CPAC Meeting 8-25-03
Transcript of CPAC Meeting 8-25-03
Combined Sewer OverflowCombined Sewer OverflowLong Term Control PlansLong Term Control Plans
An OverviewAn Overview
AgendaAgenda
What is a Long Term Control Plan? What are the steps/elements of the plan? Where is Toledo today with respect to CSO control? What are the decisions to be made? What types of projects would it include? What input is needed?
What is a Long Term Control What is a Long Term Control Plan?Plan?
A planning tool for effectively controlling CSO discharges
Identifies methods, projects, costs, and implementation timeline
Required by the Consent Decree and CSO policy
Improvements to sewer system – away from the WWTP
The Basic QuestionsThe Basic Questions
What is the plan for controlling (or eliminating) CSO discharges?
What will the water quality conditions be following implementation?
When will the elements of the plan be implemented? How much will it cost?
Contents of the PlanContents of the Plan
Actions – projects or programs
Schedules – when projects will happen
Where – locations where projects will be constructed
Costs – project expenditures; rate projections
Elements of the PlanElements of the Plan
Per Consent Decree- Flow Characterization Study- Water Quality Monitoring - Water Quality Model- Hydraulic Model- LTCP (Alternatives
Evaluation)
Public Participation ProcessPublic Participation Process
Public participation is a key element of the development of a Long Term Control Plan
The process includes: Informational/ Feedback meetings with the general
public- Later in the fall (to discuss expectations/ concerns)- Late spring (to discuss general plan options)- Next fall (to discuss a proposed plan)
Community Advisory Committee meetings Other public meetings as projects are implemented
Toledo Current ConditionsToledo Current Conditions
Toledo Current ConditionsToledo Current Conditions
Uncontrolled outfalls: 19 (overflow 20-60 times/year) Partially controlled outfalls: 12 (overflow 10-20
times/year) 4 additional overflows from tunnels, etc. Acres of combined area: approximately 12,000 Annual discharge: about 1,000 MG
CSO Area Tributary to TunnelsCSO Area Tributary to Tunnels
CSO Control InvestmentCSO Control Investmentby the Cityby the City
Previously Completed Projects- Downtown Tunnel: 5.8 MG- Swan Creek North Tunnel: 9.5 MG- Swan Creek South Tunnel: 4.3 MG- Sewer separation projects:
• St. Clair south of Williams (about 100 acres)
• New York and Summit (about 140 acres)
• Columbus area (about 600 acres)- Expenditures of over $50 million
What are the decisions?What are the decisions?
Definition of objectives – meet regulatory requirements or consider other system needs
Identify/set priorities for implementation Type of control measure to use, and where Determining the appropriate level of control How will success be measured
EPA ObjectiveEPA Objective
Meet water quality standards Improve surface waters for
aquatic life and recreation
City/Community ObjectivesCity/Community Objectives
May be multifaceted- Other regulatory requirements- Aging infrastructure- Other operational issues
Possibly include:- “Keep rates down…”- “Don’t build in my backyard…”- “Keep raw sewage out of rivers…”- “Keep sewage out of my basement...”- “Make the river safe…”
Implementation PrioritiesImplementation Priorities
Most improvement for the cost Protect sensitive areas Can be co-scheduled with other projects Have the greatest supplemental benefit
Control Method (Alternative) Control Method (Alternative) DevelopmentDevelopment
Each alternative has advantages and disadvantages- Cost- Public acceptance- Environmental benefits- “Infra-stretching” benefits
Alternative should be what is right for the specific location
More than one alternative may be used in a comprehensive plan
Types of ControlTypes of Control
Storage- Tunnels or basins
Treatment- Screening- Disinfection
Storage and Treatment- Basins
Collection System Controls- Sewer separation- Other management
options
Source controls- Runoff reduction- Pollutant reduction
StorageStorage
Storage holds excess volume from small storms
Large storms discharge to waterways
Does not include “treatment capability”
May be either tunnel or basin Reduces pollutants during
most storm events
Treatment Treatment
Partial treatment of sewage before it is discharged
Generally includes screening and disinfection of flow (public health issues)
Does not reduce pollutants of concern for aquatic life
Does not reduce amount or frequency of discharge
Disinfection process may harm aquatic life
Building would be required
Wet WeatherWet WeatherTreatment/StorageTreatment/Storage
Holds excess flow from smaller storms
Discharge during larger storms will be partially treated flow
Tank can be above or below ground
More pollutant removal than treatment or storage alone
Building required for treatment components (screens, disinfection)
Sewer SeparationSewer Separation
Eliminates discharge of sewage
May increase amount of pollutants on an annual basis due to increased stormwater discharge
May be coupled with other infrastructure upgrades
Most disruptive/highest potential service benefit to individual property owner
BeforeBefore
AfterAfter
Source ControlsSource Controls
Management method Includes a wide variety of
options Generally reduces size of
physical alternatives; does not eliminate
Includes such items as downspout disconnection, redirecting storm sewers
Level of ControlLevel of Control
How big should facilities be? At what frequency should untreated discharges occur? How much pollutant load reduction is necessary to
achieve measurable improvement in waterway? Does it meet water quality standards?
Input NeededInput Needed
Help define public expectations for level of pollution control
Identify special areas of the river that should be given priority due to existing uses or to spur development
Help the City make the best use of program funds Acceptability of projects (by type) Acceptability of various potential sites
Questions/CommentsQuestions/Comments