As long as civilization has been around there has been trash. We unearth pottery shards that are thousands of years old as evidence that people had no thought of recycling. When landfills were first implemented, the environment was not first in mind. Now landfills are designed with lines to catch water that is filtered and used as dust control.
At the close of every day, landfills must cover all trash with soil or an alternative daily cover. To generate that soil, a dozer must scrape it, stockpile it for the day, and then spread it out at the end of the day.
The amount of greenhouse gases generated at landfills can be considerable. Some modern landfills have methane capturing systems that fuel energy producing facilities on the landfill property.
The fact that we still have landfills receiving hundreds of tons of trash every day without a second thought is not the best for our planet.
Finding a use for our discarded materials is the key. Placing a ton of lead in a lake will poison for years. Take that same lead to a battery factory and you will receive a check.
A pollutant is a commodity in the wrong place at the wrong time, we just need to find the right place for each material.