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Guidance Document to Identify and Minimize the Impact of PCBs and Metals in Paint

Description:

Recent Superfund sites have seen increased costs of remediation, lower cleanup thresholds for concentrations of contaminants of concern (COCs), and the identification of atypical COCs in stormwater. These developments have resulted in some departments of transportation (DOTs) being identified as potentially responsible parties (PRPs), when they would not typically have been included five to ten years ago. For example, the Oregon Department of Transportation (ODOT), the Washington Department of Transportation (WSDOT), and the California Department of Transportation (CalTrans) have all been designated as PRPs at sediment cleanup sites in their respective states. Also, a study found PCBs in paint used on bridges by Minnesota Department of Transportation (MnDOT).

Low cleanup thresholds lead to a review of all potential sources of sediment contamination, including stormwater. Sediment cleanups costs are in part rising due to the increased complexity of controls required by regulators. Additionally, sediment remediation projects have become larger in terms of geographic extent, volume, complexity, expense, and duration. This is in part due to a more sophisticated approach to sediment projects because of advanced site investigation techniques and more detailed analysis of source control, recontamination, and bioavailability, amongst other things.

These more sophisticated approaches and further evaluation of source control and recontamination have identified the need to examine atypical COCs in stormwater. For examples, based on findings of recent studies of contamination in stormwater, the identification of newly-revealed sources has shifted the emphasis from polycyclic aromatic hydrocarbons (PAHs) and zinc to polychlorinated biphenyls (PCBs) and phthalates.

Initial research has identified two sources of PCBs in paints used as coatings on bridges and/or road paints:

PCBs intentionally added to paint as a plasticizer (1940s to 1979): The use of PCBs in the paint and coating industry reportedly began in the 1940s (Martin and Richards 2009). PCBs were added for the following reasons:

o Increased adhesion

o Increased luster

o Reduced drying time

o Corrosion resistance

o Good heat and humidity resistance

o Increased antifungal properties

Prior to the enforcement of the U.S. Environmental Protection Agency (EPA) regulation 40CFR761 (Polychlorinated Biphenyls [PCBs] Manufacturing, Processing, Distribution, Commerce, and Use Prohibitions), PCBs were manufactured and used in the U.S., including as an additive to paints. The manufacture of PCBs was ceased by its sole U.S. manufacturer in 1977, and the sale or use of PCBs in non-closed systems (such as paint applications) was banned in the U.S. on May 31, 1979 (Hess et al. 2001; Martin and Richards 2009; EPA 1979, 13; EPA 2014, 1, 10; EIP Associates 1997, 1–3). However, PCBs in coating products purchased prior to 1979 could have been used after 1979, and PCB-containing coatings applied to bridges prior to 1979 had the potential to leach into the environment after 1979.

PCBs inadvertently produced in certain pigments: Pigments produced after 1979 have been determined to inadvertently contain PCBs due to the manufacturing process. In a 2010 sampling event, PCB concentrations in modern coating products ranged from 2 to 200 ng/g in 15 of 33 sampled coating products. Pigments identified as containing PCBs from these sources included azo (yellow/red) and phthalocyanide (blue/green) pigments (Hu and Hornbuckle 2010, WSDOT-LDW 61001041 at WSDOT-LDW 61001041–045).

Beyond the potential environmental hazards, PCBs in old paint have the potential to pose an exposure risk to workers during paint removal by abrasive blasting.

Objective:

The object of this research is to identify which paints used by DOTs contain hazardous substances and develop guidance on how to determine whether those substances are impacting the environment. Key research objectives are summarized below:

  • Summarize existing knowledge about PCBs and metals in paints used by DOTs.

  • Develop a guideline that uses existing technology to evaluate paints on structures or roadways for PCBs and metals.

  • Develop a guideline document to minimize environmental impacts, worker exposure, and impacts to waterways from PCBs and metals in paints.

Benefits:

The guidance document will be a reference on how to develop and implement a hazardous paint evaluation program for DOTs. The guidance document will also include a process to evaluate the potential environmental impacts when elevated concentrations are identified.

Related Research:

A review of literature and databases was conducted to determine pertinent information about DOT use of materials and chemicals that may contain PCBs.

Highway traffic marking paints: PCBs have been detected in yellow pigment used in commercial paints (Hu and Hornbuckle 2010, WSDOT-LDW 61001041). Additionally, a study on PCB content of municipal products was performed by the City of Spokane and Ecology. PCBs were found at concentrations ranging from 0.28 to 64.88 µg/kg in the roadway paints that were tested. The city of Spokane found that striping paint used by the city contained low levels of PCBs (City of Spokane 2015).

Caulk: PCBs were found in caulk used to fill concrete expansion joints. Sample materials from an investigation in 2000 contained PCBs at concentrations up to 50,000 mg/kg. During three separate North Boeing Field (NBF) investigations, concrete joint materials near storm drain structures were sampled (King County 2016, 17; Ecology 2016, 31). The City of Tacoma found that road sealant used in the East Tacoma neighborhood was contributing PCBs to stormwater (King County 2016, 92).

Roadway use: PCBs are ubiquitous in the environment; they have also been detected in antifreeze, motor oil, lubricant, and asphalt-related products at concentrations ranging from 0.018 to 7.975 µg/kg (City of Spokane 2015, 13, 15, 19–20). Based on these findings, all vehicles, parking lots, and roadways are potential sources of PCBs.

Atmospheric Deposition: PCBs are a global pollutant in the atmosphere (Hope 2008; van Drooge et al. 2001). Atmospheric deposition of PCBs on roads can result in PCBs in stormwater (FHWA 1984).

The reviewed information detailed various levels of PCBs in products used by DOTs, but it did not provide guidance on how to minimize the release of PCBs or alternative products.

Tasks:

Step 1. Review literature and conduct interviews: This phase includes performing a literature search on a state DOT or other agency to determine what is known and what is unknown with respect to PCBs and metals in paints within different climatic regions of the U.S. Research will also include sourcing and brands of paints used for different purposes. Telephone conversations with DOTs, universities, or other references will be conducted. Research will expand internationally as appropriate.

Deliverable: A report that summarizes the findings of this process. Recommendations for the need for sampling to augment the information in the literature will be provided.

Step 2. Develop a guidance document outline, draft/final versions of a PowerPoint presentation, and draft/final versions of the guidance document: The outline and draft guidance document will be developed for TRB review and comment. A final guidance document will include updates based on TRB comments.

Deliverables: A PowerPoint presentation that can also be used as a training tool for state DOTs. A final guidance document that describes how to assess for hazardous substances in paints used by DOTs and ways to evaluate their impact on the environment.

Implementation:

Many State DOTs are currently dealing with this issue and would support and champion this research.

Relevance:

Environmental and Maintenance Divisions of State DOTs

Sponsoring Committee:ADC60, Waste Management and Resource Efficiency in Transportation
Research Period:6 - 12 months
Research Priority:High
RNS Developer:Andrew Graettinger and Christopher Moody
Source Info:Committee members
Date Posted:12/19/2016
Date Modified:01/04/2017
Index Terms:Costs, Drainage, State departments of transportation, Oregon Department of Transportation, Washington State Department of Transportation, California Department of Transportation, Paint, Minnesota Department of Transportation, Sediments, Coatings,
Cosponsoring Committees: 
Subjects    
Highways
Maintenance and Preservation
Safety and Human Factors
Bridges and other structures
Environment

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