The transformation of the Lincoln Memorial Reflecting Pool was supposed to inspire patriotism, but pieces of material peeling off the pool’s surface instead sparked more bewilderment and speculation.
President Donald Trump ordered the renovation of the pool in April, and that order included painting the floor and walls blue. Yet, weeks after the work was completed, photographs and videos of floating pieces of cerulean material that appeared to have broken away from the pool walls went viral. This material is a polyurea coating, a durable, fast-curing surface membrane that can seal out water and is often used to cover swimming pools.
We spoke with engineering and swimming pool experts to find out what could be going wrong at the embattled monument.
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On the one hand, the blue material probably has no direct relationship with the large algae blooms which also ravage the monument, according to Tim Auerhahn, president of the Aquatic Council. It is also not a simple reaction to hydrogen peroxide that the National Park Service (NPS) dumped into the water with the apparent purpose of killing algae, although that probably didn’t help either.
At this point, blaming floating coating on a single factor would be premature, says David McFayden, CEO of paint and coatings inspection company KTA-Tator.
Auerhahn agrees: “The failure of this product to adhere to the substrate probably could have been caused by many factors,” he says. However, based on videos of workers dumping hydrogen peroxide on the pool deck, he says that “it could have contributed to the problem, but it is probably not the only cause.” The Interior Department, which oversees the NPS, did not respond to a request for comment.
Hydrogen peroxide can be used as a paint stripper, but pool water would likely dilute it to the point that it couldn’t cause the current level of damage, he adds.
“It was immediately diluted when added to the water, and there are so many other factors that could contribute to the delamination of a polyurea coating on a surface like this,” he says. “It’s very likely that this is multifactorial. When we investigate technical failures, we rarely see a single cause. This coating was under many different stressors, and they probably all had some level of contribution.”
Another key factor was reportedly how the pool walls and floor were prepared before being painted “American Flag Blue” during the renovation. The cost of this renovation, initially estimated at less than $2 million, has since ballooned to nearly $15 million.
“It’s actually a very specific process to add a liner like this to any pond,” says Auerhahn.
When applying polyurea coats, workers should be sure to paint a new coat within 24 hours or less after the last coat, depending on the specific type of substance used. This ensures that the polyurea layers adhere to each other and form a solid mass, preventing water from seeping through. And different application methods can result in stronger or weaker molecular bonds. Given the short renovation time (approximately eight weeks), it is possible that the material was not applied correctly to avoid damage. The pool floor may also have been affected by the presence of heavy equipment and trucks – as well as a passing presidential motorcade at one point – during the preparation and application of the coating.
The decision to use polyurea in the first place will also require investigation, notes Auerhahn. “What material you stick this polyurea coating to is questionable,” he says. “They stuck it to the granite.”
The precise material in question, Rhino Linings’ Pipeliner 5000, can adhere to “virtually any substrate,” according to company information. commercial sheetbut granite is not specifically listed. Rhino Linings is not the contractor who applied the coating to the reflecting pool. The company did not immediately respond to a request for comment.
“There is a big question mark as to whether or not there was some compatibility for adhesion with granite,” says Auerhahn, adding that questions also remain about how the substance might respond to the high levels of ultraviolet exposure and hot summer temperatures in Washington, DC. The company that carried out the renovation is Atlantic Industrial Coatings (AIC), which did not immediately respond to a request for comment. In a statement on its website, the company said it, along with the NPS, identified areas of the pool that needed repairs.
“These areas represent only a very small portion of the massive 7-acre project and do not indicate a failure of the liner,” the company wrote. “These repairs cannot be completed until the pool is drained. As soon as it is practical for the park, the pool will be drained and AIC will return to make the necessary repairs under warranty.”
THE Trump administration has not made an official statement on the cause of the spalling, although at least five people have been arrested for alleged vandalism of the pool. On June 20, President Trump said in a social media post that the pool would likely need to be drained so repairs could take place and claimed that anonymous vandals had made a “250-foot-long gash” in the pool’s facade.
To determine exactly what happened, a full analysis of the failure should be conducted, McFayden says. This would include a review of the pool’s pH levels, as well as investigations into whether errors were made in preparing the surface to be covered and whether an inappropriate material was selected, among many other variables.
The number of things that can go wrong in a job like this, McFayden observes, are far too numerous to rule anything out at this point.
“If you’ve had a coating failure, you’ve had a coating failure,” he says. “They’re all very different. There’s probably a lot of water chemistry involved in this situation. I can’t say we’ve ever been involved in anything like this before, to be honest with you.”