Natural Gas Odorization Station System Audit and White Paper
Natural gas must be odorized gas prior to distribution to customers as a safety measure to allow customers to detect natural gas leaks by smell. Odorization of natural gas is performed by introducing concentrated liquid odorant chemicals into the natural gas distribution stream at odorization stations. The concentrated liquid odorant volatilizes into the gas stream that is delivered to the customer. Some of the failure modes that odorization stations can experience can lead to releases (leaks) of liquid odorant. The motivation for this work was the client’s desire to minimize the potential for uncontrolled releases of liquid odorant by identifying and implementing best management practices (BMPs) at client-owned odorization stations.
GEI compiled more than 50 Best Management Practices (BMPs) from the collected experience of the client’s heritage companies and a specialty subcontractor for odorization systems. The BMPs were based on input from client’s employees responsible for odorization, on input from the specialty subcontractor with respect to wider industry best practices, and on observations made by a team of client, specialty subcontractor, and GEI personnel during site visits to a limited subset of client-owned odorization stations in Missouri, Alabama and Mississippi. The BMPs were organized into three general categories: leak prevention, leak detection, and leak mitigation. GEI also prepared an odorant release response flowchart to guide the client’s immediate emergency response actions in the event of a suspected odorant release. Finally, GEI prepared an odorization station audit template to allow field the client’s field operations staff to generate data to allow the client to rank the risk of a release from each odorization station in their network.
GEI’s white paper for the installation, upgrade, and operation of odorization stations, as well as GEI’s odorant release response flowchart, were adopted by our client. The white paper has been used to inform decisions and help guide the capital improvement program for their odorant station upgrades. The flowchart has been used by the client’s field operations crews and environmental services department to respond to suspected odorant releases. GEI’s odorization station audit template was adopted by the client and implemented by the client’s field operation staff, which generated a risk ranking of the client’s odorization stations