WQ0042579_Inspection_20210916

Compliance Inspection Report
Permit: WQ0042579 Effective: Expiration: Owner : Brunswick County
SOC: Effective: Expiration: Facility: Mulberry Branch WRF
County: Brunswick Forest St Extension Nw
Region: Wilmington
Shallotte NC 28470
Contact Person: John Nichols
Directions to Facility:
System Classifications:
Primary ORC:
Secondary ORC(s):
On -Site Representative(s):
Related Permits:
Inspection Date: 06/23/2021
Primary Inspector: Bryan Lievre
Secondary Inspector(s):
Title: Utilities Director
Entry Time 10:OOAM
Reason for Inspection: Routine
Permit Inspection Type: High Rate Infiltration
Facility Status: Compliant ❑ Not Compliant
Question Areas:
Miscellaneous Questions
(See attachment summary)
Certification:
Phone: [phone]
Phone:
Exit Time: 01:45PM
Phone: [phone]
Inspection Type: Reconnaissance
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Permit: WQ0042579 Owner - Facility: Brunswick County
Inspection Date: 06/23/2021 Inspection Type : Reconnaissance Reason for Visit: Routine
Inspection Summary:
An inspection of the proposed Mulberry Branch Water Reclamation Facility (WRF) was performed on June 23, 2021 with a
follow-up visit performed on June 30, 2021. The purpose of the inspections was to determine existing conditions at the site
in order to review Permit Application W00042579. Present during the initial visit were: Donald Dixon, Brunswick County
Deputy Director, WW Operations; Bob Tweedy, Brunswick County Project Manager; Tim Webb, Brunswick County, Facility
Superintendent; Michael Garrity, Brunswick County, Facility Chief Operator; Ricky Babson, Brunswick County, Backup
Operator; as well as Morella Sanchez -King, Tyler Benson and Bryan Lievre (all with NCDEQ, DWR). Everyone above was
also present during the subsequent visit as well as Carter Hubard with WK Dickson & Co., Inc., Edwin Andrews with Edwin
Andrews & Associates, PC, and Patrick Mitchell with DWR.
The facility is proposed to be located at the same parcel as the Shallotte WWTF (Permit Number WQ0000798). The
proposed facility and the Shallotte WWTF will share a proposed headworks. A permit modification has also been submitted
for the Shallotte WWTF to provide for the proposed headworks as well as other modifications to its permit. The Shallote
WWTF is proposed to remain at the same flow of 0.5 mgd and the proposed Mulberry Branch WRF is seeking approval for
0.75 mgd
The proposed 0.75 million gallon per day (mgd) Mulberry Branch WRF generally includes;
o Two 12 inch in -line magnetic influent flow meters;
o A Headworks Station with:
• One 2,558 gallon Combination Box (aka Mixing Well) with influent autosampler;
• One 3.125 mgd rotary drum screen conveyor system with 6 mm openings;
• One manual bypass bar screen with 1" openings;
• An odor control system with carbon filtration media and 500 cfm blower;
• A grit removal chamber with 1.25 mgd stacked tray grit removal system and ;
- 250 gpm at 11.2 ft TDH submersible average flow operating pump;
- 160 gpm at 18.6 ft TDH submersible low flow sump pump;
o One 43,188 gallon Influent Pump Station with:
• Pump Station No. 1 with pumps to the Shallotte WWTP (WQ0000798), including:
- One 300 gpm at 32.4 ft TDH low flow pump;
- Two 1,650 gpm at 47.4 ft TDH peak capacity pumps;
- One magnetic in -line flowmeter;
• Pump Station No. 2 with pumps to the Mulberry Branch WRF (W00042579), including:
- One 520 gpm at 42.6 ft TDH low flow pump;
- Two 1,302 gpm at 82.2 ft TDH peak capacity pumps;
- One magnetic in -line flowmeter;
o One 355,424 gallon Equalization Tank with:
• One 2,928 gpm at 20 ft TDH jet motive pump for EQ Mixing;
• Two 450 scfm at 8 psi PD blowers;
o One Anaerobic Selector with:
• One 9,600 gallon Denitrification Tank with one 0.5 Hp mixer;
• One 81,158 gallon Bio-P Tank with one 2 Hp mixer;
