What is one way to reduce emissions from UST systems?

Implementing vapor recovery systems during fuel transfer is an effective way to reduce emissions from UST systems. Vapor recovery systems capture the vapors that are displaced during the filling of a fuel tank, preventing them from escaping into the atmosphere. This process not only diminishes air pollution but also reduces greenhouse gas emissions that contribute to climate change. By recovering vapors, these systems help maintain air quality and minimize the release of volatile organic compounds (VOCs), which can have significant environmental and health impacts.

The other options do not address emission reductions directly or effectively. Installing larger tanks could potentially lead to higher emissions if not managed properly, as a larger volume of fuel could mean more displaced vapors. Changing fuel suppliers frequently does not inherently improve emissions control and could disrupt consistent practices in managing fuel quality and emissions. Reducing the frequency of deliveries might conserve fuel usage in transport, but it does not directly lower emissions produced during the fuel transfer process. Therefore, the best method among the given choices focuses on the implementation of vapor recovery systems to manage vapor emissions effectively.