“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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