Maumee River & Swan CreekMaumee River & Swan CreekPublic Meeting #2 –Public Meeting #2 –

OptionsOptionsLong Term Combined Sewer Overflow Control Plan Input

March 9, 2005

Discussion AgendaDiscussion Agenda

• Long Term Control Plan Recap

• Control Alternatives• Common Elements• Alternative Differentials

• Alternative Descriptions

• 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, 2016.

Combined Sewer Area Combined Sewer Area OverviewOverview

Combined Area – Combined Area – Maumee River & Swan CreekMaumee River & Swan Creek

Maumee/ Swan Creek Maumee/ Swan Creek Overflow FrequencyOverflow Frequency

CSO ID

#/Year

4 16

5 28

6 14

7 30

8 4

9 25

23 13

24 5

25 15

26 17

27 23

28 1

29 <1

CSO ID

#/Year

30 7

31 6

32 7

33 33

42 3

43* 5

45 2

46 3

47 11

48 <1

50 <1

68* 9

69* 4

Maumee/ Swan Creek Maumee/ Swan Creek Overflow VolumeOverflow Volume

CSO ID

Volume mg/yr

4 7

5 30

6 5

7 77

8 1

9 115

23 5

24 <1

25 5

26 5

27 10

28 <1

29 <1

CSO ID

Volume mg/yr

30 <1

31 <1

32 2

33 38

42 <1

43* 53

45 2

46 1

47 12

48 <1

50 <1

68* 74

69* 19

Alternative EvaluationAlternative Evaluation

• Alternative evaluation is based on reducing the frequency of overflow to 0 – 12 times a year.

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

CSO Control OptionsCSO Control Options

• Three basic control options were considered:• 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.

Measurable Benefits of CSO Measurable Benefits of CSO ControlControl

• Reduced frequency of CSO discharge.

• Reduced volume of discharge.

• Reduction in pollutants discharged.

• Better water quality in rivers.

Alternative DefinitionAlternative Definition

• Alternatives have been identified for subareas of the Maumee River and Swan Creek.

• The following are common aspects of the defined alternatives.

Alternative Common Alternative Common ElementsElements• The number of overflow locations would be reduced from the

existing 26 to a minimum of 18 and a maximum of 22.

Alternative Common Alternative Common ElementsElements

• Remaining overflow would have less pollutant concentration.

Oxygen Demand (CBOD)

0

20

40

60

80

100

120

Before Low Control High Control Separation

co

nc

en

tra

tio

n (

mg

/l)

Bacteria (Fecal Coliform)

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

Before Low Control High Control Separation

co

nc

en

tra

tio

n (

cfu

/10

0m

l)

Alternative Common Alternative Common ElementsElements

• The tunnel systems would be improved to reduce overflow frequency and improve maintenance.

Alternative Common Alternative Common ElementsElements

• Overall frequency of discharge would be reduced.

CSO Frequency

0

10

20

30

40

Current Future Max Future Min

#/ y

ear

Alternative Common Alternative Common ElementsElements

• The total volume of untreated combined sewer overflow would be reduced.

CSO Untreated Overflow VolumeNot Including Existing Tunne l Systems

0

50

100

150

200

250

300

Current Future Max Future Min

MG

/ ye

ar

Alternative Common Alternative Common ElementsElements

• Some partially separated areas would be completely separated.

Alternative Common Alternative Common ElementsElements

• Outfalls would be consolidated.

Selection of AlternativeSelection of Alternative

• Siting of Facilities• East Toledo – three probable sites

• At I-280 interchange

• In International Park

• Near Miami and Oakdale

• West Toledo – two probable sites• Near Jamie Farr Park

• City owned property near Maumee Avenue

• Potential alternative – storage tunnel

Alternative OptionsAlternative Options

• There are several different options that must be considered prior to determining the final alternatives.

• These options include: type of control method technology, level of control.

Alternative OptionsAlternative Options

• Control technology• The degree of technology may vary.

Treatment Type

050

100150200250300350400

Storage Disinfection PrimaryTreatment +Disinfection

AdvancedTreatment

Co

mp

lex

ity

an

d C

os

t;

Eff

lue

nt

Qu

alit

y

Selection of AlternativeSelection of Alternative

• Technology Selection• Storage – basins or tunnels – holds excess flow until

WWTP has capacity. No disinfection of discharge. • Treatment – basin – would include disinfection.

Facilities would actually discharge more frequently than storage.

• Separation can be used where existing pipe network could be converted, and where costs are comparable to other methods.

Alternative Options – Level Alternative Options – Level of Controlof Control

• Total frequency of untreated discharge vs. cost of various alternatives.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Rel

ativ

e C

ost

0 Overflows / Year

1-3 Overflows / Year

4-7 Overflows / Year

8-12 Overflows / year

Selection of AlternativeSelection of Alternative

• Level of Control Selection• The range of level of control is between 0 – 12

overflows/ year.• Most approved plans have overflow frequencies of

2 – 6/ year. • Water quality benefits are limited if frequency is

reduced to 8/ year or less.• Costs increase exponentially as level of control goes

to zero discharges.

Selection of AlternativeSelection of Alternative

Selection of AlternativeSelection of Alternative

• Cost• The range of cost is large. • Every decision on level and type of control has a

cost implication.• There tend to be diminishing returns for larger

facilities.

How you can helpHow you can help

• Provide input on the following alternative elements:• Site Selection• Technology Preferences• Frequency of Overflow • Cost

• Provide other comments and ask questions.