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HomeMy WebLinkAboutNC0023973_Correspondence_198705063 State of North Carolina Department of Natural Resources and Community Development Division of Environmental Management 512 North Salisbury Street • Raleigh, North Carolina 27611 James G. Martin, Governor S. Thomas Rhodes, Secretary - Mr. John Bauer Director of Public Utilities P.O. Box 18lo Wilmington, NC 28402 Dear Mr. -Bauer: May 6, 1987 R. Paul Wilms Director This letter is to confirm information that a member of my staff, Trevor Clements, relayed to you by telephone. As you know, it is dif- ficult to estimate an instream waste concentration (IWC) for facilities in the lower'Cape Fear Basin due to the effect of tides on water move- ment.. In yourcase, calculation of the IWC for the two Wilmington facilities is further complicated by stream regulation in the upper basin and by diversion of water in the lower basin via the Brunswick River. The best method for estimating an IWC"for your two facilities would involve the use of fluorescent dye studies to measure tidally - averaged dilution of the effluent in the receiving waters. You may want to consider performing this.type ofstudy sometime in the future. For your immediate need regarding the headworks analyses for the Northside and 'Southside plants,"- it is recommended that you use the following'information:` IWC..= Qw x 100 --7Q10 + Qw .where: Qw =:Eff1'uent-Flow (cfs) 7Q10 —lowest 7 = consecutive day.flow w/,probability of.occurring 1 in 10 years . -IWC Instream-waste concentration (8) Pollution Prrrnlian Pays' PA Boo 27687 RakW North Cardma 276117697 ef/..�..«.—.e� wnc 919-733 7015 - For the Northside facility: Qw = 8 MGD - 12.4 cfs reg. 7Q10 = 1121 cfs @ Navassa - 448 cfs diversion Brunswick River (assumed 40%) + -28 cfs HE Cape Fear River 701 cfs IWC - 12.4 x 100 = 1.7 percent 701 + 12.4 For the Southside facility: Qw = 12 MGD = 18.6 cfs reg. 7Q10 = 1121 cfs @ Navassa + 28 cfs NE Cape Fear River 1149 cfs IWC = 18.6 x 100 = 1.6 percent 1149 + 18.6 Therefore, our best estimates as to the IWC's for the Northside and Southside Wilmington facilities are 1.7 and 1.6 percent, respectively. These estimates might be considered since they do not account for tidal mixing. However, they do include credit for all of the estimated freshwater flow which is not conservative given the width of the river and the side - stream location of each discharge. Therefore, these