Maumee River (East Side) Maumee River (East Side) Public Meeting Public Meeting

Long Term Combined Sewer Overflow Control Plan Input

February 10, 2005

Discussion AgendaDiscussion Agenda

• Program Overview• Combined Sewer Overflows

• Maumee River• Identification of Alternative Types• Potential Siting of Control Facilities• Opportunity for Input

CSO Control PlanningCSO Control Planning

• The City must control CSO discharges according to the consent decree

• Alternatives are being evaluated with respect to their feasibility, associated benefits and costs

• Public input on alternatives considered is sought in tonight’s meeting

Project TimelineProject Timeline

• The Long Term Control Plan Document is scheduled to be submitted to USEPA in July 2005

• A review and modification period will follow the plan submittal

• The work identified in the plan is to be completed by August 31, 2015

Combined Sewer Area Combined Sewer Area OverviewOverview

Maumee River (East Side) Maumee River (East Side) Combined AreaCombined Area

Maumee River Maumee River Overflow FrequencyOverflow Frequency

CSO # per Year

4 165 286 147 308 49 25

Maumee River Maumee River Overflow VolumeOverflow Volume

CSO Volume (MG)

4 75 306 57 778 19 115

Alternative EvaluationAlternative Evaluation

• Alternative Evaluation is based on reducing the frequency of overflow to 0 – 12 times / year

• Total elimination of overflows would only occur in the most costly alternatives

Type of AlternativesType of Alternatives

• Alternative selection is a combination of performance and suitability considerations

• There are a number of types of alternatives

CSO Control OptionsCSO Control Options

• Storage – holds excess flow until capacity is available

• Treatment – cleans flow before it is discharged – disinfects and removes pollutants

• Separation – provides new sanitary or storm sewers so that combined sewers are eliminated

• Flow reduction / rerouting can enhance the above options

Storage Basin Facility Storage Basin Facility Basic InformationBasic Information• Type of facility: concrete tank either concealed

or visible• Land area required: 3 – 10 acres• Typical siting locations: waterfront property,

parks, other vacant parcels near rivers• Other requirements: some sewer work to bring

flow to the site; building for support functions

Basin Storage FacilitiesBasin Storage FacilitiesStorage alternatives can be below grade as basins or Storage alternatives can be below grade as basins or tunnels. Generally some access hatches or support tunnels. Generally some access hatches or support structures are present.structures are present.

Storage Basin Facilities – Storage Basin Facilities – Pros and ConsPros and Cons• Pros

• Most work is limited to one location and the adjacent areas are not disturbed

• Volume and frequency of discharge to the river is reduced • Site can be designed to be aesthetically pleasing

• Cons• Use of land for other activities is limited• Construction activities are generally 2 – 3 years in duration

limiting the use of sites during that period• A building is required for support facilities• Some untreated overflow will remain

Storage Tunnel Storage Tunnel Basic InformationBasic Information• Type of facility: below ground tunnel• Land area required: limited land requirements –

most work is along a linear corridor and is not visible from the surface

• Typical siting locations: about 60 – 75 feet below grade; linear corridors (such as streets)

• Other requirements: drop shafts and discharge points with pump stations and control of floatables

Storage Tunnel Facilities – Storage Tunnel Facilities – Pros and ConsPros and Cons• Pros

• Most work is performed underground and at construction shaft locations, minimizing land needs

• Volume and frequency of discharge to the river is reduced • Toledo has successfully constructed similar projects

• Cons• Difficult to clean and access• Some untreated overflow will remain• A building would be required to house support facilities

Storage TunnelsStorage Tunnels

Storage tunnels primarily consist of large Storage tunnels primarily consist of large underground pipes 12 – 15 feet in diameter. underground pipes 12 – 15 feet in diameter. There are additional support structures that There are additional support structures that would be located at the end of the tunnel.would be located at the end of the tunnel.

Treatment Facility Treatment Facility Basic InformationBasic Information• Type of facility: smaller concrete tank with

screening and disinfection capability• Land area required: 2-5 acres• Typical siting locations: waterfront property,

parks, other vacant parcels near rivers• Other requirements: some sewer work to bring

flow to the site; above ground building to house equipment

Treatment Facilities – Treatment Facilities – Pros and ConsPros and Cons• Pros

• Most work is limited to one location and the adjacent areas are not disturbed. Facility footprint is smaller than storage facility.

• Small storms are stored. Larger storms discharge partially treated water.

• Water that goes to the river has been treated for bacteria.• Cons

• Treatment generally requires construction of a good size building, this building is larger than required for a storage only alternative due to more equipment.

