A student loan debt tsunami is coming. Here's how to minimize the impact.  

By the end of September, federal efforts to collect from student loan borrowers behind on their payments will resume after several years. Nearly 6 million borrowers — about the size of the population of Colorado — will again face significant financial penalties of the default system and a rocky path to getting back on top of their unpaid debt. 

Available data paints a clear picture of who these borrowers are and the challenges they face to repay their loans. For example, compared with student loan borrowers who are not in default...