those of expanding the existing plant (difference of $3 M). Consequently no present value cost was performed, given that operation of both systems would cost about the same. Spray irrigation is the only option considered possibly feasible, but it is unclear what the bases for many of the cost estimates were: • Land acquisition-389 acres; what is basis for 389 acres? Is this for entire 0.7 MGD or only additional 0.3 MGD? No soils information was submitted. • What does "Spray Irrigation Facility" include? Where does cost come from? Per Michael McAllister, 12/2/98: 0 389 acres: assumed 1/2" rainfall per acre per week, which is typical for these soils (mainly sandy). This estimate also includes required buffers to property lines, etc. 0 Spray Irrigation option considered entire 0.7 MGD capacity; I explained that it should have only considered 0.3 MGD-43% (less than half) of what was used. Since acreage included buffers, McAllister said land estimate should be reduced by about a third. With reduced acreage, cost of land would still be approximately $625,000—does not bring cost significantly closer to WWTP expansion cost. He added that pumping would cost about the same, as well as spray irrigation facility (I question this ... ). a Spray irrigation facility includes pumping facility and spray heads for entire field. I have requested a breakdown of how the cost estimate for the spray irrigation facility was derived to supplement documentation. Fax from McAllister, 12/3/98 • $8,768/acre estimate. Since this is based on acreage, it should be reduced because of lower flow. If reduction is suggested 1/3, total cost should only be $1,987,413—a difference of almost $1 M. • Savings based on a more accurate land cost and spray facility cost, then, is a total of about $1.3 M. This means the cost of spray irrigation is about 50% more expensive, instead of 90% more. • Since cost differences depend heavily on acreage, I'll make a more conservative assessment —cut land/spray facility by half and compare the costs, in case 1/3 is too small. This would save almost $2 M, which brings the total cost of spray within 28% of WWTP expansion —still too high to justify as economically reasonable. Final Assessment Installing spray irrigation for additional 0.3 MGD would incur a significantly higher cost than expanding the existing facilities at the WWTP. Also, a UV -disinfection system win replace chlorine if the plant is upgraded, which is a benefit (also avoiding additional chlorination facilities for spray). Direct discharge is the most economically feasible and environmentally sound option for this facility, and the proposed modification to the permit is recommended. 2 12/08/98 Town of Hertford WWTP (NCO021849) Flow 8005 BOb5 CBOD,, CBOO,, NH3-N NBOD NBOD BOO,, Web) (m!g1l) I (lbs/day) I Mult.* I (mg/1) (lbs/day) I (m9/1) I (mg/1) (lbs/day) (lbs/day) CURRENT PERM=ED LOAD Summer (assumed NBOO=90 m9/1) 0.4 30.0 Winter (assumed NBOD=90 mg/1) 0.4 30.0 LOAD UPON EXPANSrON Summer 0.7 15.0 Winter 0.7 30.0 CURRENT PERM=ED LOAD Summer (assumed NBOD=90 mg/1) 0.4 30.0 Winter (assumed NBOO=90 mg/1) 0.4 30.0 LOAD UPON EXPANSrON 100.08: 1.5 45.0 150.12 20.0 100.08 1.5 45.0 150.12 20.0 87.57 175.14 1.5 22.5 131.355 4.0 1.5 45.0 262.71 90 300.24 '450.4, 90 300.24 45o.4 Total Annual 900.7 18 105.084 23 6_4 36 210.168 472.9., Total Annual 709.3 2 60.0 200.16 20.0 90 300.24 500.4 2 60.0 1 200.16 20.0 90 300.24 '500.4 Total Annual 1000.8 Summer 0.7 15.0 87.57 2 30.0 175.14 4.0 18 105.084 �',280..2 Winter 0.7 30.0 175.14 2 60.0 350.28 8.0 36 210.168. -,560.4 Total Annual 840.7 100.08 100.08 *Multiplier for CBOD u1BOD5, Typically 2 is assumed for domestic wastes; however, 1.5 was used in the original model for this facility. Above is a comparison of both. December 3, 1998 fog�o' State of North Carolhia Department of Environment And Natural Resources Division of Environmental Mana8ement NPDIF,S Permit Unit Post Office Box 29535 ftleisk North Carolina 27626-053 5 Attentioa Ms. Bethany Bolt SU13JF-CT: Cost Breakdown for Engineering Alternative Analysis Town of Hertford, North Carolina Permit No. NCO021849 Dear Ms. Bolt;, The following is a breakdown for the spray irrigation facility cost that you requested. It was assumed that approximately 340 acres of land would actually be used as spray field, the remaining 49 acres would be used for buffers and the storage lagoon. The total cost was derived from a per acre cost using the following; Assume $01 spaoing on sprinklers or 16 Sprinkler I -leads per Acres ($23,00/14ead) $ 348-00 840 LF of Pipe ($10-001F) 8,400,00 %!W40 $8,768.00/Acre $9,768-00 x 340 acres $2,981,120.00 - "I —A9 Ar_KC5-' 2��-76 if you have any questions or should require additional information, please call. 11,90-7,413'., Respectfully, Michael L_ McAllister NMNVald F,E9s-l?5/bolt-bleakdown-Itr.doc OR49H ENGINEERING, PLLC