After hitting a speed bump last fall, TransCanada (TRP 0.33%) reaccelerated in early 2018, posting solid earnings and cash flow growth in the first quarter. Wall Street is expecting to hear that the momentum  continued when the pipeline company posts its second-quarter results later this week, but there are a few issues investors should be keeping a particular eye on, and three questions they'll want answers to.

1. How much of a hit did the Leach XPress incident cause?

TransCanada brought 7 billion Canadian dollars ($5.4 billion) worth of expansion projects into service last year, which helped fuel its distributable cash flow (DCF) growth of 6% during Q1 2018. And the company expects to finish an even larger CA$11 billion ($8.4 billion) slate of projects this year. Several of these expansions are already online, including (in the U.S.) the $1.6 billion Leach XPress natural gas pipeline and the $300 million Cameron Access natural gas pipeline project, both finished in Q1, as well as several projects in Canada that were completed in Q2.

Several pipelines at dusk.

Image source: Getty Images.

These expansions should boost DCF in the second quarter. However, the increase likely won't be as much as it could have been because an explosion damaged a section of the Leach XPress natural gas pipeline in June, putting it out of service for several weeks. Investors will want to hear how much this issue impacted growth during the quarter, and if the company anticipates any lingering effects.

2.Did TransCanada add more projects to its backlog?

TransCanada entered the year with CA$21 billion ($16.1 billion) of growth projects under way. However, with more than half of those expansions due to come online by year's end, the company needs to replenish its backlog so that it can keep growing. That shouldn't be a problem since it had CA$20 billion ($15.3 billion) of projects in the longer-range development stage, including the $8 billion Keystone XL Pipeline in the U.S. and the CA$4.8 billion ($3.7 billion) Coastal GasLink project in Western Canada.

While TransCanada has suggested that it could start construction on both of those projects within the next year, it has yet to add either one to its backlog, and it might not do so this quarter. In the case of Coastal GasLink, Royal Dutch Shell (RDS.A) (RDS.B) has yet to make a final investment decision on its LNG Canada project, which in turn is driving the need for TransCanada's project. While Shell executives said on their Q2 call that LNG Canada looks "very promising," they have a few things to work out before approving it.

Meanwhile, Keystone XL still must overcome a few legal hurdles before the company will be able to start construction.

But while TransCanada might not add these needle-movers to its backlog during the quarter, investors will want to know whether it was able to secure other, smaller projects to fuel its growth.

A gas pipeline under construction.

Image source: Getty Images.

3. What will the company do with its MLP?

This has been a volatile year for TransCanada's master limited partnership (MLP), TC Pipelines (TCP). The MLP's stock was one of several that plunged in March after the Federal Regulatory Energy Commission (FERC) revised a long-standing policy in a way that impacted cash flow on certain gas pipelines owned by MLPs. Because the new policy meant that TransCanada couldn't drop down assets to TC Pipelines at a fair value, it took the MLP off the table as a viable funding option. That led to speculation that the company might follow many of its peers and buy out its MLP.

However, the recently released final revision of FERC's policy change contained several options for MLPs that could mitigate its impact. That news fueled a huge rally in TC Pipelines' shares, and might change TransCanada's opinion on the company's viability as a funding source. If the company announces any changes of plans for this entity, the news could be significant.

On the lookout for continued growth

TransCanada currently has enough expansion projects under way to fuel 8% to 10% dividend growth all the way through 2021, which is an impressive pace for a company that already yields an attractive 4.7%. However, investors will still want to see that the company continued securing new projects in Q2 so that it can keep growing at a fast pace. That increased visibility would make an already excellent income stock an even better buy.