Hazardous materials waste

Transportation project construction waste disposal options include reuse, recycling, and disposal. Options and requirements depend on the type of waste.

Find information on this page under these four topics:

Requirements for all projects are available in the Standard Specifications from the Washington State Department of Transportation (WSDOT). 

Recycling & reuse

The Washington State solid waste handling rule mandates that WSDOT and our contractors recycle at least 25% of the concrete we remove. In addition, WSDOT encourages the use of recycled content materials on construction projects. Standard specifications include three categories of recycled materials: 

  • On-site and off-site sources
  • On-site sources only
  • Other projects that must be individually approved

Materials from on-site and off-site sources 

The following products and materials can be reused, even if from multiple sources.

  • Pavement mixtures including hot mix asphalt, recycled concrete aggregate, recycled glass and steel slag, see WSDOT Standard Specifications for more information/
  • Guardrail posts and blocks
  • Compost

Materials from on-site sources only 

If generated and processed on-site to specifications, the following products and materials can be reused on a construction project.

  •  Broken concrete
  •  Ground asphalt   
  •  Wood waste, as defined by Section 2-01.2 of WSDOT Standard Specifications, Disposal of Usable Material and Debris
  •  Excavated soils (includes minimally contaminated soils with appropriate county approvals)

Materials needing individual approval

To recycle or reuse other materials, you must receive approval from the WSDOT New Products Committee and testing by the WSDOT Materials Laboratory. Find the definitions and requirements for these recycled products in the following chapters of the most recent edition of the WSDOT Standard Specifications

Common hazardous materials: asbestos, lead, and creosote


Asbestos containing materials (ACM) can be found in buildings, bridges, and other structures. If your project may involve asbestos, contact the HazMat program for assistance with sampling prior to renovation or demolition as required by WAC 296-62-07721.

Once the ACM is identified and abated, contractors must dispose of the material in a permitted landfill and follow their Local Air Authority’s regulations. Some Clean Air Agencies provide alternative disposal methods for asbestos containing pipe.  


Depending on how it is managed, creosote treated wood may be reused or even excluded from the Dangerous Waste Regulations according to WAC 173-303-071.  

Refer to Ecology’s Treated Wood Exclusion information to determine if your creosote treated wood can be reused.

Hazmat specialists can help you determine how to dispose of creosote treated wood. Follow these WSDOT guidelines for creosote reuse. 


Lead-based paint (LBP) is often designated as a dangerous waste (per Chapter 173-303 WAC).

If your project may contain paint from before 1980, which is common on bridges and in buildings, contact the HazMat program or industrial hygienist so that it can be properly tested.

Contractors should characterize LBP waste in accordance with WSDOT Standard Specification 6-07.3(10)F for projects such as bridge painting and building demolitions. 

Cleanup options during construction

All contaminated waste from construction, whether generated by the project or encountered on the site, must be properly disposed of.

All projects must meet the requirements of the selected disposal facility. If your project encounters regulated materials, contact the contact the HazMat program.

Contaminated waste disposal

Because construction sites may generate many kinds of waste, including contaminated or dangerous waste, a waste disposal characterization must be made before disposal. Contaminants may include regulated waste such as asbestos, lead, or creosote.

  • Contact the HazMat program for assistance in characterizing your waste.
  • After you have received a waste disposal characterization, you can obtain a waste disposal authorization from an approved facility. Samples are generally characterized for disposal based on the requirements of the selected disposal facility and the local County Health Department.
  • Work with the chosen disposal facility to obtain approval for direct haul during construction.
  • If the waste was characterized prior to construction, the contractor must dispose of the material in accordance with the project Special Provisions.
  • If at any point in the process, sample results show that a material is a dangerous waste, follow the steps for dangerous waste disposal below.

Contaminated soil disposal

When a transportation project encounters contaminated soil or water, the Project Engineer (PE) decides the level of cleanup based on requirements, construction schedule and budget, apparent extent of contamination, and intended future use of the site.

Petroleum is the most common contaminant in soil on construction sites and is often detected by odor or a visual sheen. When this occurs, sample the contaminated soil to determine if it can be reused or if it must be disposed of.

If your project needs soil or sediment characterization or sampling, reference the following documents:

Dangerous waste disposal 

If testing has shown that your project has dangerous waste, it will require a Resource Conservation and Recovery Act (RCRA) Site ID Number from Ecology.

After dangerous waste is identified, it must be transported and disposed of appropriately in a RCRA Subtitle C hazardous waste landfill. To ensure that the waste is managed appropriately from cradle-to-grave, a RCRA Site ID Number and signed manifests are required. Dangerous waste must be reported annually to Ecology or sooner if the case is closed out.

Follow these instructions to obtain a RCRA Site ID number: