Successfully Developing & Managing
Wastewater Pipeline/ Manhole Condition
Assessment & Rehabilitation Programs
Presented from a municipal perspective…
Presented by:
Jeff Maier, P.E.
Metro Wastewater Reclamation District
Denver, Colorado
The challenges municipalities are facing:
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ASCE’s 2009 Report Card for America’s
Infrastructure:
Grade for Wastewater Infrastructure is a “D –”
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Cost effective asset management programs are
more important than ever
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Doing more with less is the new normal
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Tighter EPA & CDPHE regulations
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Funding issues & aging systems
The importance of condition assessment
and rehabilitation
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Understanding your system is vital – wastewater
infrastructure is crumbling!
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Out of site, out of mind is no longer acceptable
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Critical component of successful asset management and
budgeting
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Regulatory compliance issues
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Operation & Maintenance requirements
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Knowledge about your system = good decision making
Benefits of effective condition assessment
and rehabilitation
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Reduces overflows, violations & failures
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Prioritizes repair and maintenance efforts
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Reduces emergency repairs or dig & replace
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Modern technologies utilize trenchless condition
assessment and rehabilitation techniques
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Can save a lot of money!
Attributes of a successful condition
assessment & rehab program
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Goals and responsibilities are defined
Organized & methodical
Administered by qualified staff and/or consultants
Uses available modern technologies
QA/QC is paramount
Reduces risk
Helps asset management & maintenance efforts
Improves capital expenditure planning
Condition Assessment Technologies &
Management Techniques Available
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CCTV inspection
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Advanced Pipe Condition Assessment Systems
(Redzone, Cleanflow, PPR, etc.)
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Pole Cameras
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Manual and Entry Inspection Methods
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Database systems for inspection information
storage
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GIS interfaces & state-of-the-art inspection software
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Consistent rating systems (NASSCO’s PACP &
MACP)
Rehabilitation Technologies Available
Pipeline Rehabilitation:
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CIPP Lining
UV-Cured CIPP Lining
Sliplining
Fold & Form Sliplining
Structural Epoxy lining
Spiral-Wound & Panel lining
Cementitious lining
Trenchless Point Repair Methods
It’s critical to understand each
of the technologies; especially
strengths & limitations.
Rehabilitation Technologies Available
Manhole Rehabilitation:
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Epoxy Coating/ Lining
 Poly-Urea Coating/ Lining
 Urethane Coating Lining
 Calcium Aluminate Mortar
 Cured in Place Liners
 Fiberglass Inserts
 HDPE Manhole Inserts
 Cementitious Lining
 Polymer Mortars
Metro Wastewater’s Interceptor & Manhole
Condition Assessment & Rehab Program
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Systematic, consistent, & cost-effect
approach to assessing & rehabilitating
pipe and manhole conditions
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In-house developed program
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Collaborative effort between
Engineering, Comprehensive Planning,
and Operations & Maintenance (O&M)
Departments
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Balances operational, financial, and engineering
needs
Metro Wastewater’s Interceptor & Manhole
Condition Assessment Program
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Pipes inspected mainly by using CCTV
In-house CCTV using MWRD crews
5-category pipe condition rating system
3-category manhole condition rating system
Manholes surface & entry inspected
Utilizes advanced condition assessment
technologies
Program utilizes customized database system
and GIS interface
Defined Departmental Roles & Workflow
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O&M Department – Televise pipelines (CCTV),
inspect manholes/ structures, enter inspection info
into database, initial condition rating
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Engineering Department – Review CCTV footage,
follow-up inspection of manholes, assign final
condition rating, generate prioritization list & reports,
design & manage rehabilitation project, research new
technologies
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Comprehensive Planning – Review rehabilitation
prioritization lists & reports, update & manage
Capital Expenditure Schedule
Interdepartmental Cooperation & Responsibility:
Results in successful in-house condition assessment
and rehabilitation program.
Program Components: CCTV Inspection
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CCTV video inspections:
Minimum of 10% of pipe
segments annually
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10 year video cycle for entire
interceptor system
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CCTV work performed in-house
by O&M Department crews
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In-house CCTV ensures consistency, eliminates
scheduling issues, & ultimately saves money
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Customized 5-category rating system
Program Components: CCTV Review,
Condition Rating Classification & Reporting
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5-category CCTV review criteria developed inhouse
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Rating criteria based on reinforced concrete pipe
(RCP) conditions, but can be applied to all pipe
materials
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Rating system is comparable to NASSCO’s
Pipeline Assessment & Certification Program
(PACP), but meets specific needs of MWRD
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Specific definitions of each category define
rehabilitation urgency and time frame for
rehabilitation completion
Program Components: CCTV Review,
Condition Rating Classification & Reporting
Good – No rehab at this time, maintain 10 yr cycle
Fair – No rehab at this time, maintain 10 yr cycle
Fair-Poor – Rehab may be necessary (5-10 yrs)
Poor – Rehab is necessary (2-5 yrs)
Very Poor – Rehab needed ASAP (0-2 yrs)
Pipeline Rehabilitation report cost estimates based on
condition ratings of Fair-Poor, Poor, and Very Poor
only.
