We differentiate between the natural and anthropogenic environment. Most people probably think about the nature when hearing the term “environment”, but we also mean human settlements when talking about the environment. There are many substances in waste that can also harm the human health and thus we want to ensure that untreated waste isn’t close to human settlements for too long and also all humans handling the waste wear protective gear.
Of course simply bringing it outside of the settlement into the natural environment is also not feasible as we also want to protect the natural environment, which in itself is alredy protect-worthy in itself but also as the provider of important resources (such as water) and eco-system services (such as insect pollination).