Perspectives on Water Resources Engineering: Taylor Dayton in the Zweig Newsletter

Taylor Dayton, Project Engineer

Taylor Dayton, Project Engineer

Aspect’s Taylor Dayton was recently interviewed in the Zweig Newsletter on a range of topics — from transitioning from working at NASA as a biochemist to an engineer, to learning water rights legends, project management lessons learned, and navigating an early career in the water resources field.

Read about it here: Apple orchards and water rights

Reducing Washington State Drought Impacts in the Okanogan River Basin

In both the northern reaches, high desert region, and even the Olympic Peninsula—literally one of the wettest places in the lower 48 states historically—summer 2019 is a serious drought year in Washington State. Earlier this spring, the governor declared a drought emergency, which was able to unlock emergency relief options and funding for 27 watersheds across the entire state. In the Methow, Okanogan, and upper Yakima River watersheds, it’s particularly bad. Based on current forecasting, the Okanogan is expected to be at 58 percent of normal, and curtailment notification letters have already been sent to local water users. However, this drastic forecast has prompted forward thinking. 

In partnership with the Washington State Department of Ecology (Ecology), the Oroville-Tonasket Irrigation District (OTID) has developed a “water bank” in the Okanogan River basin to help regional water users impacted by the drought. The water bank will be used to support instream flows and to assist “junior” water users during periods of curtailment. OTID is seeding the bank with two of its senior water rights. In 2018, Ecology, with assistance from Aspect, certified these water rights through the state’s Certified Water Right Examiner process. 

Ecology is working to complete the required permitting to place the water rights in the state’s Trust Water Right Program (TWRP) to create the water bank (read more about water banks on Ecology’s website). This water bank will be seeded with about 7,500 acre feet of water, which will be made available for drought relief. From this bank, eligible water users can “withdraw” water for both irrigation and municipal or domestic uses.

 More information can be found at the following website:

https://www.aspectconsulting.com/otidwaterbank

Waiting for Water - the Columbia Basin Project

Aspect works routinely with clients suffering from declining groundwater supplies. From conservation and planning projects to aquifer storage and recovery (ASR) projects, Aspect is at the forefront of this issue. ASR projects in Othello and White Salmon are underway now that will assist in long-term certainty for public water supplies in the future. In agriculture, we are partnering with Washington State University to forecast how declining water supplies will affect commercial crop reliability and assessing the conservation, storage, and water marketing tools that exist both locally and regionally to assist them. One of the largest declining groundwater areas in the state is in the Columbia Basin.

This video “Waiting for Water – The Columbia Basin Project” produced by the Columbia Basin Development League is a great introduction into the complexities of these issues for farmers in Washington. Aspect staff assisted in the permitting and environmental review for this project.

A Peek Inside Washington State's Draft Industrial Stormwater General Permit

Stormwater discharges from over 1,200 industrial facilities are covered under Washington’s Industrial Stormwater General Permit (ISGP). The goal of the ISGP is to reduce the discharge of pollutants by improving management of stormwater at industrial sites. It originates from a combination of federal (the Clean Water Act) and Washington state (Water Pollution Control Act) law. Under the ISGP, permittees are required to implement Best Management Practices to reduce stormwater pollution, monitor their stormwater discharges, compare the results with benchmark values, and implement an escalating series of corrective actions depending on the number of times the benchmarks are exceeded. The current permit has brought compliance challenges, including expensive stormwater treatment systems and citizen law suits, to many permittees.

On May 1, 2019, the Washington State Department of Ecology (Ecology) published a draft of the next ISGP for public comment. Owen Reese, PE, Aspect’s stormwater practice lead, offers this synopsis:

What Won’t Change

Many of the key permit provisions will not change. The five core water quality benchmarks—turbidity, pH, oil sheen, copper and zinc—remain the same, and the requirements and deadlines for implementing corrective actions if those benchmarks are exceeded remain unchanged.

Proposed Changes

Increasing Focus on Infiltration to Groundwater – The most significant proposed changes relate to discharges to groundwater. Ecology is proposing changes to groundwater-related provisions that leave the impression that they intend to increasingly regulate infiltration of stormwater under the ISGP. This sets Ecology on a divergent course from the US Environmental Protection Agency (EPA), who recently issued an interpretative statement that discharges to groundwater are categorically excluded from the permitting requirements of the Clean Water Act. The interpretative statement does not apply to Washington and other states in the 4th and 9th Districts while Hawai’i Wildlife Fund v. County of Maui is pending before the Supreme Court. 

Ecology has also struck language from the permit in several locations, including key groundwater-related provisions, without identifying it as a change—which could be problematic for reviewers.

