Canada and the US offer ...

Canada and the US offer Operator Certification programs to train and certify individuals to treat wastewater.  There are four levels of certification offered (i.e. Level 1 through 4), with each level requiring passing specific training programs, having certain number of years of experience as well as advanced education; however, you can get to be a Level-IV operator without a college diploma or university degree.  While most of these programs are offered informally by gradually taking courses that are offered locally and writing exams, you can also get certified by taking online.  The most widely known program is offered by Sacramento  State University.  https://www.owp.csus.edu/courses/catalog.php   The alternative is to get a  recognized university degree in environmental engineering or chemical engineering.