no, the inspector would not know. i would suggest you call and arrange a a meeting between you, the inspector, and your contractor. tell the inspector the contractor and you disagree on whether this matters or not. regardless of how this goes, it is going to cost YOU money. either you have to tear down the deck and be out what you owed the contractor for it, or you have ot pull up and move the tank and be out this cost. like i said earlier, if the contractor hit the tank when digging the posts he knew it was there, and that is your ONLY hope of laying blame off on him. if you tank is deeper than the posts go and he did not hit it, then he had a reasonable expectation of the tank not being there just like you and the inspector. in my area the tank HAS to go where the drawing shows. the health dept tells you where on your land you can put it and then you build your house around that. i have seen people who had a choice of build the house sideways or build a different house because the health dept told them there was only 1 place they could put the tank.

Also, what are the requirements in the owner's area for replacing leach fields? If he was in Vermont it would have to be an engineered system. By messing with the leach field there is a possibility that a mound system could be required (about $10,000). I know, Vermont is nuts on this stuff. My theory on the leach field is that if it was a "designed" system and it's working okay, leave it alone. If you have heard that new state or county requirements are coming in the next few years, then it might be prudent to consider replacing it now to avoid some expensive fix a few years down the road. And, as someone said, if you are in a region where there is the possibility of having to hook on to a municipal sytem in a few years, then you might want to consider the cheapest fix you can get for now. The last one I had installed/designed called for an outgoing filter. The builder said he would never do another system without it. Pull it once a year or so and hose it off. On the pumping...when I owned mobile home parks I had about 20,000 gallons worth of tanks to keep pumped. In this area it's extremely expensive to have them pumped. I found that it was senseless to pump all of the liquids out of the tanks. Liquid was always on the bottom and would go out to the leach field anyway. We would just pump the first 2 or 3 feet making sure that all the scum and solids and semi-solids were cleared out. Think about it..if you pump the whole tank, within 3 or 4 days the tank is filled with liquids again.

I think it could be one of two different things, first with your tank going undrained for 12 years it could certainly be overdue. If it is full the water draining from your washer would be hitting the top of the full septic tank and be flowing straight to the leach field. The second thought is that you have a break in the actual drain line leading to the septic tank. Smaller valumes of water from a toilet, sink, etc might more easily get past the leak and/or sit in the septic tank long enough to mix into the content of the tank. Best guess...full septic tank. For the second time in so many days I had answered a similar question on another website and posted just this morning a blog about when and how to go about diagnosing a full septic tank and how the draining is done. Link to that blog is below or check my profile for the URL to my blogsite itself. Here is a link that might be useful: My blog on draining a septic tank

What's done is done,not much you can do to change anything now. Sound's like there's a problem with toilet vent otherwise air would escape through toilet vent stack rather than trying to come out toilet. Strange! There should be an air tite lid avaible for that green riser on tank. Bottom of riser should be mortored into hole in tank or have flat flange similar to roof vents tared to tank..