Adding Two New Industries – Ecology proposes to add two new industries to ISGP coverage: marine construction and certain heavy equipment rentals. Neither of these industries are currently required to have NPDES coverage for stormwater discharges under the Clean Water Act. What activities qualify as “marine construction” can also be challenging to define as it does not fall within easily definable Standard Industrial Classification (SIC) or North American Industry Classification System (NAISC) code, and Ecology confounds this issue by not including the definition of marine construction in the draft ISGP.

Identifying Industries by NAICS Codes – Ecology proposes to identify industries that require ISGP coverage by NAICS code, instead of SIC code. The Clean Water Act remains based on SIC codes, and there is a not a one-to-one relationship between the two codes. As a result, Ecology’s translation of SIC codes to NAICS appears to have included, perhaps inadvertently, several business sectors that previously did not require permit coverage, such as:

  • Miniwarehouses and Self-Storage Units (NAICS 531130)

  • Scenic and Site Seeing Transportation (NAICS 487990)

  • Commercial Air and Rail Equipment Rental (NAICS 532411)

Puget Sound Sediment Cleanup Sites – Ecology has re-upped the requirements that permittees discharging to a Puget Sound Sediment Cleanup site (such as the Duwamish, Elliott Bay, Commencement Bay, Port Gardner Bay, or Bellingham Bay) will need to sample stormwater sediments and clean their pipes at least once in the next 5-year permit cycle. It was not clear in the prior permit that these would be recurring obligations.

Annual Sampling to Confirm Consistent Attainment – Under the draft permit language, facilities that have achieved consistent attainment by meeting water quality benchmarks would be required to collect one sample per year (in the fourth quarter). Any exceedance of a benchmark would bump the facility out of consistent attainment and require resuming quarterly sampling.

Sampling First Fall Storm Earlier – Ecology proposes to shift the requirement to sample the first flush a month earlier, to beginning September 1 of each year. We’ll likely see more third quarter benchmark exceedances as a result, as there are fewer summer storms to sample to average with the first flush.

What the Proposed Changes Could Mean

Although ostensibly aimed at providing clarity, the revisions incorporated into draft ISGP actually increase the opportunity for confusion. If the draft ISGP language is implemented, we may see more citizen suits, particularly related to the use of NAICS codes and stormwater discharges to groundwater. Ecology could remedy some of these concerns by clearly identifying which provisions of the ISGP are based in federal law, and which originate at the state level.

Comments on the draft permit are due on June 29 and can be submitted online at: http://ws.ecology.commentinput.com/?id=k3Zx2. Ecology is also hosting three more public hearings where comments can be given in person:  

Contact Owen Reese at 206-838-5844 or oreese@aspectconsulting.com with any questions on the proposed changes and implications.

Aspect personnel collecting a sediment sample at an industrial site.

Aspect personnel collecting a sediment sample at an industrial site.

Bellingham's Waypoint Park Wins Local and National Awards

Waypoint Park touts a playground, a pier, access to the beach along the Whatcom Waterway, and now, several awards. The project recently won the American Shore and Beach Preservation Association (ASBPA)’s award for Best Restored Beach in the U.S.; and the American Society of Civil Engineers (ASCE) Seattle Section’s 2019 Local Outstanding Civil Engineering Achievement Award.

The park sits upon the site of a former Georgia-Pacific pulp mill. Aspect was a part of the team that spent seven years cleaning up the contaminated industrial area and providing geotechnical and environmental consultation throughout the design, permitting, and construction. It opened to the public last summer, and there are more redevelopment projects planned in the vicinity to continue the transformation along Bellingham’s waterfront.

Congratulations to the City and Port of Bellingham, prime firm KPFF, and the whole project team for your award-winning vision and work for this project!

Aspect’s Principal Geotechnical Engineer Erik Andersen strolls amongst the bubbles during the Waypoint Park opening celebration last summer. He developed foundations recommendations for the repurposed 400,000-pound industrial acid ball tank turned public art piece titled “Waypoint.”

Aspect’s Principal Geotechnical Engineer Erik Andersen strolls amongst the bubbles during the Waypoint Park opening celebration last summer. He developed foundations recommendations for the repurposed 400,000-pound industrial acid ball tank turned public art piece titled “Waypoint.”

Dave Cook Discusses Consent Decrees, Cleanup and Ecology’s Healthy Housing Program for Contaminated Sites at the WA Brownfields Conference on May 30, 2019

On May 30, Aspect’s Dave Cook will co-present on affordable housing development from the environmental consulting perspective at the Washington State Brownfields Conference in Spokane.

Brownfield properties represent opportunity. Dave will talk about innovative ways to turn blighted property into affordable/work force housing. Aspect’s first-of-its-kind work on the Mt Baker Housing Association’s Gateway project in the Mt Baker/Rainier Valley neighborhood in Seattle has become an example of what is possible. Mt Baker Housing Association (MBHA), as a non-profit, took on a significantly contaminated site to redevelop as affordable housing where the cost of the cleanup is more than the value of the five properties combined. Dave will join Scott O’Dowd of Ecology, Conor Hansen of MBHA and Mike Dunning of Perkins Coie to describe how these properties were purchased, investigated, liability managed, and the cleanup financed—all keys that made this pioneering project successful and sparking the State’s new Healthy Housing program .

