Work to replace and maintain roadway delineation typically includes refurbishing, delineation and replacement of missing markers. Environmental stewardship practices ensure that paints, debris and excess maintenance and repair materials remain controlled and are not released to the environment.

In September 1999, EPA redefined traffic paint into two categories, traffic marking coatings and zone marking coatings. Zone marking coatings are defined as those used on sidewalks, driveways, parking lots, curbs and airport runways and packaged in containers of five gallons or less, with Volatile Organic Compounds (VOCs) limited to 450 grams/liter or less; i.e. traditional oil-based traffic paint. Traffic marking coatings are now defined as those used for streets, highways and traffic areas as well as the purposes outlined for zone markings, with a VOC limit of 150 grams/liter. This means that traffic marking contractors must use low-VOC traffic paint when marking roadways, which in most cases will mean using latex traffic paint. In transitioning to latex traffic paint, DOTs have had to make sure that equipment is waterbase compatible, in order to avoid application and maintenance problems. Modifications have included use of stainless steel on critical wetted parts, with plated components being adequate in very few areas. New application techniques have also applied, especially for low-VOC alkyd paints which contain acetone, a product with a low flash point.

Pavement striping is used for lane stripes and other pavement markings to guide motorists. Surfaces may be swept prior to painting. Water-based paints are applied using striper paint systems. Other pavement markings may be applied using striper paint systems or stencils. Potential pollutant sources such as overspray, dust, spills and leaks may create pollutants, including paint, sediment, fuel, hydraulic fluid and oil. Water used during presweeping operations should be controlled to prevent unpermitted non-stormwater discharges. Other recommended environmental stewardship practices include illicit connection/illicit discharge reporting and removal, scheduling and planning, illegal spill discharge control, spill prevention and control, safer alternative products, vehicle and equipment fueling, vehicle and equipment maintenance, solid waste management, liquid waste management, material use, sweeping and vacuuming and water conservation practices. [N]

Raised/Recessed Pavement Marker Application and Removal

Pavement markers supplement traffic signs. Markers may either be surface mounted (raised) or placed in recessed slots in the pavement. Markers are applied using bitumen/epoxy adhesives. Damaged markers are removed using hand tools or graders and loaders. Potential pollutant sources such as excess application, spills and leaks may result in the release of potential pollutants of epoxy, fuel, hydraulic fluid and oil. Recommended environmental stewardship practices include illicit connection/illicit discharge reporting and removal, scheduling and planning, illegal spill discharge control, spill prevention and control, vehicle and equipment fueling, vehicle and equipment maintenance, solid waste management, and material use. [N]

General environmental stewardship practices for pavement marking include the following: [N]

• Schedule pavement marking activities for dry weather. Do not conduct painting or traffic marking activities during rain events.
• Replace solvent-based alkyd traffic paints with waterborne paints that contain 80 percent less organic solvents and with epoxy paints that release no solvent vapors.
• Develop paint handling procedures for proper use, storage, and disposal of paints.
• Transfer and load paint and hot thermoplastic away from storm drain inlets.
• Provide drop cloths and drip pans in paint mixing areas.
• Properly maintain application equipment.
• Street sweep thermoplastic grindings. Yellow thermoplastic grindings may require special handling as they may contain lead.
• Properly dispose of paints containing lead or tributyltin, which are considered a hazardous waste.
• Use water based paints whenever possible. If using water based paints, clean the application equipment in a sink that is connected to the sanitary sewer.
• Properly store leftover paints, if they are to be kept for the next job, or dispose of properly.

Waste from removal of yellow thermoplastic and yellow painted traffic stripe and pavement marking contains lead chromate in average concentrations greater than or equal to 350 mg/kg and less than 1000 mg/kg Total Lead. Residue produced when yellow thermoplastic and yellow paint are removed may contain heavy metals in concentrations that exceed established thresholds and may produce toxic fumes when heated. Waste from removal of yellow thermoplastic and yellow painted traffic stripe and pavement marking contains lead chromate in average concentrations greater than or equal to 5 mg/L Soluble Lead or 1000 mg/kg Total Lead. Caltrans has specified the following environmental stewardship practices for removing traffic stripe and pavement marking: [N]

• Removed yellow thermoplastic and yellow paint should be disposed of at a Class 1 disposal facility or a Class 2 disposal facility. Testing of residue is likely to require EPA's Total Lead and Chromium Method 7000 series. If the yellow thermoplastic and yellow painted traffic stripe and pavement marking residue is transported to a Class 1 disposal facility, a manifest should be used, and the transporter should be registered with the California Department of Toxic Substance Control. The Engineer will obtain the United States Environmental Protection Agency Identification Number and sign all manifests as the generator within 2 working days of receiving sample test results and approving the test methods.
• The contractor should prepare a project specific Lead Compliance Plan to prevent or minimize worker exposure to lead while handling removed yellow thermoplastic and yellow paint residue. Personal protective equipment, training, and washing facilities required by the Contractor's Lead Compliance Plan should be supplied by the Contractor.
• Prior to removing yellow thermoplastic and yellow painted traffic stripe and pavement marking, personnel who have no prior training, including State personnel, should complete a safety training program provided by the Contractor that meets state requirements.
• Where grinding or other methods approved by the Engineer are used to remove yellow thermoplastic and yellow painted traffic stripe and pavement marking, the removed residue, including dust, should be contained and collected immediately. Sweeping equipment should not be used. Collection should be by a high efficiency particulate air (HEPA) filter equipped vacuum attachment operated concurrently with the removal operations or other equally effective methods approved by the Engineer.
• The Contractor should submit a written work plan for the removal, storage, and disposal of yellow thermoplastic and yellow painted traffic stripe and pavement marking to the Engineer for approval.
• The removed yellow thermoplastic and yellow painted traffic stripe and pavement marking residue should be stored and labeled in covered containers, conforming to state provisions. The containers should be a type approved by the United States Department of Transportation for the transportation and temporary storage of the removed residue. The containers should be handled so that no spillage will occur. The containers should be stored in a secured enclosure at a location within the project limits until disposal, as approved by the Engineer.