DENVER—Senator Chris Hansen, D-Denver, wants to make sure that selected building materials used in public construction projects are environmentally-friendly. Public construction projects includes any construction by any city, town or other public entity, including school districts.
Senate Bill 20-159, introduced by Hansen on Feb. 4, would require the state Department of Personnel (DOP) to set a “maximum acceptable global warming potential” (GWP) standard for carbon steel rebar, structural steel, concrete, cement, mineral wool board insulation and flat glass used in constructing public works projects.
The legislative declaration says, “Great quantities of emissions are released during the manufacture and transport of products used in public construction projects,” and that existing public construction regulations “do not currently encourage public dollars for infrastructure projects to be spent in a way that is consistent with the state’s goals to reduce greenhouse gas emissions.”
“The department is required to set the maximum acceptable global warming potential at the industry average of facility-specific global warming potential emissions for that material and to express it as a number that states the maximum acceptable facility-specific global warming potential for each category of eligible materials,” says the bill.
The GWP is based on environmental product declarations (EPD) created by product manufacturers according to certain national and international standards.
EPDs are an assessment of how products affect the environment through greenhouse gas production from the beginning to the end of their life cycle. Such declarations are generally created by manufacturers as a marketing tool for business-to-business sales on the premise that greener is better.
The benchmark for assessing a product’s GWP emissions is carbon dioxide (CO2). Impacts of greenhouse gases produced by material extraction, production, shipping, consumption and disposal are compared to CO2, which is given a value of one.
For example, for the same mass of gas, the global warming potential of methane (CH4) is 23 times that of CO2, and nitrous oxide (N2O) has 296 times the impact according to the Intergovernmental Panel on Climate Change (IPCC).
Adding up all of the greenhouse gases released throughout the life cycle of the material results in a number the bill says must represent the “maximum acceptable global warming potential at the industry average of facility-specific global warming potential emissions for that material.”
The bill requires DOP to update the maximum limit every four years but can only adjust the number downwards “to reflect industry improvements” in limiting emissions, but cannot adjust it upward even if the industry average goes up.
Contractors are required to certify that the specific materials proposed for the project fall below the maximum acceptable GWP number.
There is currently no fiscal note attached to the bill indicating the cost to taxpayers of creating and administering the data, nor are figures for the increased costs of procuring and certifying acceptable products available as of press time.