I am compiling a database of septic tank locations to make some rough estimates of the magnitude of return flow to the groundwater system for the Floridan aquifer system. Ideally I would have a lat/long for each tank so that I can identify, at the census block level, the average number of persons per household to compute the number of gallons of flow-through per day. A dataset of this detail has been developed for the state of Florida and possibly for Georgia as well. Records for South Carolina and especially Alabama are not as robust and I would need to resort to some county-wide tally. I have only managed to find state-wide counts on uscensus.gov through 1990. Block-group level data seem to be available through American Fact Finder 2 from the 2010 census, but only for American territories such as Guam or the Virgin Islands (Topics -> Housing -> Physical Characteristics -> Sewage Disposal).
Can anyone point me toward any datasets which are at least at the county level?
Depending on the quality I may elect to use such a dataset for the entire estimation process to maintain continuity between states.
