Wetland sewage treatment are tanks imitating natural environment of marsh plants. Their main element are vegetable filters where growing aquatic plant intensify the processes of oxidation and reduction of pollution. As a result, wastewater from houses is naturally purified. Among the plants used in these filters might be include: common reed, stick, reed canary grass, iris, manna gizzard and willow. Due to the properties and resistance to frost most commonly used in these types of wastewater is a reed.