Garbage disposals can be considered bad for the environment due to their electricity usage, but good for the environment because they reduce the food waste sent to landfills. If everyone used a garbage disposal, it would tax the wastewater treatment facilities in that region, but if we had to choose one of the options, we’d say they are a net positive on the environment when used correctly. 

You may be able to install a garbage disposal on your own, especially if you're handy or have some experience with plumbing. However, if you have any concerns or want to make absolutely sure that the connections are installed correctly, you may be better off hiring a local garbage disposal installer to do the job. 

These appliances do unscrew, but you need to disconnect everything properly when you replace your garbage disposal. Make sure you shut the power off to the area first and check that it’s off with a voltage detector. Disconnect the main drain line and P-trap, and then disconnect the dishwasher drain line if you have one connected. You can then unscrew your garbage disposal using a disposal wrench. Just make sure you disconnect the electrical lines before removing your appliance.

Your garbage disposal will only affect the health of your septic tank if you’re using it too frequently, or filling it with organic waste that doesn’t fully break down. If the tank fills up with too many solids, the bacteria won’t have enough time to consume it before more is added, which can lead to an overflow in the drain field. Your tank will need to be pumped more frequently with excessive or improper garbage disposal use.