Potential Wetland Assimilation Plans for the New Orleans Wastewater Treatment Plant By Sarah K. Mack Environmental Scientist, Sewerage and Water Board of New Orleans
Wetland Assimilation
! Before Katrina ! Conventional Plant Expansion ! Wetland Mitigation Project
! After Katrina ! Wetland Assimilation ! Hazard Mitigation
Before Katrina
! Consent Decree ! EPA lawsuit over sewer discharge violations
! Corrective Action Plan ! Analysis ! Evaluation ! Upgrade of EBSTP Plant Capacity Improvement Plant Hydrograph
Plant Expansion
! $325,000,000 ! Ballasted Flocculation Unit ! Peak Wet Weather Flow ! 2010 ! Aging Pure Oxygen Process ! Parallel Treatment Train ! Conventional Activated Sludge Treatment ! Require 50 Acres of Neighboring Swamp
Wetland Mitigation
! 50 Acres Required Mitigation
! Partial Flow of Treated Effluent for Restoration
! Constructed Wetland for Peak- Wet Weather Flow
EBSTP
! Urgent Need for Restoration ! FEMFEMA- Pre-Katrina Conditions ! Primary Treatment- October 16 ! Flow 25 Million Gallons Day ! Secondary Treatment- November 16
EBSTP
! Currently 55% Restored ! Flow 70 Million Gallons Day (MGD) ! Current Pumping Capacity 180 MGD ! Electrical Power – 7 Generators ! 1.5 Year Time Frame for Restoration ! Estimated $70 Million for Restoration Now What?
!Expansion Needed? !Solids !TMDLs !Mitigation !70% Less Revenue
Wetland Assimilation
Site Convent Wetland Cost Treatment Treatment Savings Breaux $3,300,000 $664,000 $2,636,000 Bridge Mandeville $6,500,000 $1,500,000 $5,000,000
Source: Day, et al.
30 mg/L vs. 90 mg/L TSS
! 100 MGD ! $2,737,500 solids handling for 30 mg/L permit ! $912,500 solids handling for 90 mg/L permit ! 100 MGD $1,825,000 Annual Savings ! 10 MGD - $182,500 Annual Savings 10 M SPOT Satellite Image: 2 Sept 2005
UNO Lake Borgne
Treatmemt Plant Miss River Gulf Outlet Destroyed Wetlands
Tulane Potential Restoration Area French Quarter
DeWitt Braud and Rob Cunningham 10 M SPOT Satellite Image: 2 Sept 2005
UNO Lake Borgne
Treatmemt Plant Miss River Gulf Outlet Destroyed Wetlands
Tulane Potential Restoration Area French Quarter
DeWitt Braud and Rob Cunningham
Feasibility Study
! Small Bypass Design ! Peak Flow ! Wetland Mitigation for Expansion ! Comply with Consent Decree ! Full Expansion Design ! Provide Hazard Mitigation for Orleans & St Bernard ! Most Economic Savings ! Mitigation Banking – Revenue?
Plant Capacity Improvement Plant Hydrograph World Model
! Total Maximum Daily Loads (TMDL) ! 2010 ! Optimize Assimilation of Nutrients ! Policy ! Remain ! Change ! New
Funding
! Delta Regional Authority (DRA) ! Coastal Impact Assistance Program ! Louisiana Department of Natural Resources ! Louisiana Department of Environmental Quality ! Long Term Community Recovery Funds- LRA
Benefits of Using Natural Wetlands
! Improved Effluent Water Quality ! Increasingly Stringent Water Quality Criteria ! No TMDLs ! 90 TSS-30 BOD ! Financial and Energy Savings ! Lower Capital Investments ! Restore Wetlands ! Hazard Mitigation Recognition for SWBNO
! Innovative
! Environmental
! Economic
Waste is a Resource Out of Place
References
! Day, J.W., J.Y. Ko, J. Rybczyk, D. Sabins, R. Bean, G. Berthelot, C. Brantley, L. Cardoch, W. Conner, J.N. Day, A.J. Englande, S. Feagley, E. Hyfield, R. Lane, J. Lyndsey, J. Mistich, E. Reyes, R. Twilley. The use of wetlands in the Mississippi Delta for wastewater assimilation: a review. Ocean and Coastal Management 47 (2004) 671-691. ! Ko, Jae-Young, John W. Day, Robert R. Lane, Jason N. Day. A comparative evaluation of money-based and energy-based cost- benefit analyses of tertiary municipal wastewater treatment using forested wetlands vs. sand filtration in Louisiana. Ecological Economics 49 (2004) 331-347. ! www.gosserp.com ! www.mvn.usace.army.mil/ops/regulatory/recwet.htm ! www.mvn.usace.army.mil/ops/regulatory/guide.htm Technical Constraints
! Wastewater Characterization
! Design
! Construction
! Site-specific