Contact Dave (206.838.5837 and dcook@aspectconsulting.com), or learn more about prospective purchaser consent decrees, funding, and redeveloping contaminated land for affordable housing at https://www.aspectconsulting.com/affordablehousing


Aspect Talks Reclaimed Water, ASR, and Walla Walla Basin at 2019 AWWA

2019_conference_logo.jpg

Andrew Austreng, Jon Turk, and John Warinner will be presenting Thursday and Friday May 2 and 3rd at the American Water Works Association (AWWA) ‘River Runs Through It’ 2019 Section Conference in Vancouver, WA. Andrew will present on the Othello, WA Aquifer Storage and Recovery project; Jon Turn will showcase groundwater recharge strategies for a unique project involving reclaimed water in Kitsap County; and John Warinner will discuss challenges and opportunities of managing groundwater across two state lines in the Walla Walla subbasin.

The annual AWWA conference is one of the largest conferences for water professionals in the Pacific Northwest.

New GIS Tool Helps Remove Barriers to Salmon Habitat Connectivity

Clean, cold water. Lush riparian vegetation. Gravels for spawning. These are some of the elements that create healthy habitat for salmon. The Upper Columbia region has some of the best in the Pacific Northwest. Unfortunately, not all of this habitat is within the salmon’s reach. Removing barriers such as culverts and dams is a top priority for salmon recovery goals, but there are thousands of barriers, limited resources to remove them, and a diverse group of stakeholders with issues to address. What everyone wants to know first is: how do we decide WHICH barriers to remove?

Instream barriers such as culverts like this can limit fish passage to available habitat.

Enter a New Tool for Fish Habitat Decision Making

In partnership with the Cascade Columbia Fisheries Enhancement Group, the Upper Columbia Salmon Recovery Board, the Upper Columbia Regional Technical Team (RTT), and a technical steering committee, Aspect created a GIS-based decision support tool that summarizes the overall quality of ecological conditions surrounding each instream barrier within the Wenatchee Basin. This custom spatial model provides insight into critical questions regarding barrier-removal priority:

  • Is there habitat available upstream from the barrier that salmon currently cannot access?

  • Is that available habitat of sufficient quality for salmon?

  • Is there known fish usage near the barrier already?

  • Are there barriers downstream blocking fish access?

This prioritization tool provides salmon-recovery stakeholders with a common approach to answer these questions. The variables under consideration at a barrier—upstream habitat quality, local stream temperature, connectivity to other barriers, etc.—each receive a score. Those scores are then added up to a total priority tier ranking for that barrier. By assessing each barrier through this scoring process, we’ve created an actionable apples-to-apples comparison of habitat benefits associated with barrier removal.

A preview of barrier removal ranking priority data.

A preview of barrier removal ranking priority data.

A Tier 1 ranking indicates the top priority for removal, indicating more biological benefit gained from a barrier’s removal. Tier 4 ranking is the lowest priority ranking, indicating little biological benefit gained from a barrier’s removal. UCSRB and the RTT use these categories to guide decisions on proposed project funding. The rankings are updated as available data sources improve.  Preview the results HERE. This tool will allow stakeholders to align and coordinate their barrier removal work towards the larger common goal of salmon-habitat connectivity within the Upper Columbia and throughout the state.

If interested in adapting this tool for your project and/or basin(s), contact Robyn Pepin for more information.

ETA (6/3/2019): Robyn Pepin and Taylor Rulien’s poster for this GIS tool won best analytical data presentation at 2019’s WAURISA Conference. Check it out here.

Removing Barriers to Fish Passage at Icicle Creek

Like many of Washington’s waterways, Icicle Creek in Chelan County is the site of several projects with the goal of helping salmon and other fish make their way upstream to spawn. Many of the projects involve constructing structures, like a habitat-friendly culvert or a fish ladder, to balance fish passage with the many other needs and uses for the river. But a project sponsored by Trout Unlimited is focused on removing barriers—in this case, large boulders in the creek that stand in the fish’s way. Once the boulders are removed, fish will have access to another 26 miles of habitat.

This project is one of a suite of projects the recently released Icicle Programmatic Environmental Impact Statement (PEIS) recommends in the Preferred Alternative to implement the Icicle Strategy, an $82 million dollar effort to ensure a sustainable water supply and water resources for people, farms, and fish in the Wenatchee Basin through 2050. Aspect has been the technical and facilitation lead on this project since 2012. Our work includes serving the Icicle Work Group—a group of approximately 30 stakeholders from local, state, and federal governments, Tribes, irrigation districts, farmers, and non-profit groups that created the Icicle Strategy; developing the PEIS; and leading technical evaluation of proposed projects across the basin that may improve water resource management and increase instream flow during critical flow periods.

