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Home My WebLink AboutWQ0042884_Comments_20211108 NORRIS & TUNSTALL CONSULTING ENGINEERS P.C. 2602 Iron Gate Dr. Suite 102 1429 Ash-Little River Road Wilmington,NC 28412 Ash,NC 28420 (910) 343-9653 (910) 287-5900 (910) 343-9604 Fax (910) 287-5902 Fax John S.Tunstall,P.E. J.Philip Norris,P.E. T.Jason Clark,P.E. Joseph K.Bland,P.E. Robbie P. Hennelly,E.I. Thomas'.Scheetz,E.I. November 1, 2021 Mr. Bryan Lievre NCDEQ / DWR Water Quality Section — PERCS UNIT 512 N. Salisbury St., Archdale Bldg. 9th Floor Suite 925 Raleigh, NC 28604 RECEIVED Re: Village Point Estates LPSS Application WQ0042884 Review Comment Response NOV 0 8 2021 N&T Project No. 20156 NCDEQ/DWR/NPDES Dear Mr. Lievre, We are responding to your emailed comments of October 25, 2021, as follows: I. General Review: 1. A set of revised, final plans, specifications, and supplementary documents is enclosed in a CD. II. Plans/Specifications: 1. The requested pump curve is enclosed. 2. The location of watermains and stormdrains have been added to the drawings. 3. The note has been added. III. Calculations: 1. The buoyance calculations are enclosed. We have also included a revised set of pressure calculations as the preferred pump has changed from the Myers WGL 20 to a Myers VS20. Please let us know if you need any other information. Sincerely, NORRIS & TUNSTALL ONSULTIN GINEERS, .C. J. Ph Hip No s, P.E. JPN/ w 2015611-01-21 s-swr-Itr-asea-resp. c • Len McLamb NCBELS License C-3641 ` O'-- 3 '� _ TOWN OF SHALLOTTE 4'fep tl,l i)�i yN. Ai CA4�• Post Office Box 2287• Shallotte,North Carolina 28459 Telephone:(910)754-4032•Facsimile: (910)754-2740 Village Point Estates Sewer Extension Project Narrative /Downstream Sewer Evaluation Project Description: The Town of Shallotte is proposing to add ten additional residential users to the existing sewer system serving Village Point Estates. The existing sewer system is a gravity sewer that was installed in 2002 and was included under permit WQ0020398. The anticipated flow will be an additional 2100 gpd. The ten proposed lots are too low to be served by the existing gravity sewer, so a new pressure sewer line will be installed to carry the proposed flow to the existing gravity sewer. Downstream Sewer Evaluation: The existing Village Point Estates gravity sewer flows to the Brierwood Pump Station. The results for the Village Point Estates model are included in the engineering calculations. A node (#2) was placed in the model at the end of the proposed pressure sewer to model the worst case scenario. A second node (#1) was placed about halfway along the pressure sewer because the model will not run with only two nodes.The pressure sewer ties into an existing manhole (#0) in the Village Point Estates gravity sewer system. The proposed project pumps at Node #2 have an operating range of 31 gpm at 21' TDH, generating a flow velocity of 4.28 fps. The proposed pressure sewer is a 2"line, with plenty of capacity to serve the ten proposed lots. The proposed flow will be carried through the Village Point Estates gravity sewer to the Brierwood Pump Station (WQ0022816), which was expanded in 2008. The pump model that includes the Brierwood Pump Station (Node 7) indicates that the flow from that pump station will operate