On the website edX.org you can find thousands of Massive Open Online Courses (MOOC's) from many universities around the world. You can follow most of them in your own pace and time, and most are free of charge. The topics are wide-ranging; the Technical University Delft (Netherlands) for instance offers courses on business management, innovation, circular economy, entrepreneurship in emerging markets and much more. There are also a few technical water courses, such as the one on urban sewer treatment.

Have a look here and kick off 2018 by learning something new!