An apparatus and method for improving the operation of sewer systems includes a first sewer pipe connected to a source of other water and a second smaller diameter sewer pipe passing through the first sewer pipe and connected to sources of sanitary effluent. The second sewer pipe can be attached to the interior surfaces of the first sewer line by a curable adhesive material using a removable inflatable bladder to hold the second sewer pipe in position until the adhesive has cured sufficiently. As an alternative, positioning walls or arms, integral with the second pipe, form positioning spaces filled with a slurry material to hold the second sewer pipe in position. The slurry will harden in place to form an integral unit with the second pipe and the positioning walls or arms.