1 EBMUD Flow Monitoring Technologies Evaluation Study Presentation BACWA Collection Systems...

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EBMUD Flow Monitoring Technologies Evaluation

Study Presentation

BACWA Collection Systems Committee

MeetingFebruary 25, 2009

Kevin Krajewski, P.E.

V&A

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Acknowledgements

Sponsoring Agency -

Technical Assistance and Field Work -

Represented Companies

http://www.hach.com/hc/static.template/templateName=HcIndex.index_main.htm/SESSIONID%7CB3lOVEk0TXpnekptZDFaWE4wU2tkQlRFRXhNZz09QnpFNU9EUQ==%7C

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Project Overview

Flow Monitoring Technologies Evaluation Study

• 31 Sites Monitored for Flow Monitoring and I/I Study– Pipe Sizes ranged from 8-inch diameter to 105-inch diameter

– Varying types of hydraulic conditions

• 5 Types of Open-Channel Flow Monitoring Technologies

• 10 Flow Meter Models made by 6 Manufacturers

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Site Locations

• 10 test site locations to allow for

direct comparison of flow data

• Site 27

• EBMUD District MH S45

• 84-inch RCP

• 6 different flow meters

installed and evaluated

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• Area-Velocity Flow Metering

– Q = V x A, whereQ = flowV = average velocityA = wetted cross sectional area

• Primary Devices (Weirs and Flumes)– Devices that alter flow in a predictable manner so that a known

relationship between flow and measured depth can be utilized

Requirements for Measuring Flows

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Types of Metering Technologies Evaluated

Technology Manufacturer Flow Meter Model# of Meters

installed

Continuous Wave Doppler

Teledyne IscoHachADS

2150Sigma 910FlowShark

16123

Pulse DopplerTeledyne IscoTeledyne Isco

ADS

ADFM AccQMin FlowShark Pulse

121

Radar Hach Marsh-McBirney Flo-Dar 6

Transit-Time ADS Accusonic 1

Custom Compound Weir

SFE Global SFE Global 2

Transit-Time with Flume

Accuron FlowScope 1

7

Hach Sigma 920

Continuous – Wave Doppler

Field ofVelocity Measurement

Teledyne Isco 2150+ 2110

ADS Flow Shark

$6,000 - $7,000 $5,500 - $6,500 $6,500 - $7,500

O&M requirements – planned periodic (every 2 – 4 weeks)

Typical for temporary efforts.

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Pulse – Wave Doppler

Teledyne Isco ADFM Teledyne Isco AccQMin ADS Flow Shark Pulse

$17,000 - $19,000 $10,000 - $12,000 $10,000 - $14,000


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Radar

Hach Marsh-McBirney Flo-Dar

$10,000 - $12,000

O&M requirements -- responsive to questionable data and surcharge events

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Transit-Time

Accusonic Accuron FlowScope

>$20,000 $5,500 - $6,500


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Custom Compound Weir (CCW)

SFE Global


$16,000 - $17,000 Installed

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Flow Level and Submerged Pressure Transducers

• Submerged pressure transducer: measures the hydrostatic

pressure of the liquid above the transducer (proportional to

liquid level)

– Subject to fouling or “drift”

• Ultrasonic level meters transmit a pulse to the surface of the

liquid and measure the time it takes for the pulse to be

reflected back to the meter.– Down-looking (non-submerged) or Up-looking (submerged)

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Site 27 Level Data

15

20

25

30

35

40

45

25-Apr 26-Apr 27-Apr

Leve

l (in

)

SIGMA FlowSharkFloDar ADFM

Level Data

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• Accuracy and repeatability

• Uptime

• Installation/removal maneuverability

• O&M maintenance

• User-Friendliness (hardware & software)

• Compatibility (to Remote monitoring options)

• Connectivity

• Cost

Evaluation Criteria

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Analysis: Site 27

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

20-Mar 21-Mar 22-Mar

Velo

city

(fp

s)

ADFM FlowShark Pulse

SIGMA FloDar

16

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

18 20 22 24 26 28 30 32 34 36 38 40

Level (in.)

Vel

oci

ty (

fps

)

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

18 20 22 24 26 28 30 32 34 36 38 40

Level (in.)

