DEP requires registration of all boilers with at least 350,000 BTUs of power. CATS allows building owners to track both current and prior registration filings, and combines multiple properties with a single owner or manager under one online account. After logging in, owners can register their email addresses to track registrations and payment histories, and can sign up to receive reminders, alerts, and other messages such as expiration of registration. Boilers with greater than 2.8 million BTUs of power require Certificates to Operate