Potential Pipeline Hazard Mitigation/Management

Reducing the Probability of a Pipeline Product Release

Measures aimed at reducing the probability of a pipeline product release are largely outside the control of a school district. However, the following are some potential measures with which school districts can approach pipeline owners and operators toward that goal. Quantifying a reduction in probability of a release by these or other means may be possible but may be difficult to calculate, and pipeline owners, operators, or regulatory agencies may be reluctant to release relevant information without a legislated requirement.

1. More Frequent or Rigorous Pipeline Inspections/Testing
   Request operators to perform more frequent or more rigorous pipeline inspections and testing to protect system integrity. This is an operational measure that is likely to be less costly than most capital improvements, pipeline testing procedures are well-known and well-practiced, and a school district would appear quite reasonable in its request to provide an improved testing and inspection schedule.
   
   Improved testing may be smart pig testing rather than hydrotesting, as it provides more information to the operators. Different smart pigs test for different anomalies, too; one may be used to detect pits in the steel walls, while another may be used to test seams.
   
   Testing for natural gas pipelines installed prior to 1970 when the U.S. Department of Transportation Regulations Part 192 were promulgated has not until recently been required. In the aftermath of the San Bruno disaster, the California Public Utilities Commission has begun testing Class 3 and 4 pipelines installed before 1970. Class 1 and 2 pipelines are still "grandfathered".
2. Call Subscribe to USA/Dig Alert
   Companies needing to excavate in a populated area are required by law to notify Underground Service Alert (USA aka Dig Alert). USA then notifies subscribers within the vicinity of the excavation. Subscribers are generally the utility companies, that then come to the site and mark the location of their underground pipelines and other facilities; however, school districts may also join for a very nominal fee.
   
   Notified, the school district can then contact the school principal, the local emergency management services agency, and the owners or operators of pipelines in the service alert area to ask them to have a representative on site during the digging to monitor the excavation. Some pipeline operators make it a practice to have a representative at the site, but some may not. school districts may also request pipeline operators provide dig notification directly to the school district or the school. And, they may work with local building departments and city or county engineers to be alerted when they know of a planned dig.
3. More or Better Pipeline Demarcations and Signage
   Request, and expect, that pipeline owners and operators provide the required pipeline demarcations and signage, and should request signage be added in front of a school and within 1,000'-2,000', for example, in either direction of a school, as further assurance excavators are aware of the school's presence.
4. Right of Way Encroachment Protection
   Work with pipeline owners and operators to ensure pipeline right-of-way encroachment protection. Fencing is often used by railroad utilities to prevent encroachment onto their tracks and property. Since pipeline often run in the same right-of-way, they become fenced, as well. However, fences might be appropriate in other pipeline easements or right-of-ways.
5. Upgrading the Operator's Supervisory Control and Data (SCADA) System
   An operational measure school districts may want to request is an upgrade to the pipeline operator's SCADA where the current system is not modern. This was a problem with the San Bruno rupture, where gas was allowed to continue to flow for some 90 minutes after the pipeline's rupture. Pipeline operators employ SCADA systems, and may foresee the need to upgrade theirs; however, this amounts to a significant capital expenditure. The California Public Utilities Commission (CPUC) and State Fire Marshall's Office may serve as a conduit of information and the school district's request of the operator.
6. Reduce Pipeline Operating Pressure
   Request operators to reduce a pipeline's operating pressure to no more than 25 percent Specified Minimum Yield Strength (SMYS). This pressure makes it unlikely that a leak in the pipe will become a rupture.
   
   School districts can also request that a natural gas pipeline operate at Class 4 limitations in the vicinity of the school, in other words, at 40 percent of SMYS. The lower the pressure, the less danger. Class 3 (50 percent of SMYS) and Class 4 designations are for "High Consequence Areas," such as schools. Nevertheless, if a pipeline has once been designated a Class 1 line, for instance, the operator may request a permit to operate that line as a Class 1 (72 percent of SMYS) in a High Consequence Area. School districts should work with the CPUC and the federal Office of Pipeline Safety to request that such a permit not be issued.
   
   In order for a school to be identified as a Class 3 area, some portion of the campus must be within 300' feet of a pipeline. This will require the operator to do additional testing and lower Maximum Allowable Operating Pressure (MAOP), of the line. Similarly, for a school to be designated a Class 4 area, a building must be at least four stories. These measures may be useful at schools that simply cannot distance themselves from high-pressure pipelines.
7. Replace Older Pipelines
   Request pipeline owners to replace older pipelines. The utility companies may have a replacement schedule; but may be willing to advance the schedule for sections located near a school.
8. Adding Physical Pipeline Protection
   School districts (in coordination with the pipeline owner/operator) have on occasion had a concrete slab installed over a section of pipeline near the school to make accidental dig-ins much more unlikely. This should be done on the advice and under the supervision of a competent engineer to ensure that a new hazard is not being created.