Senior Geotechnical Engineer Nick Szot, PE, and Senior Engineering Geologist Mark Swank, LEG, are supporting Trout Unlimited’s goals for the Icicle Creek project by developing alternatives for fish passage and relocation of a 16-inch-diameter watermain that brings water to the City of Leavenworth. They have also provided considerations for protecting creek bank slope stability during construction, which is expected to start in summer 2020.  Learn more about the project in this recent article in the Wenatchee World.

MTCA Turns 30

Happy 30th Birthday to the Model Toxics Control Act (MTCA)­—Washington’s citizen-led law put in place to help cleanup over 7,000 sites statewide. Those thousands of cleaned up sites have led to a cleaner environment, better human health, and thriving communities. The interpretation or implementation of it has had some bumps and difficulties, but on balance MTCA has been very beneficial to the common good and, as the video discusses, an example nationally of a successful cleanup process. As a firm that helps clients interpret and cleanup sites, Aspect is proud to be a part of its effect on all of us.

Checkout Ecology’s short video for the history and highlights of this important and innovative law.

Learn about the history of Washington's citizen-led environmental cleanup law - the Model Toxics Control Act. This innovative law powers our work to investigate, clean up, and prevent hazardous waste.

Talking Field Data Collection at 2019 OCEAN Connect Conference on April 11

Over the past decade or two, technological advancements have presented opportunities to streamline field data collection. However, migrating field staff to a paperless workflow requires more than choosing the right software and hardware.

On April 11, Aspect’s John Warinner and Robyn Pepin will cover this topic and give tips on how to effectively convert field data collection from paper to digital process at the 2018 Oregon Conservation Education and Assistance Network (OCEAN) Connect Conference in Sunriver, Oregon.

Key areas of the presentation will include:

  • Overview of commercial off-the-shelf software and reporting systems

  • Case studies and lessons learned by Aspect’s field and data teams

  • Successful talking points to convince decision makers

See good field techniques and analysis put into practice, with some mountain biking thrown in for good measure here:

It's IPAD Mini vs. Trimble GPS in a mapmaking showdown on the sunny trails of the Chelan-Douglas Land Trust in the Wenatchee Valley.

And read more about our experience with how one suite of field data technology has improved our workflow.


The State’s Longest-Running Water Rights Adjudication is Coming to an End

In 1977, James J. Acquavella’s name was listed first on the summons when Ecology filed a petition for an adjudication to determine the legality of all claims for surface water in the Yakima River Basin – birthing the Ecology v. James Acquvella, et al water rights case. Forty-two years and 2,500 claimants and interested parties later, it is coming to a close. Some takeaways for this milestone moment in Washington state water management are:

  • Starting in 1977, the Department of Ecology v. Acquavella adjudication is the longest-running general adjudication in state history, determining the validity and establishing priority of surface water claims in the Yakima Basin.

  • With the issuance of the Final Decree by Yakima County Superior Court, water right holders in the Yakima Basin will finally have certainty over the authorized quantities and purposes and places of use of their water right claims.

  • Adjudicated water right certificates will be issued by Ecology for all claims determined by the Court to be valid; water right holders will no longer need to get approval of the Court to complete a change or transfer a water right, but instead file applications with Ecology like everywhere else in the State.

  • During the adjudication, stakeholders in the Yakima Basin continued to lead the state in providing innovative approaches to water resource management challenges, including early adoption of water banking and mitigation markets to ease permitting of new water rights, and development and implementation of the Yakima Basin Integrated Plan.

Aspect has worked on a variety of Aquavella claims over the decades – including hundreds of due diligence water right evaluations; helping buyers/sellers move and change these rights; and developing water banks through the State’s Trust Water Right Program to support efficient transfer of existing rights and permitting of new, mitigated water rights.

Read the fascinating tale of water management in the Yakima River Basin and the implications of this ruling in this great Department of Ecology blog post.

See what else Aspect’s Water Resources practice has been up to.

Helping Power Seattle's Tech Sector

Seattle City Light is about to unveil its new state-of-the-art substation that will transition this South Lake Union site from a Greyhound bus maintenance facility and parking lot into an “architectural marvel.” From property acquisition and contaminant remediation through design and construction, Aspect completed a full range of environmental and geotechnical services to support the redevelopment of a sleek electrical substation wedged in the heart of Seattle’s tech sector.

Check out this great Seattle Times article on the new substation and peruse some photos of the truly impressive facility.

