NC0000272_Transition Plan_20230317

Canton, NC WWTP Transition Plan and Recommendations

1

WWTP Transition Plan
Phase I
1A Initial Outage Preparation(prior to beginning of mill outage)
PH control
Surge Volume—using Primary Clarifier
Chemicals required
Sulfuric Acid, C02, Coagulants/Polymers , Supplemental Nutrients
1B Beginning of Mill Outage (Similar to shutting down for annual outage)
Timeframe (Weeks)
Continue to run WWTP as an Activated Sludge System at full capacity
Monitor flow, BOD/surrogate loading, and Food/Microorganism (F/M) ratio
Phase 1 to end when flow/loading/F/M reaches 50% of normal levels—Use rolling average numbers—3-5day rolling average

2

AB or Digester
(2.3 MG)
AB or Digester
(2.3 MG)
Aeration Basin
(3.4 MG)
Aeration Basin
(3.4 MG)

#1
Primary Clarifier
(1.01 MG)
#2
Primary Clarifier
(3.47 MG)
#3
Primary Clarifier
(3.47 MG)
#4
Secondary Clarifier
(2.82 MG)
#5
Secondary Clarifier
(2.82 MG)
#6
Secondary Clarifier
(1.85 MG)

Flow
Splitting Station
Low
Lift
Pumps
Bar Screens
Grit Chamber
City Sewer
RAS

Belt Presses
Mill Wastewater
Primary Sludge
WAS
Phase I Initial Shutdown Activated Sludge Full Capacity

3

WWTP Transition Plan
Phase II (Time frame-Months)
Tank, vessel, mill, and piping clean-up
Similar to tail end of annual outages
Reduced flow and Loading
F/M will be reduced
Begin taking excess equipment off-line
Primary Clarifiers
Stop C02
Secondary Clarifiers
Take one of the two aeration trains out of service
Continue to run activated sludge process
Belt Presses
Low lift pumps

4

AB or Digester
Down
AB or Digester
(2.3 MG)
Aeration Basin
Down
Aeration Basin
(3.4 MG)

#1
Primary Clarifier
(1.01 MG)
#2
Primary Clarifier
(3.47 MG)
#3
Primary Clarifier
Storm Surge
(3.47 MG)
#4
Secondary Clarifier Emergency Use
(2.82 MG)
#5
Secondary Clarifier
(2.82 MG)
#6
Secondary Clarifier
(1.85 MG)

Flow
Splitting Station
Low
Lift
Pumps
Bar Screens
Grit Chamber
City Sewer
RAS

Belt Presses
Mill Wastewater
Primary Sludge
WAS
Phase II Partial Shutdown Activate Sludge

5

WWTP Transition Plan
Phase III (Timeframe—Months)
Phase III begins when mill flow/loading approaches zero
Municipal flow only approximately 1 MGD except for storm flows
Long Term End Game WWTP—Flow scheme
Primary Treatment
Grit chamber, Bar screen, Low lift pump/s as required, flow splitting station
Primary Clarification
#1 Primary Clarifier-1.01 MG
#2 & #3 storm surge (6.9MG)
Secondary Treatment
One train in ASB(Aerated Stabilization Basin) once through system
2.3 MG section aerated; 3.4 MG section final aeration and settling area

6

WWTP Transition Plan
Phase III continued
Secondary/tertiary Clarification
Last part of aeration train (3.4 MG)
#6 or #5 Clarifier
#4 & #5 Out of service available for emergency use (9.6 MG)
Storm surge or off-spec quality treated water
Flow Measurement, Reaeration, and Discharge
Flume—flow compliance
Reaeration Cascade—O2 injection
Final Discharge

7

AB or Digester
Down
AB or Digester
(2.3 MG)
Aeration Basin
Down
Aeration/
Settling
(3.4 MG)

#1
Primary Clarifier
(1.01 MG)
#2
Primary Clarifier Storm Surge
(3.47 MG)
#3
Primary Clarifier
Storm Surge
(3.47 MG)
#4
Secondary Clarifier Emergency Use
(2.82 MG)
#5
Secondary Clarifier
Emergency Use
(2.82 MG)
#6
Secondary Clarifier
(1.85 MG)

Flow
Splitting Station
Low
Lift
Pumps
Bar Screens
Grit Chamber
City Sewer

Belt Presses
Primary Sludge
Phase III Municipal Flow ASB once through Operation
Leachate/ storm flow

8

WWTP Transition Plan
Further Investigation/Data Needs
O2 Addition Optimization
City of Canton– WWTP data
Industrial components of Canton wastewater
Nitrogen and Ammonia content of Canton wastewater
Normal and Maximum flows
Landfill Leachate characterization
Last Permit Renewal Priority Pollutant analysis
Mill operator input on transition plan
Treatability study to confirm needed residence time for ASB (once through) operation
Sampling and analysis planned for the week of March 20.

9