The Grouting process

Originally developed nearly fifty years ago, chemical grouting is the oldest method for impeding ground water infiltration into structurally sound sewer systems. When compared to other sewer rehabilitation processes, chemical grouting continues to stand the test of time through its versatility and years of proven success.

Chemical grouting is easily injected through leaking joints, faults, cracks, annulus at lateral openings in lined pipe and other areas. The most common points of entrance for groundwater infiltration are at manholes, joints, service line connections and within the first few feet of the service line.

Below is a comprehensive list of critical sewer connection points where chemical grouting can stop infiltration:

• Sewer Pipe Joints
• Sewer Pipe Circumferential Cracks
• Lateral to Main Connections
• Lateral Pipe Joints
• Manhole Rings and Base Joints
• Manhole Brick Structures
• Exposed Annulus Flow Between host Pipe and Liner at Lateral Cutout
• Exposed Annulus Flow between host pipe at Liner Entry into Manhole

Within these easily identified areas, chemical grouting is the only technique that permeates the external soil and voids around the leak, stopping ground water flow into the collection system and keeping sewage flows within the system.

12 Steps to Successful Infiltration Control with Chemical Grouting

Step 1. Identify collection system basins with most infiltration

Step 2. Clean the sewer lines in these basins per NASSCO Standards

Step 3. TV inspect and evaluate the infiltration sources per PACP

Step 4. Identify the worst basin segments and work up stream

Step 5. Formulate grouting specification to meet your needs

Step 6. Use national guidelines within specifications

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Step 7. Give contractors price incentives to grout to refusal

Step 8. Qualify bidders based on operators experience

Step 9. Have inspectors learn the grouting process

Step 10. Require equipment demonstration tests per ASTM

Step 11. Do the job

Step 12. Retest under contract warranty clause

Sequence of Grouting a Mainline Joint:

Step 1. Locate leak

Step 2. Inflate packer over leak

Step 3. Inject chemical grout into soil

Step 4. Air test and deflate

Sequence for Grouting a Lateral:

Step 1. Locate the lateral

Step 2. Center packer over lateral connection

Step 3. Inflate lateral packer

Step 4. Inject chemical thru leaks into soil

Step 5. Cure grout and air test

Sequence for Grouting a Manhole:

Step 1. Dual-component pump for curtain-grouting leaking manhole

Step 2. After drilling injection holes, prepare to grout the bottom of the manhole.

Step 3. Inject chemical grout into the bottom set of holes, then move up to the next row of holes.

Step 4. Impermeable grout-curtain almost complete and the leaks have already stopped.