Facility siting started in 1995 with the release of API 752 which addressed hazards for permanent structures.
Significant changes to API 752 were made in 2009 which resulted in the comprehensive view of facility siting that industry is accustomed to today. The 2024 edition expanded the fire and toxic hazard sections, most notably around using buildings as fire and/or toxic refuges.
Clients and sites face a multitude of challenges related to facility siting over their lifespan regardless of the facilities size or vintage. One of the more subtle challenges is the overall maintenance of the study, keeping it "evergreen." As facility siting falls under the PHA element in OSHA 29 CFR 1910.119 (e.1.v), it is generally accepted that facility siting studies are to be revalidated every five years. Clients and sites address this revalidation effort differently depending on the specifics of their Management of Change (MOC) process as well as the methods used for the facility siting study evaluation.
Facility siting changes can be obvious e.g., adding a new occupied building or introducing a new process unit. They can also be more subtle e.g., replacing a smaller pump with a larger one or processing a new seasonal feed composition. How companies/sites evaluate and address these changes can have lasting impacts to current and future facility siting results and mitigations.
Generally, MOC facility changes, with regards to facility siting, fall into two categories: conceptual/preliminary and as-built/implemented.
There can be several subcategories for conceptual/preliminary depending on the amount of information available. The more information that is provided will allow for a higher level of detail and reduced levels of conservatism. For example, the type of information requested for a unit revamp may include redlined equipment layouts, 3D renderings, PFDs and their associated heat and mass/material balance sheets. Information that is undetermined or unavailable will have to be conservatively estimated. As more information becomes available and layouts and process conditions are finalized, the assessment approaches the second category (as-built/implemented). At this point, the inputs should be finalized, and the completed analysis can be incorporated into the site-wide facility siting study. Construction and start-up should be generally monitored in case field decisions/changes are made that can impact the facility siting assessment.
MOC building changes are generally more straightforward on the assessment side but may present more challenges on the hazard resolution side. When addressing buildings that are not explicitly part of a remediation study, clients/sites are typically dealing with new buildings, building expansions and/or relocated buildings. For example, when considering new construction, clients/sites should evaluate the proposed building’s location, size and orientation against the current facility siting study. Such evaluation will reveal important information regarding blast loads and fire/toxic evacuation/refuge that can be used to inform the design. Addressing these potential hazards during the design phase is significantly more economical than retrofitting/abandoning a building after construction.
Whenever possible, pre-emptive facility siting/hazard assessments are preferable to post-installation/modification assessments. Settling on a system to effectively address proposed or to-be-implemented site changes for facility siting is critical to minimize operational and financial impacts. The engineers at Blast Resource Group have been working with clients over a wide range of industries with different facility siting support needs to find solutions to address ongoing facility changes for over 20 years.
For more information, visit blastresourcegroup.com.
