I've been sifting through bootstrap on a wordpress website I've made, how do i fix this issue with the footer

The website www.mottemp.co.uk has the footer overlapping the bottom image block on wordpress and I cannot for the life of me figure out what is causing it. I forgot which values I had changed when modifying the css.core file. I only know some basic CSS thats why I'm asking if an experienced user can help. Thankyou ;)