I am just thinking here.. but normally (based on being a real estate rep for 2 years of my life, and here in Canada at least).. when a rural property which is on a septic is sold, it is normally part of the 'offer to purchase' that the septic be pumped out as a 'condition' of the purchase, much like a home inspection, which is also done here most of the time as a 'condition' of the offer. This gives the purchasers of the homes an idea on the age, condition, etc., of said septic tanks. So..... if this was the case here at grandmother's home.. and if the purchasers put in their offer which was accepted, prior to WT's visit, it is possible the septic had been pumped out very recently prior to WT's visit. If so, would that lead police to think they therefore didn't need to pump it? If police had quickly 'cleared' the fosterparents (which apparently they did), perhaps they therefore thought there was no need to pump the septic, for whatever reason, (such as perhaps the lid was on, and so LE knew that WT couldn't have ended up in there accidentally and within a span of 5 minutes?). If that is the case, I'm really disturbed.. tunnel vision.. not open to all possibilities.. at least if it was done, they could say, 'it has been done and nothing was found', you know?