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HomeMy WebLinkAboutNC0025712_Instream Assessment_19930108NPDES DOCUMENT SCANNING COVER SHEET NPDES Permit: NC0025712 Hookerton WWTP Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtC) Permit Modification Complete File - Historical Report Speculative Limits Instream Assessment (67b) Environmental Assessment (EA) Permit History Document Date: January 8, 1993 This document is printed on reuse paper - ignore curvy - content on the reirerse side DIVISION OF ENVIRONMENTAL MANAGEMENT Water Quality Section/Rapid Assessment Group January 8, 1993 MEMORANDUM TO: Jim Mulligan THROUGH: Ruth Swanek Carla Sanderson FROM: Dave Goodrich SUBJECT: Modification to Instream Assessment for the Town of Hookerton WWTP NPDES No. NC0025712 Greene County 030407 An instream assessment for the Town of Hookerton was completed by Technical Support on December 7, 1992. Roger Thorpe from the Washington Regional Office requested (by telephone on January 7, 1993) the instream assessment be rerun using a BOD5 limit of 65 mg/1 instead of 55 mg/l. Hookerton has requested this higher limit to assure their compliance during the course of the SOC. Using this greater input of oxygen - consuming wastes resulted in no changes in either the net change of lliG D.V. minimumn or the increase in the length of the sag. It is therefore recommended that this modification of SOC limits for BOD5 be granted since 67(b) criteria will not be violated and no significant impact on water quality is predicted by this change. cc: Roger Thorpe Kent Wiggins Central Files Pre-SOC Post-SOC TABLE 1. Instream Assessment Summary for the Town of Hookerton Wasteflow Assumptions Design Capacity Pre-SOC (12/90 - 11/91) SOC Flow Requested Pre-SOC + SOC Flow Model Input Summary Headwater conditions: S7Q10 Qavg Design Temperature CBOD (estimated by model @ Qw) NBOD (estimated by model @ Qw) DO (90% saturation) Wastewater Inputs: 1st Wasteflow 2nd Wasteflow Pre-SOC CBOD (1.5* Requested BOD5) Post-SOC CBOD (1.5*Requested BOD5) NBOD (4.5*assumed max. NH3-N) Qw (MGD) Model Output Summary* 0.0600 MGD 0.0195 MGD 0.0405 MGD 0.0600 MGD 31 cfs 858 cfs 27.0 °C 1.2 mg/1 0.74 mg/I 7.17 mg/1 0.0195 MGD 0.0600 MGD 97.5 mg/1 97.5 mg/1 90.0 mg/1 DO Net Distance D.O. Net Min. Change <5.0 mg/I Change (me) (me) (mi) (mi) 0.0195 4.59 NA 0.0600 4.45 .14 >8.25# NA >8.25# 0.0 *Summary results for summer conditions only. • #According to the Level B model, D.O. never recovers above 5.0 mg/1 until Contentnea Creek enters the Neuse River. DMSION OF ENVIRONMENTAL MANAGEMENT Water Quality Section/Rapid Assessment Group December 7, 1992 MEMORANDUM TO: Jim Mulligan THROUGH: Ruth Swanek 'arty Carla Sanderso FROM: SUBJECT: Dave Goodrich Instream Assessment for the Town of Hookerton WWTP NPDES No. NC0025712 Greene County 030407 Summary and Recommendations An instream assessment for the Town of Hookerton has been completed by Technical Support. Roger Thorpe from the Washington Regional Office has requested an SOC for Hookerton since the plant is unable to consistently meet limits for TSS, and BOD5. Hookerton has requested to be allowed to add flow (domestic waste) not to exceed the permitted flow of 0.06 MGD. The current wasteflow has averaged 0.0195 MGD in the past 12 months. Pre-SOC flows were considered to be this average flow (0.0195 MGD) and the design flow of 0.06 MGD was used as the post-SOC flow. Technical Support has no objections to the relaxation of the limits for TSS or BOD5. During analyses for the increased BOD5 limit, it was apparent that the additonal flow will not substantially affect the instream D.O. The EMC 67(b) criteria (the D.O. minimum shall not decrease by more than 0.5 mg/1 and/or the distance the D.O. is less than 5.0 mg/1 shall not increase by more than 0.5 mile) were maintained with the additional flow. Background The Town of Hookerton WWTP discharges to Contentnea Creek which is classified C-Sw NSW in the Neuse River Basin. The 7Q10 (summer) at the point of discharge is estimated to be 31 cfs, and an average flow of 858 cfs has been estimated by the USGS. Instream data in this area show DO concentrations below the 5 mg/1 level in summer months. Self -monitoring data indicate this facility is having difficulty meeting the monthly average limitation for BOD5 and TSS. Analysis and Discussion Headwater conditions (flows and water quality characteristics) were identical in both pre-SOC and post-SOC modeling analyses. Carbonaceous BOD values for the models were input as the requested monthly average of BOD5 (55 mg/I) multiplied by 1.5. Nitrogenous BOD was assumed to be at the concentration of NH3 which secondary treatment allows (20 mg/I) multiplied by 4.5. An instream assessment was performed using the Level B framework. A comparison was made using the average monthly flow for the past year (0.0195 MGD) and the average monthly flow for the past year plus the requested increase in flow (0.0405 MGD). Some change in instream DO was noted between the two flows. However, the difference in minimum DO between the two models was <0.5 mg/l. Further, the length of the sag did not significantly increase so criteria specified in 67(b) were not violated. Contentnea Creek has been designated as an area where water quality has been impacted but the causes and sources of this impact are not fully understood. Wasteload allocations will be determined on a case by case basis while a management strategy is pending. This area has been targeted for the 1996 Neuse Basin Plan update. cc: Roger Thorpe Kent Wiggins Central Files TABLE 1. Instream Assessment Summary for the Town of Hookerton Wasteflow Assumptions Design Capacity Pre-SOC (12/90 - 11/"91) SOC Flow Requested Pre-SOC + SOC Flow Model Input Summary Headwater conditions: S7Q10 Qavg Design Temperature CBOD (estimated by model @ Qw) NBOD (estimated by model @ Qw) DO (90% saturation) Wastewater Inputs: 1st Wasteflow 2nd Wasteflow Pre-SOC CBOD (1.5* Requested BOD5) Post-SOC CBOD (1.5*Requested BOD5) NBOD (4.5*assumed max. NH3-N) Qw (MGD) Pre-SOC 0.0195 Post-SOC 0.0600 Model Output Summary* 0.0600 MGD 0.0195 MGD 0.0405 MGD 0.0600 MGD 31 cfs 858 cfs 27.0 °C 1.2mg/1 0.74 mg/1 7.17 mg/1 0.0195 MGD 0.0600 MGD 82.5 mg/1 82.5 mg/1 90.0 mg/1 DO Net Distance D.O. Net Min. Change <5.0 mg/1 Change (mom) (mom) (I) (mi) 4.59 NA >8.25# 4.45 .14 >8.25# NA 0.0 *Summary results for summer conditions only. #According to the Level B model, D.O. never recovers above 5.0 mg/1 until Contentnea Creek enters the Neuse River. f_i- Svc-4z.- or✓nl oG %GG'.�rIe7oo✓ at/t/;•6416 6/2/--mhiat.(inek Q30007 hit-f 44a a tizarn /117( 7-51r, ?ted rAni ( Ae 65:Z -4 rth%/1 (ebo Q c6,?s' //) 7/47 ree&e. // 4-1‘ /171---_742,n /KA7 /5Jry2-7-;1/. 1;57-/e6m s-6:5c/occ-Air-- /tenigl Alt. /detest, -.$-./:Y/ktif /?;.odyiti:10 / • / ‘ .�T rAn 2€vei'6pi/ A7r,nt~ /.44 .5(( /-n>et2 / nor digclicerS /tereAll, pe.ar\ 6.:14.141 OrC 0/2o/2.4 7-t/1 /5. 4///0A4, 6em e,4K y;degS h6i& 6z-' a c; r c/t 5b /ek _s7 a5 a re -co d f , ao �/ GAG Ke lst rum 111;4f mode it 07771 e'-, add //$ )_-/AL 1;.? �'� - */11/ 45 tit A141 ne4/1-K /11.71 Z4171 WA ief?/.5 tj,e1, oi1 ��yll re- �t c'/ 71-740;IS ‘15t �U C DIVISION OF ENVIRONMENTAL MANAGEMENT 1 December 1992 MEMORANDUM TO: Ruth Swanek Instream Assessment Unit FROM: Roger Thorpe SUBJ: Water Quality Supervisor Washington Regional Office Instream Assessment Town of Hookerton Greene County The Town of Hookerton has applied for a SOC and requests additional flow (copy of application is attached). The design of the Hookerton lagoon system is 0.06 MGD and discharges to Contentnea Creek. The current average flow based on DMR data is 0 .95 MGD. I would anticipate including interim limits in the SOC of BOD - 55 mg/1 and TSS - 150 mg/1. Attached is a copy of the DMR data. The Town has requested that it be allowed to add flow under the SOC up to its design capacity. Please evaluate this request and advise me if this additional flow increase will result in significant stream degradation. Attachment RECEIVED DEC 0 2 f992 TECHNICAL SUPPORT BRANCH WASHINGTON�OFFICE 00I 0 1 1992 State of North CarolinaDA l410 Department of Environment, Health, and Natural Resouroes Division of Environmental Management .. APPLICATION FOR A SPECIAL ORDER BY CONSENT (INFORMATION REQUIRED FOR FACILITIES REQUESTING AN SOC) I. GENERAL INFORMATION: 1. Applicant (corporation, individual, or other ): Town of Hookerton 2. Print or Type Owner's or Signing Official's Name and Title (the person who is legally responsible for the facility and its compliance): Gene Hill, Mayor 3. Mailing Address: PO Box 296 City: Hookerton State: NC Zip: 28538 Telephone No.: ( 919 ) 747-3816 4. Facility Name (subdivision, facility, or establishment name - must be consistent with name on the permit issued by the Division of Environmental Management): Hookerton WWTP 5. Application Date: September 2, 1992 6. County where project is located: Greene II. PERMIT INFORMATION FOR THE FACILITY REQUESTING THE SOC: 1. Permit No.: NPDES No. NC0025712 2. Name of the specific wastewater treatment facility (if different from I.4. above): 3. Issuance Date of Permit: April 1, 1989 4. Expiration Date Of Permit: February 28. 