WATER. WAST9WATER. .5 URVEY114G, PLANNING. PROJECT MANAGEMENT �03 K. q,0LDFSQRQ ST. PO DOX 609 WItSON N­-, 17093 TEL 2512.2S7.S365 PAX 252.243.7489 GREEN Eq6Q(;OCENTRAL,C0M t4ppes ENGINEERING ALTERNATIVES ANALYSIS WASTEWATER TREATMENT PLANT IMPROVEMENTS TOWN OF HERTFORD, N.C* November 1998 Prepared By: GREEN ENGINEERING9 P.L.L.C. 303 North Goldsboro Street Wilson, North Carolina 27893 252-237-5365 1. Gen The Town of Hertford currently operates a 0.40 MGD wastewater treatment plant under current NPDES Permit No. NCO021849. The facility named "Hertford Wastewater Treatment Plant" is located on NCSR 1108 north of Hertford in Perquimans County. Telephone number (252) 426-8182. The Town wishes to increase the flow from this facility and has applied to the North Carolina Department of Environment and Natural Resources to expand this flow to 0.70 MGD. Any questions regarding the information contained in this report may be directed to: Michael L. McAllister Green Engineering, P.L.L.C. Post Office Box 609 Wilson, North Carolina 27893 (252)237-5365 The existing sanitary sewer collection system consists of six-inch (6") diameter through twelve -inch (12") diameter gravity sewer mains and'six (6) wastewater pumping stations. The system does have problems with infiltration/inflow during periods of extreme wet weather. Studies have been done and repairs have been made to correct this problem. The wastewater treatment facility is currently operating at 76% of capacity, based on the 1997 average flow. Therefore, it is necessary to expand—tNe —capacity of the treatment facilities to accommodate the expected and proposed growth in accordance with T15A:02H.0223(l) of the North Carolina Administrative Code. The followingt is an evaluation of these needs' The population growth of the Town of Hertford is anticipated to increase at a moderate pace over the next 20 years according to the North Carolina Office of State Planning (State Data Center). The following table shows the estimated population increase of 1246 for Perquimans County and the 262 for the Town of Hertford based on the census of 1990. 1990 2000 Perquimans Co. 10,477 10,945 Town of Hertford - 2,244 2,349 2005 2010 2015 2020 11,112 11,3 52 11,500 11693. 2,384 2,434 2,465 Based on 60 GPD per person, this equals an additional flow of 15,720 GPD (Reference T15A:02H.0219) and a Permit No. WQ001,099 �has recently been issued by NCDENR for the Perquimans Commerce Centre that allocates 144,000 GPD of additional flow. Also, the Town of Winfall wishes to discharge 0. 10 MGD to the p, lant. _1� 0,157 �- (),1444 4 0,[0 r- 0,4CD'I -14( 0.5 M (I D -;�7-�-7 Ii. It is planned to use as much of the existing wastewater treatment plant 'facilities as possible; however, most of the mechanical components are quite old and in need of repair. It is anticipated that some of the equipment and tankage can be used in the proposed upgrade, The following is a list of existing equipment and its planned use as part of this expansion. Existing Bar Screen and Structure: The current plan calls for this structure to be abandoned. A new mechanical bar screen and grit removal system is to be installed on the southeasterly portion of the site. /2. Existiniz Aeration Basin: This structure will be retained and modified for conversion to a sludge holding basin. A new multi -channel oxidation ditch will be constructed on the so ' utheasterly portion of the site. The floating aerators and mixers located in this structure shall be reused in the proposed aerobic digester. v:C Existing Clarifier: This unit will remain in service as part of the expansion. A new clarifier will be built adjacent to it as part of the expansion. Existing Chlorine Contact Basin: This structure is to be demolished since size is inadequate for the required detention time required Wi—th the additional ­AQW.,.-A n�ew�ultra---�f6fa-digfrif6diidii unit will be-biu-illf ,,"'5. Existing Sludge Return Pump Statio : The current RAS pump station is old, unreliable and of insufficient size. A new station is to be built near the clarifier. V 6. Existing Aerobic Digest : This structure will remain and be converted to apost aeration basin. A new aerobic digester shall be built elsewhere,on the site. V'17. Existing Sludge DI:yi:ng Beds: These will remain as is. Due to the nature of this type of facility; phasing of construction is not possible. Evaluation of Dinosal Alternatives The following is a brief evaluation of several disposal alternatives. Connection to a publicly owned treatment works (LPOTMO: There is not a facility of this type large enough within a five (5) mile radius capable of receiving the discharge. v,' �B Connection to a t)rivatelv owned treatm�e in the area. v� Individual Subsurface System:, A gravity this is not a feasible option. No facility of this type exists system is currently in place,