A Thousand Photos to Better Storytelling: The Aspect Photo Contest

In the earth science consulting world, our work is innately photogenic. Stream gauging at a quiet bend in the river. Installing new pin piles at a pier on a scenic city waterfront. Even the “grimy” photos, like well sampling at a contaminated site, provoke interest and fascination. Staff take pictures to document their technical work and those same photos are the lifeblood of firm branding and storytelling. However, Aspect’s marketing team, tasked with telling our firm’s story, can struggle with harvesting high-quality visuals. The photos are out there, yet they may be buried in forgotten file locations or staff’s work phones. Just asking “Have you got any good pictures?” yields scattershot results, which often then means reusing the same tired photos again and again.

So, a year ago, our marketing group decided that we needed a better way to consistently draw out quality photos. What better incentive than a friendly contest?

I love it, it gives me glimpse to what our field people are up to, since I am in the office 100% of the time and not a field person, I envy them the fun they have when in gorgeous location in beautiful weather and not so much when they are bundled in the snow and rain.

- Mirka Ramsey, Accounting Lead

The Idea: Prizes and Public Recognition

We started with a weekly raffle, awarding tickets to all contributors and bonus tickets for the week’s best photos – all leading up to a cash prize drawing and winners that we celebrated at quarterly firm-wide meetings. After the first call for entries, staff responded with 54 pictures. Where had these all been hiding?

If we had only received those first 50 photos, that would have been a modest success. However, we were surprised and amazed that the photos kept coming week after week. We knew we had something special when, at the first quarter’s staff meeting, the photo contest became a highlight. It turned the meeting into an informal art exhibit, where the employees and their beautiful, funny, and, often times, poetic snapshots of field and office life were the stars of the show. The idea continued to gather steam and, by the end of the year, we’d received over 1,100 photos.

It’s awesome! I love seeing the work that other folks are doing. I think it improves our company culture: gives us something to talk about with staff we might not interact with otherwise, and also gives me a better sense of pride in some of the work that I’m doing when I share my photos.

- Hannah McDonough, Staff Geologist

The Takeaways

One thousand photos later, if there’s one general takeaway, it’s that being curious and asking staff what they are working on—and learning what they’re excited about—is always worthwhile. The photos gave our marketing team materials to help tell Aspect’s story, but also delivered an unexpected benefit: they shone a light on firm culture. Over the photo contest’s first year, we found that:

The field staff’s photos remind everyone of the aesthetics of working in environmental consulting – they are outdoors a lot in both beautiful settings and grimy conditions. It’s a way to appreciate the beauty and commiserate when things are grim.

It’s not just about the projects. We got many photos of what staff are doing outside of work –biking trails, climbing mountains, running races, vacationing in places sunnier than the Pacific Northwest.

Sharing our work brings staff of all levels together around firm culture and put names to faces before people may have met in person.

Aspect staff are now in the field, at industry functions, or just in the office, with an eye out for photo opportunities.

Submitting on a regular basis helps keep taking photos in the front of my mind so I have more photos of my projects which helps when putting together reports. I enjoy seeing others as it gives insight into what the rest of the company is up to. I often get a sense of a “can-do” attitude mixed with people enjoying what they are doing.

- Bryan Berkompas, Senior Hydrologist

A Hub for Storytelling

As the photo contest enters Year Two, the marketing team now has an established source of photos to illustrate our work in proposals and spotlight our culture for recruiting. Field staff have told us that taking photos helps them with their project work and report writing. And everyone enjoys seeing what our colleagues are up to and takes pride in our collective work.

Follow our photographers on Aspect’s Instagram page.

Meet Daniel Babcock!

Staff Scientist Daniel Babcock recently joined Aspect’s Seattle office. Here are five questions we asked to get to know him better.

Daniel Babcock - Staff Scientist

Daniel Babcock in Farmington, New Mexico

Daniel Babcock in Farmington, New Mexico

  1. Where are you from? If you’re not from the Pacific Northwest, what brought you here?

    I was born in Wichita, Kansas and had lived there my whole life up until now. After living in a place with no trees or mountains for 26 years, my wife and I decided it was time for a change of scenery! Western Washington satisfied everything we were looking for in a new home i.e., opportunities, mountains, trees, and multiple Chipotle locations.

  2. What inspired you to pursue environmental science What made you curious about it?

    My background is in Geology and I fell in love with learning about the natural word—I also knew I didn’t want to work behind a computer 24/7. It seems to have worked out perfectly that I was able to find a career that allows me to combine my love for science while allowing me to work both in and outdoors.

  3. What do you like best about your area of expertise? What excites you and keeps you motivated?

    At the end of the day, it is rewarding work. There is a sense of pride that goes along with being part of a team that remediates sites and knowing that you contributed to that. It is work that feels bigger than yourself.

  4. What do you like to do when you aren’t working?

    I enjoy most things outdoors—hiking, backpacking, mountain climbing, camping, kayaking, downhill mountain Elk riding…well maybe one of those isn’t a real activity… yet. But, I also enjoy playing a few instruments like the guitar, bass, and ukulele.

