Septic tanks in Turkey are very different to those of UK, they are soak aways, however not all are, some in Ovacik, Hisaronu need to be empties as they are built on solid rock, newer properties are built to link to the sewer system, like some properties now in Fethiye Calis etc.. our villa was built 2003, we purchased from new and I asked the builder about the tank, and he explained they system to me, and we have not had it emptied and lived in it permanently for nearly 6 years. The only thing we have to do is put bends in pipes and a few other plumby bits.