Enrollment for Florida Keys Aqueduct Authorities discount program for qualifying senior citizens or disabled American veterans residential customers is open. Customers who have previously participated in the program must re-apply before Friday, March 31, to avoid interruption of a discount. Applications will be accepted through the website, mailed in or at three area offices: Lower Keys: 1100 Kennedy Drive, Key West, FL 33040; 3200 Overseas Highway Marathon, FL 33050; or 91620 Overseas Highway, Tavernier, FL 33070.