“Cured In Place Piping” (CIPP) 
Over the next 12 years, the City of Atlanta will inspect, repair
and where necessary, replace every foot of the 2,200 miles of
sanitary sewers. This unprecedented $1.2 billion project is an
integral part of the City’s comprehensive efforts to meet
and surpass all federal and state water quality standards.
The successful completion of the Clean Water Atlanta projects
will benefit Atlanta’s citizens and ratepayers, and our
neighbors downstream and throughout the region by providing the
infrastructure necessary to improve water quality and sustain
Atlanta’s economic vitality.
The SSES project is the first step in bringing Atlanta’s
aging sewer system up to world class/modern-day standards and
protecting Atlanta ratepayers’ quality of life by eliminating
Sanitary Sewer Overflows (SSOs). Through the efforts of the SSES,
approximately 60,000 manholes and 2,200 miles of sanitary sewers
will be inspected for cracks, collapses, and blockages. After
extensive investigation and documentation of defects is completed,
a rehabilitation plan will be developed, identifying necessary
sewer repairs and replacement. In severe situations, immediate
repair may be required.
This document explains a method of sewer rehabilitation known
as “Cured In Place Pipe” which may be used during
the SSES project. It also outlines what you might expect during
the project.
What is “Cured In Place Pipe” lining?
The concept was first put into practice in London, United Kingdom
in 1971. Since then, nearly 10,000 miles have been installed worldwide.
The cured-in-place pipe (CIPP) lining process involves inserting
a resin-saturated flexible lining into the existing sewer. The
lining looks like a very large sock or flexible tube. Air or water
under pressure is forced into the tube, which turns the lining
inside out and causes it to fit tightly to the existing sewer
walls. Hot air or water is circulated throughout the tube to harden
the resin, completing the curing process. When the curing process
is completed, a new pipe has been created that is free of cracks
and holes that allow rainwater and roots to enter the sewer and
cause operational problems such as stoppages and overflows.
What conditions allow for CIPP to be used?
The sewer must be prepared for lining; this includes removing
roots, sediment, and grease from the sewer and cutting out intruding
connections. The sewer will then be inspected using closed circuit
television (CCTV) and the locations of connections from homes
and other properties noted. Manholes will also be inspected.  Like
many other forms of pipe renewal/replacement, CIPP requires bypass
pumping, which re-routes sewer flow around the segment being worked
on during installation. Occasionally a local repair may be carried
out on the existing sewer where the pipe has collapsed, before
the CIPP lining is installed. Cured-in-place lining can be manufactured
to suit many shapes and can accommodate small deformations and
changes in the direction of the sewer.
What are the benefits of CIPP?
CIPP has many advantages, including:
- CIPP allows for replacement of pipes without disturbing surface
structures or other utilities.
- It produces a seamless, jointless pipe lining with minimal
reduction of the original pipe diameter and leaves no voids
to be grouted after the liner is installed.
- Though the liner system reduces pipe size by the thickness
of the liner, the smooth interior of the liner reduces friction,
which increases flow capacity.
- Private service connections are reconnected without excavation.
A dimple is formed where the lining passes a service connection.
CCTV easily locates the dimple and cuts out the lining using
remote techniques.
- The finished product has a 50-year design life, the same as
that of a brand new pipe.
Why does the City need access to my property for 180
days?
The actual process of CIPP lining will likely take less than
one day to complete. However, there are several activities that
may require access to property to ensure rehabilitation is successfully
completed. These activities include the following:
1. Inventory of fences, trees, etc. that may impede free access
for construction/maintenance equipment.
2. Determining location of proposed cleanouts and existing private
service connections to main sewer.
3. Assessment of logistics to disconnect/reconnect service connections.
4. Soil testing.
5. Landscaping (pre- and post- CIPP lining)
6. The management of flows from property, which includes planning
and actual maintenance of flows.
7. Dye testing to confirm abandoned (as opposed to active) connections,
as well as connections between buildings and sewers.
For additional SSES Project information, please
call the CWA Hotline at 404.529.9211
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