Identification, Sampling and Testing of Demolition Wastes
Designation is identification of waste. It is the process used to find out if a waste is a regulated dangerous waste. The generator is legally required to designate wastes. Designation includes determining if any waste from building construction or demolition is a dangerous waste. Dangerous waste has specific management requirements, including transport on a dangerous waste manifest to a facility with a permit to treat, store or dispose of hazardous waste.
The most accurate way to determine lead, asbestos, polychlorinated biphenyls (PCBs) and other environmental hazards at a site is to hire an independent hazard assessment expert to survey for them. An assessment contractor should be separate and financially independent from any environmental remediation companies that could be hired to remove the hazards. (Note that asbestos is regulated under air quality regulations, but not under dangerous waste regulations.)
Waste designation is especially important at industrial or commercial sites which may have used hazardous chemicals for manufacturing, wastewater treatment, maintenance, or other purposes. Some residential buildings may have served as dental, veterinarian or health clinics and used lead shielding around x-ray equipment, or improperly disposed of chemicals to on-site septic systems. Pesticides, oil, toxic heavy metals or PCBs may also be present at some sites, complicating designation issues. Containers, tanks and equipment need to be evaluated for presence of hazardous materials.
Initial Site Assessment
Knowledge about the site can be useful in identifying dangerous waste. If adequate knowledge about the building is available, such as its age, past usage and screening test data, that knowledge can be used to aid in the designation process. For example, the building may have been constructed after 1978, when lead based paint was banned for interior and exterior residential uses. If there are no other dangerous waste issues, testing is not necessary and the demolition debris would not be a dangerous waste.
Before beginning a demolition project, the property owner or contractor should do an initial dangerous waste assessment on the buildings and other structures on the site. Any containers of spent rags, drums of unknown waste, or other accumulated debris must be designated. When possible, remove hazardous materials prior to demolishing the building. For example, lead pipes and flashing, fluorescent lamps and PCB ballasts should be removed and recycled.
Common dangerous waste issues encountered in demolition projects may include:
Residential demolition debris is not considered household hazardous waste and must be designated. Materials removed as part of regular maintenance, including replacement of windows or exterior siding, would be excluded as household hazardous waste. Recycled scrap metal is another commonly used exclusion.
Sampling and Testing Demolition Debris
Dangerous Waste testing regulations do not regulate how many waste samples to take or where to take them as long as one representative sample is done of each waste to be tested. A representative sample is defined in the Dangerous Waste Regulations at WAC 173–303-040 as "a sample which can be expected to exhibit the average properties of the sample source."
Sampling of entire buildings or parts of buildings for lead and other hazardous materials is difficult and is not currently addressed in the Dangerous Waste Regulations.
Lead based paint is the most common problem encountered in older buildings. Buildings constructed prior to 1960 used paint with high lead content, and lead continued to be used in latex paint up to 1978. Older buildings intended for demolition should be sampled and tested for lead.
The suggested sampling plans describe two basic approaches (with variations) for designating a lead painted building:
Either approach is acceptable to Ecology. The sampling plan guidance discusses pros and cons of six different sampling plans. Using the first approach, it is more likely that at least some of the building components will be dangerous waste. With the second approach, it is not likely the entire building will designate. This is because the concentration of lead compared to the total volume of debris is usually low.
Note that historically lead-based paints may have contained fifty percent or more total lead, which could cause an entire building to designate for lead in some cases. Screening test methods, such as portable X-ray fluorescence technology (XRF), can be used to determine total lead concentration. Knowledge of total lead concentration can be useful in designation and to isolate and appropriately manage building materials with high lead concentrations.
Sampling of contaminated sandblast grit, wash water, HEPA filters, solvent solutions, paint chips and so on at a work site should be done following the advice of the dangerous waste testing laboratory, and any relevant testing guidance given in the following publications.
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