  5. Where in the world would you like to travel next?

    It may not sound as cool as saying Paris or Australia but, I have always wanted to visit the New England area of the United States. I love history, and as far as the USA goes, there is a lot of history out there and I have never been out east before. So, Vermont, New Hampshire, Maine, and Massachusetts are high on my list.

From Brownfields to 500 Units of Affordable Housing – Aspect in the News

The Daily Journal of Commerce takes a look inside Mt. Baker Housing Association’s pioneering affordable housing work in South Seattle. Aspect, overseeing the environmental effort for the MBHA team, continues to drive the idea of brownfield sites as unique opportunities for affordable housing – including the 160+ unit Maddux project and the 350+ unit Grand Street Commons project.

READ HERE

Learn more: www.aspectconsulting.com/affordablehousing

The $82 Million Icicle Creek Subbasin Watershed Plan Hits a Milestone

This Seattle Times article provides an in-depth look at the complex mix of aging alpine dams, world-renowned wilderness area, and the potential of changing climate patterns in the Icicle Creek Subbasin. The spotlight’s on this North Central Washington region as the 6+ year Icicle Creek Subbasin strategy hit a recent milestone with the release of the project’s Programmatic Environmental Impact Statement.

Since 2012, Aspect has been the facilitation and technical lead for this effort, serving a broad working group of city and county agencies, tribes, fisheries, irrigators, and the community. The overall program is designed to improve instream flows, assist in agricultural sustainability, and provide for local domestic growth beyond the year 2050 at an investment of $82 million over the next 10 years.

Tales from Bertha: Till, Fill, and Dewatering

As Seattle weathers the close of one historic stretch of Highway 99 and awaits the opening of a brand new one (at the time, the largest soft-ground tunnel bore in the world), we’re recapping a tale that played out in connection to one of the more dramatic milestones of the tunneling project: Bertha gets stuck.

In December 2013, the mega tunnel boring machine known as Bertha overheated and broke down 1,000 feet into its journey. Eager to keep the project moving, crews working for Washington State Department of Transportation (WSDOT) quickly designed and excavated a deep rescue shaft to get in front of the stuck machine and repair it. It was a complicated effort to drill down to Bertha considering the unique geology and human history that has defined Seattle’s waterfront.

Peering into the 130-foot-deep rescue shaft. Photo credit: Seattle Times

How an Inch of Displacement Can Cause Trouble

Stabilizing the ground to create the 130-foot-deep shaft required a significant amount of dewatering [1] that had to be done quickly. This dewatering caused the surrounding soils to settle much more than was anticipated from the planned tunnel construction—the settlement reached over a wide half-mile radius, and about an inch in some places, and even more than that close to the shaft.

An inch may not seem like a lot, but for the underground maze of City of Seattle (City) utility infrastructure, including aging, brittle water and sewer lines (some over 100 years old), any additional settlement was problematic. This unforeseen settlement was enough to trigger an expedited program to assess and replace the utilities where risks were unacceptably high. The City, in need of expertise on local geology, hydrogeology, tunneling, and soil behavior, brought on Aspect to investigate problems resulting from the rescue shaft construction and help design repairs.

The aerial image of the Seattle waterfront shows locations of satellite radar altimetry points TRE Altamira used to measure precise changes in ground surface elevation from May 2014 through February 2015, which included the period of Bertha rescue shaft dewatering. The colors of the dots represent the cumulative change in elevation, with hot colors showing subsidence and cool showing uplift. The orange and red areas show the broad pattern of ground subsidence associated with the shaft dewatering. For more information on this technology, visit TRE Altamira.

Aspect’s role was four-fold: determine what parts of the City’s infrastructure were being most affected by the settlement; assess vulnerability of other areas further along the tunnel route; assist with geotechnical engineering recommendations for replacing infrastructure damaged by the settlement; and help the City understand the cause of the settlement.

Till + Fill + Development = Complex Subsurface Challenges

Our investigation started with an extensive review of the waterfront’s underlying geology. Deep beneath the City lies a complex history of multiple glacial advances and retreats, separated by long interglacial periods. Sediments from glaciations include tills, layers of glacial lake and marine silts and clays, and sheets of glacial outwash sand and gravel. These glacial soils are interbedded with floodplain silts and sands and gravelly channel deposits transported by rivers flowing from the surrounding mountains, including lahar deposits (large volcanic mudflows) from as far away as Mount Rainier.

These strata were deposited in more-or-less horizontal and generally orderly ways, then subsequently compressed and compacted by repeated advance of glacial ice sheets. In the Pioneer Square area, a present-day look at the resulting stratigraphy is, however, far from orderly, due to its setting within the Seattle fault zone. This zone of tectonic compression repeatedly ruptured during prehistoric earthquakes, and much of the strata are now sheared, tilted, overthrust, and truncated. All of this was then overlain by weak estuary, beach, and tide flat deposits—and then extensively modified by humans.

