Imagine for a moment that ACME Coatings Contractor has recently completed an important water tank exterior coatings project. The job, which involved removing lead-based paint from the 40 meter (135-ft) tall, 3.7-million liter, legged tank, went well from start to finish. The owners are happy, final payment has been rendered, and the project manager is filing the last bit of paperwork when the owner’s representative calls and asks, “Out of curiosity, how can we be sure that ACME didn’t leave lead dust under or around the tank?”
There are several subjective answers the foreman could provide, such as, “Our crew is highly trained in the use of containment. We didn’t leave any behind.”
But in this day and age, the foreman might be wise to have an objective response at hand. To do so, he’ll need two pieces of information: How much lead was present in the soil before the project started, and how much lead was present afterward.
That’s why contractors involved in abrasive blasting of lead-based painted surfaces increasingly rely on pre-project and post-project site surveys as quantitative proof that they left the jobsite in the same, or better, condition than before they began remediation.
Before and after site surveying typically involves collecting soil samples and sending them to a lab for testing. Collecting methodology depends upon circumstances, but for a typical tank, samples might be taken beneath the tank, under the drip line, and horizontally in a 360 degree area equivalent to the height of the tank.
Within the context of providing quantitative information, the ACME foreman is not overly concerned about lead levels before the project began—the site might have been heavily contaminated beforehand—but should stand ready to offer pre- and post-project site surveys as proof that his crew did not add to the lead burden.
Chris Lovelace, Technical Contributor.
Founder of The Lovelace Group, Chris has more than 25 years’ experience and is a nationally recognized leader, educator, and curriculum developer in the field of hazardous materials handling (lead, asbestos, etc.). For more information contact Chris at Chris.com or phone (678) 764-8963.