Reducing the Severity of Consequences of Pipeline Releases on Schools

The following are examples of potential mitigation measures that focus on limiting the effects of a pipeline release and ignition should one occur. The list is divided into design and operational measures. The list is not exhaustive and qualified professionals should evaluate the value and effectiveness of any measure or combination of measures and decision makers need to consider them individually and collectively on a case-by-case basis. In most cases it will be difficult to quantify the improved safety by implementation of mitigation measures other than distance. Some will be of little or no cost to implement while others will be very expensive. Ultimately, the school district's governing board of trustees will need to make informed decisions about what is necessary, desired, and acceptable to implement. Many of the mitigations will require an ongoing commitment to ensure operational effectiveness, and as such, the California Department of Education (CDE) prefers design solutions over operational ones.

1. Design Measures
   1. Alternative School Site Locations Farther from Pipelines
      Longer distance from a pipeline, preferably beyond the 1,500 foot assessment or any worst case hazard footprint, is the most effective means of reducing risk from pipelines. Thus, alternative sites located farther away should be the first option evaluated. Weighing all other potential hazards, site issues, constraints, and costs, does the governing board find alternative sites farther from pipelines that will still meet its siting objectives? Reviewing alternative sites will require the local educational agency (LEA) to bear some additional expense for screening reports.
   2. Larger On-Site Setbacks from Pipelines
      For sites within an area of a pipeline hazard footprint for which no better alternative sites exist, separation of school uses (especially for outdoor use areas) from the pipeline by way of a setback may be an effective means of reducing risks from that pipeline. This can be one of the lease expensive mitigations if sufficient useable acreage is left for proposed uses. The effectiveness of the specific setback distance (which could be several hundred feet) will be dependent upon the hazard footprint and school site acreage requirements determined on a case-by-case basis. The setback area should be clearly marked with restricted access for school uses; however, uses like landscaped areas and other non-student uses may be considered. If the projected flames and overhead heat are high enough to where no location on campus will provide an acceptable level of protection, the district should either request that the pipeline be relocated or the school be moved beyond the unacceptable zone.
   3. Locating Buildings or Open Space Uses Closer to Pipelines
      While sufficient distance is the best mitigation, the following discussion is applicable for situations where useable portions of a school site must be located within a pipeline hazard area in which setbacks are either only partially feasible, or not at all, and the safest layout of buildings versus open space is being considered. The question whether buildings will provide any shelter, or shelter for more than a few seconds or minutes, must be made with an understanding of a pipeline's potential heat generation, the likely height of the flames, and the distance from the flames and heat. In cases where the potential heat and overhead flames are low enough to where buildings made of certain materials would provide secure protection, a school district might find the placement of buildings nearer a pipeline acceptable; whereas, where the potential heat and overhead flames are projected to be higher, a governing board might decide playfields should be closer and buildings farther from a pipeline.
      
