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Home My WebLink AboutNC0023884_Correspondence_19930727State of North Carolina Department of Environment, Health and Natural Resources Division of Environmental Management James B. Hunt, Jr., Governor Jonathan B. Howes, Secretary A. Preston Howard, Jr., P.E., Director David W. Treme City Manager P.O. Box 479 Salisbury, NC 28145 DEHNR July 27, 1993 Subject: Relocation of Grants Creek WWTP to the Yadkin River NC0023884 Rowan County Dear Mr. Treme: I have reviewed the diffuser design submitted by Peirson & Whitman on your behalf. While the model results indicate that this diffuser should provide significant dilution of your wastewater, there may be installation and maintenance difficulties with such a complex design given the physical characteristics of the Yadkin River. EPA recommends initial dilution due to a diffuser be at least 10:1 for toxic discharges. Model runs indicate that this dilution is achievable with a fairly simple diffuser with one or two properly sized and directed ports rather than the sixty proposed by Peirson and Whitman. The wasteload allocation for the Grants Creek WWTP discharge to the Yadkin River is on hold pending additional information from the City. A cross-section of the river at the discharge point with width and depths is needed. In addition, vertical profiles of temperature and DO should be taken at quarter points across the river to determine if there is any stratification. If you have any questions about these comments and requests, please call me at (919) 733-5083. Sincerely, Betsy obfison Environmental Modeler cc: Coleen Sullins Mooresville Regional Office Central Files P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-5083 FAX 919-733-9919 An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper �2-3 f t� 73 4/9Z Jerk _ Row w 30 crs CO/LMO( SD 5o .3 25� G�MM� ga ✓L i.✓l _._ low Aat 2?co (O alb _ J ✓ti 36 � � 7?Q-e.c1 ��- p s la -no iv 7.s Ale as D a s Co2Mk�t = c �a — Lt,n. �S - 'v 3.81 Cb n-n x. ^ ., k <s` —s? \L& CONIA \>c Frew �u, ( ) Cb;-1 e�dK _ -tom. Lutay - • Cz Cout tx ? '-.� c� lnji • Z 0 ak �a w w G2.�1/ ✓vim•-' CORMIX SESSION REPURl: XXxxXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXxxxxxxxxXxxxxxxxXxxxxxxXXXxxxxx CORNELL MIXING ZONE EXPERT SYSTEM Parent system: CORMIX v.2.00 July 1992 SITE NAME/LABEL: Yadkin River -'- DESIGN CASE: relocation FILE NAME: salis2 Using subsystem CORMIX2: Submerged Multiport Diffuser Discharges (Version: CMX2 v.2.10 July 1992) Start of session: 07/26/93--10:20:27 ******»********************************************************************** SUMMARY OF INPUT DATA: AMBIENT PARAMETERS - Cross -SeCbi0f-I = bounded Width BS = 150 m Ambient f1owrate QA = Average depth HA 2.5 m Depth at discharge HD = 2.5 m Ambient velocity UA = P.0777 m/s Darcy-Weisbach friction factor F = 0.0361 Calculated from Manning's n = .025 Wind velocity UW = 2 m/s Stratification Type STRCND = U Surface temperature = 27 degC Bottom temperature = 27 degC Calculated FRESH -WATER DENSITY values: Surface density RHOAS = 996.51 kg/m^3 Bottom density RHOAB = 996.51 kg/m^3 __________________________________ DISCHARGE PARAMETERS: Submerged M41tiport Diffuser Discharge Diffuser type DITYPE = unidirectional perpendicular