Good morning, Allison:
In NC, portions of land which has been filled with trash are required to be shown by the surveyor on the subdivision plat. Landfills have closure procedures and monitoring requirements. There are also aerial photographs of Union Co which go back to the early 1900's. Reviewing these with County planners would show the pattern of use and development. If you appreciate an answer, please give thumbs up. For the most helpful answer, please say thanks with a best answer click.