CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION...
Transcript of CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION...
![Page 1: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/1.jpg)
CONDITION ASSESSMENT
AND CORROSION CONTROL
FOR
CAN-TYPE PUMP STATIONS
Douglas Sherman, P.E., Principal Consultant
Randy Nixon, Principal Consultant
2017 WEAT Biosolids and Odor and Corrosion Control Conference
![Page 2: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/2.jpg)
OVERVIEW
• Can-type Pump Stations – Construction
and Installation
• Corrosion Mechanisms and Causes
• Identifying and Monitoring these Problems
• Corrosion Repair & Mitigation Methods
• Summary
![Page 3: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/3.jpg)
CONSTRUCTION AND
INSTALLATION
![Page 4: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/4.jpg)
![Page 5: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/5.jpg)
![Page 6: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/6.jpg)
![Page 7: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/7.jpg)
![Page 8: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/8.jpg)
CONSTRUCTION AND
INSTALLATION
• Prefabricated
• Epoxy coating – internal & external
• Commonly designed with CP (mag
anodes)
• Installed quickly
![Page 9: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/9.jpg)
CORROSION MECHANISMS
AND CAUSES
![Page 10: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/10.jpg)
CORROSION MECHANISMS
AND CAUSES
• Internal corrosion
– O2/moisture-driven
– Controlled with coatings
• External corrosion
– At breaches in coating
– Installed CP not beneficial
![Page 11: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/11.jpg)
CORROSION MECHANISMS
AND CAUSES
• Installed by developers who don’t
know, care
• Coatings not applied with great
quality (esp. at welds)
• Backfill disrupts coating
• Dry well not electrically isolated
• Anodes not connected
![Page 12: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/12.jpg)
UNDERSTANDING THE CORROSION
OF UNDERGROUND, FERROUS METAL
STRUCTURES & PIPING
![Page 13: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/13.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
• Electrolytic – Oxygen-driven
• Stray Current
• Graphitic – Cast iron, ductile iron
• Galvanic – Dissimilar metals, coupled
• Microbiologically Influenced Corrosion
(MIC)
![Page 14: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/14.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
• Electrolytic – Oxygen-driven
• Stray Current
• Graphitic – Cast iron, ductile iron
• Galvanic – Dissimilar metals, coupled
• Microbiologically Influenced Corrosion
(MIC)
![Page 15: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/15.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
Electrolytic – Oxygen-driven
![Page 16: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/16.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
Electrolytic – Oxygen-driven
• Microstructural composition differences in metal
surfaces produce anodic, cathodic sites
• Can also result from differential soil conditions
• Resulting potential differences
cause corrosion current to
flow from anodes to cathodes
• Corrosion rate influenced by
moisture content, oxygen,
resistivity, chemical
contamination
![Page 17: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/17.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
Stray Current
• PS near cathodically protected gas mains or 3rd-rail
DC train systems
• Driven by stray DC current leaving the steel PS to
return to circuit
• Typically involves a few
isolated or one deep pit at
the location of stray current
departure
• May be confused with
electrolytic corrosion
![Page 18: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/18.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
Anode-to-Cathode Area Relationship:
The smaller the anodic area relative to the
cathodic area, the higher the corrosion rate.
![Page 19: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/19.jpg)
EXTERNAL (SOIL-SIDE)
CORROSION MECHANISMS
Concentration of Corrosion
at Coating Breaks & Pinholes
Rate of penetration related to
area from which metal is taken
![Page 20: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/20.jpg)
IDENTIFYING AND
MONITORING CORROSION
![Page 21: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/21.jpg)
IDENTIFYING AND
MONITORING CORROSION
Visually inspect walls, floor, welds
• Corrosion
• In-leakage of ground water
• If false floor, gain access and examine floor
plates
![Page 22: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/22.jpg)
![Page 23: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/23.jpg)
![Page 24: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/24.jpg)
IDENTIFYING AND
MONITORING CORROSION
Ultrasonic Thickness Testing of Shell,
Floor Plates
• Need original thicknesses
• If false floor, gain access and UT floor plates
![Page 25: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/25.jpg)
IDENTIFYING AND
MONITORING CORROSION
Structure-to-soil Potential
Measurements
• To determine if structure is corroding (-300 to
-500 mV vs. Cu-CuSO4)
• To check original cathodic protection
![Page 26: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/26.jpg)
![Page 27: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/27.jpg)
IDENTIFYING AND
MONITORING CORROSION
Is Corrosion Likely in the Future?
