Update on the Metro Nashville
Consent Decree Program
Scott Potter
2
Why We Are Here
• Planned actions to meet Clean Water Act
• The types of projects that will be constructed
• The impacts of these projects
• The costs of the Program
• The benefits of the Program
What is a Consent Decree?
The consent decree is an agreement based on
enforcement for violations of the Clean Water
Act between the following parties:
• Metro • EPA
• U.S. Department of Justice
• Tennessee Department of Environment and Conservation
4
Nashville is Not Alone:
Utilities with Consent Decrees
Atlanta $ 3 billion Birmingham $ 3 billion Cincinnati $ 1.5 billion Columbus, OH $ 2.5 billion Indianapolis $ 1.3 billion Louisville $ 850 million Northern KY San. $ 880 million Dist. No. 1
Program Communication Plan
• Proactive communication to advise Council
Members in advance of project
• Community meetings as needed prior to
construction
• On-going neighborhood communications
during construction
6
Combined and Separate Sewer Systems
Frequently Used Terms
ISSUE: SSO – Sanitary Sewer Overflows PLAN: CAP/ER – Corrective ISSUE: CSO – Combined Sewer Overflow PLAN: LTCP – Long Term8
• 2 ½ years to develop plans:
̵ Corrective Action Plan / Engineering Report for SSOs Long Term Control Plan for CSOs
• 11-year implementation period after approval • Stipulated penalties:
̵ $1,000 / SSO occurrence
̵ $3,000 / SSO occurrence after December 2014
• Corrective Action Plan / Engineering Report for SSOs – submitted September 2011
• Long Term Control Plan for CSOs – submitted September 2011
• Regulatory Response: none to date
• Implementation: Proceeding with key elements of the Program
10
Progress in Reducing SSOs
Corrective Action Plan / Engineering
Report – Sanitary Sewer Overflows
12
CAP / ER
Sources of
Inflow and
Infiltration
(I / I)
CAP / ER Sewer Defects Identified by Televised Inspection
14
CAP / ER
Defects identified in MWS sewers
CAP / ER
Hydraulic
Modeling for
2-year storm
event
61 permanent
and 144
temporary flow
monitors
16
CAP / ER – Hydraulic Modeling
Hydraulic model identifies level of sewer
surcharge in manholes during 2-year storm event.
Project type alternatives modeled to reduce
surcharging to
CAP/ER Project Types
18
CAP/ER – Project Types
CAP / ER Project Types
Inflow / Infiltration Reduction – Sewer Rehabilitation Cured-in-place Lining
20
CAP / ER – Project Types
CAP / ER – Project Types
22
CAP / ER – Project Types
Dry Creek Service Area
MWS
Sewer
Service
24
Dry Creek Projects
24
Conveyance Improvements: 7,900 feet (gravity)
22,900 feet (force main) Pumping Upgrades and Storage: 5 pumping
station upgrades and one 10 MG tank
Sewer Rehabilitation: 168,000 feet
Whites Creek
Projects
Sewer Rehabilitation: 250,000 feet Storage Upgrades: 4 tanks totaling 31 MG Conveyance Upgrades: 43,900 feet26 26 Sewer Rehabilitation: 250,000 feet Conveyance Upgrades: 43,900 feet Storage Upgrades: 4 tanks totaling 31 MG
Whites Creek
Projects
Central Projects
Sewer Rehabilitation: 1,250,000 feet
2 pumping station
upgrades and 6 storage tanks totaling 86 MG Conveyance Upgrades: 49,900 feet (gravity) 4,600 feet (force main)
28
Mill Creek Trunk
• Six miles of upsized sewer, ranging from 72 to 102 inches in diameter
• Extends from south of Briley near I-24 to the existing Barker Road / Omohundro storage
facility
• Requires significant easement acquisition
Mill Creek / Opryland Storage
• Phase I: 15 MG Barker Road / Omohundro
storage tank – existing • Phase II: New 15 MG
tank on existing property • Phase III: Four additional
15 MG tanks and 100 mgd pump station
30
CAP
/
ER Cost Summary
Central 73% Dry Creek 10% Whites Creek 17% Conveyance 35% Pump Station 5% Rehabilitation 38% Storage 22%
Total CAP
/
ER Cost:
Long Term Control Plan
32
34
Combined Sewer Systems
36
Nashville
Combined
Sewer
System
32 CSO
sites in 1990
8 CSO sites
in 2009
38
Water Quality Impacts
Mill Creek Whites Creek
Browns Creek Richland Creek
Water Quality – Recreation Areas
Mill Creek Whites Creek Browns Creek Richland Creek Riverfront Park40
CSO Alternatives – Level of Control
Performance curves modeled to identify cost-effective controls for typical rainfall year:
Public Input Highlights
Citizens Advisory Group and public meetings generated community input including:
• Value and concern for the Cumberland River
• Limit neighborhood impact
• Balance investment for improvements with impact to
ratepayers
• Priority for green solutions when appropriate
42
Recommended Level of Control
CSO Site
Overflows
(typical year)
Driftwood 0
Boscobel 0
Benedict & Crutcher 2
Schrader 2
Washington 11
Kerrigan 9
Washington
CSO Area
44
Cost: $ 17 million Status: Operational
Washington Level of Control
46
Kerrigan
CSO Area
Kerrigan CSO Discharge Site
Greenway
48
Kerrigan Level of Control
Green Initiatives for
50
Green
Infrastructure
Proposed for
Combined
Sewer Area
Proposed Green
Infrastructure Project
for Metro Parks
52
Low Impact
Development
Manual
Requires
Capture for 1”
Rainfall
Proposed MWS Incentive for Reducing
Runoff to Combined Sewers
Facilities installing green roofs would receive reduced sewer
54
Cost Summary for Consent Decree
CAP / ER $ 770 M 68%
LTCP $ 300 M 26%
Sewer Rehab (non-CAP/ER) $ 70 M 6%
Total * $ 1,140 M 100%
Cost Impact for Consent Decree
• Developed cash flow needs for program
• Impact: No immediate need for rate adjustment
• Developing revenue study to address long-term
56
Consent Decree Implementation
• Revise CAP / ER and LTCP if necessary
• Program Manager – CDM / AECOM
• Construction Manager – GSP / CH2MHill
• Project Set Designers:
5 Teams for equalization tanks and pumping stations 8 Teams for conveyance improvements
15 Teams for sewer rehabilitation 6 Teams for SBE engineering firms