Diffuser length LD 91.4 m Nearest bank = right Diffuser endpoints YB1 = 29.3 m;__~� YB2 = 120.7 m Number of openings NOPEN = `60/ Spacing between risers/openings SPAC = 1.54 m Port/Nozzle diameter D0 = .15 m Equivalent slot width B0 = 0.01 m Total area of openings A0 = 0.0176 m^2 Discharge velocity U0 = 0.30 m/s Total discharge 00 = .3286 m^3/s- Discharge port height H0 = ~8 m Nozzle arrangement BETYPE = unidirectional without fanning Diffuser alignment angle ALIGN = 90 deg Vertical discharge angle THETA = 30 deg Horizontal discharge angle SIGMA = 0 deg Relative orientation angle BETA = 90 deg Discharge temperature (freshwater) = 28 degC Corresponding density RHO0 = 996.23 kg/m^3 Density difference DRHO = 0.28 kg/m^3 Buoyant acceleration GP,"__,) = .0028 m/s^2 Discharge concentration C0 = 100 percent Surface heat exchange coeff. KS = 0 m/s Coefficient of decay KD 0 /s _________________________________________________________________________ FLUX VARIABLES PER UNIT DIFFUSER LENGTH: Discharge (volume flux) ' q0 = 0.003595 m^2/s Momentum flux m0 = 0.001114 m^3/s^2 Buoyancy flux j0 0.000010 m^3/s^3 DISCHARGE/ENVIRONMENT LENGTH SCALES : 1m' = VVVVV.V m 10' = VVVVV.y m la = TTY44.4 m ^^ .(Tb&se refer to the actual discharge/environment length scales.) . NON -DIMENSIONAL PARAMETERS: Slot Froude number FRO Port/nozzle Froude number FRD0 Velocity ratio R = = 54.81 15.24 3.98 MIXING ZONE / TOXIC DILUTION 70NE / AREA OF INTEREST PARAMETERS: Toxic discharge = no Water quality standard specified = no Regulatory mixing zone = no Region of interest = 1500.00 m downstream ***************************************************************************** HYDRODYNAMIC CLASSIFICATION: *____-______ 1 FLOW CLASS __________* *------------------------ * This flow configuration applies to a layer corresponding to the full water depth at the discharge site. Applicable layer depth - water depth = 2.5 m ***************************************************************************** MIXING ZONE EVALUATION (hydrodynamic and regulatory summary): X-Y-Z Coordinate system: Origin is located at the bottom below the port center: 75 m from the right bank/shore. NEAR -FIELD REGION (NFR) CONDITIONS : Note: The NFR is the zone of strong initial mixing. It has no legal implication. However, this information may be useful for the discharge designer because the mixing in the NFR is usually sensitive to the discharge design conditions. Pollutant concentration at edge of NFR = 1.7851 percent Dilution at edge of NFR = 56.0 NFR Location: x = 45.70 m (centerline coordinates) y = .00 m z = 2.50 m NFR plume dimensions: half -width = 47.32 m thickness = 2.50 m FAR -FIELD MIXING SUMMARY: Plume becomes fully vertically mixed at 200.90 m downstream. ************************ TOXIC DILUTION ZONE SUMMARY ************************ No TDZ was specified for this simulation. ********************** REGULATORY MIXING ZONE SUMMARY *********************** No RMZ and no ambient water quality standard have been specified. ***************************************************************************** DESIGN CASE: rel tion FILE NAME: salis2 Subsystem CORMIX2: Submerged Multiport Diffuser Discharges (Version: CMX2 v.2.10 July 1992) END OF SESSION/ITERATION: 07/26/93--10:36:46 XxSXxxx3xxxXXxxxXxXxXxxxXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.XXXXXXXXXXXXX CORMIX PREDICTION FILE: 2222222222222222222222222222222222222222222222222222222222222222222222222222222 CORNELL MIXING ZONE EXPERT SYSTEM Subsystem CORMIX2: Subsystem version: Submerged Multiport Diffuser Discharges CMX2 v.2.10 July 1992 __ ------------------------- CASE DESCRIPTION Site name/label.