By Anne Broache

As you may have seen on this blog before, we are all about finding ways to reduce how much waste our projects send to landfills—both to leave our environment better than we found it and to save taxpayers money.

Fully intact, the house makes its move across the street toward its new location.

But usually we’re talking about practices like reusing soil and recycling concrete during highway construction. That’s why the scene atop Renton’s Talbot Hill neighborhood on a recent Tuesday morning was a bit unusual.

At a bend in Davis Avenue South overlooking downtown Renton and Lake Washington, an entire 3,300-square-foot house rested on steel beams and sets of wheels in its original lot. Over the course of a day, a small contractor crew used a winch and pulley system to roll the two-story structure to a vacant lot across the street.

Our agency bought the home and lot last year to prepare for an important road project for the area (more on that below). Often, when we purchase property, the most cost-effective next step is to demolish and remove whatever buildings remain.

A few hours after beginning its slow move, the structure has almost reached its final resting spot.

In this case, however, we emphasized the need for recycling when seeking demolition contractors. As a result, the winning contractor found a way to reuse and relocate most of the house—at a price nearly 90 percent less than what we had budgeted.  Bottom line: The house is no longer in the way of our project, and the contractor can now finish readying the house for new residents.

We’re excited that we secured not only an affordable bid but also a green one—recycling at its best. We eliminated potential waste from tearing down the house, erased the emissions and fuel usage that would have occurred as haul trucks made numerous trips through Renton neighborhoods, and prevented the need for construction materials to build a new home on the vacant lot.

Making way for traffic improvements 

The property is one of several ongoing acquisitions related to the I-405/SR 167 Direct Connector project.

This visualization shows a planned new flyover ramp to connect the SR 167 HOT lanes with the I-405 carpool lanes.

We plan to improve traffic flow and safety by building a new flyover ramp that connects the High Occupancy Toll (HOT) lanes on SR 167 with the carpool lanes on Interstate 405. We don’t have funding for construction yet, but we’re moving forward with property purchases and design so that we’re ready to start building once funding is in place.

If you’d like to learn more and follow our progress, be sure to bookmark the I-405/SR 167 Interchange Direct Connector Project webpage.

By guest blogger Chelsey Funis from Flatiron Construction

The I-405 Bellevue to Lynnwood project reuses soil moved from other parts of the project area to build retaining walls, shown above, and sections of new roadway.

Most of us follow that old mantra of Reduce, Reuse, Recycle without a second thought everyday, whether we’re recycling our used aluminum cans or bringing our reusable grocery bags to the grocery store. But did you know that crews building the latest batch of I-405 improvements are also following that mantra? 

As part of the I-405 NE 6th Street to I-5 Widening and Express Toll Lanes Project, our crews and contractor, Flatiron Constructors, are using a number of sustainable practices to build a better project for our environment and taxpayers. In this case, going green also helps us save a little green. And who doesn’t like that?

So what are we doing to reduce our carbon footprint?

To reduce impacts on nearby aquatic resources, project crews have built three mitigation sites. Improvements completed this October in Kirkland, shown above, include new trees, plantings, rocks and drainage pipes.

Recycling soil and fill material excavated from the 17-mile project site
Major construction projects typically truck in thousands of cubic yards of soil, crushed rock and other organic materials from off-site locations. Using a little creativity, we were able to design the I-405 project and schedule the construction in a way that recycles tested and approved soil and earthen fill material directly from the project site. We then use the recycled soil and fill material in other places on the job. For example, we’re building two retaining walls and a noise berm in Kirkland by reusing earthen material dug up from the footprint of a new northbound I-405 on-ramp in Bothell and other locations throughout the project area.

By reusing soil on site instead of disposing it off-site and buying new material, our crews:

• Cut back on heavy trucking at longer distances.
• Save fuel and decrease carbon emissions.
• Prevent damage to our roads.
• Reduce the cost and space used at off-site disposal locations.

Because we’re recycling and reusing soil and fill materials, we’ve also eliminated about 300,000 cubic yards of excavation. To put things into perspective, that’s enough soil to build a pile nearly 136 feet tall onto a football field – or nearly two-thirds of the way up to CenturyLink Field’s roof, which rises about 200 feet above the ground. In addition, our commitment to reusing 100 percent of the remaining excess material on site will result in a 2,100-ton reduction of greenhouse gas emissions over the life of the project. That’s the equivalent of a little more than 4,000 cars’ annual greenhouse gas emissions.

Recycling demolished concrete structures
We’re removing  many concrete structures, such as roadway barriers, so that they can be updated to current standards. For this project, crews haul all of this rubble to local recycling facilities that process and repurpose the steel and concrete for other local projects.

Recycling old asphalt pavement
We’re also removing existing asphalt pavement that is past its service life. Crews are grinding and breaking the removed asphalt to build temporary access roads and embankments, as well as reprocessing it back into new asphalt for this and other local projects.

Installing bioswales: smarter drainage ditches
Urban stormwater – the rain and snow melt that runs off surfaces like rooftops, sidewalks, paved streets, highways and parking lots – is one of the biggest environmental threats to the Puget Sound region. Left untreated, stormwater runoff can carry pollutants like oil, fertilizers and pesticides into our waterways, harming creeks, streams and rivers that provide important habitat for fish and wildlife.

Cleaning pollutants from this water and reducing the rate of runoff is a critical component to the Bellevue to Lynnwood project in order to help protect the many nearby wetlands.

To clean pollutants and control the rate of runoff, this project will construct:

• Eight new or enlarged standard treatment and detention ponds.
• 3,550 linear feet  (more than half a mile) of biofiltration swales, also known as bioswales, which help capture and treat stormwater by filtering the water through vegetated channels comprised of organic materials like grass and shrubs. 
• 11,200 linear feet, or more than two miles, of new media filter drains, which we construct along the highway shoulder area. The media filter drains consist of a no-vegetation zone, a grass strip and a mix of native vegetation. These pollutant filters are great for where there is limited space.

Want more information?

• Visit the project Web page.
• Sign up online to receive email alerts about closures and construction activities.