C&D WORLD: CERL Finds Negligible Lead Levels

Results of a study of crushed concrete that included slabs of material coated with lead-based paint are indicating the traces of lead are well below levels considered dangerous.

Attendees of the C&D World Exposition & Conference in New Orleans in late January were the first to hear the encouraging results, presented by Steve Cosper of the U.S. Army Construction Engineering Research Lab (CERL).

Cosper and CERL conducted the study on concrete debris generated at the demolition site of the Fort Ord complex in California. The study to determine levels of lead within the crushed concrete was funded by the Construction Materials Recycling Association (CMRA) and the National Association of Demolition Contractors (NADC).

Although Cosper is still finalizing the full draft of the report that will summarize his research, he offered C&D World attendees a preview.

Noting that 400 parts per million (ppm) is the EPA limit for material to not be considered a hazardous waste, Cosper said that only paint chips tested alone surpassed this limit, testing at 3,500 ppm following TCLP (toxicity characteristic leaching procedure) testing methods.

Otherwise, concrete fines generated by crushers on the site tested at just 110 ppm; crushed concrete tested at just 17 ppm; and soil located near the crushing plants tested at just 30 to 60 ppm.

Air quality was also tested, with no hazards revealed in the air likely to be encountered by equipment operators working in the area.

Cosper noted that the contractor crushing the obsolete concrete, some of which was painted, did a good job controlling dust, and also said that at 110 ppm, there is enough lead in the fines stream to “merit careful handling.”