The hydrodemolition process generates wastewater (slurry water). The wastewater contains suspended particles (ranging up to 15,000-ppm total suspended solids [TSS]) and typically has a pH of 11 to 12.5. Controlling, collecting and processing the wastewater has often been viewed as one of the more difficult tasks associated with the use of hydrodemolition. However, with proper planning and installation of a collection system, wastewater removal is easily managed.
Containment and collection of the wastewater is the first step. Water containment and collection systems will vary depending on the type of structure and location of collection areas. They range from Dry Hydro® where the wastewater is collected at the hydrodemolition robot to systems using gravity to transport the wastewater to areas where it can be contained and pumped to a treatment area. Often on bridge decks, an artificial berm or dam is built to catch and pond the water at the low end of the bridge. From there the wastewater is pumped to the treatment area.
Other drains and scuppers located in the work area should be plugged to prevent any wastewater from leaving the work area or plugging the drains.
In structures, such as parking garages, wastewater can be directed to the slab-on-ground (SOG) using pumps or the existing drainage system. Wastewater can flow through the structure to SOG or through the existing drains. Disconnecting the drains below the underside of the lowest supported level will insure the water is directed to the containment area.
During scarification projects, where the rebar is not exposed, the Dry Hydro® method can be used to collect the wastewater using our specialty designed vacuum trucks. This method is very effective at collecting the wastewater at the source (hydrodemolition robot) and preventing it from reaching travel lanes or leaving the work area.
Regardless of the type of structure and the depth of removal, Rampart has an effective and efficient method of controlling the wastewater.