Georgetown Wet Weather Treatment Station – making construction sustainable


the Georgetown wet weather treatment station is being built right in the heart of Georgetown this treatment station will collect and clean up to 70 million gallons per day of wastewater and stormwater that would have spilled into the Duwamish River in heavy rains King County wanted construction to be just as sustainable as the new facility will be the first step in a large construction project may be removing what’s already on site which could include existing buildings contaminated soils or other materials and preparing the site for construction of our facility King County is memorialized our commitment to green or sustainable building this commitment continues all the way from planning through construction to operations and maintenance within the wastewater treatment division the whole project team contributes ideas to what we refer to as a sustainable scorecard this scorecard helps us to track activities and progress towards our goals in addition the county strategic climate action plan has targets for zero waste of resources with economic value by the year 2030 for this project we set a goal of an 85 percent diversion rate so we want to divert 85 percent of the wastes from construction and demolition from landfill disposal we look for ways to recycle and reuse materials and we track what we’re diverting to see how it best meets our goals on the Georgetown project site we needed to tear down five buildings and remove concrete surfaces and underground equipment the buildings and concrete allowed us opportunities to recycle but also presented some challenges with lead painted surfaces and contaminated soils from past activities on this project we’re doing the demolition remediation phase I call it the site prep phase so we demolished five buildings we removed about seven thousand tons of contaminated soil and when we’re all done we will be capping the site with four inches of erosion control Rock we’ve been in business for a little over ten years demolition remediation is always in part of our business model the diversion goals have definitely gotten a lot loftier in years some of them of and easily achievable depending on the composition of the project and some have been a lot more challenging to achieve project we were able to achieve upwards of 90 percent a lot of that came from salvage of old-growth Timbers I old-growth timbers or something that just aren’t made anymore so it’s a rare commodity and there’s only so much bit to go around some things that can typically be reused on site is the concrete you can crush on-site and uses recycled aggregate what was clean was hauled off site to be recycled and then recycled concrete was brought in for backfill sustainable building is not just saving cost but it’s also looking at our impacts at community and trying to minimize that with the types of materials on site we needed to keep water runoff and dust under control environmental regulations are going to continue to become more stringent especially in terms of air quality and surface water impacts so the biggest thing is water you got to keep everything wet keep everything from getting airborne in the first place this job in particular we had great success with keeping everything wet we had a very dry summer so dust control was challenging all the way around but we were real successful in using our engineering controls to limit any impact at the community our contractors worked very hard and was very successful maintaining these controls during demolition you know I think this project King County did an above average job at the pre-planning phase and also planning for community impacts they have a whole team dedicated to community outreach and I think that that pre-planning speaks for itself this is a very successful project sustainable building helps lower our long term operations and maintenance costs which results in savings to our ratepayers King County’s Green Building ordinance ensures that we’re working toward our goals