acoustic inspection of sanitary sewer lines to prioritize ... · acoustic inspection of sanitary...
TRANSCRIPT
Alex Churchill – InfoSense, Inc.Steve Jonson – CH2MHill
March 19, 2014
Acoustic Inspection of Sanitary Sewer Lines to
Prioritize Cleaning Operations
PRESENTATION OUTLINE
• Acoustic Inspection Overview
• Project Background and Objectives
• Summary of Results
• Conclusion
PRESENTATION OUTLINE
• Acoustic Inspection Overview
• Project Background and Objectives
• Summary of Results
• Conclusion
• Overflows are a Symptom – Not the Problem
WHAT IS THE PROBLEM?
• Cleaning a pipe costs about the same as inspecting a pipe
• >80% of pipes less than 12”, accounts for >90% of SSOs
• Historical GIS – Helpful –But Insufficient
• Where & When to Deploy Cleaning Resources
• Cost Effective & Timely Condition Information
PROBLEM: INFORMATION
INSPECTION METHODS
Manhole Inspection
Push Camera
Zoom CameraACOUSTIC
• CCTV/Robotic Camera• Pipe Wall Defect Scanners• Pipe Profiling / Robotic Multi-Sensor
INSPECTION METHODS
Acoustic
Blockage
Pipe Condition
Pipe Wall DefectDetailed
Pipe Profiling
Insp
ectio
n Re
solu
tion
Relative Cost
HIGH
LOW
HIGHLOW
ZoomCamera
Manhole Inspection
No Contact with Flow: Contact with Flow:
Wastewater PipeCondition AssessmentApplications
Push Camera
CCTV
ACTIVE ACOUSTIC PIPE INSPECTION BACKGROUND
• Patented technology• Gravity-fed sewer focus• Developed in Charlotte with
CMUD as key partner
• Over 3M feet inspected• Rapid assessment helps
better focus cleaning and CCTV resources
ACOUSTIC INSPECTION TECHNOLOGY
• How Does it Work?
ACOUSTIC SCORING
10
5
0
8
2
Obstructed
No Obstructions
Root Fibers Limited GrowthGrease Limited Build Up
Root Fibers and/or GreaseCamera Can Pass
Root Fibers and/or GreaseCamera Cannot Pass
Blockage Assessment 2
Blockage Assessment 5
Blockage Assessment 10
HOW MUCH CLEANING IS WASTED?
0 1 2 3 4 5 6 7 8 9 100
100
200
300
400
500
600
700
Blockage Assessment (0-Blocked thru 10-Clean)
Rel
ativ
e O
ccur
ance
9%
14%19%
58%
• Target Historical Problematic Areas
– >50% Pipes Essentially Clean
– <10% Need Immediate Action
• Cleaning a Clean Pipe ⇒Wastes Resources
• Not Cleaning a Dirty Pipe ⇒ SSO
Acoustic Inspection Results~1Million Feet of Pipe
$/fo
ot
Insp
ecte
d
$-
$0.02
$0.04
$0.06
$0.08
$0.10
$0.12
$0.14
at $16/hr
at $33/hr
Feet Inspected/Day
SL-RAT Acoustic Inspection Cost
Municipal Cleaning
~$1.00/foot
Typical Operating
Range Fully Loaded Wage Rate
COST EVALUATION
1
KEY FEATURES OF ACOUSTIC INSPECTION
• No Flow Contact / No Confined Space Entry
• Simple to use – train operators in minutes
• Low Cost–Pennies/foot• Rapid Onsite Results –
Under 3 min./segment• Portable < 30 lbs• GIS Integration – GPS
Enabled• Archive Pipe Segment
Blockage Assessments
PRESENTATION OUTLINE
• Acoustic Inspection Overview
• Project Background and Objectives
• Summary of Results
• Conclusion
PROJECT BACKGROUND• Ft. Leonard Wood, MO
o Established in 1940o Trains 80,000-90,000
military and civilians every year
o 62,911 acreso 78 miles of sewer lines
o 6” – 42” diametero 41% VCP, 53% PVC, 6% RCP
PROJECT OBJECTIVESSL-RAT is primarily used as a prioritization tool for cleaning/camera operations in 6” to 12” sanitary sewer lines
• Evaluate acoustic inspection as a tool for inspecting sanitary sewer lines
• Compare acoustic inspection results with pole camera
• Compile data of overall system condition at Ft. Leonard Wood
PRESENTATION OUTLINE
• Acoustic Inspection Overview
• Project Background and Objectives
• Summary of Results
• Conclusion
SUMMARY OF RESULTS• Performed 460 Acoustic Measurements (89,571 ft)
(included several repeat measurements for verification)
SUMMARY OF RESULTS• Acoustic inspection performed in 12 days• 391 unique segments inspected (75,355 ft)
Legend:SL-RAT In FieldPipe Assessment0: 1-3: 4-6:7-10:
FT. LEONARD WOOD
9 10 5 8 6 612
58
154
90
11
0
20
40
60
80
100
120
140
160
180
0 1 2 3 4 5 6 7 8 9 10
8.7% Poor 6.5% Fair84.8% Good
Acoustic Score
#
Histogram of Acoustic Scores
PRESENTATION OUTLINE
• Acoustic Inspection Overview
• Project Background and Objectives
• Summary of Results
• Conclusion
APPLICATION OF ACOUSTIC INSPECTION
Application Area How to Use Acoustics
Pre-Cleaning AssessmentPrioritize/focus cleaning often see >50% cleaning reduction – “focus on cleaning the dirtiest pipes”
Condition Surveys Quickly & economically assess large areas for asset management & planning
Cleaning Interval Determination
Only clean specific segments when below blockage threshold
Post-cleaning QA Low-cost method to check cleaning effectiveness and prevent downstream SSO’s
Optimize SSES ContractResources
Use acoustics to prioritize pre-cleaning & camera resources for contract advantage
Performance-Based Contracting
Use acoustic inspection to enable SSO targets in cleaning/inspection contracts
Condition Based Maintenance Program
The “holy grail” – economics of acoustics enables a CBM strategy to focus maintenance activity
QUICKHITS
FULLPOTENTIAL
CONCLUSION• Acoustic Inspection was shown to be an Effective
Method to Make Blockage Assessmentso Quicko Cheapo Easy / Safe
• Acoustic Inspection identified pipe blockages that were not picked up by a zoom camera
• Acoustic Inspection Does Not Replace Cleaning or Detailed Inspectiono Helps Determine how to Effectively Deploy Cleaning and
CCTV resources