at a minimum of 173 gpm at 191' TDH with a velocity of 4.32 fps to the WWTP. The total permitted flow into the Brierwood Pump Station will be 54,770 gpd, or 38 gpm,so there is plenty of capacity in the existing pump station. ` • •b o '�i/ o • / • AL i • 16729 fo, �' , 9L'ZHc,NE� �v e 10/30/21 67(419i-rorv%� 11) i4Y"6- oi' • tokir • 0 r j ' 10 2, - �� Z� ■ 10 . __ ► • �� . ' 011TO Ivri.,,,,.... ,,:.7, . aplak� 9� „low ( AT (1 c � r Z cs,s.,,,#,,LF f 1 ... y ! HSys ' ■ tlio #401W.4k f F ■17 Acioseo/zIII r- +� 1;: 1 .4.0,- -- 4 0 a R I. 47- a 4 r/J\ ------' il "—i 'l 7— r\be 2a. V 41- I tia _ %6/ 54), Vitilab i 'l laS� O� I.II II\ZP:ir __,„.id‘r''' � VI a i 0LI-ol ,O/4'T SST TES -",_&:5Y, ^ - F� * * * * * * * * * * * * * * * * * * »» PUMP «« * * * * * * * * * * * * * * * * * * A PROGRAM FOR DETERMINING * * PIPE FLOWS AND SYSTEM HEADS * * OF A PRESSURIZED SEWER SYSTEM * * * * * * * * * * * * * * * * * * ENGINEER / FIRM : :C al/f�`4 STREET ADDRESS : CITY, STATE, ZIP : PROJECT NAME 1/://fire 111&41e54 PUMPS OPERATING : &/Je ierlee, ihsp TOTAL PUMP FLOW : / / DESIGN FLOW : GRINDER PUMP : EFFLUENT PUMP : LIFT STATION PUMP : INPUT DATA FILENAME = vilestl.DAT TABULATED OUTPUT FILENAME = vilestl.OUT POSTPROCESSING RESULTS FILENAME = vilestl.RES THE FOLLOWING UNITS ARE SPECIFIED: FLOWRATE IS EXPRESSED IN GPM AND PRESSURE IN PSIG PIPE TYPES FOR THIS SYSTEM DIAMETER DIAMETER PIPE LENGTH NOMINAL I.D. ROUGHNESS TYPE (ft) (in) (in) COEFFICIENT 1 308.00 2.00 2.05 130.000 2 300.00 2.00 2.05 130.000 3 50.00 1.50 1.72 130.000 + PUMP DATA FOR THIS SYSTEM PUMP TYPE # 1 IS DESCRIBED BY THE FOLLOWING DATA: HEAD DISCHARGE (ft) (gpm) 138.00 0.000 120.00 18.000 100.00 31.000 + FITTING TYPES FOR THIS SYSTEM FITTING MINOR LOSS TYPE COEFFICIENT 1 1.00 + PIPELINE DATA FOR THIS SYSTEM PIPE UPSTREAM DOWNSTREAM PIPE LENGTH DIAMETER ROUGHNESS MINOR LOSS NUMBER NODE NODE TYPE (ft) (in) COEFF. COEFF. 1 1 0 1 308.00 2.05 130.000 1.00 2 2 1 2 300.00 2.05 130.000 1.00 + SUMMARY OF DATA FOR PIPES ASSIGNED ASSIGNED CONNECTING LENGTH DIAMETER ROUGHNESS MINOR LOSS PIPE NODE (ft) (in) COEFF. COEFF. 3 2 50.00 1.72 130.000 1.00 + JUNCTION NODE DATA FOR THIS SYSTEM JUNCTION ELEVATION PUMP PIPE FITTING PUMP NUMBER (ft) TYPE TYPE TYPE STATUS TE 44.00 1 42.00 0 2 1 ---- 2 40.00 1 3 1 OPEN + **************************************** SIMULATION RESULTS **************************************** THE RESULTS ARE OBTAINED IN 52 TRIALS --- ACCURACY = 0.00000 PIPE FLOWRATE DIAMETER VELOCITY HEAD LOSS MINOR LOSS PUMP HEAD NUMBER (gpm) (in) (ft/s) (ft) (ft) (ft) 1 31.000 2.05 3.01 6.86 0.14 0.00 2 31.000 2.05 3.01 6.68 0.14 0.00 7�, r�- s 3 31.000 1.72 4.28 2.62 0.28 20.72 144 �' 11:4, + HYDRAULIC JUNCTION JUNCTION ELEVATION GRADE PRESSURE NUMBER (ft) (ft) (psi) 1 42.00 51.00 3.90 2 40.00 57.82 7.72 ***** MYERS PUMP ANALYSIS COMPLETE ***** • »»PUMP«« • • A PROGRAM FOR DETERMINING • • PIPE FLOWS AND SYSTEM HEADS • *OF A PRESSURIZED SEWER SYSTEM• •• • •• •• ••a• ••••• • ENGINEER/FIRM : /avn d01✓;4/A STREET ADDRESS : CITY, STATE, ZIP: ./ A / PROJECT NAME : OV/q,/1.41 /�s/� PUMPS OPERATING : Trco p i "4/.