NASSCO’s Pipeline

Assessment and Certification

Program (PACP) Overview

Rod Thornhill, PE

White Rock Consultants

Dallas, Texas

MWEA Collections Seminar

October 1, 2009

Introduction to NASSCO

Founded in 1976, NASSCO is the National Association of Sewer Service Companies.

Our mission is to set industry standards for the rehabilitation of underground pipelines and to assure the continued acceptance and growth of trenchless technologies.

NASSCO is an impartial organization serving all facets of the sewer service industry.

NASSCO’s 4-Step Industry

Education Approach

Step 1:Understanding Deterioration Mechanisms

Educate the Industry on how to identify problems in their sewer infrastructure system with a common defect identification program – PACP, MACP, LACP.

Define sewer pipeline deterioration modes that are common to systems containing similar materials but in different locations and climate conditions.

Assist Engineers and Municipalties on setting renewal priorites based on the documented condition of the sewer system.

Step 2:Understanding Available Technologies

Continually educating the industry on the existing and developing technolgies that can be used to renew the sewer infrastructure

Provide the tools for selecting the correct renewal technology for the sewer pipeline documented conditions

Working with the Trenchless Technology Center (TTC) of Louisiana Tech University to develop a computerized Trenchless Assessment Guide for Rehabilitation (TAG-R). This guide will give the industry the tool to quickly and effectively determine correct technology applications based on the existing condition of the pipeline

Step 3:Understanding Specifications

Write standard performance-based specifications that are made available to the Industry

Include quality assurance and quality control standards that promote quality product installation/application/construction

Provide standards for testing of the installed products to verify that the customer receives the product purchased

Step 4:Inspector Training

Certify and train project engineers and field inspectors to better understand each technology and how the technology is constructed in the field

Understanding key elements of the contract specifications to ensure successful installations

Define quality assurance requirements

Provide standard checklists and forms for accurate field documentation

We Need to Avoid Sewer

Problems Finding Us!

0

20000

40000

60000

80000

100000

120000

140000

1880 1900 1920 1940 1960 1980

Mil

es o

f P

ipe

History of Sewer Pipe Installation

EPA Gap Analysis

0

10

20

30

40

50

60

70

80

90

100

1910 1930 1950 1970 1990 2010 2030 2050

Average Age of Sewer PipesA

ge

in

Ye

ars

EPA Gap Analysis

3

5

69 19

5

FailurePoor/Very PoorFairGoodExcellent

Estimated Condition

of Sewer Pipes In 1980

EPA Gap Analysis

12

3333

11

9

FailurePoor/Very PoorFairGoodExcellent

Estimated Condition

of Sewer Pipes In 2020

EPA Gap Analysis

0

10

20

30

40

50

60

70

80

90

100

Failed Poor/Very

Poor

Fair Good Excellent

1980

2000

2020

Estimated Change in Pipe ConditionP

erc

en

t

EPA Gap Analysis

Summary Of

TV Inspection History

Only been around about 45 years

Made possible the creation of the trenchless

technology industry

Most sewers today were only televised years

after construction

Large amount of existing TV data

Need effective way to manage volume of data

Industry Parallels

Standard Methods for the Examination of Water and Wastewater (Standard Methods) standardmethods.org

Joint Publication of APHA, AWWA, WEF

Began in 1905, now in 20th, Edition, 350

separate measurements

Proactive Renovation

and Replacement using APWA Paver

programThe pavement

Management

industry has used

condition

assessment to

justify cost-

effective

proactive

renovation

Origin of Water Research

Centre (WRc)

Condition CodesUK codes initially developed late 70s, early 80s.

Adaptations for use in Australia, Canada, and elsewhere.

Prior to NASSCO codes US industry had no single standard coding system.

WRc codes were modified and widely used in North America, however no standard version was ever established

Origin of WRc

Condition Codes (Cont’d)

Applied to help correlate sewer condition and

sewer rate charges after privatization of

industry in the UK.

NASSCO obtained assistance from WRc in

2001 and first PACP class held in Jan 2002

Standardization concept more important

than the benefits of one code system

compared to another.

Reasons for CCTV Survey

Routine Operational Requirements –

Proactive inspection to identify potential

failures and for planning routine O&M and

renovation programs.

Troubleshooting – Investigation of problem

incidents to select remedial action

Compliance with Mandated Programs –

Inspection and data collection to support

programs such as C-MOM and GASB-34.

Reasons for CCTV Survey

(Cont’d)

• Acceptance Testing – Inspection of new or renewed sewers to insure that construction met specifications and to document as-built conditions.

• I/I or CIP Projects – Examples of the type projects normally conducted by specialty firms or engineering consultants.

The PACP emphasized that all TV Inspections should be

conducted thoroughly and consistently regardless of the

reason for TV

Record and Archive All Descriptive Data

Develop a Condition Rating for Each Line

Provide Follow-up Recommendations

Display Results on a Map

Establish Benchmarks To Compare With Future Inspections Of Same Line

Estimate Probability of Failure and Life Expectancy

Desired Results of

a CCTV Survey

Why Standardization of

Codes is Important

Allows for more effort to be placed on

consistency of data and utilization of data rather

than development of utility-specific or project-

specific standards

Provides the capability of benchmarking sewers

within a single utility as well as from one

geographical area of the US to another

Provides the ability to detect change due to

deterioration over time

Why Standardization

of Codes Important (Cont’d)

Provides better opportunities for integrating data from different software programs

Improves confidence in the description of pipe conditions that will provide cost savings during renewal

Creates many opportunities for continual improvement by consistently describing conditions in a standard way over time

Advances the professionalism of TV Inspection industry

Summary of NASSCO

Pipeline Assessment and Certification

Program (PACP)

Modification/Adoption of standard codes and ratings

Training and certification of operators

Standard NASSCO data format

Certification of software vendors

Defect Grading and Severity Ratings for pipelines

Protocol for Quality Control of PACP data

Now includes manhole assessments (MACP) and soon lateral assessments (LACP)

Modification/Adoption of

standard codes and ratings

Adapt UK codes to the United States market

Re-enforce maintenance related defect codes

Add codes for corrosion evaluation/assessment

Develop codes specific to rehabilitated sewers

Training and Certification of Users

Understanding of codes and interpretation of

defects

Use of codes in forms and software

Two day course with certification exam

Includes review of pipeline deterioration

mechanisms.

