WQ0020808_Inspection_20190417

ROY COOPER
Gov'„o'
MICHAEL S. REGAN
s,,mr hvr
LINDA CULPEPPER
Director
NORTH CAROLINA
EnvirnrknneWal QualRy
April 1.7, 2019
Mr. Stanley Carter - Environmental Coordinator
[e-mail]
3M Company
Moncure, NC
Subject:
Dear Mr. Carter,
Permit No.W00020808
3M - Pittsboro Plant
Domestic Wastewater and Reclaimed
Water System
Chatham County
Staff of the NC Division of Water Resources (DWR), Water Quality Regional Operations Section
(WQROS), Raleigh Regional Office (RRO) inspected the 3M Company Wastewater Treatment and
Reclaimed Water Utilization Facility Permit No. W00020808 on April 16, 2019 as part of the permit
renewal process. James Zieglmeier, Stanley Carter and Randall Jarrell assisted during the inspection.
The site file has a copy of the current permit which was issued May 15, 2014 and expires November
30, 2019. Randall Jarrell is designated as ORC and Chad Leinbach is designated as Back-up ORC.
The reclaimed water from the on -site wastewater treatment facility and the City of Pittsboro
Reclaimed Water Distribution System is used in the on -site pug mill and cooling tower operations. A
records review was performed during the inspection. An O&M Plan and cross -connection protection plan
are followed and records maintained. All required analyses are reported monthly. All NDMR reports appear
to be accurate and lab reports indicate accurate reporting. O&M records are maintained on -site per the
permit.
The system is permitted for 5900 gpd and typically processes 1400 to 2000 gpd.
The flow meter was calibrated in 2018. The treatment unit including septic tank, pump tank, anoxic
section, aerobic section, membrane filtration, disinfection, pH adjustment and storage tank all appear well
maintained and properly operated. The septic tank was last cleaned January 14, 2015. The eight UV bulbs
are properly maintained and were replaced February 26, 2019. The membrane filters were changed April
8, 2014 and are monitored to make sure they adequately filter the wastewater. DO and pH meters are
calibrated by the ORC daily. All piping is properly color coded throughout the facility. The Pittsboro
Reclaimed Water supply tank is equipped with a turbidity meter to insure quality of incoming Reclaimed
Water. There is an automatic conversion valve if Pittsboro Reclaimed Water tank level drops to lower limit
and on -site reclaimed water volume is low, the system will switch to potable water with backflow
prevention valve in use. An automatic transfer switch is in place if turbidity exceeds 6 ntus, the system will
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switch to potable city water source with back -flow preventer in place. There is an auto -dialer for continuous
monitoring alarms for the system.
A connection for portable generator is in place in the event power fails for the site. A portable
generator can be installed and the switch manually transferred to keep wastewater treatment system active
even if plant is shut down by power failure.
A septic tank has been installed next to the guard shack. The tank is periodically pumped and
hauled to the W WTP on site. 3M intends to buy equipment to do the hauling themselves in the near future.
The backpulse tank is typically filled automatically, but a sensor has failed, so the ORC is manually
filling it until the new part arrives.
The ORC reported that the system is very efficient and that sludge has only been hauled on 3
occasions since it became operational in 2001.
On the day of the inspection, the system appeared to be operating in compliance with the permit
and is properly managed and maintained.
If you have any questions, please feel free to contact me via email at [e-mail]
or at [phone].
Sincerely,
j f 7,:� _.._.
6"Ray Uloslh�
Environmental Specialist
rav [e-mail]
919 791-4240
cc: RRC-WQRCS Files
DWR Central Files
Randall Jarrell via email@[e-mail]