Dust resulting from coring operations (after the slurry dries) and cement loading and storage contribute to dust in precast operations, but controls can be put into place to help suppress it.
Precast concrete production facilities use materials and processes that can be noisy, dirty and sometimes dangerous. Dust, in particular, is produced by a number of processes. Cement dust from conveyors, bins, drop points, saws and mixers are sources of particulate matter in plant air. Material stockpiles and roads in the yard also produce airborne dirt and dust from traffic and wind currents.
These processes and locations must be controlled to protect human health. In this article, NPCA asked Anthony Gentile, safety director for Americast Inc.’s Ashland plants in Virginia, and Chad Jensen, safety director at South Okanagan Concrete Products Ltd. in Osoyoos, British Columbia, to discuss dust control issues in the precast industry.
Q. In your opinion, what is the No. 1 source of air pollution from dust in the precast industry?
A. Gentile: The No. 1 source may vary between different plant operations. For us at the Ashland plant it would be the dust produced by our coring operations. Cutting or coring concrete produces very fine particulates in large quantity. As an industry, I would say the most common source would be leaks from loading or storing cement.
Q. What measures are taken to control dust in precast facilities?
A. Gentile: Engineering controls like alarm systems on cement silos to prevent overfilling are the most effective. Administrative controls like preventive maintenance programs and written standard operating procedures can further minimize dust emissions.
A. Jensen: We installed a dust collection system for the batch plant, we sweep and wash down roadways on an as-needed basis, and inside the plant we have daily sweeping and cleaning of floor debris and dust. We have also enclosed our precast plant and installed geothermal and radiant floor heat. The aggregate storage is enclosed, reducing dust and controlling the aggregate temperature more easily.
Q. What is the latest available technology for precasters to reduce dust pollution, and is it economical?
A. Gentile: There are many dust suppressants on the market that help to keep fugitive dust from spreading. These products need to be applied properly and continuously to be cost effective. We must also keep in mind that some are more friendly to the environment than others. We have also looked at a few concrete slurry recycling systems that compact the coring byproduct into hardened discs that can be easily discarded. Older systems collect the slurry, but when it dries into a fine dust it is still easily carried by the wind.
A. Jensen: The dust collection system works great: You reuse the cement dust that would otherwise be all over the truck and ground. We save a lot on labor and cleaners that would be needed to keep our trucks looking as good as they do.
Q. Is dust control a major issue with neighboring communities?
A. Gentile: We have multiple sites and some are adjacent to residential communities, while others have only industrial neighbors. Dust is a major issue in either situation. It has the ability to affect a residential neighbor’s quality of life or an industrial neighbors’ business operations.
A. Jensen: Increasing every year.
Q. What is your policy or practice as it relates to dust control?
A. Gentile: Dust control is a major part of our operations. We are governed by a Department of Environmental Quality (DEQ) Air Permit and a Stormwater Permit at our Virginia sites. Dust particulate control is a main focus of both permits. We have created and maintained a Storm Water Pollution Prevention Plan (SWPPP), along with an Air Pollution Prevention Plan (APPP), to identify all sources and eliminate all dust emissions.
A. Jensen: Try to reduce our impact on the environment and be a good neighbor.
Anthony Gentile came to Virginia from the U.S. Navy in 1999. He has worked as an electrician, superintendent and project manager in the construction industry since 2001. Gentile received OSHA and EPA certifications during that time and became the Health Safety and Environmental (HSE) director for Americast Inc. in 2008.
Chad Jensen is part-owner of South Okanagan Concrete Products and is a third-generation precaster. He is in charge of daily operations and has been safety officer since 1996. Chad’s son, Holdyn, will one day be a fourth-generation Jensen precaster.