Lincoln Memorial Reflecting Pool Coating Failure Prompts Federal Investigation

Federal court documents reveal that the polymer coating of the Lincoln Memorial Reflecting Pool has exhibited specific failures, directly identifying polyurethane foam as the culprit behind this ongoing controversy.

The motion filed by the U.S. Department of Justice dismissed the charges against the contractor while accusing the Department of the Interior and the National Park Service of withholding key information.

The polymer coating is at the center of the controversy surrounding the Lincoln Memorial Reflecting Pool, and a government-filed motion to dismiss has revealed new information, for the first time providing precise technical details about where the failure occurred and why it failed.

The case involves former Olympic athlete David Hearns, and the related judicial proceedings have now evolved into a dispute among multiple departments. The U.S. Department of Justice now accuses the Department of the Interior and the National Park Service of withholding information, while also questioning the quality of the coating work.

Apply multiple coating layers to the surface of the tank.

According to this motion document, the coating system consists of multiple layers of coatings with different chemical formulations. Several layers of Rhino 406 epoxy resin coating were applied on the substrate, followed by two layers of Rhino 5000 pipeline lining polyurea material. Both products are manufactured by Rhino Linings.

Polyurea coatings are renowned for their durability and outstanding impact resistance. Similar formulations are commonly used in spray-on truck bed liners, which is sufficient proof of their wear resistance and impact performance. When applied with proper construction techniques, this type of polymer material can form a high-performance protective barrier layer.

The expansion joint sealant was identified as the source of failure.

The motion documents show that coating application at the expansion joints posed significant challenges. The contractor conducted at least three independent trials in an effort to identify a suitable sealant for these critical areas, ultimately selecting Rhino-Flex 11-35 flexible polyurethane foam.

This failure raises two core questions: Where is the failure location of the coating? What is the root cause of the failure? This motion to dismiss document repeatedly states on pages 9, 10, and 15 that the failure occurred in the Rhino-Flex 11-35 material, rather than in the epoxy layer or the polyurea layer.

Physical evidence also supports this conclusion. The failed and detached coating material floats in the pool water, which is impossible for the denser epoxy resin and polyurea coatings. The illustration on page 14 of the motion document shows that the failed material exhibits a porous structure, but due to the limited image quality, a definitive conclusion cannot be drawn.

This conclusion indicates that the defect is a localized issue rather than damage to the entire surface of the pool. Considering the scale of the construction project, this can be regarded as a major positive development.

Various parties have speculated on the reasons for the failure, but no definitive conclusion has been reached yet.

The contractor had visited the site to discuss the failure issue and possible repair solutions. The record noted that “all parties discussed various hypotheses,” but no reliable conclusion was reached. One of the hypotheses suggested that the XP adhesive may have had an application defect, while other contributing factors could not be ruled out.

The document also mentions that during construction, Pipeliner 5000 was sprayed onto the 11-35 foam layer and also onto the surface of the already-cured existing Pipeliner 5000 coating, which may result in insufficient coating adhesion at the corresponding locations.

There remains a risk of failure in the future.

Apart from the failure issues that have already occurred, this coating system also carries the risk of further failures emerging over time. A contractor representative stated: “The likelihood of a large number of similar failures occurring subsequently is low, but this cannot be guaranteed.”

This uncertainty calls into question the long-term durability of the entire coating system, and this iconic national memorial building may continue to face maintenance challenges.