By today’s thinking, mixing stormwater and sanitary drainage in a single pipe/system seems a less than brilliant idea—yet this was the norm and recommended practice only 100 years ago. What has...

By today’s thinking, mixing stormwater and sanitary drainage in a single pipe/system seems a less than brilliant idea—yet this was the norm and recommended practice only 100 years ago. What has happened in the past 50 or so years to change attitudes and practices in this area?