San Juan Hills High School Site and Risks (historical reference): Outside Review Questions Validity of CUSD Study

In preparation for the Board meeting on Monday night, CUSD Trustees have been provided a memo containing responses to their questions concerning the pipeline adjacent to San Juan Hills High School. This memo was prepared in response to questions posed by CUSD Trustees after receiving Pipeline Safety Hazard Assessment prepared by Dr. Fitzgerald, of The Planning Center.

The following review of Dr. Fitzgerald's memo was prepared by Richard Kuprewicz, President of Accufacts, Inc. Mr. Kuprewicz is an internationally recognized expert in the field of pipeline safety. He was not paid for his review.

Mr. Kuprewicz wrote on Sat, 9 Aug 2008 11:43:33 -0400:

I have had an opportunity to review the memorandum to Superintendent Carter, Greg Bergman, Ron Lebs, dated July 31, 2008 and have the following general observations related to pipelines and the San Juan Hills High School. In a previous email I indicated that too many engineers and pipeline operators do not understand the unique dynamics that can be associated with transmission pipeline releases. Again, my purpose is not to alarm but to insure that informed and prudent decisions related to pipeline risk management are made concerning this very difficult situation. One sure sign of problems associated with very poor risk management approaches is the violation of the physical laws of science governing sound pipeline management and engineering practices, such as those identified below, rebutting some of the observations from the above 7/31/08 memorandum:
Explosive Vapor in the Atmosphere
The statement “Explosion of vapors in the open atmosphere cannot occur under the conditions present at the site.” is in all probability in serious error. While the specific conditions of the site that would prevent explosion are not identified in the memorandum, all forms of hydrocarbons, especially hydrocarbon mixtures, can explode or detonate, even in open fields, under the conditions related to many transmission pipeline releases, especially ruptures. It is a myth reflecting much inexperience, that hydrocarbon releases cannot explosively detonate in the “open,” and cannot generate serious overpressure in such situations. Many models fail to properly capture the critical factors that can result in detonation of pipeline hydrocarbon releases in such unconfined environments. The good news is that blast overpressure forces generated in the open that can be lethal, dissipate with distance quickly. As a result, high heat flux radiation associated with combustion following detonation usually controls the maximum size of the potential impact zone and mortality.

Please note that liquid hydrocarbon pipeline rupture releases are inappropriately modeled by pool or flash fires given the very high turbulence, aerosoling of the liquid, and extreme mixing associated with these very high mass rate releases. The assumption to model a gasoline release as if it where hexane, does not properly capture the release and detonation characteristics of a pipeline release which is moving a highly complex mixture of hydrocarbon compounds such as that in gasoline.
Risk of Asphyxiation
The memorandum statement “There is no risk of asphyxiation with a release from the pipeline in the open atmosphere” is in error. Hydrocarbon release, especially high rate releases from this product pipeline can generate large volumes of heavier than air hydrocarbon vapors which will flow like water settling into low spots displacing air. For individuals in such low spots, death by asphyxiation is a bona fide risk as has been well demonstrated by other pipeline releases with asphyxiation fatalities for individuals located in the “open.”
Danger to Evacuation Routes
The memorandum comment that “there is no conceivable way that fuel could flow onto the school site,” appears to not sync with the terrain and location of the school and surrounding infrastructure as well as previous documents that have been provided regarding this matter. Vapor release of heavier than air-fuel mixtures will quickly flow wherever gravity will take them. It appears that the analysis is ignoring or missing the large vapor generation. Ruptures are highly turbulent aerosoled events. Given the rapid dynamics of such releases, while emergency response plans are needed, no credit should be taken in risk management for emergency responder or other human field responder interaction, as usually such actions come too late to mitigate consequences given the rapid release dynamics. All too often I have observed that crediting emergency response in risk management approaches is a sure sign that the risk approach is fatality flawed!
Sustained Fire
A pipeline rupture explosion followed by fire (or if one is lucky, just a fire event) will not be a fire from a burning pool of liquid generating vapor from “evaporation.” Ruptures are highly turbulent releases of many hundreds of tons of fuel boosting vapor generation from aerosoling in a relatively short period of time. Detonation and or ignition generate tremendously high heat radiation flux and thermal dosages associated with very high mortality. This mortality is especially sensitive for unsheltered individuals such as those who may be in school open fields who will be least likely to survive upon receiving such extreme thermal dosages.

It should be also noted that pipeline hydrocarbon releases do not need an outside ignition source such as a flame to initiate combustion as such releases can generate their own source of ignition (e.g., from static electricity or rock sparking).
Increased Fuel Flow Due to Fluid Compression & Line Packing
All hydrocarbon liquids are compressible in the pressure ranges operated by transmission pipelines and yes the bulk modulus (which is the inverse of compressibility) is indeed approximately 200,000 psi for gasoline. Compressibility must be taken into consideration in all pipeline operations especially as it relates to rupture impact as release rates are substantially increased over pumping capacity because of this factor. While I do not know what position or experience is reflected in Mr. Morones of KM not knowing the term line pack in liquid pipelines, this term is readily used in hydrocarbon liquid pipeline pressure transient analysis/application, pipeline safety design, as well as failure/release dynamics.

Transient effects associated with hydrocarbon compressibility can easily render liquid pipeline leak detection “moot and ineffective” during the critical time or early stages of pipeline failure. Failure to properly account for compressibility/line unpacking seriously extends the time for remote determination and response at a time when system release rates are at their highest, well beyond pump capacity. Failure of KM to understand compressibility and line pack effects raises serious questions and concerns about the stated or implied capability of the KM leak detection system to determine a leak, especially a rupture, within 5 minutes of an event. On liquid pipeline systems 5 minutes is a very short time to pickup signals, determine, and then react to such possible release indicators, even rupture.
Circumstances Under Which Fuel Might Reach the School Site
A closer evaluation of the pipeline, the terrain, and the school are called for, in which realistic release volumes and surface flow characteristics and patterns (especially for vapor) as a function of time are properly stated and evaluated to confirm whether the memorandum statement “there is no physical way for product to reach and flow onto the school.” is valid.

I find very confusing the comment in the memorandum, in reply apparently to Mr. Christensen’s comments, “Nevertheless, the period of time assumed for shutdown of the pumps is not considered in the “worst case” scenario, which is based on liquid in the pipeline flowing for an indefinite period of time reaching the storm drain, and flowing beneath the school site.” We find no evidence in previous documents that support this claim. In fact given the limitations and technical errors imposed by critical assumptions in these previous studies and this memorandum, the validity and conclusions of these previous risk analysis reports should be called into serious question.