cpac meeting 12-15-03
TRANSCRIPT
Water Quality UpdateWater Quality Update
Presented to CPAC
January 12, 2003
Objectives of Objectives of PresentationPresentation
• How tasks fit together to support the Long Term Control Plan
• What has been accomplished
Tools to Understand CSO Tools to Understand CSO ImpactsImpacts
• Flow Characterization• System Characterization and Flow Metering
• Hydraulic Sewer Model• Water Quality Study• Water Quality Model• Long Term Control Plan
Consent Decree Consent Decree RequirementsRequirements
• All study efforts required by consent decree
• CD included specific items each study must include
• Study work plans were approved April 7, 2003
• Reports for Flow Characterization and Water Quality Study are due in April 2004.
• Long Term Control Plan Report due October 2005.
System CharacterizationSystem Characterization
Subcatchment
Overland flow
Infiltratio
n
Domesticwastewater
Bayview WaterReclamation
Facility
Industrial wastewater
Flow MeteringFlow Metering
Subcatchment
Overland flow
Infiltratio
n
Domesticwastewater
Bayview WaterReclamation
Facility
Dry Weather Flow
StormwaterFlow
CombinedFlow
Combined SewerOverflow
Industrial wastewater
Flow toPOTW
Hydraulic Sewer ModelingHydraulic Sewer Modeling
Subcatchment
Overland flow
Infiltratio
n
Domesticwastewater
Bayview WaterReclamation
Facility
Industrial wastewater
Water Quality StudyWater Quality Study
Subcatchment
Overland flow
Infiltratio
n
Domesticwastewater
FLOW
Bayview WaterReclamation
Facility
Industrial wastewater
Water Quality ModelWater Quality Model
Subcatchment
Overland flow
Infiltratio
n
Domesticwastewater
FLOW
Bayview WaterReclamation
Facility
Industrial wastewater
Long Term Control PlanLong Term Control Plan
Subcatchment
Overland flow
Infiltratio
n
Domesticwastewater
FLOW
Bayview WaterReclamation
Facility
CSO StorageFacility
Industrial wastewater
How Monitoring/ Models Are How Monitoring/ Models Are Used in Long Term Control Used in Long Term Control PlanningPlanning• Monitoring
• Shows current conditions• Helps identify unusual operating conditions• Provide data to make sure models make sense
• Models• Fill in the gaps where we can’t monitor• Predicts what will happen with different rainfall
conditions• Allows evaluation of changes to the system
2003 Flow Metering 2003 Flow Metering LocationsLocations
2003 Flow Metering 2003 Flow Metering ProgramProgram• Meter Installation • Meters Installed May through August• Site Visits – Site Check/Data Download weekly
Metering Locations – data Metering Locations – data setset
Data SetData Set
• 1999 City-wide Flow Monitoring Study – 48 meters
• SCADA data – 47 data collection locations• 2003 Data – 36 metering locations• Point Place - __ metering locations• Overall – 130+ metering locations with
consistent data analysis techniques
2003 Metering Period 2003 Metering Period Rain EventsRain Events• Several Rain Events Greater than One Inch
Date of Wet Weather Event
Amount of Rain (inches)
Percentage of Meters Recording Data
May 9, 2003 2.01 42%
May 31, 2003 1.07 88%
June 11, 2003 1.36 97%
July 7, 2003 1.58 97%
August 3, 2003 2.66 73%
September 1, 2003 3.57 91%
Sanitary Area Flow Sanitary Area Flow ContributionsContributions• Percent Capture – 1999 and 2003
Sanitary Area Flow Sanitary Area Flow ContributionsContributions• Peaking Factor – 1999 and 2003
Sanitary Area Flow Sanitary Area Flow ContributionsContributions
• Separated portions of the sewer system will contribute significant flow in wet weather.
• There are a number of very wet areas of the system where flow reduction work is encouraged
• The sanitary flow rates during wet weather are important to consider in evaluating CSO control alternatives and the overall impact on the plant
Combined Area Flow Combined Area Flow ContributionsContributions• Combined Area Flow
(Hydrologic) Response• This is a critical
parameter for modeling.
• Values fall within typical ranges
• 73% of Combined Area Monitored
Estimated Capture Rates Estimated Capture Rates 20032003
0102030405060708090
100
% f
low
cap
ture
d
Combined Flow SummaryCombined Flow Summary
• Data collected to calibrate model
• Ability of flow to be delivered to the interceptor varies significantly by regulator• Variability in frequency of discharge• Overloading of interceptor system
Windermere Pump Windermere Pump StationStation9/1/03 Response9/1/03 Response
System Hydraulics - System Hydraulics - observationsobservations• The system backs up during wet weather events
• The majority of the back up seems to start at the WWTP
• Because of the backups, flow reverses direction in the sewers. More overflow to the waterways also occurs.
