Metropolitan Water Reclamation District of Greater Chicago finishes green roof construction at Racine Avenue Pumping Station
The Metropolitan Water Reclamation District of Greater Chicago (MWRD) recently completed the construction of a green roof at the Racine Avenue Pumping Station (RAPS).
RAPS is a building that houses main sewage pumps that pump wastewater to the Stickney Water Reclamation Plant. The coarse screen building extension houses a conveyor system that removes trash from wastewater. Removing this trash helps prevent damaging water treatment pumps. The structure's total building roof area is 33,000 sq ft. approximately 4,500 sq ft is structurally-rated to handle the additional vegetative roof loading.
Originally constructed in 1939, the most recent roof replacement was performed in 1996 with a 10-year warranty. The 19-year-old tar roof showed its age; numerous leaks and worn-out repairs required replacement.
Instead of replacing the roof with heavy, impermeable tar, the new roof is a combination of asphalt and plantings. Because of their ability to withstand harsh weather conditions, a variety of Sedum plants were installed. These native plants are low maintenance; irrigation is needed initially to establish the plantings and during drought periods, and routine weed removal will help the roof maintain its appearance.
The MWRD will also continue to monitor the success of the plantings and maintenance costs and use this information as we continue to seek other opportunities for green/vegetative roofs.