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

Trans Mountain Expansion Project 2016

421

15

Pipeline risk assessment

Trans Mountain must file with the NEB,

at least 6 months prior to commencing

construction

, the following information for Line 2 and the new delivery pipelines:

a) the results of the updated risk assessment in a tabular format similar to

that provided in its Line 2 Consequence Report (Filing A3Z8G5). The risk

assessment tables must also include:

i)

any updates to High Consequence Areas;

ii) the risk mitigation method(s);

iii) the mitigated Environmental Risk Scores;

iv) pre-mitigation maximum outflow volumes; and

v) the outflow volumes after mitigation;

b) Environmental Risk Score acceptance criteria, with supporting rationale; and

c) a detailed description of the adequacy of the following from its Line 2 Consequence

Report (Filing A3Z8G5):

i)

the coefficients used in the scoring system equations; and

ii) the values from the scoring tables.

X

16

Quantitative Geohazard Frequency Assessment

Trans Mountain must file with the NEB,

at least 6 months prior to commencing

construction

, an updated Quantitative Geohazard Frequency Assessment for the

new Line 2 and delivery pipeline segments that contains a re-assessment of the

Frequency of Loss of Containment (FLoC) values based on the results of site-specific

field assessments and any required mitigation as determined in the detailed

engineering and design process.

Trans Mountain must provide in the assessment a plan to manage and mitigate

geohazards at any location where the FLoC value is greater than 10

-5

events per year

to reduce the level of risk to as low as reasonably practicable (ALARP), including a

detailed explanation of how the ALARP level has been attained at each location.

X