- Design case. - FILE NAME: Time of Fortran run: Yadkin^River relocation cormix\sim\salis2 .cx2 07/26/93--10:25:35 ENVIRONMENT PARAMETERS (metric units) section 150.00 AS = 375.00 = 2.50 HD = 2.50 .078 F = .036 2.000 UWSTAR= .2198E-02 Bounded BS = HA UA UW Uniform density environment 996.51 DIFFUSER DISCHARGE PARAMETERS (metric DITYPE=unidirectional perpendicular BETYPE=unidirectional without fanning BANK = RIGHT DISTB = 75.00 QA USTAR units) YB1 = = 29.17 29.30 YB2 = -120.70 'GAMMA'= 90.00 THETA = 30.00 SIGMA = .00 BETA = 90.00 U0 = .310 Q0 = .329 = .3286E+00 RHO0 = 996.23 DRHO0 = .28 GPO = .2756E-02 CO = .1000E+03 CUNITS= percent !POLL = 1 KS = .0000E+00 KD = .0000E+00 FLUX VARIABLES - PER UNIT DIFFUSER LENGTH (metric units) q0 = .3595E-02 m0 = .1114E-02 j0 = .9907E 05 SIGNJ0= 1.0 Associated 2 d length scales (meters) lQ=B = .012 lM = 2.42 lm .18 Imp = 99999.90 lbp = 99999.90 la = 99999,90 FLUX VARIABLES - ENTIRE DIFFUSER (metric units) 00 = .3286E+00 M0 = .1018E+00 J0 = .9055E-03 Associated 3-d length scales (meters) LQ = 1.03 LM = 5.99 Lm = -4.10 Lb = 1.92 Lmp 99999.90 Lbp = 99999.90 NON -DIMENSIONAL PARAMETERS FRO = 54.81 FRD0 = 15.24 R (slot) (port/nozzle) FLOW CLASSIFICATION 222222222222222222222222222222222222222222 2 Flow class (CORMIX2) = MU2 2 2 Applicable layer depth HS = 2.50 2 222222222222222222222222222222122222222222 = 3.98 MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS CO - .1000E+03 CUNITS= percent NSTD = 0 CSTD = .1000E+07 REGMZ = 0 REGSPC= 0 REGVAL= 99999.90 XREG = .00 WREG = .00 AREG XINT = 1500.00 AMAX = 1500.00 X-Y-Z COORDINATE SYSTEM: ORIGIN is located at the bottom and the diffuser mid -point: -75.00 m from the RIGHT bank/shore. X-axis points downstream, Y-axis points to left, Z-axis points upward. NSTEP = 10 display intervals per module _____________________________________________________________________________ BEGIN MOD201: DIFFUSER DISCHARGE MODULE Profile definitions: BV = Gaussian 1/e (37%) half -width, in vertical plane normal to trajectory BH = top -hat half -width, in horizontal plane normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any) X Y Z S C BV BH .00 .00 .80 1.0 .100E+03 .01 45.70 END OF MOD201: DIFFUSER DISCHARGE MODULE - BEGIN MOD271: ACCELERATION 70NE OF UNIDIRECTIONAL CO -FLOWING DIFFUSER In this zone the diffuser plume becomes VERTICALLY FULLY MIXED over the entire layer depth (HS = 2.50m). Full mixing is achieved after a plumaedistance of about five layer depths from the diffuser. uv = myer oeptn vvertzcaiiy mzxeo/ top -hat half -width, in horizontal plane normal to trajectory S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any) X Y Z S C BV BH .00 .00 2.50 1.0 .100E+03 2.50 45.70 4.57 .00 2.50 56.0 .179E+01 2.50 45.31 9.14 .00 2.50 56.0 .179E+01 2.50 45.01 13.71 .00 2.50 56.0 .179E+01 2.50 44.79 18.28 .00 2.50 56.0 .179E+01 2.50 44.61 22.85 .00 2.50 56.0 .179E+01 2.50 44.46 27.42 .00 