Copper Pipe Pinhole Leaks - Marco Island, Florida · The City of Marco Island A Worldwide Problem Comes to Marco Copper Pipe Pinhole Leaks The City of Marco Island ... 1 Orla n d

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The City of Marco Island

A Worldwide Problem Comes to Marco

Copper Pipe Pinhole Leaks


A Worldwide Problem Comes to Marco

Copper Pipe Pinhole Leaks

March 19, 2007March 19, 2007

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A Worldwide Problem Comes to Marco Island…A Worldwide Problem Comes to Marco Island…

Nationwide Distribution of Locations Reporting Pinhole Leaks Between 2000 and 2004

AND THE LEAKS GO ON….. Pinhole leaks in copper water pipes are leaving many experts perplexedand driving hundreds of Maryland homeowners to distraction. Theories abound, ranging from poor materials to improper installation to what's in the water. In the end, it's still a mystery.

July 1, 2000 Sandra Fleishman

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July 2000 WSSC

"The Washington Suburban Sanitary Commission (WSSC) experts believe that pinhole leaks are not the result of corrosive water but of dissimilar metals interacting and starting a battery of reactions that just consume the pipe.Otherwise, dissolving of the copper would be a widely spread problem.”(Washington Post, July 2000)

Pinhole leaks in copper plumbing are a

widespread problem that affects property

owners throughout the United States and

elsewhere in the world. Although much

research has been conducted around the

issue, no definitive cause has been

determined to date. As the leaks were

discovered in our area, Sarasota County

Utilities was quick to establish a local task

force to research the problem and potential

solutions.

A Worldwide Problem Comes to Marco Island…A Worldwide Problem Comes to Marco Island…

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Where Have Leaks Been Detected?Where Have Leaks Been Detected?

• A nationwide issue- EPA studies- AWWA studies

St. Petersburg FloridaPin hole leaks in copper piping have reached alarming proportions, and seems to be gaining momentum. Much has been written on this subject.Some say the pin hole pox is due to inferior grades or imported copper tubing. Some have CopperKnight.com published such scholarly works

on the subject that would leave world class Rocket Scientists scratching their heads.There have been many methods tried over the years

in an attempt to deal with this problem. They all had one thing in common: each attempted to deal with the effects of the problem instead of the cause.

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February 1997 Richard A. Dunham and Clifford A. Russell

FLORIDA WATER RESOURCES JOURNALPinholes in copper plumbing are a major problem in Central Florida as well as other parts of the state and the country. Why do they occur in certain areas and not in others? Perhaps more important, what can be done to prevent the problem in the first place? The Water Quality Laboratory at Orlando Utilities Commission began examining the problem in 1984. In 1991 it began a more in-depth study………..Beginning ResearchIn 1991 Orlando Utilities and CH2M-HILL engineers started a research project sponsored by the American Water Works Association Research Foundation. The purpose of the study was to study the effects of electrical grounding on water quality.One of the long held theories of pinhole leaks is that they are caused by electrolysis, i.e., stray currents conducted along copper plumbing. Stray currents are causedby load imbalance between the two conductors in a 220- volt system. The imbalanceis transferred to the plumbing at various points in a home. Grounding of the electricalsystem to the cold water system allows the phenomenon to occur.

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Water TreatmentPlant Locations

Water TreatmentPlant Locations

South PlantRO Membrane

North PlantLime Softening

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Drinking Water Production 2005 & 2006Drinking Water Production 2005 & 2006

0

2

4

Time: Jan 05 - Dec 06

Millio

ns o

f Gall

ons P

er D

ay

10

8

6

Total Water Produced

Lime Softening Plant

RO Plant

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06 Apr-06 Jul-06 Oct-06

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Water DistributionWater Distribution

North PlantLime Softening

South PlantRO Membrane(Blended)

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• Area served by the North Plant (Lime softening)• Cold water and horizontal copper pipe• Type M copper pipe

• Predominately homes-condos built from 1987-1996

• Seasonal used homes/condos

Type

M (thin wall)

L (medium wall)

K (heavy wall)

¾”½”

0.028

0.040

0.049

Pipe Diameter

0.032

0.045

0.065

Tallwood Condos – 2 Buildings1985 – L Type – no problem1989 – M Type – 10 leaks

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Water Treatment SystemWater Treatment System

• EPA (early 90’s) required removal of most natural occurring soluble organics that coat copper pipes

• Use an inorganic corrosion inhibitor (orthophosphate and polyphosphate)

• Lime plant pH 8.31• RO plant pH 8.29

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North WTP 2001 - 2006North WTP 2001 - 2006

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

Jan-01 Jul-01 Jan-02 Jul-02 Jan-03 Jul-03 Jan-04 Jul-04 Jan-05 Jul-05 Jan-06 Jul-06

pH ( Between 6.5 - 8.5)

Cl2 Residual (Between 0.6 - 4.0)

Alkalinity

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0

50

100

150

200

250

300

350

400

450


Chloride (Max 250)Ca HardnessT HardnessTDS (Max 500)

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0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400


Finish Aluminum (Max 0.2)

PO4 (Max 1.0)

NH3 (Max 1.0)

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South WTP 1999 - 2006South WTP 1999 - 2006

0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

Jan-99 Jul-99 Jan-00 Jul-00 Jan-01 Jul-01 Jan-02 Jul-02 Jan-03 Jul-03 Jan-04 Jul-04 Jan-05 Jul-05 Jan-06 Jul-06

Chloride (Max 250)TDS (Max 500)Conductivity (Max 750)Calcium HardnessTotal Hardness

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0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0


Alkalinity

Temp C

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0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00


Turbidity( Max 0.3)pH (Between 6.5 - 8.5)

CL2 Residual (Between 0.6 - 4.0)

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Where is Pitting Occurring?Where is Pitting Occurring?