Approximately 9,000 Users trained and

adopted by several hundred utilities

PACP Training Explains use of

Coding

Code Value Circumferential location

Inches

Distance (feet)

Video Ref Group /

Descrip Modifier / severity

Continuous defect

S/M/L 1st 2nd

%

Joint

At / from

To

80.3 FM J 08 05

Pipe has a

combination of

longitudinal and

circumferential

cracks

Hydrogen Sulfide Attack

STAGE 1

Inverted Syphon / Force Main

Under anaerobic (septic) conditions, sulfate present in the wastewater is

converted to sulfides within the slime layer inside the pipe. Force mains

generally flow full with little aeration therefore likely points for sulfide

production. Dissolved oxygen levels must be near zero in order for sulfide

production to occur.

STAGE 2

Discharge manhole/gravity sewer

Sulfides in the wastewater are released by turbulent conditions at discharge

point into the sewer atmosphere and form hydrogen sulfide gas (H2S).The

H2S condenses on the pipe surfaces and is converted by bacteria into a weak

sulfuric acid. The sulfuric acid attacks concrete and metal surfaces.

STAGE 1

Gravity sewer

Under anaerobic (septic) conditions sulfate present in the wastewater is

converted into sulfides within the slime layer. Sewers with laminar flow

therefore little aeration are most susceptible to low dissolved oxygen

levels

STAGE 2

Turbulence releases dissolved sulfides into the sewer atmosphere in the

form of hydrogen sulfide (H2S). The H2S then condenses on sewer

surfaces in the form of sulfuric acid. The sulfuric acid attacks cement

based materials and metals.

PACP Concrete

Pipe/H2S Damage Descriptors

Roughness increased (SRI)

Aggregate visible (SAV)

Aggregate projecting (SAP)

Aggregate missing (SAM)

Reinforcement Visible (SRV)

Reinforcement Projecting (SRP)

Reinforcement Corroded (SRC)

Missing Wall (SMW)

Roots - Medium (RM)

Code Value Circumferential

location

Inches

Distance

(feet)

Video

Ref Group /

Descrip

Modifier /

severity

Continuous

defect S/M/

L 1st 2nd

%

Joint

At /

from

To

251.6 RM S 01 20 J 07 05

Used when the roots are

50% or less of the

cross-sectional area

Certification of Software Vendors

All data fields conform to NASSCO standards

Software has the ability to export and import seamlessly to NASSCO standard data format

Data exported from one certified software is identical to software from another

PACP Standard database template freely available to anyone

PACP Data Standards

Data dictionary defines:

– Field names

– Field character number and format

– Valid field data entries

Standard Database Format (ACCESS)

Provide the ability to seamlessly

combine data from various projects

PACP QA/QC Protocol

Implementation ImportantProcess for confirming the accuracy of

PACP coding

Efficient collection of PACP data requires

accurate coding (only code once)

PACP inspections are selected randomly

for checking by Expert

Score is based on percentage of correct

entries divided by total possible entries

PACP QA/QC Protocol (Cont’d)

Protocol will find gross errors or

misinterpretations by technicians very

early in the PACP coding process

Can be used by utilities, contractors, or

engineers

Relatively small sample set can control a

large number of inspections by using

random selection of inspections once

Examples of common errors can be

used to improve coding quality

Although the Missing Wall code (SMW) and the Hole code (H)

describe similar defects, missing wall is used where the concrete is

completely deteriorated, with no pipe material left.

VC pipe material

Keys to Re-Engineering

TV Data Management

Pick a standard, preferably a nationally accepted standard

Understand TV Data Management is a program, and commit to it

Process all data from all sources consistently

Think long term, big picture

PACP Essential Tool for

Estimating Remaining Life

Records in detail the current condition of pipe

Identifies deterioration factors inside the pipe that affect rate of deterioration

Benchmarking of old and new inspections is used to ground truth rates of deterioration

Long term use of standard codes provides continual improvement

PACP-based Life Expectancy estimates will constantly be “corrected” using updated TV inspection condition data.

Utilities need to Establish

Level of Service Objectives

Traditional Levels of Service are

– Occurrence of overflows

– Frequency of maintenance calls

Emerging Levels of Service are;

– Current condition of pipeline

– Life expectancy of pipe

– Probability of Failure

Don’t Ignore Retrofitting

Existing DataVery inexpensive compared to obtaining new

data

Audio and Video often of excellent quality

Can add up quickly to a considerable portion of

the system

Provides immediate ability to assess rate of

deterioration by comparing “old” data to “new”

Summary

Standardization will increase confidence in data and

the use of the data

Develop condition ratings and recommended follow-

up for every line televised

Make mapping of results an integral part of the

process

Don’t ignore value of the existing TV data

Standardized pipe condition data will be an essential

tool for short term and longer sewer collection

system management