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