National_Energy_Board_Report Page445

No.

Conditions with initial ﬁlings due prior to commencing construction, or prior to

commencing construction of speciﬁed Project component(s)

CPCN

OC2

OC49

Temp

Pump1

Pump2

Tanks

Deact

National Energy Board

426

Burnaby Mountain tunnel option – design, construction, and operation

For the tunnel between the Burnaby Terminal and the Westridge Marine Terminal

and related delivery pipelines,

at least 6 months prior to commencing Burnaby

Mountain tunnel construction activities

, Trans Mountain must:

a) ﬁle with the NEB for approval:

a description of the selected tunnel lining method with the rationale for its

selection; and

ii) tunnel conﬁned space entry procedures during construction and visual

inspection, and, if applicable, following construction; and

b) ﬁle with the NEB:

the results of any geotechnical or geophysical feasibility surveys completed

since the evidence ﬁled in the OH-001-2014 hearing;

ii) a description of the tunnel portals and permanent road access, if applicable;

iii) a description of the selected tunnel excavation method with rationale for its

selection;

iv) a description of the tunnel backﬁlling method with rationale for its selection;

v) a description of the methods to be used for pipe handling and welding;

vi) a discussion on the adequacy of the pipe support methods for the new delivery

pipelines during construction, commissioning, hydrostatic testing and operation,

if applicable;

vii) a discussion on the adequacy of the selected leak detection methods;

viii) information demonstrating how the precautionary design of the new delivery

pipelines would mitigate issues related to limited accessibility for future

maintenance and repairs; and

ix) the ﬁnal tunnel cross-sectional design drawings.

Burnaby Mountain tunnel option – backﬁlling

Trans Mountain must ﬁle with the NEB,

at least 6 months prior to commencing

Burnaby Mountain tunnel construction activities

, the following information

on backﬁlling the tunnel between the Burnaby Terminal and the Westridge

Marine Terminal:

a) a discussion of the adequacy of the measures to be taken during tunnel

backﬁlling to eliminate or mitigate potential damage to the delivery pipelines;

b) the method(s) that will be used to conﬁrm the consistency and continuity of the

tunnel backﬁll (i.e., backﬁlling is completed without any spatial gaps);

c) the method(s) that will be used for holiday detection and coating repair prior to

backﬁlling;

d) the methods that will be used to conﬁrm the integrity of the delivery pipelines in

the tunnel, both prior to and after backﬁlling, but prior to commissioning; and

e) the methods that will be used for monitoring, maintaining, and repairing backﬁll

during operations, considering conditions such as ﬁll deterioration and a

potential increase in permeability.

Burnaby Mountain tunnel option – cathodic protection

Trans Mountain must ﬁle with the NEB,

at least 6 months prior to commencing

Burnaby Mountain tunnel construction activities

, the following information on

the cathodic protection system for the delivery pipelines in the tunnel between the

Burnaby Terminal and the Westridge Marine Terminal:

a) a description of the cathodic protection system design;

b) risk mitigation measures for all potential cathodic protection performance

issues, such as shielding from the backﬁll material; and

c) a method for verifying the eﬀectiveness of the cathodic protection system

during operations.