2.50 56.0 .179E+01 2.50 44.35 31.99 .00 2.50 56.0 .179E+01 2.50 44.27 36.56 .00 2.50 56.0 .179E+01 2.50 44.22 41.13 .00 2.50 56.0 .179E+01 2.50 44.20 45.70 .00 2.50 56.0 .171EY01 2.50 44.19 Cumulative travel time = � ,��. � END OF MOD271: ACCELERATION ZONE OF UNIDIRECTIONAL CO -FLOWING DIFFUSER BEGIN MOD251: DIFFUSER PLUME IN CO -FLOW Phase 1: Vertically mixed, Phase 2: Re -stratified Phase 2: The flow has RESTRATIFIED at the beginning of this zone. This flow region is INSIGNIFICANT in spatial extent and will be by-passed. END OF" MCID251: DIFFUSER PLUME IN CO -FLOW The width predictions in the following module will be adjusted by a factor of 1.07 in order to satisfy mass flux conservation in the far -field. BEGIN MOD241: BUOYANT AMBIENT SPREADING Profile definitions: BV = top -hat thickness, measured vertically BH = top -hat half -width, measured horizontally in y-direction ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any) Plume Stage 1 (not bank attached): X Y Z S C BV BH ZU ZL 45.70 .00 2.50 56.0 .179E+01 2.50 47.33 2.50 2.50 46.79 .00 2.50 56.1 .178E+01 2.50 47.44 2.50 .00 47.87 .00 2.50 56.3 .178E+01 2.50 47.55 2.50 .00 48.96 .00 2.50 56.4 .177E+01 2.50 47.65 2.50 .00 50.04 .00 2.50 56.5 .177E+01 2.50 47.76 2.50 .00 5i.13 .00 2.50 56.6 .177E+01 2.50 47.87 2.50 .00 52.21 .00 2.50 56.8 .176E+01 2.50 47.98 2.50 .00 53.30 .00 2.50 56.9 .176E+01 2.50 48.09 2.50 .00 54.39 .00 2.50 57.0 .175E+01 2.50 48.19 2.50 .00 55.47 .00 2.50 57.1 .175E+01 2.50 48.30 2.50 .00 56.56 .00 2.50 57.3 .175E+01 2.50 48.41 2.50 .00 Cuox"lative travel time = 688. sec END OF MOD241: BUOYANT AMBIENT SPREADING uourom cooroznave ror rmx_ric"u i5 u��uwrmzxoo oy e,w/ngm umpu`, nro - .="."`/ ~ .. , _ ------------------- BEGIN MOD261: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT Vertical diffusivity (initial value) = .268E-02 m^2/s Horizontal diffusivity (initial value) = .335E-02 m^2/s Profile definitions: BV = layer depth (vertically mixed) BH = Gaussian 1/e (37%) half -width in horizontal plane normal to trajectory ZU = upper plume boundary (Z-coordinate) AL = lower plume boundary (Z-coordinate) S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any) Plume Stage 1 (not bank attached): X Y Z S C BV BH ZU ZL 56.56 � .00 2.50 57.3 .175E+01 ,2.50 48.41 2.50 .00 Plume interacts with BOTTOM. The passive diffusion plume becomes VERTICALLY FULLY MIXED within this prediction interval. 200.90 .00 2.50 57.5 .174E+01 2.50 48.61 2.50 .00 345.25 .00 2.50 57.8 .173E+01 2.50 48.81 2.50 .00 489.59 .00 2.50 58.0 .172E+01 2.50 49.01 2.50 .00 633.93 .00 2.50 58.2 .172E+01 2.50 49.21 2.50 .00 778.28 .00 2.50 58.5 .170+01 2.50 49.41 2.50 .00 922.62 .00 2.50 58.7 .170E+01 2.50 49.60 2.50 .00 1066.97 .00 2.50 58.9 .170E+01 2.50 49.80 2.50 .00 1211.31 .00 2.50 59.2 .169E+01 2.50 50.00 2.50 .00 1355.66 .00 2.50 59.4 .168E+01 2.50 50.19 2.50 .00 1500.00 .00 2.50 59.6 .168E+01 2.50 50.39 2.50 .00 Cumulative travel time = 19244. sec Simulation limit based on maximum specified distance = 1500.00 m. This is the REGION OF INTEREST limitation. END OF MOD261: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT CORMIX2: Submerged Multiport Diffuser Discharges End of Prediction File 2P2PP222222222222222Pp222222222222P2222P2P222222P2PPP222P2P2222ER2PP2222PPPPP2E