Why an Affordable Septic Tank Is Within Reach for Most Homeowners An affordable septic tank is more accessible than most people think — especially when you understand your options, maintain the system regularly, and choose the right local provider. Here's a quick look at what makes septic ownership affordable: Tank cost: Plastic low-profile tanks (like 1,250-gallon models) typically range from around $2,263 to $2,500 Pumping frequency: Every 3 to 5 years for most households k