estimates should be used with care and with full acknowledgement.of their uncertainty. DEM is recommending them for use in your headworks analysis. At this point in time, we are not recommending them for use in determining whole -effluent -toxicity limits. DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW ULT. BOD OF WASTE MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL. DISPERSION K1. K2 : WILMINGTON SOUTHSIDE CAPE FEAR RIVER 4.00 FEET 2500.00 FEET 450.00 CFS 12.00 MGD : 110.00 MG/L 1.60 KNOTS :10000.00 SO.FT. 0.77 MI/DAY 2.86 SO.MI./DAY 0.49 PER DAY 0.50 PER DAY BOD AT OUTFALL = 1,93705346588 MG/L. D.O. AT OUTFALL = 4.03537886516 MG/L MILEPOINT UPSTREAM NOD UPSTREAM D.O. 0.00 1.94 4.04 -0.25 1..68 4.07 -0.50 1.46 4.11 -0.75 1.26 4.15 -1.00 1.10 4.20 -1.25 0.95 4.25 -1.50 002 4.29 -1.75 0.72 4.34 -2.00 0.62 4.38 -2.25 0.54 4.43 -2.50 0.47 4.47 -2.75 0.40 4.50 -3.00 0.35 4.54 MILEPOINT DOWNSTREAM BOB DOWNSTREAM DO 0.00 1.94 4.04 0.25 1.80 4.01 0.50 1.67 3.99 0.75 1.55 3.99 1.00 1.43 3.98 1.25 1.33 3.98 1.50 1.23 3.99 1.75 1.14 4.00 2.00 1.06 4.02 2.25 0.98 4.03 2.50 0.91 4.05 2.75 0.65 4.07 3.00 0.79 4.09 1.0=. A.77 A.i 17, 3.50 0.68 4.14 3.75 0.63 4.17 4.00 0.58 4.19 4.25 0.54 4.22 4.50 0.50 4.24 4.75 0.46 4.27 5.00 0.43 4.29 5.25 0.40 4.32 5.50 0.37 4.34 5.75 0.34 4.37 6.00 0.32 4.39 6.25 0.30 4.41 6.50 0.27 4.44 6.75 0.25 4.46 7.00 0.24 4.48 7.25 0.22 4.50 7.50 0.20 4.52 7.75 0.19 4.54 8.00 0.17 4.56 8.25 0.16 4.57 8.50 0.15 4.59 8.75 0.14 4.61 9.00 0.13 4.62 .9.25 0.12 4.64 9.50 0.11 4.65 9.75 0.10 4.66 10.00 0.10 4.68 THE WASTELOAD ALLOCATION FOR WILMINGTON SOUTHSIDE IS 110 MG/L DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW ULT. ROD OF WASTE MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL. DISPERSION K1. K2 : WILMINGTON SOUTHSIDE CAFE FEAR : 4.00 FEET 2500.00 FEET 450.00 CFS 12.00 MGD : 110.00 MG/L 1.60 KNOTS :10000.00 SOFT. 0.77 MI/DAY 5.72 SQ.MI./DAY 0.49 PER DAY 0.50 PER DAY ROD AT OUTFALL = 1.40341659617 MG/L. D.O. AT OUTFALL = 4.24280213232 MG/L MILEPO.T.NT UPSTREAM ROD UPSTREAM D.O. 0.00 1.40 4.24 -0.25 1..28 4.26 -0.50 1.17 4.27 -0.75 1.07 4.29 -1.00 0.97 4.31 -1.25 0.89 4.33 -1.50 0.81 4.35 -1.75 0.74 4.37 -2.00 0.67 4.40 -2.25 0.61 4.42 -2.50 0.56 4.44 -2.75 0.51 4.46 -3.00 0.47 4.49 MILEPOINT DOWNSTREAM ROD DOWNSTREAM DO 0.00 1.40 4.24 0.25 1.32 4.23 0.50 1.25 4.23 0.75 1.18 4.22 1.00 1.11 4.22 1.25 1.05 4.23 1.50 0.99 4.23 1.75 0.93 4.23 2.00 0.88 4.24 �.25 