olavs/Shutterstock When you pour grease down the drain it sticks to the inside of your pipes and the pipes in the street. This can cause the entire pipe to become clogged over time. Other oil-based products are also dangerous to pour down your drain, such as cooking oil, salad dressings, butter, mayonnaise, and fat. If needed, make sure to let the grease cool first, then dispose of it in the trash instead.
MaraZe/Shutterstock Flour coagulates when mixed with water. This can clog your pipes by coating the edges and catching other bits of disposables trying to make their way down. Always throw your flour, whether mixed with water or not, in the garbage. These are the items you should never put in your dishwasher.
Mangpor nk/Shutterstock If you flush your unused or expired medication or crush it up and pour it down the drain, those chemicals will be leaked back into your drinking water and the environment. Always make sure to dispose of unwanted medication at your local pharmacy or police department, which will have access to medical waste disposal units.