1994 5. Attach a listing of all effluent parameters addressed in the permit, including limitations and monitoring requirements. III. COMPLIANCE HISTORY FOR FACILITY REQUESTING THE SOC: Please attach a listing of all SOC(s) and amendments, Judicial Order(s) and amendments, EPA 309 letter(s), EPA Administrative Order(s), civil penalty assessment(s), notices of violation(s), etc. issued for this facility during the past 5 years. This listing must contain the issue dates, reasons for issuance, when the facility returned to compliance and actions taken to return the facility to compliance. FORM: SOCA 10/91 Page 1 of 5 PAGE 3 (10/91) SOC REQUEST VI. REQUESTED TIME SCHEDULE TO BRING THE FACILITY INTO COMPLIANCE WITH ALL PERMIT CONDITIONS AND STATE REGULATIONS/STATUTES The applicant must submit a detailed listing of activities along with time frames that are necessary to bring the facility into compliance. This schedule must include interim dates as well as a final compliance date. The schedule should address such activities as: 1. Request any needed permit(s) 2. Submit plans, specifications and appropriate engineering reports to DEM for review and approval 3. Begin construction 4. Occurrence of major construction activities that are likely to effect facility performance (units out of service, diversion of flows, etc.). 5. Complete construction 6. Achieve compliance with all effluent limitations 7. Complete specific Infiltration/Inflow work 8. Have all pretreatment facilities achieve compliance with their pretreatment permits 9. Conduct needed toxicity reduction evaluations ('IRE) VII.IDENTIFY FUNDING SOURCES TO BE USED TO BRING THE FACILITY INTO COMPLIANCE The applicant must provide an explanation as to the sources of funds to be utilized to complete the work needed to bring the facility into compliance. Possible funding sources include but are not limited to loan commitments, bonds, letters of credit, block grants and cash reserves. This explanation must demonstrate that the funds are available or can be secured in time to meet the schedule outlined as part of this application. VIII. REQUEST FOR ADDITIONAL FLOW Only facilities owned by a unit of government may request to add additional flow to the treatment system as part of the SOC in accordance with NCGS 143-215.67(b). If a request is made, it must contain the following information: 1. If domestic wastewater flow is requested for residential and commercial growth, a justification must be made as to the flow being requested. This flow request must be based on past growth record, documented growth projections, annexation plans, specific subdivision commitments, etc. The justification must include a listing of all proposed development areas and associated flows. The total additional domestic flow that is needed during the term of this requested order is See Attached gallons per day. Page 3 of 5 PAGE 5 (10/91) SOC REQUEST b. The nonrefundable SOC processing fee of $400.00. The check must be made payable to The Department of Environment, Health and Natural Resources. Applicant's Certification: 1, cJ.-e,,2_ .►'- k ` , attest that this application for an SOC has been reviewed by me and is accurate and complete to the best of my knowledge. I understand that if all required parts of this application are not completed and that if all required supporting information and attachments are not inclua,'d, this application package will be returned as incomplete. Signature ---- A4:e Date -,2-97-- THE COMPLETED APPLICA11'ION PACKAGE, INCLUDING ALL SUPPORTING INFORMATION AND MATERIALS, SHOULD BE SENT TO THE FOLLOWING ADDRESS: NORTH CAROLINA DIVISION OF ENVIRONMENTAL MANAGEMENT WATER QUALITY SECTION FACILITY ASSESSMENT UNIT POST OFFICE BOX 29535 512 NORTH SALLSBURY STREET RALEIGH, NORTH CAROLINA 27626-0535 TELEPHONE NUMBER: 919/733-5083 Page 5 of 5 SUPPLEMENT TO APPLICATION FOR A SPECIAL ORDER BY CONSENT Town