Here’s a fairly common item I see while performing home inspections. What you’re looking at in the picture is the discharge and overflow hoses from a water softener tying into the homes sewer drain system. Why is this an issue? Because of the way they are connected. Appliances like your water softener should not be directly connected in this way. They should have an “air gap” connection. An air gap connection prevents sewage from being pushed into the appliance in the case of a back-up in the drain system. This is a very important item for preventing potable water contamination in your home!
There are many ways to create an “indirect connection” for dishwashers, water softeners, clothes washers, and other water-using appliances that require them. You should reach out to your preferred plumbing contractor to fix any improper connections you may have. This YouTube video goes deeper into indirect waste connections if you would like to learn more!