This OP actually did do some calling to the "agencies" before I bought the home and property. The area is considered rural, but practically on the city limit boundary. Didn't even think twice about the drain field as my real estate agent minimized that minor concern and had me focusing on whether or not the 1/2 acre parcel was in an Urban Growth Development area or recently designated wetland, as it is extremely close to a protected estuary and waterfront state park. I had told my agent that I would need some good assurance that the land was sellable and buildable before I bought it as I wasn't interested in retaining the parcel for long. It added about $50k to the deal, and didn't need it, didn't want it.
Got a lot of agency voice mail and no call backs. My agent went in person to speak with a living breathing bureaucrat at the planning and permits dept. who assured her that my land wasn't subject to any "environmental" restrictions, although I have no idea if they discussed the drain field. Probably not. My agent--who worked for years at the county tax assessor's office--is seemingly and convincingly land savvy. She had said all I would need was an easement for the drain field--case closed. In retrospect, it was pretty dumb not to see that the easement was a legal issue and I should have either ditched the deal or talked to an attorney about it. It's a poor excuse but...all I can say is I'm a sewer kind of guy and don't know a septic system from a hole in the ground. I'm kinda finally getting into the gravity of the situation, though.
Upon closing, my agent said to call her when I wanted to sell the land because she had eight buyers lined up for my "hot property." I took her up immediately on the offer and that's when she did a one-eighty. Not only doesn't she have any interested clients, she also suggested I explore options about the drain field with the city planner or an attorney. It threw me for a loop her telling me that now, because at no time prior to closing did she ever bring up the drain field beyond the initial disclosure that some of it was contained within the 1/2 acre parcel, nor did she suggest I talk to anyone about it.
All this enlightenment happened to me before the weekend--naturally. I have to sit on the edge of my seat of pins and needles until I can call someone's voice mail on Monday. I found the forum while I was researching septic stuff and getting increasingly concerned about it. It's hitting home that I may have a problem selling the land. Still not too sure who to contact next...don't know if this is an attorney issue or a health department issue or maybe even a surveying issue now. I agree with Jimmler that a person can get a whole lot of crappy answers from the local agencies. Thanks for all the advice and responses. --MJ