Insight H20- From Plant to Tap- Optimizing Drinking Water Distribution Systems

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OPTIMIZING YOUR DISTRIBUTION SYSTEM

INSIGHT H2O™ PRESENTS:

FROM PLANT TO TAP:

• Q&A will be held at the end. To submit a question, click on the question tab located on the dashboard

• To receive a certificate indicating 1 hour of continuing education, email Ben Klayman at [email protected]

• This webcast is being recorded. An email will be sent to participants with a link to the recording.

TO GET THE MOST OUT OF TODAY’S WEBCAST

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mailto:[email protected]

• Distribution system overview

• Corrosion and metals release

• A proactive approach to managing distribution systems

AGENDA

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• Dr. Ben Klayman, Black & Veatch

• Dr. Daniel Giammar, Washington University in St. Louis

• Brandy Thigpen, Black & Veatch

• Water main

• Storage tanks

• Utility service line

• Customer service line

• Premise plumbing

DISTRIBUTION SYSTEM COMPONENTS

4

• Regulations • Lead and Copper Rule

• Sets action level for 90th percentile

• NDWAC Lead and Copper Working Group

• Long term revisions due out 2017

• Disinfectants / Disinfection Byproduct Rule

• Total Coliform Rule

DISTRIBUTION SYSTEM CONSIDERATIONS

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• Aesthetic / Public Health • Increased microbial activity

• Taste and odor

• Cloudy or colored water

• Metals release

• Maintaining integrity of the distribution system • Operations

• Maintenance

• Replacement program

DISTRIBUTION SYSTEM CONSIDERATIONS

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• Managing water quality

• Managing infrastructure

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DISTRIBUTION SYSTEM OVERVIEW (SIMPLIFIED)

Hydraulic / Quality Analysis

Risk-Consequence

Prioritized Improvement

s

WATER QUALITY

8

WATER QUALITY

06/23/2009

• Three categories:

• Biological stability

• Metals solubility and uniform corrosion

• Particulate scale release and transport

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• Disinfectant residual and ORP • Maintain residual throughout system

• Temperature, organic carbon, nutrients

• Measure overall microbial activity • ATP or HPC

• TCR data

• Nitrification data (NO3-, NO2

-, ammonia)

• Impacts chemistry and metals release

10

BIOSTABILITY

CORROSION AND METALS RELEASE

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Daniel E. Giammar, Ph.D., P.E.

Department of Energy, Environmental, and Chemical Engineering

Washington University in St. Louis

• Active versus passive corrosion

• Iron and red water

• Copper and blue water

• Lead corrosion and corrosion control

Aquatic Chemistry Laboratory Aquatic Chemistry Laboratory 12

Corrosion

• Corrosion involves the oxidation of the metal to result in the pipe scales

of solid products or the release of metals to the water.

• Stability and solubility of the pipe scales controls concentrations of

metals in water and whether corrosion is active or passivated.

Source: MWH, 2005, Water Treatment Principles and Design


Iron and Red Water

• Perturbations that disturb the scale

mobilize iron.

– changes in pH

– removal of corrosion inhibitor

• Red water complaints.

• Iron corrosion consumes chlorine,

making it harder to maintain residual.

Source: Water Quality and Treatment, 5th Ed., AWWA, 1999 http://events.nace.org/library/corrosion

/Experiments/rust-chemistry.asp


Copper and Blue Water

• Corrosion at low pH (< 6.5)

• Can be subject to pitting corrosion

(high pH low alkalinity)

• Blue water complaints (even in

new buildings)

Source: MWH, 2005, Water Treatment Principles and Design

Source: Lytle and Schock, 2008, Journal AWWA


Lead in Drinking Water

• Historical use of lead (plumbing = Pb)

for conveying and storing water.

• Widespread use starting in the late 19th

century in service lines that connect

residences to water mains.

• Use dropped off in 1930, but not

prohibited until 1986.


