National Guard service members and U.S. Park Police were patrolling the deck around the Lincoln Memorial Reflecting Pool on Monday, as Donald Trump’s administration faces a self-imposed deadline to fix a botched renovation and cleaning efforts ahead of the nation’s 250th anniversary celebration.

The patrols come two days after Trump said authorities had made “multiple arrests” of people he insisted were responsible for damage to the peeling coating after an algae bloom occurred. The liner was installed as part of his $14 million-plus project.

The president has confirmed the problems likely require draining the pool again for liner repairs, and he promised a quick fix. But the timeline was not clear Monday, and the administration did not immediately respond to questions about a new round of work. Contractors and federal workers in recent days have been using chemicals and ozone nanobubbles to combat the algae.

Trump pitched the original improvements as intended to clean, beautify and reinforce an iconic site that he said had become dilapidated and dirty because of previous presidents’ neglect. Algae has plagued the pool for a century, and Trump insisted that a newly installed ‘American flag blue’ coating, which he selected himself, would turn the pool into a gleaming expanse along the National Mall.

Yet within weeks of Trump declaring the rehabilitation completed in time for Independence Day, the water was plagued by a vivid green algae bloom that clouded the pool’s coating. An approximately 4 foot-square piece of the liner was observed last Friday to be partially floating in the pool. The Associated Press observed additional pieces in the water Monday.