System Hydraulics - System Hydraulics - consequencesconsequences• Once the WWTP can process more flow
• System backup should be reduced• Less CSO discharge to the waterways• Less risk of basement backup
Water Quality StudyWater Quality Study• Instream (CSO Area)
• Dry weather sampling (2 events)• Wet weather sampling (2 events)
• Upstream Boundary (Watershed)• Dry/wet, 17 weekly sampling events
• Intensive DO Monitoring• Two 2-week periods
2003 Sampling Locations2003 Sampling Locations
Wet Weather Event Wet Weather Event MonitoringMonitoring• May 1, 2003:
• Fast-moving spring storm (shown)
• 0.6” at Toledo Express• CSO duration ~ 2 hours
• September 1, 2003– Slower-moving late summer
storm– 2.6” at Toledo Express– CSO duration ~ 14 hours
Peak Fecal Coliform, Wet Weather Event #2
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
O1 O2 O3 O5 O5.5
Sampling Station
fec
al c
olif
orm
(#
/10
0 m
L)
Peak Fecal Coliform, Wet Weather Event #1
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
O1 O2 O3 O5 O5.5
Sampling Station
fec
al c
olif
orm
(#
/10
0 m
L)
WW Monitoring Results - WW Monitoring Results - BacteriaBacteriaOttawa River:• WW1 – low concentrations,
dominated by upstream
• WW2 – high upstream + significant in-stream contribution
• Decreased concentrations downstream due to Maumee Bay mixing
Primary Contact Recreational Standard
Primary Contact Recreational Standard
Mid-event DO, Wet Weather Event #2
0
2
4
6
8
10
12
14
M1 M2 M4 M6
Sampling Station
dis
so
lve
d o
xy
ge
n (
mg
/L)
Mid-event DO, Wet Weather Event #1
0
2
4
6
8
10
12
14
M1 M2 M4 M6
Sampling Station
dis
so
lve
d o
xy
ge
n (
mg
/L)
WW Monitoring Results – WW Monitoring Results – Dissolved OxygenDissolved Oxygen
Mid-event DO, Dry Weather Sampling
0
2
4
6
8
10
12
14
M1 M2 M4 M6
Sampling Station
dis
solv
ed o
xyg
en (m
g/L
)
• Maumee River• WW1 – Aeration elevates DO
• WW2 – CSOs also reduce downstream DO
Consent Decree Consent Decree Requirements – Hydraulic Requirements – Hydraulic Sewer ModelSewer Model• Workplan, approved April 7, 2003
• Develop sewer model to predict:• Flows • Hydraulic grade lines and capacities • CSO frequencies and volumes
• Use in conjunction with WQ model to support Long Term Control Plan
Hydraulic Model CoverageHydraulic Model Coverage
Status of Hydraulic ModelStatus of Hydraulic Model
• East Side model is operational• Calibrated to 2003 metering data• Calibration is preliminary, pending:
• West Side and 10-Mile Creek calibrations - consistency
• Runs with complete model - reasonableness
• West Side calibration not far behind
• 10-Mile Creek to be calibrated in December
East Side Hydraulic East Side Hydraulic SubmodelSubmodel
Calibration to 2003 Metering Calibration to 2003 Metering DataData
• Also important to accurately estimate flows to interceptor (example: Eastside Interceptor)
0
10
20
30
40
50
60
70
80
May-30 Jun-1 Jun-3 Jun-5 Jun-7 Jun-9 Jun-11 Jun-13 Jun-15 Jun-17 Jun-19
flo
w (
cfs
)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
rain
(in
ch
es
)
rain monitoring data model results
Consent Decree Consent Decree Requirements – WQ ModelRequirements – WQ Model
• Workplan, approved April 7, 2003
• Model shall be capable of:• Accurately modeling WQ in the 3 streams
• Under wide range of conditions
• Assessing impacts of CSOs on WQ• Assessing changes in CSO impact due to Long Term
Control measures under evaluation
SummarySummary
• Flow Characterization Study - close to completion
• Water Quality Study - on schedule• Hydraulic Model - on schedule about ready to
use• Water Quality Model – will build off of
hydraulic model• Long Term Control Plan – will use the models
as tools to develop alternatives
Next StepsNext Steps
• Long Term Control Plan – begin evaluation of alternatives
• Gather input from stakeholders and the general public