Filling in pool with dirt?

[Kyle Neville]

I just found a super sweet duplex for a great price. Minimal work needed. However, upon closer inspection it looks like there used to be a pool in the backyard. When I google earthed the house, sure enough there was a nasty old pool filled with junk. Im worried that the previous owners didn’t fill it correctly by taking out the pool and then filling it. They are asking $260k for it. If I confirm my suspicions that they just threw dirt into it, can I negotiate a cheaper price? Or is it okay to fill pools that way? If I ask for a cheaper price, how low should my offer be?