• Facility is more complex to operate and maintain than a storage only basin.

Treatment FacilitiesTreatment Facilities

Three large treatment facilities in the Detroit Three large treatment facilities in the Detroit Area. These facilities generally require a Area. These facilities generally require a fairly large building.fairly large building.

Sewer Separation Sewer Separation Basic InformationBasic Information• Constructs a new sewer to separate flow• Generally requires 3 – 6 months to complete

work on a street; 1 – 2 years to complete work in an area

• Generally doesn’t involve land acquisition

Sewer Separation – Sewer Separation – Pros and ConsPros and Cons• Pros

• Upgrades the sewer system• Eliminates CSO discharges• Minimal property requirements

• Cons• May increase total amount of pollutants to the

waterways• Disruptive to individual property owner

Sewer SeparationSewer Separation

Sewer separation requires construction of new Sewer separation requires construction of new sewers in areas where a single pipe system exists.sewers in areas where a single pipe system exists.

Flow Reduction/Rerouting – Flow Reduction/Rerouting – Pros and ConsPros and Cons• Pros

• Addresses problem at the source• Could be considered best environmentally• Could reduce basement or surface flooding

• Cons• Generally not adequate to solve the entire

problem• Most disruptive to individual property owners• Administratively intensive program

Flow Reduction / Rerouting Flow Reduction / Rerouting PhotosPhotos

EPA CriteriaEPA Criteria

• The primary concern in other CSO Plans around the country is the frequency at which CSOs discharge

• The control of bacteria is important• Other items of concern

• Volume of discharge• Pollutants in discharge• Measurable impacts on waterways

Siting Issues / ConcernsSiting Issues / Concerns

• Consider• Areas of open space (sites), reasonably close to

outfalls• Current use of existing sites & associated impacts

due to construction or long term use• Ownership of sites• “Fatal flaws” such as environmental or geotechnical

issues• Opportunities for secondary benefit – e.g.

brownfield reuse, coordination with other projects

Maumee (East Side) Maumee (East Side) Potential SitesPotential Sites• Potential sites

• Potential sites have been identified based on location of open space

• Currently evaluating the feasibility of these sites• No decisions have been made about the use or non-

use of any site

Locations for Potential Locations for Potential Storage or TreatmentStorage or Treatment

Potential Flow ReductionPotential Flow Reduction

Storage Basin Sizing – Storage Basin Sizing – I-280 Right of WayI-280 Right of WayFrequency of Overflow

Required Storage Volume

0 per year 9 MG

1-3 per year 2 MG

4-7 per year 0.4 MG

8-12 per year 0.2 MG0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0 per year 1-3 per year 4-7 per year 8-12 per year

Potential Sites – Potential Sites – I-280 Right of WayI-280 Right of Way

Storage Basin Sizing – Storage Basin Sizing – Main St. & Nevada OverflowsMain St. & Nevada Overflows

Frequency of Overflow

Required Storage Volume

0 per year 20 MG

1-3 per year 8 MG

4-7 per year 3 MG

8-12 per year 1 MG 0.0

5.0

10.0

15.0

20.0

25.0

0 per year 1-3 per year 4-7 per year 8-12 per year

Potential Sites – Potential Sites – International ParkInternational Park

Storage Basin Sizing – Storage Basin Sizing – Oakdale AreaOakdale AreaFrequency of Overflow

Required Storage Volume

0 per year 34 MG

1-3 per year 14 MG

4-7 per year 3 MG

8-12 per year

1 MG

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 per year 1-3 per year 4-7 per year 8-12 per year

Potential Sites – Potential Sites – Oakdale AreaOakdale Area

Storage Tunnel AlternativeStorage Tunnel Alternative

Storage Tunnel SizingStorage Tunnel SizingFrequency of Overflow

Storage Volume / Diameter

0 per year 63 MG 28 ft

1-3 per year

24 MG 17 ft

4-7 per year

6 MG9 ft

8-12 per year

3 MG6 ft

0

10

20

30

40

50

60

70

Existing Tunnels 0 per year 1-3 per year 4-7 per year 8-12 per year

Evaluations Are ContinuingEvaluations Are Continuing

• Additional cost development and comparison to benefits are ongoing

• Better definition of potential sites and discussions with property owners / operators

• More technical evaluations (will support cost assessment)

How You Can HelpHow You Can Help

• Provide feedback on the alternative types through the various stations

• Let us know what you like and don’t like and the type of alternative

• Give us feedback on the potential sites • Provide other comments on what is important to

you• Ask questions at the various station locations