ESL Federal Credit Union has been open since 1996. It's the 3rd largest credit union in New York and the 20th largest in the United States with assets totaling $6.66 Billion and providing banking services to more than 364,000 members. Membership: The credit union is a member-owned financial cooperative providing financial banking services to multiple member groups, but primarily serves chemical industry employees. Membership is also open to immediate family of current members.