Presented by: Rich Grant, PE
21st Century Biofilm Reactors “TREATING FOR TROUT”
Northport/Leelanau Township Wastewater Treatment Facility
A Revitalizing Story: importance of collection The Technology; intro Benefits & Costs
Operations Energy Green
Robust; glacier country Stewardship
Concepts
Project Issues Small lots with old/failing
drainfields (or no system) Locally high groundwater table Poor draining soils Steep slopes Health Dept. not approving
on-site wastewater disposal
Service District Village of Northport Leelanau Township (portion) REUs- 450 Residential & 215
Institutional & Commercial
Project Background
Wastewater Treatment Facility Design 132,000 gpd 20-yr Avg. Day Design Flow
Design Influent Wastewater Strength Design: 275 mg/L BOD-5 & TSS 34 mg/L NH-3, 46 mg/L TKN 8 mg/L Total Phosphorus
Effluent Limits (Groundwater Discharge Venting to Surface Water)
0.3 mg/L Total Phosphorus 30 mg/L BOD-5 (8 mg/L) Total Nitrogen (treatment goal;
not effluent limit)
Project Background
Treatment Processes: Influent Fine Screening Pre-Anoxic Basin/Influent Equalization Moving Bed Biological Reactors (MBBRs) Cavitation Air Flotation (CAF) Effluent Equalization/Settling Basin Tertiary Filtration (Sand Filters in Series) Chemical Storage/Feed (Ferric Chloride) 2nd Treatment Basin (Future 2nd MBBR
reactor) Storage/Stdby Biosolids Storage Basin Rapid Infiltration Basins for final
discharge
Project Background
Highly polished effluent before discharge at R.I.B.s
Entirely Gravity Flow Hydraulic Design
Dual Polishing Filters, In Series
Rapid Infiltration Basins (RIBs)
3 New RIBs at Base of Hillside
2 Ex. Facultative Lagoons
Re-Constructed to Serve
as RIBs
MBBR: Moving Bed Biofilm Reactor (see also “IFAS”)
Technology: Norway for 1992 Lillehammer Winter Olympics
Attached growth system; similar to trickling filter, RBCs
Biofilm grows inside free-floating plastic media carriers in the tank(s)
Biofilm acclimates to operating conditions,
with reactors for anoxic & aerobic treatment
MBBR Process Description
50% to 90% smaller footprint required for the same treatment as conventional activated sludge
Reduces mixing energy required
Aeration design is due to oxygen demand not mixing requirement
MBBR is Energy Efficient
Source Mark Steichen, et al “Carbon Footprinting of Wastewater Treatment Technologies”
MBBR is “Green”
Smaller “carbon footprint” lifecycle
Current DEQ standards for “green” show the Northport WWTP Project meets the definition of a "Categorical GPR Project” under
1) "Energy Efficiency" guidelines "use of improved technologies & practices to reduce energy consumption of water quality
projects” “use energy in a more efficient way” MBBR blower energy used for dual purposes, mixing and aeration. Smaller reactor = less energy for mixing Mixing energy = aeration energy (not typical of conventional RAS) MBBR biofilm carriers provide increased oxygen mass transfer efficiency, Increased Transfer Efficiency = reduced aeration and energy requirements. 2) "Environmentally Innovative" guidelines, " ... demonstrating new and/or innovative approaches to delivering services or managing water
resources in a more sustainable way.”
MBBR “Green Business Case”
Cost Comparisons For Various Performance
Example 25mgd WWTP
Source: “When is IFAS the Right Choice?” Johnson et al, Black & Veatch WEFTEC 2006
MBBR is “Innovative” MDEQ
Northport is first full-scale MBBR in Michigan
ACEC/MI – Honorable Conceptor Award for Engineering Excellence
National ACEC recognition award
Maintain Heat
Address Oxygen Depletion Failures (others)
Advantage of Free Carbon Source
Pre-Anoxic Basin Tri-Fecta
Maintain Heat
Traditional Nitrification Cut-off: 50-55F
This Project: Consistent Nitrification/De-Nite to 38F
Best available project site located on a hillside
Wetlands bordering bottom of hillside & surrounding area
Adjacent ex. facultative lagoons property donated to Village to incorporate with new WWTF
Loamy or clay soils a challenge for groundwater discharge
Installation and prove-out of infiltration/collection trenches
Site Challenges
Accumulation in Solar-Energy-Mixed Pond
Land-Applied at Agronomic Rates
Biosolids Reuse – Fertilizer Product
… important for discharge in Northport Creek Watershed
Millpond stocked annually with trout for the Derby
Some trout remain … and Northport Creek is so-designated
Preferred temperatures: 52-62F summer
Low nutrients
Low BOD
High D.O.
Treating for Trout
Trout like the typical Michigan Groundwater temperatures!
… Not required, but highly recommended
Highly recommended, given venting location to Northport Creek
Highly recommended , for groundwater quality, nitrates control
Included in the Design Year ‘Round with Cold Weather Operations
Classic Activated Sludge Performance: TYPICALLY LIMITED TO 50F
Consistent Performance This MBBR
At 38F !
1.4 mg/L Ammonia avg
6.8 mg/L TIN avg
30F Nitrification/De-Nite
… important for discharge in Northport Creek Watershed
Secondary + Tertiary Treatment
RIB Discharge to Groundwater, polishing and cooling in-ground
Groundwater Venting to Surface Water
Natural Polishing & Cooling
Northport WWTF & Collection System Operations & Maintenance Provided by OMI, Inc.
Lead Operator - Mark Huggard
District Manager – Chris Keister
Operation Manager - Scott Blair
Operations Overview
Questions?
Contact : Rich Grant, PE 800-494-5202
21st Century Biofilm Reactors “TREATING FOR TROUT”
Northport/Leelanau Township Wastewater Treatment Facility