Putting Earth Day into Practice Every Day: Life Cycle Cost Analysis and the Environment

1. Putting Earth Day into Practice Every Day:Life Cycle Cost Analysisand the Environment Dr. Kevin Gardner Co-Director, RMRC April 22nd, 2008

2. Develop economic evaluation tools/software to assess short-term costs, life-cycle costs and life cycle impacts of using recycled materials in transportation infrastructure. Through outreach get these tools used and lessons learned to the community. Understand environmental behavior of recycled materials and provide clear guidance on appropriate use and potential risks. Objective

3. A tool that can help with understanding the broader impacts of a material or process. What are environmental costs and benefits of using recycled materials? Are there additional environmental or societal benefits that off-set potential site-specific risks? Life Cycle Assessment

4. Modeling Tools • Pavement Life Cycle Assessment Tool for Environmental and Economic Effects (PaLATE) • Materials, design parameters, equipment, maintenance and cost inputs • Provides full life cycle costs and environmental assessment. • Macro-scale analysis based on Dept of Commerce census data • Provides estimates of life cycle air emissions, contaminant releases, water and energy consumption and cancerous and non-cancerous human toxicity potentials • Provides estimates of difference in impact due to transportation distance or different type of construction materials (virgin vs recycled) 5

5. Case Study 1 • NH DOT Construction Project in central NH • Portion of project will utilize rubblization of an existing concrete roadway • Investigate alternative materials and compare life-cycle costs and life cycle impacts (environmental effects) • Data from DOT engineers put into PaLATE – small investment in time.

6. NH DOT Case Study • Initial Construction • Option 1 • Mill off the existing Pavement • Rubblize (Recycle) Concrete / Cover with (Recycled) Pavement Millings • Widen with Virgin Materials • Pave with 3.5” on New Hot Mix Asphalt • Option 2 • Remove Concrete Slab and landfill • Construct 12” of Gravel & Crushed Gravel full width • Pave with 5.5” of New Hot Mix Asphalt

7. NH DOT Case Study (cont) • Maintenance Option 1 • Years 4 & 8: Crack Seal • Year 12: Resurface – 1” Wearing Course • Years 16 & 20: Crack Seal • Year 24: Resurface – 1” Wearing Course • Maintenance Option 2 • Year 1-11: nothing • Year 12: Hot In-Place Recycling (HIPR) • Year 13-23: nothing • Year 24: HIPR

8. Life Cycle Costs: NH DOT Case Study virgin virgin Recycled Recycled virgin Recycled • Initial Construction cost for rubblization is about half that of using virgin materials • Maintenance cost of crack sealing & resurfacing is about twice that of HIPR

9. University of Wisconsin Pilot Scale project located in Lodi, WI Roadway description: 305 m length 10.4 m width pavement 13.4 m width base & sub-base Materials: Bottom ash Control – crushed rock Legend Case Study 2: Wisconsin Bottom Ash Control 125 mm AC 125 mm AC Lysimeter 115 mm Crushed Aggregate Base 115 mm Crushed Aggregate Base 140 mm Salvaged Asphalt Base 140 mm Salvaged Asphalt Base 600 mm Bottom Ash Subbase 840+ mm Excavated Rock or Subbase Subgrade Subgrade

10. Scenario (2) • Lysimeters underneath test sections collect leachate generated. • Groundwater – 5 m below sub-base • Soil composition of site: silty-loam (USGS reports) • Material source distances • 50 mi • 100 mi • Contaminants analyzed: Cd, Cr, Se, Ag

11. PaLATE Results (2) • Impact ratio = or <1 for all impact categories, except HTP Cancer • HTP Cancer – human toxicity potential due to cancer • HTP Cancer – Impact from bottom ash is higher than impact from crushed rock • Transportation factor: • For all impact categories, except SO2, transportation distance affects impact • NOX and HTP non-cancer, most affected by transportation distance.

12. Modeling Tools (2) • Hydrus 2D • Finite element modeling program for simulating movement of water, heat, and multiple solutes in variably saturated media. • Predicts local scale transport of contaminants from recycled materials to groundwater over several hundred years.

13. Hydrus 2D Results • Hydrus 2D simulation for transport of Cr from bottom ash in road sub-base to groundwater (5 meter below recycled materials layer) over 200 years. • Assumes constant influx of contaminant into system

14. Hydrus 2D Results (2) • Hydrus 2D simulation for transport of Se from bottom ash in road sub-base to groundwater (5 meter below recycled materials layer) over 200 years • Assumes constant influx of contaminant into system

15. Hydrus Results (2) • Leaching potential for Wisconsin roadway is higher than published leaching studies and for Cd, higher than MCL • PaLATE results based on Morse et al (2001) data – SPLP test results • Hydrus2D predictions based on UWisc data • PaLATE used material’s potential leaching quantities in HTP cancer predictions • Quantities reaching groundwater are significantly less than MCL – as predicted by Hydrus2D

16. Case Study Scenario (Pittsburgh) • Divided PA DOT PGH region into 20 blocks. • Identified highest road density locations. • Sourced aggregate from virgin locations currently approved or IBPs from their location of generation. • Analyzed life cycle impact from aggregates (virgin vs. industrial byproducts) Aside: we are developing a GIS-based tool that will enable users to view recycled materials sources on Google Earth with data layers (material type, amounts, location, contact information, etc.).

17. Embodied Energy in Road (from aggregate only!) Text Note: none of the analyses presented consider impacts associated with separate disposal/management of industrial byproducts (that analysis is forthcoming).

18. Impacts (person equivalents)

19. Hey Pittsburgh: Want to save $3 million?

20. In Summary • We can use recycled materials to help the Earth AND save money at the same time. • There is still research and outreach work that needs to be done. • What to do you think needs our attention? • RMRC & pooled fund study can be used to leverage research and outreach.