I like to know if the bank decides to remove the ATM machine and completely not offer ATM services, does it require notification to regulator or approval from the regulator beside notifying the customers 30 days in advance?

There is no requirement to notify a regulator of discontinuing ATM services. Prior to doing so, you may want to perform an analysis to make sure that the removal of this service will not have a disparate impact on low or moderate income customers and also be sure to update your CRA Public File to reflect the changes.

Thank you for the information! Will definitely look into the suggestion.

Before you proceed, check whether there are any state laws on the question. It may be nothing more than a notice requirement, but do check it out.