• Inside• Outside

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Causes of Corrosion in Copper PipeCauses of Corrosion in Copper Pipe

• Surface imperfection (during manufacturing)• Dirt or particle/impurities that get into the pipe

(during installation)• Impurities pipe wall (during manufacturing) • Stray electrical currents • Stagnant water in pipes• Low pH water (below 7) “soft” water• Pipe touching concrete (exterior pipe pitting)

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Pipe Wall

Perfect Copper PipePerfect Copper Pipe• No pits or cracks• No dirt particles• Uniform copper composition• No pitting• Components of copper pipe – 99.9% Cu & Ag Plus

0.04% P

Oxygen 2 to 8 parts per million (ppm)Water Flow Chlorides 50 to 150 ppm

pH 6 to 10

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Surface Imperfection Inside PipeSurface Imperfection Inside Pipe

• A surface imperfection inside the pipe allows chlorides and sulfates to concentrate at a point promoting copper pit corrosion

Pipe Wall Cu

Cu+2

ClCl

Cl 2 electrons

Water Flow

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Particle on WallParticle on Wall

• Particle on wall causes concentration changes allowing copper pipe to dissolve

CuCu+2

Pipe Wall

Chlorides, sulfates diffuse to pipe surface

Dissolved OxygenChloridesSulfates

LowerIncrease Increase

Solid

2 electrons

Water Flow

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Pipe Wall

Impurity in the Copper PipeImpurity in the Copper Pipe

• Impurity point is anodic where copper dissolves

Cu

Cu+2

Impurities

2 electrons

Water Flow

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Cu+2

Pipe Wall

2(OH)

2 electronsCu

O2

Water Flow

Pitting Inside Copper PipePitting Inside Copper Pipe• Metallic copper dissolves at one point

Cu Dissolves Cu 2 electronsCopper pipe Copper dissolved

in water2 electrons travel in pipe

from pit (i.e. anode)

+2 +

½ O H2O 2 electrons 2(OH)2 + +Dissolved in water

• Dissolved oxygen diffuses to pipe wall

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Pitting in Copper PipingPitting in Copper Piping

• Dissolved copper and hydroxide ions react to form hydroxide copper oxide, a solid that attaches to the pipe wall by the pit

CuSolid

Cu+2 + 2(OH)Dissolved

(OH)2

O2

Pipe Wall

2 electronsCu

Cu+2

2(OH)Cu O

Solid

Water Flow

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Corrosion From Outside of PipeCorrosion From Outside of Pipe

Condensate with Dissolved Solids

Water Condensateon Outside of Pipe

2 electronsCu

Concrete Cinder Block

Hydroxide Sulfate Calcium

Water Flow

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City’s ActionCity’s Action

• Retained Professor Steve Medlar, P.E.- Rutgers University- Water treatment expert- Published Books, Manuals, Papers on

corrosion

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• Evaluate any water quality modifications/adjustments to decrease any potential pitting may include:- Increase pH above 8.5-Must get DEP approval- Modify the current method for pH adjustment

by using CO2 - Evaluate the current use of phosphate for

coating

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• Evaluate the copper vs. plastic piping- Surface imperfection (during manufacturing)- Dirt or particle/impurities that get into the

pipe (during installation)- Impurities pipe wall (during manufacturing) - Stray electrical currents

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• Continue Flushing in dead-end points- Stagnant water in pipes

• Educate Homeowners on impacts of individual household water systems- Low pH water (below 7) “soft” water

• Continue to evaluate the location and installation of pipes- Pipe touching concrete (exterior pipe pitting)

• Continue to review electrical grounding with LCEC

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Drinking water quality is a complex science. We are committed to continue to provide the highest quality water to you.

The City with various experts and agencies are continuing to evaluate the possibilities of adjusting water quality to aid in eliminating this problem that exists worldwide.

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A Worldwide Problem Comes to MarcoCopper Pipe Pinhole Leaks

Q & A


A Worldwide Problem Comes to MarcoCopper Pipe Pinhole Leaks

Q & A

March 19, 2007March 19, 2007

Nationwide Distribution of Locations Reporting Pinhole Leaks Between 2000 and 2004

Documents

Copper Pipe Pinhole Leaks - Marco Island, Florida · The City of Marco Island A Worldwide Problem Comes to Marco Copper Pipe Pinhole Leaks The City of Marco Island ... 1 Orla n d