It's been a tough summer for the MBTA and its riders, with seemingly constant news of derailments and delays. You'd almost forget that the biggest T project in decades, the Green Line Extension to Somerville and Medford, is still in progress. It turns out there are delays with that, too. WGBH Radio’s Arun Rath got an update on the Green Line Extension from WGBH News Transportation Reporter Bob Seay. This transcript has been edited for clarity.

Arun Rath: So what's the latest on the Green Line Extension?

Bob Seay: Well at the Fiscal Control Board meeting yesterday, representatives from the project came forward and were asked some pretty tough questions about some delays they have been experiencing.

The biggest delay — and the one that concerns the fiscal control board — has been the relocation of the Lowell line commuter rail tracks. Now this is necessary because the new Green Line tracks will be running along the existing commuter rail tracks from East Somerville to College Avenue in Medford. All of that was scheduled to happen next month, but now that's been pushed back about two months, to November. And the concern is that that relocation has to be completed before the start of winter or the work becomes much more difficult in the cold weather.

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Rath: It’s getting all complicated. Is that why officials are concerned now?

Seay: Well, they're concerned about the track relocation, but also about the rate of spending so far on this project. It's been just above the forecast level — it's now at $185 million — which is what officials want to see to make sure the project is on schedule. But that spend rate is forecast to quickly ramp up to $965 million in the next three years. And there is some concern that there won't be enough people and resources to keep up with that rate of spending.

And as fiscal control board Chairman Joe Aiello put it at yesterday's meeting, "Throw everything you've got at it. I can't tell you how important it is to get this project on schedule, but you've got to get more people on the job.” So the project reps were there and took in everything that Joe and the fiscal control board members had to say. They said they will be putting more people on the job — they expect to hire another 55 this fall. And they also feel that there's enough time to catch up before the project's scheduled completion date of 2022.

Rath: So can you talk a bit more about the concern over drainage at the construction site?

Seay: Well both the Secretary of Transportation, Stephanie Pollack, and fiscal control board Chairman Joe Aiello mentioned that they had seen standing water along the commuter rail tracks several times, most recently last week, during some heavy rains. And they were very concerned that this drainage issue was going to further delay the project. Now the people who were there yesterday from the project said that they will be installing some new, bigger drainage systems. Once again, this is a corridor that basically is a trench in the ground. So it lends itself to flooding fairly regularly. They're really putting a lot of effort into expanding the drainage systems even over and above what they had originally planned to put in there.

Rath: Sounds like they've got a real sense of urgency. This seems like a make or break moment, the way that they're laying it out.

Seay: I think it should be noted that a lot is at stake here, and it's not only completion of what will be the T’s first major expansion project in the last several decades. There's a lot at stake politically, as well.

When Gov. Charlie Baker was elected and got into office, he got the project back on track. And in his $18 billion transportation bond bill that he's filing, he's asking the legislature to back it. But as Joe Aiello told the board yesterday, “He and we took a big risk — the ‘we’ includes the secretary as well — to get this project back on track. We need to convince the legislature that we are deserving of the recommendation that the governor put in his transportation bill to be able to complete the job that this organization set out to do about four years ago.” And Aiello was also quoted in The Boston Globe as saying: “Count us as very worried.”

I think the next important development will be whether or not they can meet that pre-winter deadline of relocating those tracks. And in fact, if there's any delay in that process, then there will be a serious chance that this whole project could be delayed, and I think that was the concern of the board yesterday. They were literally trying to light a fire under these construction people, saying, 'We really have to get this going and meet this deadline because the entire project could fail if we don't.'

Rath: Gotta get it done before the bad weather comes.

Seay: That's right, as we know.