Presentation Outline Project Background
Treatment Process Overview
Historic Operations
Operational Challenges
Regulatory Changes
Process Modifications
Steuben County Landfill/LTP Leachate Treatment Plant
New Bath Landfill
Old Bath Landfill
Steuben County Leachate Pre-Treatment Plant (LTP) Commissioned Late 1990s
Pretreatment of Leachate for New/Old Bath Landfills
Processes: Chemical Precipitation (pH Adjust)
Heavy Metals Biological Treatment (Sequencing Batch Reactors)
BOD (Biological) Ammonia (Nitrification)
Discharge to Village of Bath WWTP Industrial Discharge Permit 5 Mile Long Force Main 275’ Elevation Gain (many high points)
Industrial Discharge Permit Bath Operates Under “Mini” Pretreatment Program
Historically 5 Industrial Discharge Permits (Now 4)
Leachate Treatment Plant
Flow (110,000 gpd Max / 88,000 gpd – Ave)
BOD – 300 mg/L
TSS – 300 mg/L
Ammonia (NH3) – 50 mg/L
pH 5-9
Several “Monitor Only” Parameters
Steuben County LTP
EQ Tanks MRRs
SBRs
Leachate Treatment Process Steuben County Landfills
Outside Facilities: ~50% of Flow
IEQ Tanks
SBR A
SBR B
EEQ Tank
To Village of Bath WWTP
MRR A
IEQ Tank
MRR B
Force Main Discharge
~5 Miles 5” HDPE ~200 Elevation Gain
LTP
SBR - Jet Aeration SBR – Concept
Treatment Occurs in One Tank
2 SBRs (Alternating Sequenc) 354,000 Gallons ~18-22 Depth
PD Blowers Mix w/ Recirculation Pumps
Blowers: 1370 scfm Jet Pumps: ~6,000 gpm
Jets Provide High Transfer Mixing of Air/Leachate
Est. 300 lb/hr. O2 Delivery
Sequencing Batch Reactor 4 Phases/Cycle/SBR
React/Fill – 240 min. React – 700 min. Settle – 300 min. Decant (Effluent) – 60 min. Waste (Control MLSS)
~24 Hour Cycle Time/SBR
DO/pH Monitoring
Provisions for Chemical Addition
1,000,000 BTU/hr Boilers
SBR Advantages Conventional/Proven Treatment Process
All Processes Occur in Single Tank Aeration/Reaction
Settling/Decant
Sludge Removal
Provides Additional Equalization/Buffering 15% Volume Change/Cycle
Jet Aeration (vs. Diffused) Provides Effective Anoxic Mixing
Well Suited For Leachate High Turbulence Limited Clogging Potential
LTP: 20 Years of Operations Limited Chemical Addition/No /Change in Performance
Good Compliance Record
Outside Sources of Leachate Sought
Increased Flows/Loading to Plant EQ Tanks at Plant Provide Flexibility
Wet Weather Flows Ability to Recirculate (During Drought)
Source of Outside Revenue ($$) 5 non-Steuben County Operated LFs
PLUS Other Industrial Wastewaters
LTP: 20 Years of Challenges 20 Year Old Plant
Pump, Blower Replacements
Tank Recoating
SCADA/Instrumentation
Several Systems Not Longer Used
Flow/Loading Variability
Multiple Landfills
Seasonality/Variability of Leachate Low Flow/High Conc (Summer)
Insufficient Flows (e.g., Drought 2016) Have Operated w/ One SBR
High Flow (Spring/Winter)
Operator Turnover
Force Main Discharge Hydraulics
Nitrification Review Nitrification Ammonia Removal
Nitrification Reactions
NH3 NO2 (Nitrosomonas)
NH3 + 1.5 O2 => NO2- + H+ + H2O
NO2 NO3 (Nitrobacter)
~4.6 lb O2: 1 lb NH3
Consumes Alkalinity/lowers pH
~7.1 lb Alkalinity:1 lb NH3
Nitrification & Leachate Challenges Kinetics Inhibitory Conditions TDS/Conductivity Ammonia Heavy Metals (not significant)
