How long does weed killer stay in the ground and impact the environment?

Weed killer can stay in the ground and impact the environment for varying lengths of time, depending on the specific type of weed killer used. Some weed killers can persist in the soil for weeks to months, while others can last for years. The impact on the environment can also vary, with potential risks to plants, animals, and water sources. It is important to follow label instructions and use weed killers responsibly to minimize environmental harm.