What are the servicing costs for a wastewater treatment plant?

An annual service inspection costs €60–80. Septic tank sludge removal (once every 1–2 years) costs €60–80, which translates to €30–80 on an annual basis. Total annual service costs are therefore €60–160. With a reed bed treatment plant, you do not need any spare parts because the system contains no mechanical components. For comparison, servicing a conventional biological WWTP costs €150–250 per year.