0.83 4.25 2.50 0.78 4.26 2.75 0.74 4.27 3.00 0.70 4.28 3.50 0.62 4.31 3.75 0.59 4.32 4.00 0.55 4.33 4.25 0.52 4.35 4.50 0.49 4.36 4.75 0.46 4.38 5.00 0.44 4.39 5.25 0.41 4.40 5.50 0.39 4.42 5.75 0.37 4.43 6.00 0.35 4.45 6.25 0.33 4.46 6.50 0.31 4.48 6.75 0.29 4.49 7.00 0.27 4.50 7.25 0.26 4.52 7.50 0.24 4.53 7.75 0.23 4.54 8.00 0.22 4.56 8.25 0.20 4.57 8.50 0.19 4.58 8.75 0.18 4.59 9.00 0.17 4.60 9.25 0.16 4.62 9.50 0.15 4.63 9.75 0.14 4.64 10.00 0.14 4.65 THE WASTELOAD ALLOCATION FOR WILMINGTON SOUTHSIDE IS 110 MG/L DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW ULT. ROD OF WASTE MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL. DISPERSION K1 K2 : WILMINGTON SOUTHSIDIDE : CAFE FEAR 4.00 FEET 2500.00 FEET 450.00 CFS 12.00 MGD 110.00 MG/L 1.60 KNOTS :10000.00 SO.FT. 0.77 MI/DAY 9.73 SO.MI./DAY : 0.59 PER DAY 0.50 PER DAY ROD AT OUTFALL = 0.991849013242 MG/L. 1 D.O. AT OUTFALL = 4.35349860384 MG/L MILEPOINT UPSTREAM ROD UPSTREAM D.O. 0.00 0.99 4.35 -0.25 0.92 4.36 •-0.50 0.86 4.37 -0.75 0.80 4.38 -1.00 0.74 4.39 -1.25 0.69 4.40 -1.50 0.64 4.41 -1.75 0.60 4.42 •-2.00 0.56 4.44 -2.25 0.52 4.45 -2.50 0.48 4.47 -2.75 0.45 4.48 -3.00 0.42 4.49 MILEPOINT DOWNSTREAM DOD DOWNSTREAM DO 0.00 0.99 4.35 0.25 0.94 4.35 0.50 0.89 4.35 0.75 0.85 4.35 1.00 0.80 4.35 1.25 0.76 4.35 1.50 0.72 4.35 1.75 0.69 4.35 2.00 0.65 4.36 2.25 0.62 4'.36 2.50 0.59 4.37 2.75 0.56 4.38 3.00 0.53 4.38 "i.99 8.90 4.39 3.50 0.47 4.40 3.75 0.45 4.41 4.00 0.43 4.42 4.25 0.41 4.43 4.50 0.38 4.44 4.75 0.37 4.45 5.00 0.35 4.46 5.25 0.33 4.47 5.50 0.31 4.48 5.75 0.30 4.49 6.00 0.2B 4.50 6.25 0.27 4.51 6.50 0.25 4.52 6.75 0.24 4.53 7.00 0.23 4.54 7.25 0.22 4.55 7.50 0.20 4.56 7.75 0.19 4.57 8.00 0.1B 4.58 8.25 0.17 4.59 8.50 0.17 4.60 8.75 0.16 4.61 9.00 0.15 4.62 9.25 0.14 4.62 9.50 0.13 4.63 9.75 0.13 4.64 10.00 0.12 4.65 THE WASTELOAD ALLOCATION FOR WILMINGTON SOLITHSIDIDE IS 110 MG/L DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW ULT. ROD OF WASTE MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL. DISPERSION K1 K2 : WILMINGTON SOUTHSIDE : CAFE FEAR 6.00 FEET 2500.00 FEET 450.00 CFS 12.00 MOD 110.00 MG/L 1.60 KNOTS :15000.00 SQ.FT. 0.51 MI/DAY 2.86 SQ.MI./DAY 0.59 PER DAY 0.50 PER DAY ROD AT OUTFALL = 1.21376225855 MG/L. D.O. AT OUTFALL = 4.24234597021 MG/L MILEPOINT UPSTREAM ROD UPSTREAM D.O. 0.00 1.21 4.24 -0.25 1.06 4.26 -0.50 0.92 4.28 -0.75 0.80 4.31 -1.00 0.70 4.34 -1.25 0.61 4.38 -1.50 0.53 4.41 -1.75 0.46 4.44 -2.00 0.40 4.47 -2.25 0.35 4.50 -2.50 0.31 4.53 -2.75 0.27 4.56 -3.00 0.23 4.59 MILEPOINT DOWNSTREAM ROD DOWNSTREAM DO 0.00 1.21 4.24 0.25 1.11 4.23 0.50 1.01 4.23 0.75 0.92 4.23 1.00 0.84 4.23 1.25 0.76 4.24 1.50 0.69 4.26 1.75 0.63 4.27 2.00 0.58 4.29 2.25 0.52 4.31 2.50 0.48 4.33 2.75 0.43 4.35 3.00 0.40 4.37 7 _^c4 A.?L a _io 3.50 0.33 4.42 3.75 0.30 4.44 4.00 0.27 4.46 4.25 0.25 4.48 4.50 0.23 4.50 4.75 0.21 4.52 5.00 0.19 4.54 5.25 0.17 4.56 5.50 0.16 4.58 5.75 0.14 4.60 6.00 0.13 4.61 6.25 0.12 4.63 6.50 0.11 4.65 6.75 0.10 4.66 7.00 0.09 4.67 7.25 0.08 4.69 7.50 0.07 4.70 7.75 0.07 4.71 8.00 0.06 4.73 8.25 0.06 4.74 8.50 0.05 4.75 8.75 0.05 4.76 9.00 0.04 4.77 9.25 0.04 4.77 9.50 0.03 4.78 9.75 0.03 4.79 10.00 0.03 4.80 THE WASTELOAD ALLOCATION FOR WILMINGTON SOUTHSIDE IS 110 MG/L DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW ULT. ROD OF WASTE MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL. DISPERSION K1 K2 : WILMINGTON SOSUTHSIDE : CAFE FEAR 4.00 FEET 5280.00 FEET 450.00 CFS 12.00 MGD 110.00 MG/L 1.60 KNOTS :21120.00 SQ.FT. 0.36 MI/DAY : 2.66 SQ.MI./DAY 0.59 PER DAY 0.50 PER DAY ROD AT OUTFALL = 0.870121025661 MG/L. D.O. AT OUTFALL = 4.41851398381 MG/L MILEPOINT UPSTREAM ROD UPSTREAM D.O. 0.00 0.87 4.42 -0.25 0.76 4.43 -0.50 0.67 4.44 -0.75 0.59 4.46 -1..00 0.52 4.48 -1.25 0.45 4.50 -1.50 0.40 4.52 -1.75 0.35 4.55 -2.00 0.31 4.57 -2.25 0.27 4.59 -2.50 0.24 4.61 -2.75 0.21 4.63 -3. 00 0. 1,8 4.65 MILEPOINT DOWNSTREAM ROD DOWNSTREAM DO 0.00 0.87 4.42 0.25 0.79 4.41 0.50 0.71 4.41 0.75 0.65 4.42 1..00 0.59 4.42 1.25 0.53 4.43 1.50 0.48 4.45 1.75 0.44 4.46 2.00 0.39 4.47 2.25 0.36 4.49 2.50 0.32 4.51 2.75 0.29 4.52 3.00 0.27 4.54 ;.)n 6.-4 4.SA 3.50 0.22 4.57 3.75 0.20 4.59 4.00 0.18 4.61 4.25 0.16 4.62 4.50 0.15 4.64 4.75 0.13 4.65 5.00 0.12 4.67 5.25 0.11 4.68 5.50 0.10 4.69 5.75 0.09 4.71 6.00 0.08 4.72 6.25 0.07 4.73 6.50 0.07 4.74 6.75 0.06 4.75 7.00 0.05 4.76 7.25 0.05 4.77 7.50 0.04 4.78 7.75 0.04 4.79 8.00 0.04 4.79 8.25 0.03 4.80 8.50 0.03 4.81 8.75 0.03 4.81 9.00 0.02 4.82 9.25 0.02 4.82 9.50 0.02 4.83 9.75 0.02 4.64 10.00 0.02 4.84 THE WASTELOAD ALLOCATION FOR WILMINGTON SOSUTHSIDE IS 110 MG/L DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW LILT. DOD OF WASTE_ MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL. DISPERSION K1 K2 : WILMINGTON SOUTHSIDE : CAFE FEAR RIVER 4.00 FEET 2500.00 FEET 450.00 CFS 12.00 MGD 8.00 MG/L 1.60 KNOTS :10000.00 SQ.FT. 0.77 MI/DAY : 