Left in the Dust - the Truth About Slag Safety
Lab Confirms Orcem Samples Fail to Meet EPA Standards
Ecocem Slag Mill - Ireland
Apologists for the VMT/Orcem waterfront slag cement project continue to lecture about the environmental benefits of substituting blast furnace slag for some of the limestone clinker used in ordinary cement. Nobody’s contesting that some potential exists for cutting total emissions from producing cement, but what exactly is the lesson we're expected to apply to this particular project proposal? That south Vallejo should be willing to take one more hit for the greater good? Sacrifice the future development potential of our waterfront and live with the pollution and traffic impacts laid out in the environmental impact report while we watch most of the economic benefit leave town? The debate is not about whether recycling slag could help the cement industry reduce overall emissions. The question is whether an abandoned industrial site now surrounded by neighborhoods and schools is an appropriate place for this kind of heavy industry today.
The residents of south Vallejo have already sacrificed more than their fair share for the greater good by virtue of living in an industrial corridor. They suffer significantly elevated rates of respiratory illness which would be further exacerbated by piling on an additional load of smog and diesel soot from this ill-conceived project. The applicant’s economic impact report says it’s a “branding opportunity” for the City, but calling the product 'green cement’ doesn’t change the fact that the daily operation of the mill would be anything but clean and green. Instead of credulously accepting everything the corporate interests who stand to profit tell us, how about a critical examination of the information that's available?
Dust covers a 'green cement' slag milling site in Europe.
We've heard repeatedly that the industrial waste slag that the cement mill project would import from Asia would be completely innocuous, and no cause for concern. Orcem assured the Vallejo School District in 2015 that the slag they want to grind to powder on the waterfront is a "harmless, clean material." In stark contrast, the material safety data sheets for granulated blast furnace slag from the US Steel Corporation label it a hazard to human health, and very toxic to aquatic life. It specifies that: "Individuals with chronic respiratory disorders (i.e., asthma, chronic bronchitis, emphysema, etc.) may be adversely affected by any fume or airborne particulate matter exposure.” (See Not So Harmless for more details)
We need to dig deep into the appendices attached to the technically dense EIR to find the laboratory testing results for the handful of slag and other raw material samples that the applicants supplied. A closer examination of that data reveals that in fact the test results do NOT demonstrate those handpicked samples are harmless. The recent experience of residents in Davenport, California should sound an alarm bell with warning lights flashing for anyone inclined to accept the applicant's reassurances on the subject.
Site of the proposed cement mill on the south Vallejo waterfront
The small town of Davenport, up the coast from Santa Cruz, hosted a portland cement plant for well over a century. The Mexico-based manufacturing giant Cemex took control in 2005 and ‘modernized’ the operation to import blast furnace slag and mill it to make ‘green cement.' In 2008 it was discovered they had contaminated the local schoolyard with chromium 6, the cancer- causing form of the heavy metal that gained notoriety with Erin Brokovich. The blast furnace slag was identified as the source. After sticking the county with a half million dollar cleanup bill, the cement plant shut down for good in 2009, leaving a big hole in the local economy. In Vallejo, the applicants for the cement mill project have been less than forthcoming when talking about this issue, although it is one that Orcem’s Mr. Bryan should know well. It was his former employer, Cemex, that poisoned Davenport.
Shuttered Cemex Plant - Davenport, California
The applicants have tried to claim that there would be no slag dust escaping, although the Environmental Impact Report assumes that even with best management practices there would be loss at each of the many stages of moving the material. The prevailing wind coming across Bay would pick up some of that fugitive dust and send a plume skyward as it hits the back slope of the site, to settle out over south Vallejo. They tried to claim that it was somehow chemically impossible for slag from iron smelting to contain chromium 6, when it’s easy to find safety data sheets for iron slag that specifically list it as a hazard. So what should we make of the lab testing data offered as evidence that the imported slag would be safe?
In each slag sample test for chromium 6 that shows nothing above the detection limit, the lab result comes with a coded data qualifier, like a scientific asterisk. When we look up the code we find that the samples were held too long before testing to still be considered accurate, but were tested anyway at the customer's request. The EPA mandates that a valid test for chromium 6 must be made within 24 hours once the sample is taken. A call to the testing lab confirmed that two samples tested positive for chromium 6, and of the handpicked slag samples that tested negative, all were tested past the hold time at the applicant’s request.
We know nothing about possible sources for the slag in Asia, or how much heavy metal contamination might vary from batch to batch and among suppliers. Is there any reason to think that Asian slag is harmless and clean while domestic slag from US Steel is hazardous? Given what looks like a deliberate attempt to conceal a real health risk, why would we trust anything Orcem and company say about this or any other aspect of this project? Even if new valid samples were submitted at this late date, how could we have any confidence they truly represent the material that would be milled over the next sixty five years?
Their proposed dust control methods rely heavily on spraying down the site and the open slag storage piles while they work with massive quantities of City-supplied tap water. The environmental impact report reveals that routine dust suppression for offloading equipment and the road network on the site alone could require 3,285,000 gallons annually. The cement mill itself would use 1,320 gallons per hour, and attempting to hold down dust when disturbing the huge open storage slag piles would use another 2,400 gallons of water each day. According to the EIR, the proposed project would require a combined maximum of 46,082 gallons of water per day, but only generate 2,400 gallons of wastewater. Where would the rest end up after washing down all that slag dust classified as very toxic to life in the Napa River?