• Obtain soil samples and test/assess for
corrosivity
![Page 28: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/28.jpg)
Soil Description Smooth, moist, brown, dense clumps with organic matter.
Resistivity as-received (Ω-cm) 1,600
Resistivity soil/water paste (Ω-cm) 1,300
Water Content (%) 15
pH 7.0
Alkalinity (mva1/kg) 1.0
Acidity (mva1/kg) N/A
Redox (mV, platinum vs. Ag/AgCl) +190
Chloride (mg/kg) 120
Sulfate (mg/kg) 387
Sulfide (yes/trace/no) no
Particle Size Analysis
% Sand
% Clay
% Silt
45.3
30.3
24.4
Soil Classification Clay Loam
SOILS CORROSIVITY ANALYSIS
Soil Test Results
![Page 29: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/29.jpg)
SOILS CORROSIVITY ANALYSIS
![Page 30: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/30.jpg)
IDENTIFYING AND
MONITORING CORROSION
Is Corrosion Likely in the Future?
• Obtain soil samples and test/assess for
corrosivity
• Know ground water fluctuation range and
elevations
• Check electrical isolation from connected
piping
![Page 31: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/31.jpg)
![Page 32: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/32.jpg)
IDENTIFYING AND
MONITORING CORROSION
Is Corrosion Likely in the Future?
• Obtain soil samples and test/assess for
corrosivity
• Know ground water fluctuation range and
elevations
• Check electrical isolation from connected
piping
• Check/measure for stray current effects
![Page 33: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/33.jpg)
CORROSION REPAIR &
MITIGATION METHODS
![Page 34: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/34.jpg)
CORROSION REPAIR &
MITIGATION METHODS
Localized, Deep Corrosion
• Install lap-welded patch on
interior
• Repair coating
![Page 35: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/35.jpg)
CORROSION REPAIR &
MITIGATION METHODS
Existing Corrosion or Potential for
Future Corrosion
• Rely on original coating and CP system (rare
for original CP system to be effective)
• If in good-to-fair condition, use monitoring
approach
![Page 36: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/36.jpg)
CORROSION REPAIR &
MITIGATION METHODS
Existing Corrosion or Potential for
Future Corrosion
• If in poor or questionable condition, install
new CP system (determine if should be
sacrificial anode or impressed current)
• If structurally compromised, excavate and
replace or make localized weld repairs; and
install CP
![Page 37: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/37.jpg)
CORROSION REPAIR &
MITIGATION METHODS
The Maxim of Corrosion:
Anodes corrode.
Cathodes don’t.
Make a structure sufficiently cathodic,
and corrosion will stop.
![Page 38: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/38.jpg)
CORROSION REPAIR &
MITIGATION METHODS
Steel Structure Protection with
Coating but no CP
![Page 39: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/39.jpg)
CORROSION REPAIR &
MITIGATION METHODS
Steel Structure Protection with
Coating and CP
![Page 40: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/40.jpg)
Sacrificial Anode
Cathodic Protection
VS
Impressed Current
Cathodic Protection
CORROSION REPAIR &
MITIGATION METHODS
![Page 41: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/41.jpg)
CP – Sacrificial Anode System
CORROSION REPAIR &
MITIGATION METHODS
![Page 42: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/42.jpg)
CORROSION REPAIR &
MITIGATION METHODS
CP – Impressed Current System
![Page 43: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/43.jpg)
![Page 44: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/44.jpg)
SIMPLIFIED GRAPHIC:
I.C.C.P. SYSTEM for
CAN PUMP STATION
![Page 45: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/45.jpg)
![Page 46: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/46.jpg)
TYPICAL ICCP SYSTEM LAYOUT
![Page 47: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/47.jpg)
SUMMARY
• Reasonable condition assessment and
repair/mitigation approach without
excavation or interruption of operation.
– $15 to $25K to repair vs. couple $100K to
replace.
• For corroding (or potentially corroding)
can-type PS, if CP is properly designed
and maintained, it will extend life of PS,
and mitigate any future corrosion.
![Page 48: CONDITION ASSESSMENT AND CORROSION CONTROL FOR · PDF fileCONDITION ASSESSMENT AND CORROSION CONTROL FOR ... cathodic sites ... •Know ground water fluctuation range and](https://reader034.fdocuments.us/reader034/viewer/2022052515/5a761b517f8b9ad22a8d23fa/html5/thumbnails/48.jpg)
Thank you!
Any Questions?