The simple answer is not to put anything down the drain or in the toilet that could cause problems. This includes: fats, oils and grease, medications, wipes and hazardous liquids. Fats, oils and grease clog sewer lines, and medications and hazardous liquids pose challenges for the sewage treatment process. Also, never connect any storm drain to a sewer lateral. This would greatly increase the flow in the sewer system during wet weather and could lead to spills, overflows and other problems.