Bottom lines containing fuel are  referred to as “wetlines.”

		Wetline Incidents and Reporting

Wetline incidents result from collisions involving tank trucks that lead to  the release of flammable liquid from wetlines. PHMSA is responsible for regulating the safe and secure transportation of  hazardous materials to reduce the risks to people and the environment. PHMSA’s Incident Data Cannot Be Used to Reliably Identify Wetline Incidents, Although Efforts to Improve Data Quality Have Been Implemented

PHMSA’s incident data do not reliably capture the risks and  consequences of wetline incidents because these incidents are not  specifically identified in its database, and PHMSA’s incident data also  contain inaccuracies. Consequently, to identify wetline incidents, PHMSA officials must review  carrier-reported narratives and other information, a review that is  resource-intensive. Moreover, this review may not result in an accurate  accounting of the number and consequences of wetline incidents  because the information does not always clearly indicate whether the  incident is wetline-related and because of inaccuracies and omissions in  the data. PHMSA has made efforts to improve its data, such as  implementing quality checks, but this does not affect how wetline  incidents are reported, and errors remain. Other narratives did not  indicate a collision resulting in a flammable liquid release. Some stakeholders’ concerns with the wetline purging system apply to  other options as well, such as concerns about the safety of retrofitting  cargo tank trucks. PHMSA Analyzed Costs and Benefits for a Proposed Wetlines Rule, but Uncertainties Limit the Usefulness of the Analysis

		PHMSA Proposed a Rule to Address Wetline Safety Risks and Analyzed Associated Costs and Benefits

In January 2011, PHMSA issued a notice of proposed rulemaking to  prohibit the transport of flammable liquid in the bottom lines of cargo tank  trucks unless the vehicle is equipped with bottom damage protection  devices, along with an analysis of the proposal’s costs and benefits. We also found uncertainty in PHMSA’s data and assumptions related to  benefits:
Fatalities. Questions over  PHMSA’s wetline fatality analysis have been raised before. However, PHMSA did not account for this uncertainty in a  sensitivity analysis. Without adjusting its cost-benefit analysis to  account for the uncertainties due to the limited market for the purging  system and limitations with PHMSA’s incident data, the consequences of  wetline incidents remain unclear and the costs and benefits of wetline  regulation may not be accurately calculated in PHMSA’s regulatory  analysis. Recommendations for Executive Action

To improve the reliability of data used to identify wetline incidents, we  recommend that the Secretary of Transportation direct the Administrator  of PHMSA to take the following two actions:
Revise incident reporting to better capture wetline incidents and their  consequences, such as by requiring specific reporting of wetline  incidents by modifying the reporting form to include a specific indicator  of such incidents, and adjusting the incident reporting form to indicate  whether there are minimal costs versus no costs when costs are  below the $500 reporting threshold. The  department did not agree or disagree with our recommendations, but  provided technical comments that we incorporated as appropriate. Appendix I: Objectives, Scope, and Methodology

	Objectives

This report discusses (1) the extent that the Pipeline and Hazardous  Materials Safety Administration’s (PHMSA) data can be used to reliably  identify wetline safety risks, (2) options for addressing wetline safety risks,  and (3) how well PHMSA has assessed the costs and benefits of  addressing these risks through regulation. We reviewed documents on and  interviewed PHMSA officials about the agency’s prior and ongoing efforts  to improve the quality of its hazmat incident data.focuses specifically on the issue of wetlines, we did not assess PHMSA’s  progress in improving its hazardous materials incident data in general.
Why GAO Did This Study

Cargo tank trucks deliver gasoline and other flammable liquids daily for consumer use. Trucks are loaded and unloaded through external bottom lines that, after loading, may contain up to 50 gallons of liquid and are known as "wetlines." Concerns have been raised about the safety of wetlines, since a collision may rupture them, releasing flammable liquid and possibly causing fatalities and property damage. PHMSA is responsible for regulating the safe transportation of hazardous materials and has proposed rules prohibiting the transport of flammable liquids in wetlines.
In 2012, The Moving Ahead for Progress in the 21st Century Act required GAO to examine this issue. This report discusses (1) the extent that PHMSA's data reliably identify wetline safety risks, (2) options for addressing wetline safety risks, and (3) how well PHMSA has assessed the costs and benefits of addressing these risks through regulation. GAO analyzed PHMSA's wetline incident data for 1999 to 2011, reviewed PHMSA's regulatory cost-benefit analyses, and interviewed agency officials and industry and safety stakeholders.

What GAO Found

The Department of Transportation's (DOT) Pipeline and Hazardous Materials Safety Administration's (PHMSA) incident data cannot be used to reliably identify risks from incidents involving collisions with and spills from tank trucks' bottom lines ("wetlines") because the incidents are not specifically identified in PHMSA's database and the data contain inaccuracies. PHMSA requires carriers to report hazardous material incidents, but the reporting form does not specifically capture wetline incidents. PHMSA officials identify wetline incidents through a resource-intensive process of reviewing carrier-reported incident narratives and other information. However, GAO found that the narratives do not always clearly indicate whether an incident is wetline related and that information about the consequences of incidents, including fatalities, is not always accurate. PHMSA has made efforts to improve its data, such as adding quality checks, but this has not affected how wetline incidents are reported, and inaccuracies remain.
One technology to purge liquid from wetlines exists, but use of this system is limited, and industry and safety stakeholders expressed concerns about it, such as concerns about the safety of retrofitting existing trucks with the device and its cost. Although other options have been proposed to address wetline risks, none has been pursued, and there are concerns about their safety and feasibility as well. For example, wetlines could be drained at loading terminals, but this creates issues over storing the drained fuel and whether it could be resold.
PHMSA analyzed the costs and benefits of its proposed 2011 rule to prohibit transportation of flammable liquids in unprotected wetlines, but did not account for uncertainties in its analytical assumptions and limitations in the underlying incident data. For example, PHMSA's analysis overstated the number of fatalities the proposed rule would prevent when considering actual past incidents. Furthermore, PHMSA based its cost analysis on the assumption that carriers would install a certain type of wetline purging system, but its limited adoption makes that cost uncertain. Federal guidance recommends that agencies account for uncertainty in regulatory analysis, such as limitations in PHMSA's data and uncertainty in its assumptions. Without having done so, PHMSA's analysis may not accurately represent the costs and benefits of its proposed rule.

What GAO Recommends

DOT should improve its wetline incident data by requiring carriers to specifically report wetline incidents and by improving its information on incident consequences. DOT should also address uncertainty in the assumptions and data underlying its regulatory cost-benefit analysis. DOT did not agree or disagree with the recommendations, but provided technical comments.