Lead Phases in Lead Service Lines

• Lead(IV) oxide (PbO2) and lead phosphate solids are the least soluble.

• Lead carbonate and hydroxycarbonate can have solubility minimized by

controlling pH and alkalinity.

• Changes in distribution system water chemistry can destabilize

corrosion products in premise plumbing.

CO3 2-, PO4

3-

OCl- Cl-

Pb 2+

Pb(IV)O2, Pb3(CO3)2OH2, PbCO3, Pb5(PO4)3OH

Lead Pipe Pb(0)

CO3 2-, PO4

3-, Cl-

Pb2+

Particulate

Pb(II) Pb(IV)


Formation and Dissolution of PbO2

• PbO2 can only be formed in the presence of free chlorine.

• When free chlorine is depleted, PbO2 dissolves and releases lead to the water.

• Switching from free chlorine to chloramine (e.g., for control of disinfection

byproducts) can result in lead release from PbO2.

• Presence of reductants, including dissolved organic carbon, enhances the

dissolution of PbO2.

Mn2+, Fe2+

Br-, I-

DOC

H2O

PbO2(s)

Pb(II)(diss) Pb2+, Pb(II)-CO3 complexes

reductants

HOCl/OCl-


Lead Service Line Replacements

• Required if corrosion control does not decrease 90th

percentile of tap water lead concentrations below 15 µg/L.

• Examples include Washington, DC and Providence, RI

• Partial replacement can be worse than no replacement.


Possibility for Galvanic Corrosion

• Service line had been all lead, but the replaced part is now copper, which

is connected to the remaining lead pipe.

• Electrical connection of dissimilar metals can allow a current to develop.

copper lead brass

Pb2+

O2

2e- 2e-

anode cathode

DeSantis, WQTC 2009

brass

lead pipe

lead copper

brass


Bench-Scale Experiments with DC Pipes

• Use lead pipes harvested from distribution systems and

connect them to copper tubing used in replacements.

• Make connections using commercially-available couplings.

• Operate with intermittent flow and stagnation.


DC Lead Pipes with Different Connections 6-h stagnation

• More lead released with brass couplings than with plastic.

• Dielectric couplings resulted in lower lead release but did not prevent galvanic corrosion.

• Replicates are important.

• These effects persisted for at least six weeks.

0

50

100

150

200

250

300

350

1 2 1 2 1 2 1 2 1 2

To

tal P

b (

µg

/L)

Mean

Brass Brass die Plastic -ex Plastic LL-Brass

max

median

min

75th percentile

25th percentile

galvanic corrosion

not possible

galvanic corrosion occurring

From Wang, Mehta, Welter, and Giammar Journal AWWA, 2013


Preparing for a Transition in Water Chemistry

• Pipe loop studies are valuable for evaluating implications of source or

process changes that influence water chemistry.

Providence evaluation of orthophosphate addition to high pH water (~10.4). From Welter, Schock, Miller, Razza, and Giammar, WQTC 2015


Providence Dissolved Lead

From Welter, Schock, Miller, Razza, and Giammar, WQTC 2015

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• Orthophosphate has immediate and clear impact

on dissolved concentrations.

• Concentrations are higher at higher temperatures.

-25

-20

-15

-10

-5

0

5

10

15

20

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

Dis

solv

ed L

ead

(p

pm

)

Pipe Loops - Dissolved Lead

1b-C

2b-C

5b-C

8b-C

1a-P

2a-P

5a-P

7b-P

Temp (fresh)

Temp (24-hr)

Temperature

with orthophosphate

control

(no orthophosphate)


Providence Total Lead

From Welter, Schock, Miller, Razza, and Giammar, WQTC 2015

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• Benefits for total lead take longer to be achieved.

• Replicate experiments valuable for distinguishing impacts

from noisy data associated with use of real pipes.