Changing Conditions 2016 Drought
Reseeding (Tank Maintenance) Temperature (15 deg C) Higher Oxygen Demand (4.6 lb O2/lb BOD) Alkalinity Requirements
Summer 2106
Summer 2106
~800 mg/L
Meanwhile…… Village of Bath WWTP 1.0 MGD (Permitted) <<0.5-0.8 MGD (Actual) Five SIUs (now 4) but only 1 Landfill
Revised SPDES Permit (Chesapeake Bay TMDLs) Total P: 1960 lb/yr Total N: 61,000 lb/yr
Upgrade completed 2016 Incorporated Anoxic Zones for Denitrification Long/Difficult Startup
Nitrogen Sources
Village of Bath WWTP Landfill Approached Spring 2016
“Fact Finding Mission”; New Monitoring Parameters TN TKN Nitrates/Nitrites TP
Industrial Users Will Have Modified Permits Landfill Likely to Have TN/TP Limits Awaiting Final Decision/New Permit Limits
Nitrification is NOT Nitrogen Removal NH3 NO3
Total Nitrogen Total Nitrogen = Organic N + NH3 + NO3+NO2
Raw Leachate: >99% NH3 (<100-2,000 mg/L) TKN ≈ NH3 NO3/NO2 = ND Total N ≈ NH3 (Typically)
Nitrification Removes Ammonia Nitrates
Denitrification Removes Nitrates Nitrogen Gas
Denitrification Uses Nitrates vs. Dissolved Oxygen Requires Anoxic (Low DO) Conditions (~0.3 mg/L)
Denitrification and SBRs SBRs (typically) well suited for Denitrification
Can Enhance Process (Provide Additional Alkalinity)
Typical Enhancements
Increased Anoxic Reaction
Carbon Source – Increase Denitrification Rate
Denitrifiers Tend to be More Resilient that Nitrifiers
May Effect Allowable Flow/Loadings
1 More Reaction Added
Desire for Outside Leachate/Revenue
Was it Already Happening?
Current Operating Parameters Have Substantial Idle Time
Settle ~ 5 Hours/Cycle
Decant ~ 1 Hour/Cycle
Idle ~ 2 Hours/Cycle
However, (currently) no Anoxic Mixing Capabilities
Total N and NO3/NO2 Sampling Initiated June 2016
Nitrate Hach Testing (2017)
Nitrogen Removal Evaluation
Period of Recirculation (No Discharge)
~20-60% N Removal
SBR (During Reaction)
Effluent Tank (Post Reaction)
Force Main Effluent ~ 12 Hours Retention
Raw Leachate
Village of Bath TMDL= 61,000 lb/yr
Effluent Tank
Total Nitrogen Removal Without Any Process Modifications, Some
Nitrogen Removal is Occurring
Current Conditions:
Settling, Decant, Idle Times Provide (Unmixed) Anoxic Conditions
Residual BOD provides carbon source
Long Retention Time in Force Main ~6-18 Hours
However…. No Guidance Provided on Future Permit Conditions
Process Enhancements Completed: In-House Testing Capabities (Total N)
Invaluable for Process Control/Contingencies
SCADA Upgrades (Summer 2017) New system to provide real-time monitoring/data collection for
DO/pH/others (likely ORP)
Increased Flexibility in Operations
Blower Performance/Efficiencies
Provide Opportunity for Pilot Testing
Remote Operations/Callouts
NEXT: Denitrification Pilot Testing Repurposing Exist Chemical Feed Systems
Apple Juice is Waiting
Summary SBR Proven Effective for “Moderate” Strength Leachate
For Steuben County: ~400-600 mg/L NH3 – Consistent Treatment Have Been Successful up to 800 mg/L NH3 Depends on Flow
Changing Conditions Signficant Challenge
Low Flows
Inadequate Loading
Chesapeake Bay TMDLs
What’s Next?
Denitrification Rate/Capacity is tbd
Questions?