Denise,
Your county health department might be the place to start. Incidence of aplastic anemia in the U.S. is estimated to be from 1 to 5 people per million per year. You could alert them to the unusual incidence of aplastic anemia in such a small town.
Something similar happened last year in northern San Diego County (California) when it was reported that several children were diagnosed with aplastic anemia. See, for example,
http://www.nbcsandiego.com/health/11264809/detail.html. The CDC got involved too but could not find enough information to define the area as a disease cluster.
One of the problems with the low EXPECTED frequency of aplastic anemia, is that anything more frequent is very worrisome. It's unlikely that there is much you can do for yourself or your family to prevent aplastic anemia other than to avoid the known causative agents like benzyne and some pesticides.
If you decide to contact any local authorities, please let us know how they respond.
Hope this helps.
Ruth