Lassila Liquid Waste Disposal is a local family owned business serving the Prescott area since 1970. As one of the oldest and most dependable septic pumping services in the area, we pride ourselves on fast, efficient and low cost service. Hire our services about septic tank pumping table and explanation of when septic tanks (on-site sewage disposal system holding tanks) should indeed be pumped and related information readers should see pumping frequency.