This map shows the rescue shaft – and the southern portion of the tunnel route – in or below what was formerly the beach and tide flats of Elliott Bay. Pioneer Square was a tidal marsh area. These areas were infilled over the century with sawmill wood waste and soil fill, making the ground throughout the (now) Pioneer Square area both geologically and historically complex. Map credit: Aspect

This map shows the rescue shaft – and the southern portion of the tunnel route – in or below what was formerly the beach and tide flats of Elliott Bay. Pioneer Square was a tidal marsh area. These areas were infilled over the century with sawmill wood waste and soil fill, making the ground throughout the (now) Pioneer Square area both geologically and historically complex. Map credit: Aspect

A major part of Aspect’s analysis focused on the location, thickness, and nature of the weak and shallow soils draped above the strong glacial soils, intertwined with the historical changes that occurred as Seattle developed its waterfront. The Pioneer Square area was a small upland Native Americans had lived on for millennia. Occidental Square was a shallow coastal lagoon, and most of the area south of King Street was tide flats. As timber and shipping industries flourished in the 1800s, much of the waterfront was developed with piers and trestle bridges, then filled with sawdust and wood waste from waterfront mills and soft muck sluiced from nearby hills.

On top of all that, roads, sewer lines, water lines, and buildings were constructed on the new ground. Not surprisingly, these weak fills have settled over time, resulting in bumpy roads, tilted sidewalks, and tall curbs in the Pioneer Square neighborhood. But these same soils were also highly susceptible to further consolidation when the water table was rapidly lowered by the Bertha rescue shaft dewatering.

Historical Record Sleuthing

To assess the areas of vulnerable underground utilities, we dug into the historical records—maps dating from the original land surveys of Seattle to locate the original shorelines, and previous drilling investigations going back decades to reveal the subsurface data. Aspect compiled soil records of hundreds of borings and wells to develop a database that could be mapped in three dimensions and used to identify the areas where weak soils were present. When combined with the City’s utility maps, Aspect’s weak-soils map allowed the City to easily spot areas where weak soils and vulnerable infrastructure overlapped.

Aspect also assisted the City in pursuing remote surface elevation surveying techniques including use of synthetic aperture radar (InSAR), a satellite-based radar distance measuring technique that permits detection of precise changes in ground surface elevation over time. These studies looked at time-series analysis of data beginning well before tunneling started through shaft dewatering and continuing to the time of the study. They showed an unmistakable correlation between rescue shaft dewatering and broad areas of ground settlement.

Dewatering: The Science of Making a Wet Excavation Dry

Dewatering the excavation required pumping, but at a rate and depth to keep water pressure low (too high could risk “blowing out” the bottom of the 130-foot-deep shaft). There are two aquifers beneath the rescue shaft site and Pioneer Square area – one shallow and one deep. Because the shaft bottom sat in the “deep” aquifer, pumping targeted that aquifer, which was thought to be confined from the shallow aquifer and the vulnerable utilities sitting above it.

However, because settlement happened in the shallow aquifer area, Aspect’s forensic analysis looked at answering several questions: how susceptible are the utilities to pumping a deep aquifer? Does pumping the deep aquifer cause dewatering of the much shallower aquifer? And if so, does pumping the deep aquifer or dewatering the shallow aquifer cause most of the settlement that the City was observing? Understanding the hydrogeologic connections between pumping the two aquifers and the net effects of dewatering on soil behavior required multidisciplinary consideration of many factors.

This graph from TRE Altamira shows the elevation of a single point on the map near the area of greatest ground subsidence. The dots show the date of the satellite pass, and the elevation difference from the baseline series. The sharp drop in elevation between October and December 2014 corresponds to the period when shaft dewatering began. These satellite altimetry data correlated well with elevation control data collected by others using traditional on-the-ground surveying methods.

To understand the amount of shallow dewatering that had occurred, Aspect developed a comprehensive groundwater monitoring program that instrumented existing wells to collect data while the dewatering pumps were running. Then, once the pumps were shut off, before and after comparisons of water levels could be made to see the changes brought on by dewatering. Data collection continued until dewatering had ceased and groundwater levels had returned to normal.

Fixing the Faults Caused by the Fault

Ultimately, the project team concluded that there had been localized impacts to the shallow aquifer that were related to pumping of the deep aquifer. Some of those impacts were the result of leakage from the shallow aquifer downward along the outside of the Bertha rescue shaft, and some from leakage between the shallow and deep aquifers that occurred along zones of disrupted strata that the Seattle fault created to form the complex geology below Pioneer Square. The data collected by our team provided strong support that the Bertha shaft dewatering caused enough settlement to require replacement of vulnerable utilities. This led to a program in 2015 to replace the large water main buried below Western Avenue, with Aspect providing the geologic analysis used for the design. The drive along Western Avenue is now much smoother, and the section of new water main is now less vulnerable to the next big construction project or major earthquake.

