Assumption #1 - Oil Heat is a "dirty" heat
Answer - Come to find out, oil used in home heating is biodegradable and can burn with close to zero emissions in today's newer systems. Of course you don't want to have major oil spills and need to perform regular maintenance on your system, but a good running system can burn just as "clean" as other fuels. Also, the strong odor could be considered to be a natural warning device. If your begin to smell a strong oil smell from your system, something is wrong! It's one of the first warning signs that you need to call in a specialist.
Assumption #2 - There is only one type of oil used in home heating
Answer - False! There have been major advances in recent years to incorporate reusable fuels ("BioHeat"), such as soy bean oil (biofuel). Many home heating oil providers sell fuels with 3-5% biofuel concentrations and a few have higher concentrations. Oils with biofuel can actually burn even more efficiently and cleaner than regular fuel. The only concern is that older systems should have their seals updated to handle the new substance to eliminate and chance of leaks. Newer systems should be compatible with the biofuel.
Assumption #3 - Most leaks from systems are in the tank or burner.
Answer - False! Most leaks occur in the line connecting the tank to the burner. Make sure your lines are checked yearly along with the tank and furnace.
Fuel tanks are changing too. Currently, newer below ground tanks have a double layer system that includes an inner plastic tank surrounded by a galvanized steel tank. This technology should be more readily available for in home above ground tanks in the near future.
To find out more about oil heat or to learn about potential ways to save money if you currently have an oil system, go to http://www.massoilheat.org/