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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.