cpac meeting 12-15-03

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