two bachelor degrees problem concerning Stat PhD application

[BadTasteTea]

I'm currently studying mathematics and computer science at a well known university in Europe(ETH Zurich) and I had a relatively good GPA here, about 3.7/4. It would be my second bachelor degree though, I got my first bachelor degree in Civil Engineering from an another lesser-known university with a very low GPA, about 2.9/4. 

I'm worrying that the low grades in my first Bachelor degree would have a negative impact on my application. My dream school is Columbia, is it still possible for me to get in Columbia?