PRACTICES

NEIL HANDLER, EPA SENIOR ENFORCEMENT
COORDINATOR, STATED, “THE EPA IS ENCOURAGED
TO SEE THAT LATERAL LINING TECHNOLOGY
HAS PROGRESSED TO A POINT WHERE IT CAN
FURTHER ELIMINATE INFLTRATION ISSUES AND
EXFLTRATION ISSUES.”
Until recently, the focus of sanitary sewer
rehabilitation was primarily on relining the
main sewer pipe manhole to manhole, and
then sealing the manhole structures. Laterals
were reinstated, and groundwater allowed
back into the system. In some instances,
lateral connections were grouted, but a
permanent solution was never applied, and
lateral pipes were neglected because of the
complexities. First was the issue of ownership.
Who is responsible for the connection
and lateral pipe, and to what extent? Second
was the limited technology available in the
market place which could permanently rehabilitate
the lateral with minimal disturbance
to residents, sewer service and surrounding
environment.
Technology has caught up to the demand
in the market place and now allows the
lateral to be lined and a watertight mainline
connection to be made during the same
installation. The integration of lateral lining
into a comprehensive rehabilitation approach
is a new and effective solution. Lateral lining
is the final rehabilitation step which yields the
The integration of lateral lining into a comprehensive rehabilitation approach is a new and effective solution
Technology now allows the lateral to be lined and
a watertight mainline connection to be made during
the same installation
most cost-effective use of public expenditures
by permanently sealing the sanitary sewer
collection system, reducing/eliminating
infiltration, and also eliminating exfiltration
- the final piece of the “comprehensive” sewer
rehabilitation puzzle.
Issues of lateral pipe ownership were
discussed when designing the scope of work
for the Norwood project. The town owns
the connection and the lateral pipe up to the
property line (approximately a lateral length
of 20 feet from the mainline to property
line). However, infiltration and exfiltration
problems were not only occurring in
the first 20 feet, they were also occurring
beyond this limit and needed to be resolved
once and for all. The town’s engineering
personnel took the leadership role and made
the decision to line up to within 10 feet of
the house foundation.
This design decision pushed the limits of
the trenchless technology available for lining
the lateral from host pipe without need for
secondary access (i.e. no cleanout installed).
The EPA was on board supporting the approach
and was pleased to see the town take
a leadership role permanently addressing the
environmental issues facing its aging collection
system. The town took a leap of faith the
trenchless market could rise to the occasion
and, by using the comprehensive approach to
sewer rehabilitation, could execute its vision
to get this crucial work done with minimal
disruption to the homeowner.
During Phase 1 of the project in 2011,
the installation contractor was still required
to install a secondary means of access (i.e.
cleanouts) in order to rehabilitate the lateral
to the lengths that the town desired. From
2012 – 2014, National Water Main Cleaning
Company (NWMCC) was the successful low
bidder on the subsequent project Phases 2, 3
& 4. Each project Phase focused on a specific
subarea and required the entire network to
be sealed – mainline, manholes and laterals.
While the quantities for each subarea varied,
the total approximate quantities for the 3
subarea Phases were 27,600 feet of mainline,
185 manholes and 490 laterals rehabilitated.
Each Phase of the project was unique
and presented several challenges because a
high proportion of the lateral connections
were break in connections that entered the
main pipe at various angles. Additionally, the
majority of the laterals did not have access via
a clean out. Many of the property lots were
large with houses situated far back in the lot
resulting in long lateral lengths. The average
lateral length was in the mid 40-foot range
with several laterals reaching lengths up to
100 feet long. The town required the lateral
pipe to be cleaned, inspected and relined
from the main sewer pipe, and wanted to
avoid any disruption to private property
(installation of a cleanout).
42 NASTT-NE NORTHEAST JOURNAL OF TRENCHLESS TECHNOLOGY PRACTICES 2016 | WWW.NASTT-NE.ORG