April 10, 2002 Jon KreischerCVEN 689 - GIS Identifying Critical Sewer Lines

April 10, 2002 Jon Kreischer CVEN 689 - GIS

Identifying Critical Sewer Lines


Project Definition

Identify Critical Sewer Lines in College Station– Necessary Step by Utilities Mngr– $3 million budget

• $1.9M Treatment• $1.1M Collection

Research CS Preventative Maintenance Capabilities & Strategies


Sewer Maintenance

Historical Perspective– Reactionary vs. Proactive Strategies

Cost Effectiveness– Material Type– Life Cycle Costs

College Station– $3M Sanitation Budget, $1.1M for O&M of

sewer collection system


Preventative Maintenance

Types of Preventative Maintenance– Mechanical Sealing– External Grouting– Root Removal– Cleaning: Jet Rodding– Biological Agents: De-Greaser Bugs

College Station’s Tools– Jet Rodding, Bugs, TV equipment


Critical Categories of Sewers

Category A– High Impact System on

surrounding environment– Post-failure Rehab is

twice as expensive as planned replacement/four times cost of scheduled rehab

– Require preventative maintenance

Category B– Less critical than A

because of reduced failure cost and effect.

– Preventative action is still cost effective

Category C– Non-critical Sewers– Preemptive Work in

these sewers would not be cost effective


Critical Sewer Characteristics

Old Age Deeper than

average Clay pipes Located under busy

streets Difficult access

Located in Poor Soil Conditions

Difficult to bypass Require Frequent

Inspection or maintenance

Near sensitive environmental area


Critical Sewer Lines in College Stations

Large Lines – 13” or greater Busy Street – Texas Ave Require Frequent Maintenance

– Vitrified Clay Pipe– Tree roots and grease


Original Sewer Lines ThemeSewer lines range from 4” to 32”.

There is over 1.2 billion liner feet of sewer lines.


Sewer Line Attribute TableLENGTH MAINSIZE DIA_FT MATERIAL MTR_CODE96.75355 6 0.50 VCP 6

294.09395 8 0.67 VCP 6324.90152 8 0.67 VCP 6161.64467 8 0.67 VCP 6931.82030 15 1.25 VCP 6485.49871 8 0.67 VCP 6447.62065 8 0.67 VCP 6337.35006 18 1.50 VCP 6208.00240 18 1.50 VCP 6299.79420 6 0.50 VCP 6257.57717 6 0.50 VCP 6258.94015 6 0.50 VCP 6340.38884 6 0.50 VCP 6313.46700 6 0.50 VCP 688.28927 6 0.50 VCP 6

433.87736 6 0.50 VCP 6


Critical Sewer Lines - 1

Large sewer lines account for 1/8 of the network and include 215,000 liner feet of sewer lines.


Critical Sewers Lines - 2

Texas Ave is the primary road through College Station and Bryan.


Critical Sewer Lines - 2

The resulting Arcview Query identified only 14 of 4600 sewer segments that intersected Texas Ave. 6 of the 14 lines were larger than 13”.


Critical Lines - 3

6” – 8” clay lines account for nearly 1/2 of the entire line segments and over 500,000 liner foot of sewer lines.


The Project Continues

Working with Manholes– Manhole Point Theme– Network Analysis

Conclusions


Sanitation Work Force

Preventative Maintenance

Locating the Manholes


Any Questions

Documents

April 10, 2002 Jon KreischerCVEN 689 - GIS Identifying Critical Sewer Lines