Julie Clopper / Shutterstock.com Garden Chemicals Illegal in Garbage & Drains Household Hazardous Waste Julie Clopper / Shutterstock.com HHW must be dropped off by appointment – click for more info. Never Pour Down the Drain Garden chemicals, such as weed killer and fertilizer, can never be dumped down storm drains, home drains or tossed in the garbage. Regular drains are not equipped to handle these chemicals, and they will leach into the environment. Don't Water Grass After Using Do not water grass after applying garden chemicals. Not only will the runoff end up in local waterways, it also ruins the effectiveness of your pesticides. Don't Use if It's Going to Rain Avoid using chemicals before a storm. If you do, rain will wash them down storm drains and into local waterways. Rinse Empty Concentrate Containers Containers that held concentrate need to be rinsed out three times before they are thrown in the trash. To do this, add any remaining concentrate to the spray tank. Next, add water to the container, swirl, then transfer it to the tank. Add water, swirl and transfer it twice more. Ready-to-Use Containers Empty containers that held ready-to-use chemicals can be thrown in the trash without rinsing them out. Ways to Reduce Avoid Purchasing Concentrates Consider purchasing ready-to-use products. Purchasing concentrations to dilute on your own can expose the body to harmful chemicals. Also the use of under-diluted chemicals is more damaging to the air, water and soil. Buy What You Need Reduce the impact of garden chemicals on the environment by buying only what you need. Give away any unwanted or leftover products, which saves you the hassle of disposing of them as hazardous waste.