• One 15,359 gallon Selector Tank with one 0.75 Hp mixer;
o Two 458,466 gallon Oxidation Ditches with:
• An Inlet Distribution (Diversion) Box;
• An automatic weir;
• A Jet Mixing System with a total of six 1,775 gpm at 25 ft TDH solids handling pumps;
• An aeration system with three 475 scfm at 8 psi PD blowers;
• A Combination Effluent Box;
o Two 133,137 gallon Clarifiers with effluent weirs;
o RAS/WAS Pump Station with:
• Pump Station No. 4 — RAS Pumps with:
- Three 394 gpm at 93.8 ft TDH self priming pumps;
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Permit: WQ0042579 Owner - Facility: Brunswick County
Inspection Date: 06/23/2021 Inspection Type : Reconnaissance Reason for Visit: Routine
- One in -line magnetic flow meter;
• Pump Station No. 5 - WAS Pumps with:
- Two 250 gpm at 102 ft TDH self priming pumps;
- One in -line magnetic flow meter;
o Two 1,875 mgd Disc Filters, each with a 41 gpm at 110 psi submersible backwash pump;
o Two banks of UV disinfection within each of two channels (1 backup), each bank with 12 bulbs;
o A turbidity sensor;
o An Effluent and Non -Potable Pump Station with:
• A 16,755 gallon wet well;
• An effluent autosampler;
• Pump Station No. 3 with:
- One 330 gpm at 24.9 ft TDH self priming low flow pump to infiltration basins;
- Two 1,302 gpm at 70.3 ft TDH self priming peak capacity pumps to infiltration basins;
- An in -line magnetic flow meter;
• Pump Station No. 9 with:
- Two 60 gpm at 189 ft TDH vertical turbine washdown pumps;
o One 594,520 gallon Aerobic Digester (aka Sludge Tank) with:
• One 5,856 gpm at 22 ft TDH solids handling pump;
• Three 322 — 580 scfm at 8 psi PD blowers;
o Pump Station No. 6 — Sludge Transfer with:
• Two 740 gpm at 44.1 ft TDH self priming pumps;
o Pump Station No. 7 - Drain Pump Station with:
• One 2,130 gallon tank;
• One 400 gpm at 22.4 ft TDH low flow self priming pump;
• One 800 gpm at 47.2 ft TDH peak flow self priming pump;
o Pump Station 8 - Scum Pump Station with:
• One 1,077 gallon tank;
• Two 275 gpm at 75 ft TDH vertical cantilever chopper pumps;
o Three High -Rate Infiltration Basins with separate flow meters and:
• 383,013 gpd, 86,459 ft^2 of surface area and loading rate of 4.43 gpd/ft^2 for Basin A;
• 227,082 gpd, 51,260 ft^2 of surface area and loading rate of 4.43 gpd/ft^2 for Basin B;
• 309,130 gpd, 69,781 ft^2 of surface area and loading rate of 4.43 gpd/ft^2 for Basin C;
• Proposed groundwater monitoring wells MW BA 1, MW BA 2, MW BA 3, MW BB 1, MW BB 2, MW BB 3, MW BC
1, MW BC 2, MW BC 3, MW W1 and MW W2;
o A gravity drain groundwater lowering system surrounding the High -Rate Infiltration Basins with two outfalls with level
spreaders and flow meters; and,
o All associated pipes,valves and appurtenances.
An visual inspection was performed on both dates of the proposed infiltration basins. Vegetation encountered was found to
include mostly pine trees with some small hardwoods with sparse to thick low lying brush with some native grasses.
Surficial soils appeared to be mostly fine sands and on both dates, surficial soils were dry. On June 30, 2021, several
shallow soil borings were advanced by Patrick Mitchell. No issues were encountered on -site to dispute proposed activities,
although concerns were noted about being able to maintain vegetation around each of the proposed basins.
Page 3 of 4

Permit: WQ0042579 Owner - Facility: Brunswick County
Inspection Date: 06/23/2021 Inspection Type : Reconnaissance
Reason for Visit: Routine
Type
Yes No NA NE
Lagoon Spray, LR
❑
Infiltration System
❑
Reuse (Quality)
❑
Activated Sludge Spray, LR
❑
Single Family Spray, LR
❑
Single Family Drip
❑
Recycle/Reuse
❑
Activated Sludge Drip, LR
❑
Activated Sludge Spray, HR
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