Ironically, while past activity along the Seattle fault was largely responsible for the complex hydrogeology that made dewatering the Bertha rescue shaft a challenge, it was concerns about future rupture of the Seattle fault (or one of the other regional faults) that triggered replacing the Viaduct with the tunnel to begin with. This in turn led to the rebuilding of the waterfront seawall and reconstruction of Pier 62.

As some Aspect geologists are fond of saying – “geology explains everything.” With a site as complex as the Seattle waterfront, it takes an expert “read” of the geology and a skilled team of geologists, hydrogeologists, and engineers to inform design for projects that make Seattle safer and better for the future.

The Waterfront’s Next Chapter – Highway 99 Tunnel

While the water main beneath Western Avenue was being replaced and groundwater monitoring continued, WSDOT crews had Bertha repaired and chugging along beneath the city, breaking into daylight near South Lake Union in April 2017. Seattle now awaits the opening of the tunnel Bertha cleared that will move traffic through the complex web of geology, hydrogeology, infrastructure, and development that makes up the Seattle waterfront.

WSDOT’s map shows the new Highway 99 tunnel through downtown Seattle to South Lake Union. Map credit: WSDOT

[1] Dewatering is the process of pumping water to keep an excavation dry.

Environmental Consulting Lessons Learned from the World of Analytical Chemistry

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The story of environmental consulting projects often start with what the laboratory results tell us. However, all results are not created equal, and it’s important to know the big picture – site subsurface conditions, regulatory criteria, and chemistry principles – when uncovering culprit contaminants.

At one of Aspect’s recent, ongoing Technical Exchanges, Staff Scientist Andrew Yonkofski invited Mike Erdahl from Environmental Laboratory Friedman and Bruya to discuss the role of analytical chemistry in environmental consulting, including general petroleum chemistry, gas chromatography, and interpreting those results. Part of the discussion was focused on an Aspect-specific case study from a Seattle-area waterfront site. This site presents a unique look at how organic matter in the subsurface can affect results from the NWTPH-Dx analysis.

Lessons learned from the talk included:

  • Common petroleum hydrocarbon mixtures, such as gasoline and diesel, contain thousands of unique organic compounds. The NWTPH-Gx and NWTPH-Dx analytical methodologies attempt to capture the wide range of organic compounds found in petroleum hydrocarbon mixtures.

  • While the laboratory provides a reproduceable, quantifiable number for total petroleum hydrocarbon (TPH) results, those results often need to be interpreted in light of the chromatographic results. For instance, the higher boiling end of gasoline overlaps into the diesel-range. As the gasoline weathers, the proportion of material in the diesel range increases in relation to the total TPH value. Qualifying the diesel results as overlap from gasoline contamination can reduce the number of site-specific contaminant of concerns.

  • Likewise, results using both the NWTPH-Gx and NWTPH-Dx methodologies can sometimes include organic compounds from natural sources including degradation of organic material in the subsurface.

  • To properly characterize a site, environmental consultants must use multiple lines of evidence to determine the nature and extents of contamination. This includes interpreting analytical results and the associated chromatograms in the context of the historical site use.


This chromatogram illustrates how gasoline can overlap into the diesel-range. The diesel results reported by the lab do not indicate a separate diesel release from the gasoline release but rather illustrate how gasoline can overlap into the diesel-range as the product becomes weathered in the subsurface.

This example shows what a chromatogram may look like when there are multiple sources (both gasoline and diesel) present in a sample.

This example shows what a chromatogram may look like when there are multiple sources (both gasoline and diesel) present in a sample.

Dan Haller Presents to the Water Mitigation Task Force

Aspect is routinely involved in helping inform State policy makers on implications of existing and proposed legislation. Our staff track and comment on existing legislation, help our clients propose new legislation, and interact with State agencies as they propose and shape new water policy. Aspect’s Dan Haller was asked in the summer of 2018 to provide a presentation on mitigation projects and mitigation sequencing to the Washington State Joint Legislative “Water Mitigation Task Force”. This Task Force is charged with evaluating how the law could be changed to adopt mitigation standards for water projects where water-for-water cannot be supplied for a project in-time and in-place. Often the “in-time” component of mitigation is the most challenging element as supply and demand are hard to match perfectly.

Dan speaks about several mitigation projects Aspect staff have worked on in recent years, including:

  • Town of Twisp / Methow Valley Irrigation District, which paired an irrigation project rehabilitation with water banking to offset growth in the Town for the next 20 years.

  • Lake Roosevelt Drawdown, which re-operates Grand Coulee Dam by 1 foot making that supply available for agricultural reliability, instream flow, and municipal use.

  • Kittitas County Consumptive Use Pilot, which seeks to clarify the exact nature and magnitude of indoor domestic use.

  • Chelan County Alluvial Storage Pilot, which seeks to engineer natural storage log jams to retime water from spring to summer.

Check out the video of Dan’s presentation below.