Ve

loc

ity

(fp

s)

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

18 20 22 24 26 28 30 32 34 36 38 40

Level (in.)

Vel

oci

ty (

fps)

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

18 20 22 24 26 28 30 32 34 36 38 40

Level (in.)

Ve

loc

ity

(fp

s)

Sigma 910 ADFM

Flo-Dar Flow Shark Pulse

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A Marsh-McBirney Flo-Mate Portable Velocity Meter was used for velocity profiling. Multiple

point velocity readings were measured throughout the flow stream to create an accurate

velocity profile so as to determine average velocity. This is necessary with the Marsh-

McBirney Flo-Dar.

Velocity profiling was conducted multiple times at various times of the day (high flow, low flow,

etc.)

Flow

Velocity Profiling

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Analysis: Site 27

*velocity taken from period 3/20/2008 to 4/26/2008

Meter TypeAverage Velocity*

(fps)

Hach Sigma 910: 2.87

Teledyne Isco 2150: 2.61

Teledyne ADFM: 3.05

ADS FlowShark Pulse: 2.61

Hach Marsh-McBirney Flo-Dar: 2.95

Accusonic: 2.63

Average Velocity per Velocity Profiling:

2.91

Minimum/Maximum % Difference:

±8%

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• Regardless of manufacturer’s specifications, it cannot be assumed that

velocity measurements for any meter will be accurate within ±2%. Velocity

profiling should be conducted with any meter selected for use in a large

diameter pipe.

• Continuous-Wave Doppler flow meters are not appropriate for long term

installations in large (39” or greater) diameter pipes with flow depths of the

magnitude measured in Site 27.

Conclusions for Site 27

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Continuous – Wave Doppler

Limitations

Low Flow (~14-18”)

Sensor penetrates most of flow, most accurate velocity

Medium Flow (~24-36”)

Sensor less than half of flow, does not pick up peak velocity.

High Flow (36”+)

Sensor minimal portion of flow, velocity not representative of actual flow

Velocity Sensor Range (~16”)

Velocity Sensor – offset at 5:30

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Meter Summary: % Usable in Study Locations

74%74%74% 3%

45%

58%

87% 16% 10%16%

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Meter Summary: Continuous Wave

- Best used in 8-inch to 42-inch pipe (generally – depends on site conditions)

- Good flexibility in most situations

- Good for surcharged conditions

- Cost effective option

- Isco and Sigma: more user friendly, slightly less expensive

- ADS Flow Shark slightly better data, expect connectivity issues

- Required periodic maintenance

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Meter Summary: Pulse-Doppler

- Best used in larger diameter pipe meeting minimum flow conditions.

- More expensive (generally)

- ADFM and AccQMin: Slightly better data, but expect issues in pipe with sediment. More expensive than ADS.

- ADS Pulse: Can handle sediment, less expensive, user friendly


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Meter Summary: Radar

- Can be used on nearly all sized pipelines

- Good flexibility for most situations

- Sometimes only option, especially high velocity, small pipe diameter sites, or dangerous confined space entry situations

- Questionable for surcharged conditions

- More expensive

- Expect connectivity issues for DC powered sites (AC power okay)

- Requires responsive maintenance (surcharge events)

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Meter Summary: Transit-Time Accusonics

- Best used in larger diameter pipe

- Requires commitment for metering site (difficult to remove)

- Accurate Velocity Data

- Required periodic maintenance: Most O&M to clean sensors

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Meter Summary: Transit-Time Flow-Scope

- Only for smaller diameter pipe with tight tolerances.

- (will be) Cost-Effective

- Emerging technology. Not ready just yet.

- Best for 8 to 12 inch pipe with low velocity, low level flows.


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Meter Summary: Custom Compound Weir

- Best for specific applications: high turbulence, convergence of two lines, or extremely low flows

- Expensive

- Dedicated permanent site, each site custom built.


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Results Summary

[1] Pipe Size Definition: Small = 15” and below, Medium = 18” to 36”, Large = 39” and above.[2] This category was defined by the number of flow monitoring sites within the EBMUD project (31 sites total, pipe diameters ranging from 8 inches to 105 inches, and all types of hydraulic conditions) wherein the given type of meter could have been appropriately used for obtaining good flow monitoring results. Most = >80%, Several = 60% - 80%, Many = 40% to 60%, Unique = <40%. Note – these results will vary depending on the characteristics of the collection system being evaluated.[3] $ = $5,000 - $9,000, $$ = $9,000 - $14,000, $$$ = $14,000 - $19,000, $$$$ = greater than $19,000.

