Environmental Review Process

During the environmental review process, we will:

  • Consider environmental information (impacts and mitigation) before committing to a course of action.
  • Identify and evaluate probable impacts and mitigation measures, emphasizing important environmental impacts (including cumulative, short-term, long-term, direct, and indirect impacts).
  • Encourage public involvement in decision-making; and
  • Prepare concise and easily understood environmental documents.
River view

Fish and wildlife habitat will be considered as part of the environmental review process.

Environmental Resource Areas

The environmental review documents will describe existing conditions of the project area in multiple environmental resource areas (see below). We will consider both beneficial and unfavorable effects, as well as direct and indirect consequences of implementing a proposed action or the no-action alternative. We will measure the significance of an impact based on the context, intensity, and effect on the environment. Then we will identify possible mitigation measures to avoid or minimize any unfavorable impacts.

Water Resources and Erosion Control

Managing the affects our daily activities and construction projects have on groundwater and surface water helps us protect and improve water quality and habitat.

Fish and Wildlife

Riparian and aquatic areas provide important habitats for sensitive wildlife species. Transportation projects can affect these resources and Pierce County is committed to identifying and mitigating impacts.

Wetlands and Streams

Wetlands consist of any lands where soil is sometimes covered by water, including rivers, lakes, streams, and estuaries. Pierce County works to prevent net loss of wetlands and minimize affects if they are unavoidable during the development of transportation projects.

Air Quality

Emissions from vehicles may have an effect on particulate matter and toxins in the air.


Noise generated on our roadways may require mitigation when it reaches certain levels.

Cultural Resources

Pierce County is committed to mitigating impacts to archaeological sites; historic buildings, roads, and bridges; and places on the landscape that are historically significant to Washington State.

Hazardous Materials

Materials including lead, creosote, asbestos, chemically contaminated sediment, releases from underground storage tanks, or other solid waste may be encountered or generated by our transportation projects. Pierce County works to ensure these materials are contained and disposed of properly.

Social, Community, and Visual Resources

These can include social, economic, community, equity, and relocation impacts. This analysis examines how the proposed transportation improvements affect the people who live, work, and play in the vicinity of the project.

Section 4(f) Resources

These resources include public parks and recreation lands, wildlife and waterfowl refuges, and historic sites. Under Section 4(f) of the U.S. Department of Transportation (USDOT) Act of1966, projects that receive funding or approval by any USDOT must avoid impacts to Section 4(f) properties. When a project cannot avoid Section 4(f) properties, Section 4(f) requires documentation and approval by the federal lead USDOT agency.