Project: Mercury Cleanup at a University Hospital
Chase Environmental Group, Inc. (Chase) was contacted by to evaluate potential mercury contamination in the Clinical Engineering department. The initial request was in response to a mercury spill that occurred in the subject area and as a result of subsequent airborne mercury vapor monitoring performed by the University.
Chase utilized Lumex 915 – Light mercury vapor analyzer to define potential contamination in the spill area, elsewhere in the Clinical Engineering space and throughout the adjacent corridors. The affected area was divided into four zones for staging, screening and subsequent removal of items.
1. Hot Zone (Area 1) - All items were staged onto carts in this area and removed for subsequent screening. The entrance to the area was double flapped with 6 mil polyethylene sheeting to control vapor migration from the affected area. The HVAC was shut down and return air ducts were sealed prior to work in this area.
2. Warm Zone (Area 2) –As carts exited the hot zone, a Lumex RA 915- Light was used to screen all items prior to being transferred onto a clean cart for transportation to the release zone (Area 3). Reusable instruments, personal items, and other materials that could be readily treated were cleaned with Mercon wipes and other mercury-specific chemicals to all practical extent. Non-cleanable items removed were segregated in the warm zone and packaged as necessary for disposal;
3. Release Zone (Area 3) - As pre-screened items were transferred onto clean carts into the final release zone, a second Lumex RA 915- Light was used to recheck all items. Items in excess of defined release levels were re-cleaned or returned to the warm zone for additional cleaning.
4. Support Zone (Area 4) – The area between the second partition and the third partition was used as the support zone. All PPE and supplies were staged in this area. This area remained at ambient levels throughout the cleaning process.
All remaining desks, shelves, tools, light fixtures, sink basins, sink traps, walls and floors were screened and detail cleaned through the use of mercury vacuum systems, wet mopping, wet wiping and use of chemical wipes. This process was completed multiple times for each item or area remaining until all surface measurements and ambient readings were <1µg/m3.
Waste characterization testing was performed on discarded personal protective equipment, cleanup supplies, and other solid waste that was deemed to be potentially contaminated. Items shown by testing to be non-hazardous was disposed of as solid waste. Known or presumed contaminated items were handled as hazardous waste and delivered to the University's hazardous waste storage facility for proper handling and disposal.