-25

-20

-15

-10

-5

0

5

10

15

20

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

Tota

l Lea

d (

pp

m)

Pipe Loops - Total Lead

1b-C

2b-C

5b-C

8b-C

1a-P

2a-P

5a-P

7b-P

Temp (fresh)

Temp (24-hr)

Dates for temperature data are approximate,

Tem

per

atu

re

with orthophosphate

A PROACTIVE APPROACH TO MANAGING DISTRIBUTION SYSTEMS

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BRANDY THIGPEN, INFRASTRUCTURE PLANNING BLACK & VEATCH

DISTRIBUTION OPTIMIZATION - BEYOND HYDRAULICS

Distribution

System Optimization

Hydraulics

Energy Management

GIS & Asset Management

Water Quality Hydraulics

Infrastructure Sizing

Pressure

CIP Development

Fire Flow

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Water Quality

Water Age

Strategic Flushing

Plans

Tank and System

Operating Plans

Source Trace

WATER QUALITY OPTIMIZATION

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Locate high water age areas and limit the need for sampling.

Evaluation of Corrective Strategies

Tank Operations

Strategic Flushing

Rerouting Water

Water Age

Chlorine Residual

Nitrification

Tank Management

DBP

How can computer models help lower Water Age?


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Flushing Plans

Improve water Quality

Sediment Accumulation

Biofilm Removal

Clean water Mains

Evaluate the effectiveness / non-effectiveness of conventional flushing programs

Identify modifications to address any deficiencies

Develop strategic Flushing Plans

How can computer models help with flushing?


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CONVENTIONAL FLUSHING

Max Velocity during Hydrant Flushing (fps)

<1.0

1.0-2.0

2.0-3.0

3.0-4.0

4.0-5.0

>5.0

UNI-DIRECTIONAL PLAN

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Source trace used to track water movement throughout the system

Source Blending or New Source

Holistic Approach to Operating Plans to achieve quality goals

Managing a Contamination Event

How can computer models help with source and contamination management?


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• Identify high water age and focus sampling sites

• Trace introduction of new source(s)

• Identify changes in velocity or flow direction

• Evaluate benefits of potential operational changes

• “What-if” scenarios to find most effective solution

BENEFITS OF WATER QUALITY MODELING

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GIS AND ASSET MANAGEMENT

GIS and Asset Management

Likelihood of Failure/

Identify High Risk

Infrastructure

Visualize System

Components

Map modeling results and Identify and

alert affected Population

Facilitate Effective Capital

Planning

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LINKING ASSET MANAGEMENT WITH WATER QUALITY

R3 = Replace the Right Facility at the Right Time with the Right Material.

Hydraulic / Quality Analysis Risk-Consequence Prioritized Improvements

Locational water quality

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MOVING FROM COMPLIANCE TO OPTIMIZATION

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CLOSING THOUGHTS

• Understand the water quality in your distribution system

• Updated hydraulic model

• Distribution system monitoring plan

• Biological and chemical stability

• Parameters, frequencies, and locations

• Minimize change in water quality within system

• Have a system wide unidirectional flushing program

• Minimize water age and variability

• Understand the potential impacts from changes to source or treatment

• Re-evaluate asset replacement program risk prioritization model

RECOMMENDATIONS

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• Increased public health protection

• Reducing the potential for waterborne pathogens to reach customer’s tap

• Reducing metals release

• Proactively achieving regulatory compliance

• Preparing for future regulations

• Lower overall asset management program cost

• Improved public confidence and agency coordination

MOVING FROM COMPLIANCE TO OPTIMIZATION

37

• To submit a question, click on the question tab located on the dashboard

Q&A

38

• Thank you for your participation today

• To receive a certificate indicating 1 hour of continuing education, email Ben Klayman at [email protected]

• This webcast is being recorded. An email will be sent to participants with a link to the recording as well as the Q&A log.

• This webcast is part of a continuing series.

CLOSING THOUGHTS

39

mailto:[email protected]

Date post:	25-Jan-2017
Category:	Engineering
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