      A number of other factors to consider are: frequency of use/occupancy patterns and the ability to manage them; amount of time spent indoors and outdoors; high/low concentrations of people, age, vulnerability, and ability to escape (e.g., child-care, disabled); possible penetration of un-ignited pipeline fumes into buildings' potential ignition sources in the buildings; potential secondary sources of fires from fuels (e.g. vehicle gas tanks); and spreading of building fire/smoke. Providing small fire/heat shelters at various locations in the areas away from buildings may also be considered if their effectiveness is determined to be warranted.
   4. Pipeline Shut-off Valves
      Valves, manual or automatic, are often spaced long distance from each other. Requesting automatic shut-off valves on either side of school decreases the amount of time gas or other fuel can escape a ruptured or leaking pipe. They are purported to be expensive, and they are unpopular with pipeline owners and operators because of the additional maintenance required. Nonetheless, the quicker the flow of fuel is shut off, the shorter the duration the danger.
   5. Pipeline Leak, Monitoring, Alarm Systems
      Gas detection monitoring systems can be installed along the length of pipes near schools. These devices provide an emergency alarm notification should there be any escaping gas prior to ignition. This alarm should allow site occupants more time for evacuation and activation of other safety measures prior to an ignition and inferno. These improvements will require coordination with the pipeline owner and the LEA will likely have to bear the costs. The amount of additional time that is gained for action prior to ignition could be either minimal or significant, depending upon ignition sources.
   6. School Building Heating, Ventilation, and Air-Conditioning (HVAC) Auto Shut-offs
      In the event of a pipeline leak or rupture, it is possible that gas fumes can, prior to ignition or smoke after ignition, be introduced into buildings through their HVAC intake systems. Providing automatic, immediate shut-off switch could prevent such an intake and either prevent internal ignition or air contamination.
   7. Fire Resistant Roofs and Walls, Avoidance of Combustible Materials, Protection of Structural Integrity
      While buildings will provide an initial, and often very brief, shelter from fire radiation, buildings will catch fire if they are within a critical distance of the heat flux, forcing an evacuation. Use of fire resistant materials on roofs and walls facing pipelines may add some additional time, depending on the size and pressure of the pipe, for safe occupation of buildings until the source of the flames is quelled, allowing safer evacuations. This measure will likely only be effective for smaller diameter, lower pressure lines.
   8. Eliminate Ignition Sources Near Pipeline
      Removal of ignition sources near the pipeline may prevent or delay the combustion of oxygen and gas from leaking pipes and thus allow more time to put emergency plans into action once a leak is detected. Ignition sources may include boilers, water heaters, certain electrical equipment, electrical wiring, vehicles, cigarettes, and other sources.
   9. Berms and Walls (to Divert Liquids from the Site and Debris Protection)
      Berms and walls may provide protection by preventing the release of liquid from encroaching on the school site. Owing to the potential height of ignited natural gas and the distance debris is thrown from pressure explosions, these structures will not provide protection against heat radiation and very little against thrown debris. Unless engineered correctly, walls will not provide overpressure blast protection, can be prohibitively expensive, and can create secondary hazards.
   10. Windows - Blast and Breakage Improvements, Minimization of Glass Exposure
       When subject to pressure waves, extreme heat or thrown debris, windows will shatter and the flying fragments can cause injuries. In order to minimize this hazard, buildings can be designed to minimize glass facing the pipeline(s). Glazing can be added to windows that will limit breakage and fragmentation Frame reinforcements can increase the structural integrity of the windows.
   11. Reduce Building Walls Parallel to Pipelines
       Orienting buildings at an oblique angle to the pipelines may reduce pressure wave effects.
   12. Relocating Pipelines Farther from the School
       Relocation of pipelines and easements farther away accomplishes the same thing as relocating the site farther from the pipelines. This mitigation measure requires cooperation with the pipeline owners and significant associated coast may be entirely the expense of the school district. Depending on the new pipeline location, the district may meet significant resistance form other surrounding property owners who may experience a hazard increase.
2. Operational Measures
   1. Emergency Evacuation Plans, Coordination with Local Agencies, Training, Education, Communication with Parents, Staff, and Students, and Drills
      All schools are required to have a comprehensive school safety plan, pursuant to Education Code sections 32280 et seq. Where pipelines are in the vicinity of the school, having a site-specific Emergency Response Plan (Plan) for pipeline incidents in place must be a standard requirement. Preparation of the Plan includes coordination with emergency responders. All potentially affected parties must practice Emergency Response Plans. Risk Management Plans should also be sent to the utility companies and public permitting agencies to allow better coordination and communication.
      
      The Plan should be part of the Comprehensive School Safety Plan. This site specific Emergency Response Plan should include routes and areas that are marked and safe for staging and exiting from all sections of buildings and the campus. Emergency exit gates need to be located appropriately. Pipeline leaks and ruptures should result in unique campus alarms that communicate the nature of the emergency.
   2. Dig-In Notification Subscription Lists
      Affected schools should request to be put on all third-party dig notification lists (USA Dig Alert) regarding any excavation or other activities near the pipeline and school. With this notification, the school staff can increase awareness of emergency plans or consider changing the timing or location of events on the campus.
   3. Responsibility to Notify Pipeline Operator of Any Dig-ins Near Pipeline
      Key school site personnel need to be designated the responsibility to notify pipeline operators of any extraction or drilling activities near the pipeline and school.
   4. Pipeline Operators' Notification to LEAs of Any Leaks or Activities Such as Pressure Testing That Would Increase the Potential of a Leak or Rupture
      School districts should formally request the pipeline operators maintain close communication to ensure immediate notification of any leaks, and advance alerts for planned maintenance, excavation, drilling, or activities such as pressure testing that might increase the potential of a pipeline leak or rupture. Notification should include e-mail, landline, and cell phone contacts with key personnel at the campus. With this notification, the school staff can increase awareness of emergency plans or consider changing the timing or location of events on campus.