New Century and Integrity Plus Blog

Not Every HCA Analysis is Created Equal: Part I

Posted by Nicole Tebow & Ryan Huntley on Mar 16, 2017 1:03:34 PM

Performing High Consequence Area (HCA) analysis correctly is a critical initial step to Integrity Management Program (IMP) success, and if it is not done correctly, can be a substantial liability for companies. In this three part blog series, we will be discussing a set of key components and challenges involved in liquid HCA projects including:

 Key Components:

  • Meeting all regulatory requirements conservatively
  • Performing HCA analyses to accomplish goals within IMP
  • Obtaining realistic results that provide value
  • Reducing potential impacts and costs


  • Incorporating a variety of formats of data to prepare for analyses
  • Providing accurate, realistic response times
  • Obtaining accurate and updated HCA data
  • Performing adequate QC/verification of results

While most operators routinely use commercially available software packages, or retain vendors to do their analyses, and appear to be satisfied with their results, Integrity Plus has noted a number of potential vulnerabilities that operators should carefully consider.  The reality is that spill modeling software applications are incredibly sophisticated calculators that are used to simulate pipeline ruptures and determine could-affect status, and as with any calculator, the input of the wrong “numbers” will generate inaccurate results. In purchasing these applications or partnering with third party vendors who do little to no consulting prior to setting up model parameters, operators are opening themselves to substantial regulatory and business risks.  Inaccurate could-affect analysis could certainly become exposed during a regulatory audit, and result in enforcement action. In addition, some operators are finding out that their analyses are incorrect at the absolute worst time, after a release.  A segment that had previously been identified as non could-affect has a release, and the product migrates to an HCA. That being said, let’s dig in to exploring some of the most common pitfalls, associated Pipeline and Hazardous Materials Safety Administration (PHMSA) guidance, and potential solutions to HCA analysis.

…it is an operator's responsibility to ensure that it has identified all high consequence areas that could be affected by a pipeline segment. An operator is also responsible for periodically evaluating its pipeline segments to look for population or environmental changes that may have occurred around the pipeline and to keep its program current with this information. (Refer to §195.452(d)(3).)

Common Concern: “Operator’s IM process fails to provide provisions to periodically re-examine and update the list and boundaries of HCAs”

FAQ 3.8 What are PHMSA Pipeline Safety expectations for operators to determine new or changed HCAs?

The Rule requires operators to develop their own HCA dataset and use it in their IMP.

FAQ 3.9 When must newly-identified HCAs be included in the program?

Over time, new HCAs may be identified as population distributions change, or new drinking water or ecological resource data becomes available. Newly identified areas must be incorporated into the Baseline Assessment Plans within one year of identification.

Protocol Question: IMP High Consequence Areas HCA Identification - Do records show that locations and boundaries of HCA-affecting segments are correctly identified and maintained up-to-date?

First, let’s recall that the intent of performing an HCA analysis is to truly identify all potentials of what HCAs could be impacted if a pipeline/facility were to fail. Note that we mention facilities, as this is a sleeper that could creep up on operators and is discussed later in this blog series. PHMSA identifies a starting place for HCAs via the National Pipeline Mapping System (NPMS), and they are divided into the following categories: high population areas (HPA or HPOP), other population areas (OPA or OPOP), drinking water areas (DW), ecologically sensitive areas (ESA or ECO), and commercially navigable waterways (CNW). A common trap that operators fall into is that they neglect to identify HCAs beyond those identified by NPMS, however, regulatory guidance is more than clear that operators are required to routinely evaluate pipeline segments for growing and new population or environmental areas along their pipelines.

Thus, NPMS HCAs are the backbone of any HCA analysis; however, operators’ IM manuals should have detailed processes for the identification of HCAs beyond those identified by PHMSA. In the case of changing population areas (Figure 1, Changing Population Areas), numerous operators monitor for change by employing right of way change detection by using line riders and/or corrosion technicians. Another means for the identification of population change is the use of imagery from sources like National Agriculture Imagery Program (NAIP), Bing or Google, as they typically provide frequent updates.

Figure 1: Changing Population Areas

As with population growth, ECO areas also require special consideration, as NPMS data can be incomplete and/or become outdated. Numerous operators are addressing this issue by routinely contacting state wildlife agencies or Natural Heritage Programs for supplemental environmental information. This information can be transmitted to operators in the form of shapefiles that are easily integrated with their HCA analysis process. Other operators go to the extent of retaining independent environmental consultants to assess areas along their right of ways to identify potential sensitive environmental receptors. 

Identifying HCAs and their boundaries is just the first step in this important analysis process. Check back tomorrow for our second installment of the series. We’ll be discussing the importance of incident response times and generating release scenarios. Have questions already? contact us to discuss, and check out how we can assist in identifying HCAs.

Topics: NPMS, HCA, High Consequence Area

Subscribe to Email Updates

Recent Posts

Posts by Topic

see all

Follow Us