of Hookerton The following explanation and information corresponds to numbered requests on DEM Form SOCA 10/91. II. Effluent Limitations Parameter Monthly Average Units BOD5 30.0 mg/1 Flow .06 MGD TSS 90.0 mg/1 III. Compliance History for Facility Requesting the SOC The Town of Hookerton operates a facultative lagoon system. The effluent limit on BOD was violated on six occasions between May, 1991, and March, 1992, as detailed in Attachment A. In addition, the effluent limitation on total suspended solids was violated on four occasions between October, 1991, and Januarys 1992. These violations are also shown in Attachment A. Because of these violations, an assessment of civil penalties was issued to the Town of Hookerton dated June 29, 1992. IV. Explanation as to Why SOC is Needed In spite of efforts by the Town to bring the lagoon system into regular compliance, it has become obvious that these violations cannot be avoided by normal maintenance and operational attention. There is no known explanation for the non- compliance which began in May of 1991. Consequently, there is no reason to believe that the system will come back into compliance on a regular basis. As you know, the operation of a facultative lagoon system has a low potential for operational corrective action. V. Explanation of Actions Taken by the Applicant to Maximize the Efficiency of the Facility Prior to Requesting the SOC 1 The Town of Hookerton has sought advice from several sources in our unsuccessful attempt to bring the lagoon system into compliance. The previous engineers for the Town were not able to offer helpful advise, nor was the regional office of DEM. In addition, the Town has sought the help of the Rural Water Association but has thus far been unable to solve the problem. The Town has recently retained a new engineering firm, Hobbs, Upchurch & Associates, P.A., to assist in reaching a long- term solution to the problem. Two attempts have been made to increase the efficiency of the lagoon system by adding pumps to spray and aerate the wastewater in an effort to increase the treatment efficiency. The Town is presently attempting to filter the final effluent to reduce the BOD and TSS. The Town will continue to implement any suggestions made by their consulting engineers or other authorities which might offer advise. VI. Requested Time Schedule to Bring the Facility Into Compliance With All Permit Conditions and State Regulations/Statutes Before a compliance schedule can be made, it will be necessary to allow time for our engineering consultants to do research into the problem and make a decision on the plan to be implemented. The funding source has not yet been identified. This could play a major role in scheduling of the project. VII. Identify Funding Sources to be Used to Bring the Facility Into Compliance The Town's consulting engineers are presently exploring the funding sources which might be utilized for this project. Among these sources will be State Revolving Loan Funds from the Department of Environmental Management, Farmers Home Administration funding, bond sales, and various grant programs. VIII. Request for Additional Flow The Town requests that they be allowed to add additional domestic flow as allowed by the current NPDES discharge permit. The non-compliance of lagoon systems is generally caused by environmental conditions which promote algae growth or other upsets in the lagoon and are not directly related to the magnitude of the influent flow. In the event that additional industrial flows are needed, the Town will make a request to DEM based on actual commitments from the industry. 2 As mentioned, it is not expected that additional flow to this facility within the current permit limits will have an adverse effect on the performance of the lagoon. RH/rjp/augll 3 ATTACHMENT A EFFLUENT LIMITS VIOLATIONS FOR BOD5 *Reported pate parameter Value/Unit Monthly Limits May 91 BOD5 42.50 mg/1 30.0 mg/1 June 91 BOD5 39.50 mg/1 30.0 mg/1 Sep. 91 BOD5 38.50 mg/1 30.0 mg/1 Jan. 92 BOD5 36.00 mg/1* 30.0 mg/1 Feb. 92 BOD5 41.50 mg/1 30.0 mg/1 March 92 BOD5 44.50 mg/1 30.0 mg/1 EFFLUENT LIMITS VIOLATIONS FOR TSS Oct. 91 TSS 104.0 mg/1* 90.0 mg/1 Nov. 91 TSS 115.5 mg/1 90.0 mg/1 * Dec. 91 TSS 92.0 mg/1 90.0 mg/1 Jan. 92 TSS 134.0 mg/1 90.0 mg/1 * The reported values are based on monthly averages. * = Not assessed.