2.86 SQ.MI./DAY 0.59 PER DAY : 0.50 PER DAY BOB AT OUTFALL = 0.633572046446 MG/L. D.O. AT OUTFALL = 4.57384218583 MG/L MILEPOINT UPSTREAM ROD UPSTREAM D.O. 0.00 0.63 4.57 -0.25 0.54 4.59 -0.50 0.47 4.60 -0.75 0.40 4.62 -1.00 0.35 4.64 -1.25 0.30 4.66 -1.50 0.25 4.67 -1.75 0.22 4.69 --2.00 0.19 4.71 -2 25 0.16 4.72 -2.50 0.14 4.74 -2.75 0.12 4.75 -3.00 0.10 4.77 MILEPOINT DOWNSTREAM BOD DOWNSTREAM DO 0.00 0.63 4.57 0.25 0.58 4.56 0.50 0.53 4.56 0.75 0.49 4.56 1.00 0.45 4.56 1.25 0.41 4.56 1.50 0.38 4.56 1.75 0.35 4.57 2.00 0.32 4.57 2.25 0.30 4.58 2.50 0.27 4.59 2.75 0.25 4.60 3.00 0.23 4.61 3.50 0.19 4.63 3.75 0.18 4.64 4.00 0.16 4.65 4.25 0.15 4.66 4.50 0.14 4.67 4.75 0.13 4.68 5.00 0.12 4.69 5.25 0.11 4.70 5.50 0.10 4.71 5.75 0.09 4.71 6.00 0.08 4.72 6.25 0.08 4.73 6.50 0.07 4.74 6.75 0.06 4.75 7.00 0.06 4.76 7.25 0.05 4.76 7.50 0.05 4.77 7.75 0.05 4.78 8.00 0.04 4.78 8.25 0.04 4.79 8.50 0.04 4.80 8.75 0.03 4.80 9.00 0.03 4.81 9.25 0.03 4.81 9.50 0.03 4.82 9.75 0.02 4.82 10.00 0.02 4.83 THE WASTELOAD ALLOCATION FOR WILMINGTON SOUTHSIDE IS 8 MG/L DISCHARGER NAME OF ESTUARY DEPTH WIDTH FRESHWATER INFLOW WASTEWATER FLOW ULT. BOB OF WASTE MAX TIDAL VELOCITY CROSS-SECTION AREA ADVECTIVE VEL.. DISPERSION Ki K2 S WILMINGTON SOUTHSIDE I CAPE FEAR 7 4.00 FEET 2500.00 FEET I 450.00 CFS 2 12.00 MGD 2 17.50 MG/L 2 1.60 KNOTS :10000.00 SO.FT. I 0.77 MI/DAY 9.73 SO.MI./DAY 0.59 PER DAY I 0.50 PER DAY BOB AT OUTFALL = 0.412597069154 MG/L. D.O. AT OUTFALL = 4.67266209742 MG/L MILEPOINT UPSTREAM BOD UPSTREAM D.O. 0.00 0.41 .4.67 -0.25 0.38 4.68 -0.50 0.36 4.68 -0.75 0.33 4.66 -1.00 0.31 4.69 -1.25 0.29 4.69 -1.50 0.27 4.70 -1.75 0.25 4.70 -2.00 0.23 4.71 --2 25 0.22 4.71 -2.50 0.20 4.72 -2.75 0.19 4.72 -3.00 0.17 4.73 MILEPOINT DOWNSTREAM ROD DOWNSTREAM DO 0.00 0.41 4.67 0.25 0.39 4.67 0.50 0.37 4.67 0.75 0.35 4.67 1.00 0.33 4.67 1.25 0.32 4.67 1.50 0.30 4.67 1.75 0.29 4.67 2.00 0.27 4.67 2.25 0.26 4.68 2.50 0.24 4.68 2.75 0.23 4.68 3.00 0.22 4.69 ; . 9 4 1i.^1 4.A9 3.50 0.20 4.69 3.75 0.19 4.70 4.00 0.18 4.70 4.25 0.17 4.70 4.50 0.16 4.71 4.75 0.15 4.71 5.00 0.14 4.72 5.25 0.14 4.72 5.50 0.13 4.72 5.75 0.12 4.73 6.00 0.12 4.73 6.25 0.11 4.74 6.50 0.11 4.74 6.75 0.10 4.75 7.00 0.09 4.75 7.25 0.09 4.75 7.50 0.09 4.76 7.75 0.08 4.76 8.00 0.08 4.77 8.25 0.07 4.77 8.50 0.07 4.77 8.75 0.07 4.78 9.00 0.06 4.78 9.25 0.06 4.79 9.50 0.06 4.79 9.75 0.05 4.79 10.00 0.05 4.80 THE WASTELOAD ALLOCATION FOR WILMINGTON SOLITHSIDE IS 17.5 MG/L