What environmental concerns should Shari and Carlton have as they consider purchase and development of this property?

Shari and Carlton live outside a small but bustling city in Ohio. They are looking to invest in property just outside of town, hoping to build a housing development on the land to meet the growing needs of the community. There is a 100-acre parcel just beyond the city limits that used to hold a small manufacturing business, but that company declared bankruptcy and shut down about 20 years ago.
What environmental concerns should Shari and Carlton have as they consider purchase and development of this property?