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General Decision Treedepth < 1 inch 1 < depth < 3 3 < depth < 12 12 < depth < 24 depth > 24

vel < 0.5 fps

Sigma, Isco, FlowShark, AccQMin, ADFM, Accusonics, Flo-Dar, CCW, FlowScope



Sigma, Isco, FlowShark, AccQMin, ADFM, Accusonics, Flo-Dar,

CCW1, FlowScope1


0.5 < vel < 4.0





CCW1, FlowScope1

Sigma4, Isco4,

FlowShark4, AccQMin, ADFM, Accusonics, Flo-Dar, CCW, FlowScope

4.0 < vel < 8.0


CCW2, FlowScope2

Sigma3, Isco3,

FlowShark3, AccQMin, ADFM, Accusonics, Flo-

Dar, CCW2, FlowScope2

Sigma3, Isco3,

FlowShark3, AccQMin3, ADFM, Accusonics, Flo-



CCW1,2, FlowScope1,2

Sigma4, Isco4,

FlowShark4, AccQMin, ADFM, Accusonics, Flo-Dar, CCW, FlowScope

vel > 8.0


CCW2, FlowScope2

Sigma3, Isco3,

FlowShark3, AccQMin, ADFM, Accusonics, Flo-


Sigma3, Isco3,

FlowShark3, AccQMin3, ADFM, Accusonics, Flo-Dar, CCW, FlowScope


Sigma4, Isco4,

FlowShark4, AccQMin, ADFM, Accusonics, Flo-Dar, CCW, FlowScope (also see note 6)

vel > 18 fps5



Sigma3, Isco3,

FlowShark3, AccQMin3, ADFM, Accusonics, Flo-Dar, CCW, FlowScope


Sigma4, Isco4,

FlowShark4, AccQMin, ADFM, Accusonics, Flo-Dar, CCW, FlowScope (also see note 6)

Legend: Black = Meter can be considered, Grey = Meter may be considered, GreyStrikeThrough = Meter should not be considered

Notes: 1 Depends on depth relative to pipe size. May not be recommended if depths exceed recommended range of weir/flume.2 Velocities may exceed the weir/flumes abilities to accurately alter hydraulics -- evaluated on a site-by-site basis, possibly post-installation3 High velocities may hit submerged sensor(s) and cause a hydraulic jump ("fish-tail effect"). In this case, this type of meter should not be used.4 As depths increase > 24 inches, the accuracy of the velocity may decrease for these meters5 Velocities > 18 fps may not be able to be metered accurately with any meter6 Velocities > 8 fps with Depths > 24 inches -- Safe entry into the pipe channel for mounting a submerged sensor may not be possible (effects all meters except Flo-Dar)

Flo-Dar General Note: It is advisable to run an in-situ velocity profile for all installationsFlo-Dar's, Sigmas, Iscos, FlowSharks not recommended when Vel < 0.5 fpsSigma's, Isco's, FlowSharks not recommended when Depth < 1 inchAccQMin not recommened when Depth < 3 inchesADFM's not recommended when Depth < 12 inches

, Pulse

, Pulse , Pulse

, Pulse , Pulse

Pulse

Pulse

Pulse

Pulse

, Pulse

, Pulse

, Pulse

Pulse

Pulse

Pulse

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Decision Tree (cont.)

Output from Depth/Velocity Matrix

Sediment > 2 inches?

ADFM and AccQMin Meters must be mounted at the pipe invert and may not be

appropriate.

Permanent vs. Temporary Installation:Meter Maintenance

Submerged sensor meters (all meters except the Flo-Dar) are prone to fouling and may require a confined space entry for

sensor maintenance.

Required Accuracy vs. Cost

What are the overall requirements for accuracy? Are the flow results to be used for billing purposes (high accuracy required)? To monitor for potential surcharge situations (high

accuracy not required)?

Pipelines known to have repeated surcharging?

Submerged sensor meters perform better in surcharge situations than Radar, Weir and

Flume meters

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Q & A

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