Low Carbon Concrete Initiative
The City of Portland’s 2016 Sustainable Supply Chain Analysis identified construction services as the top spend category contributing to the City’s supply chain greenhouse gas (GHG) emissions. Within construction services, concrete is one of the most GHG-intensive materials typically used on City construction projects. As a result, in 2019, after gathering both internal and external stakeholder input, the City established its Low Carbon Concrete Initiative to reduce the overall carbon intensity of the concrete mixes used on City projects. This Initiative is being carried out in phases, with the first few phases focused on gathering the data needed to inform the final phase of establishing concrete mix requirements that will lower the overall carbon intensity of concrete mixes used on City projects.
Phase 1: Environmental Product Declaration (EPD) Requirements
Beginning January 1, 2020, the City added the following requirements to the approval process for the supply of Portland Cement Concrete (PCC), including: Commercial Grade Concrete (CGC), Plain Concrete Pavement (PCP), and High-Performance Concrete/Structural Concrete (HPC) for City construction projects.
- All Portland Cement Concrete submitted to the City of Portland Materials Testing Lab for inclusion on the City’s (Pre)Approved Concrete Mix Design List will need to have a product-specific Type III Environmental Product Declaration (EPD) that is 3rd party verified and within its 5-year period of validity.
- All Portland Cement Concrete not on the City’s (Pre)Approved Concrete Mix Design List that are proposed for use over 50 yd3 on a City-owned or solicited construction project will need to have a product-specific Type III Environmental Product Declaration (EPD) that is 3rd party verified and within its 5-year period of validity.
Phase 2: Data Collection, including Lower Carbon Concrete Pilot Projects
The City, in collaboration with Oregon DEQ's Materials Management Program, spent time in 2020 collecting baseline data on various concrete mixes used in the Portland Metro Area to better understand current mix designs, applications, and associated environmental impacts. This data came from a variety of sources, including EPDs, historical project usage, and pilot projects.
In order to understand how lower-carbon concrete mixes perform compared to traditional 100% cement mixes, the City is performing pilot tests of different lower-carbon concrete mixes. The first pilot project took place in Spring 2020 and tested low-carbon concrete mixes on sidewalk applications with the Portland Bureau of Transportation (PBOT). The results of this pilot project are presented in the following case study. The Sustainable Procurement Program is currently working on several other pilot tests during 2021.
The Sustainable Procurement Program also funded the development of a Portland-area average EPD for mobile mix producers. Four mobile mix producers in the Portland area contributed to the EPD. A copy of the EPD can be found on the ASTM EPD website. Compared to the cost of an EPD for a stationary plant that may produce over 100 mixes, the cost per mix of an EPD for a mobile mix producer is significantly higher. Thus, the Sustainable Procurement Program pursued a local industry-average approach and invited any mobile mix producer supplying the Portland area to participate.
Phase 3: Establishing Global-Warming Potential (GWP) Thresholds
By December 2021, the City intends to publish maximum global-warming potential (GWP) thresholds for concrete on City construction projects (by type of concrete and strength class). The data collected throughout 2020-1 is informing a stakeholder engagement process to develop these thresholds. The goal is to require concrete used on City construction projects to meet the GWP thresholds starting in 2022, so that over time, the City's concrete carbon footprint is reduced.
- Oregon Concrete EPD Program from Oregon DEQ and Oregon Concrete & Aggregate Producers Association
- Webinar: Local Government Policies to Drive Low-Carbon Concrete (February 4, 2020)
Clean Air Construction Regional Initiative
To improve the air quality in Portland Metro area, the City of Portland, Multnomah County, Port of Portland, Metro, and Washington County are working together to include Clean Air Construction Requirements in their construction contracts. You can find more information on the Clean Air Construction Regional Program website.
Contractor Code of Conduct
Work on a Contractor Code of Conduct is on hold while Procurement Services updates its Social Equity in Contracting programs.
Sweatshop Free Apparel
The City's Sustainable Procurement Policy requires the City to purchase apparel products from manufacturers that comply with the City's Code of Conduct for Apparel Contractors [Attachment 1 of the Sustainable Procurement Policy]. The Code of Conduct requires that contractors, and their supply chain partners utilized to supply apparel to the City, comply with labor and health & safety standards that ensure workers are not subjected to sweatshop conditions.
Sweatshop Free Forms for Apparel Contractors
The City discloses the "cut and sew" factory locations where apparel items on City contracts are made. This information is available via the Sweatfree LinkUp database.