Program Components:
Manhole/ Structure Inspection
Manhole surface & entry inspection examples:
Program Components: Manhole/ Structure
Condition Rating Classification & Reporting
Good – No rehab at this time, maintain 10
year inspection cycle
Fair – No rehab at this time, maintain 10 year
cycle, monitor as needed
Poor – Rehabilitation is necessary (1-3 yrs)
Program Components: GIS Mapping
Example GIS Map & Legend
Program Components: Interceptor
Infrastructure System Database (IIS)
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CCTV & Manhole inspection data
maintained real-time in IIS database
IIS database developed in-house
Oracle based system
Manages inspection data, physical
pipe & manhole info, and GIS system
Streamlined condition assessment program
Access searchable pipe & manhole/ structure
condition information
Program Components:
Supplemental Pipe Coring Activities
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Core drill sampling on selected pipe segments
Coring used to confirm remaining pipe thickness
Candidates for coring are pipe segments that may
be rated in either category (i.e. fair-poor or poor)
Coring work done by outside contractor
Info entered into IIS database, compare to
existing data & reevaluate current condition rating
Samples used to verify & check CCTV rating
system
Research & Development
New Condition Assessment Technologies
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Ongoing research of non-destructive methods to
determine pipe condition & wall thickness
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Laser profiling, sonar systems, &
combo assessment technologies
(RedZone, CleanFlow. PPR)
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Will replace supplemental coring
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Will help improve rehabilitation
prioritization
CCTV will still provide majority
of inspection information
(CCTV ~90%, new method ~10%)
Research & Development
Testing & Product Evaluation
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MWRD’s 6-Step Manhole/ Concrete
Rehabilitation Product Evaluation Program
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In-house developed program
Evaluates products and applicators
Helps ensure QA/QC
Severe Wastewater Analysis Test (SWAT)
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Evaluates coating/lining effectiveness & longevity in
severe wastewater headspace environments
Laboratory and real-life test comparisons
Accelerated test chamber & electrical impedance tests
Long-term Capital Expenditure Planning
Interceptor Pipes
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Assumes pipes will be rehabilitated with CIPP lining for
cost estimating purposes
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Other rehab methods considered during design (slip
lining, fold & form, epoxy-lined, etc.)
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Cost estimates based on past MWRD rehab projects
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Historical CIPP cost data for pipe sizes 8”-60”
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Current MWRD CIPP cost estimate data (installed price):
8”- 30” = $3.75 per in/ft
31” – 41” = $4.50 per in/ft
42” – 60”+ = $6.00 per in/ft
Long-term Capital Expenditure Planning
Manholes/ Structures
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Assumes manholes will be
be rehabilitated with epoxy
coating/lining for cost
estimating purposes
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Other rehab methods
considered during design
(other coating/liner types,
CAM, fiberglass, HDPE)
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Cost estimates based on
past MWRD rehab projects
Prioritization for Pipe & Manhole
Rehabilitation Projects
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Pipe segments rated “very poor” will be repaired on priority
basis (i.e. next available rehab project)
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Adjoining “poor” segments will be added when shared
bypass pumping cost savings can be realized
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Assumed that only 75% of “poor” and “fair-poor” rated
pipes will ever reach “very poor” condition
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Projected timing for when pipe segment or manhole will
deteriorate and reach “poor” or “very poor” is considered
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Manholes rated as “poor” will be repaired on priority basis
(i.e. next available rehab project)
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10-year Capital Expenditure Schedule updated
accordingly
Conclusions
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A well-run Condition Assessment & Rehabilitation
Program provides a systematic, consistent, & costeffective approach to asset management
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Supports long term capital expenditure planning
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Effective in forecasting future maintenance needs,
prioritizing resource allocation, and costs based on
inspection & condition assessment ratings
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Reduces potential overflows, violations & failures
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Utilizes trenchless technology
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Can save a lot of money!
Questions?
Jeff Maier, P.E.
Metro Wastewater Reclamation District
Denver, Colorado
303-286-3285