* 5 Gore it~Jews') TOTAL PUMP FLOW : / DESIGN FLOW : GRINDER PUMP : EFFLUENT PUMP : LIFT STATION PUMP : INPUT DATA FILENAME =vilest2.DAT TABULATED OUTPUT FILENAME-vilest2.0UT POSTPROCESSING RESULTS FILENAME=vilest2.RES THE FOLLOWING UNITS ARE SPECIFIED: FLOWRATE IS EXPRESSED IN GPM AND PRESSURE IN PSIG PIPE TYPES FOR THIS SYSTEM 4 2 50.00 1.72 130.000 1.00 + JUNCTION NODE DATA FOR THIS SYSTEM JUNCTION ELEVATION PUMP PIPE FITTING PUMP NUMBER (ft) TYPE TYPE TYPE STATUS TE 44.00 1 42.00 1 3 1 OPEN 2 40.00 1 3 1 OPEN + **************************************** SIMULATION RESULTS THE RESULTS ARE OBTAINED IN 51 TRIALS --- ACCURACY = 0.00001 PIPE FLOWRATE DIAMETER VELOCITY HEAD LOSS MINOR LOSS PUMP HEAD NUMBER (gpm) (in) (ft/s) (ft) (ft) (ft) 1 62.000 2.05 6.03 24.75 0.56 0.00 2 31.000 2.05 3.01 6.68 0.14 0.00 3 31.000 1.72 4.28 2.62 0.28 30.21 =-C 0ft' lag 4 31.000 1.72 4.28 2.62 0.28 39.03..X4e 4/1v y/5 + HYDRAULIC JUNCTION JUNCTION ELEVATION GRADE PRESSURE NUMBER (ft) (ft) (psi) 1 42.00 69.31 11.84 2 40.00 76.13 15.66 ***** MYERS PUMP ANALYSIS COMPLETE ***** Performance Data and Dimensions 3450 RPM Product Capabilities Capacities To 58.5 gpm 221.41pm [Dimensions in mm] if185ft. 56.34 m ��t 577 Heads To I i17] 11.69' [297] Liquids Handling domestic raw sewage Intermittent Liquid Temp. up to 140'F up to 60'C ill ��tr�7 Winding Insulation Temp. 311'F 155'C alai- . ar ii� (Class F) Motor Electrical Data 2 hp,3450 rpm 870' !Single phase motoraare capacitor awl 1 ph-capacitor start/run. type.Myers control panel.or capacitor kits [221] an recommended for proper operation and 230 volts;60 Hz warranty.) 3 ph-induction run 1-1/ 200,230,460 volts,60 Hz 15.81' NPT [402] Std.Third Party Approvals CSA ii i/mg Acceptable pH Range 6-9 7.13' Specific Gravity .9-1.1 -� � [i:17 Viscosity 28-35SSU Discharge(Flange Dia.) 1-1/4 in. 31.75 mm Min.Sump Diameter Simplex 24 in. 61.0 cm Duplex 36 In. 91.4 cm Construction Materials 2HP Pump Curves 200.00 -------- --- Motor Housing,Seal Housing, Cast Iron,Class30, Cord Cap and VoluteCase ASTMA48 —vs20 eons i-- — — """-__—.—_. _vx20 — Impeller Semi-Open,Stainless Steel —ergo MechanicalSeals: moo Standard Double Tandem Carbon and Ceramic Optional Lower Tungsten Carbide Pump,Motor Shaft 416SST. 2000 -- — Fasteners 300 Series SST y100.00 • --- ------ ------ - Rotating Cutter, 440 SST t Stationary Cutter 57-60Rockwell 60.00 00.00 40.00 i 20.00 —-- — 0 10 20 30 40 50 60 70 now(epm) + PENTAIR c). 1 1 1101 Myers Parkway I Ashland,OH 44805 I Ph:855.274.8948 I pentair.com/pentalr-myers Alltrademarks and logos are owned b•Pentair.All other brands or product names are trademarks or registered marks of their respective owners. Be auseiwer are co nY Because we are continuously improving our products and services,Pentair reserves the right to change specif ications without prior not ice.Pentair is an equal opportunity employer. 0694(02/07/19l:11.2019 Pentair plc.All Rights Reserved. • Village Point Estates WETWELL FLOTATION CALCULATIONS David B.Bowman,PE Wetwell Floatation Calculations Diameter: 36 inches Depth: 6 feet Buoyant Force=[PI(R)"2]*[H*62.41bslcf] Fb= 2646 lbs. VOLUME OF CONCRETE REQUIRED=Fb(Ib)I WEIGHT OF CONCRETE IN WATER(87.6 lb/cf) V,= 30.21 cf WEIGHT OF V,= V,*WEIGHT OF CONCRETE IN AIR(150 lb/cf) Wye': 4532 lbs VOLUME OF BASE(Vb)=(PI(Cl2)2* B]+ [PI(C/2)2-PI(D/2)2]*A D WETWELL DIA. WETWELL A CONCRETE BASE DIAMETER C I THICKNESS WITH WETWELL A= 1 ft FULL THICKNESS B= 1 ft CONCRETE BASE DIAMETER C= 5 ft WETWELL DIAMETER D= 3 ft Vb= 32.20