For many facilities using, producing, and/or storing harmful chemicals, leak prevention and active detection systems are recommended by industry guidelines as best practices. In addition, there are numerous legislative and regulatory requirements that govern the monitoring and reporting of hazardous substance releases by RPs; these are discussed in Appendices C and D. Briefly, for facilities that handle hazardous substances, serve as “point source” dischargers of pollutants into bodies of water, or are emitters of hazardous air pollutants, the EPA has implemented monitoring and reporting requirements under EPCRA, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Clean Water Act (CWA) and the Clean Air Act (CAA). Active detection systems used to fulfill these requirements can range from simple visual inspections to automated, electronic data-gathering instruments, to sophisticated consoles and computer systems. Such systems may use liquid sensing cables, soil vapor monitoring, or emissions tests. Most include automatic leak alarms.4 For example, the Prologue describes near-immediate detection of chlorine release from a rail tanker by the facility’s chlorine gas sensors.12 Similarly, telemetry data provided by a chemical plant’s refrigerated trailers was used to predict the stability and potential for hazardous decomposition of reactive chemicals in the wake of Hurricane Harvey.3 In most cases, facility detection systems will trigger an alert before enough harmful material has been released.
Other specialized facilities also regularly monitor for contaminants. For example, pursuant to the Safe Drinking Water Act (SDWA) and the EPA’s Unregulated Contaminant Monitoring Rule (currently UCMR 4), local water systems must monitor for selected common contaminants of concern. Through this program, chemical releases may be detected downstream of their sources. However, since only a few chemicals are monitored, many incidents may go unrecognized. For example, the Prologue describes a chemical release that was not detected by the RP or by the downstream water treatment utility’s monitoring system, as the leaked chemical was outside of that utility’s normal testing regime; instead, the release was recognized via the public’s noticing of an odor.4
Thus, although environmental monitoring systems can play an important role in incident recognition, they have limitations. Further, if the test results are not available in real time, releases may be recognized only retrospectively (unless there is a chronic leak). The most obvious limitations are the logistical, analytical, and cost constraints that preclude the widespread use of these monitoring systems. Additionally, most environmental and facility monitoring systems are specific to the chemicals being stored or processed on site, and cannot detect chemical hazards outside of the system’s configuration. Intentional releases away from storage or processing plants or accidents during transportation also may not be recognized immediately.
Footnotes
3. CSB. (2018, May). Organic Peroxide Decomposition, Release, and Fire at Arkema Crosby Following Hurricane Harvey Flooding. Report Number: 2017-08-I-TX.
4. CSB. (2017, May). Chemical Spill Contaminates Public Water Supply in Charleston, West Virginia. Report Number: 2014-01-I-WV.
12. National Transportation Safety Board. (2019, February 11). Hazardous Materials Accident Report: Rupture of a DOT-105 Rail Tank Car and Subsequent Chlorine Release at Axiall Corporation, New Martinsville, West Virginia, August 27, 2016. (Report No. NTSB/HZM-19/01).