Emerging Contaminants – Perfluorinated Compounds

Perfluorooctanesulfonic acid (PFOS)

The EPA identified Perfluorooctanesulfonic acid (PFOS)—used in stain repellants—as an emerging contaminant.

You could say that perfluorinated compounds (PFCs) are the Superheros of chemicals. They resist heat and other chemicals, have dielectric properties, make things slippery, and repel grease and water. That’s why they’re used in fire-fighting foams, semiconductor manufacturing, medical implant devices, pharmaceutical tubing, non-stick cookware, and coatings for carpet, clothing, and food packaging. In fact, they are so useful, in 2013 the global market value reached $19.7 billion, and global manufacturing of products that either contained PFCs or used them in processing reached more than $1.2 trillion (FluoroCouncil, preliminary estimate, January 2014).

Because of so much use, PFCs are now found everywhere throughout the world—in soil, groundwater, lakes, rivers, etc.—and also in human beings (detected in blood and breast milk). They also have a tendency to stick around in the environment, so there is concern about bioaccumulation/biomagnification in people and in animals and the potential for long term health effects.

Although there are hundreds of different PFCs, none are identified as a pollutant or contaminant under the Clean Air Act (CAA), the Safe Drinking Water Act (SDWA), or the Clean water Act (CWA); nor are any identified as a hazardous or toxic constituent or substance under the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), or the Toxic Substances Control Act (TSCA).

However, the EPA has identified two of the most commonly found PFCs as “emerging contaminants” and in 2009 established “provisional short term health advisory levels” for drinking water at 400 parts per trillion for Perfluorooctanoic acid (PFOA) and 200 parts per trillion for perfluorooctanesulfonic acid (PFOS). These concentrations are equivalent to adding less than a quarter teaspoon into an Olympic-size swimming pool.

Given the widespread occurrence of PFCs in the environment and the extremely low concentrations of concern being considered by EPA, this group of chemicals will likely have significant future impacts on industries involved with water treatment, wastewater treatment, and contaminated site remediation.

What Do Tree Trunks and Fish Ears Have in Common?

Burbot Otolith

Burbot otolith (Photo: Maria Sandercock)

Long-nose sucker otolith (Photo: Maria Sandercock)

Long-nose sucker otolith (Photo: Maria Sandercock)

Most of us know about tree rings—a tree forms a new one every year in its trunk. When counted, they tell us the tree’s age. But trees are not the only living things to produce annual rings. All fish produce small calcium carbonate structures just below their brains called “otoliths.” Fish add calcium carbonate and protein to these structures throughout their life. In a similar process to trees, rings occur on an otolith when a fish’s growth slows down during colder months and the deposit appears white, compared to darker/translucent deposits as their growth speeds up in warmer months. This results in yearly rings that coincide with the fish’s age.

Biologists can extract a fish’s otoliths and, using a microscope, count the rings to get an estimate of the fish’s age. Aging fish is useful for understanding age structure and population trends in a fishery. Otoliths vary in size and shape from one species to another, and can be used to identify the species it came from. This helps biologists trying to understand marine food webs—they can use otoliths found in the stomachs of seals, sharks, and other fish to identify what fish they eat.

Try your hand at aging an otolith

Top Ten Reasons to Take a Tablet


There aren’t many photocopiers at some of our jobsites. This is just one of the reasons to carry a tablet into the field.

Paper? Don’t talk about paper. Are you kidding me? Paper?

Many engineering firms document field work using paper. However, using computer tablets improves communication and quality, and cuts cost. As with everything on the Internet, this requires a top 10 list.  Here are our top 10 reasons to take a tablet into the field.

 1. Fewer Hours Charged to the Client

When an employee saves time by using a tablet, that time can be allocated to other tasks or eliminated altogether.

2. Better Integration of GIS Capabilities

Taking a GPS point, geotagging a photo, and describing field conditions with a single device is more efficient than using several devices.

3. Consistent Data Entry

When staff handwrite field notes on standard forms, headings and other information must be rewritten on each page. Not so with electronic forms, which can be easily copied forward.

4. Richer, More Informative Field Reports

With a tablet, we can add geodata, attach photos, and include other information with ease.

5. Ability to Stream Site Video

Using video capabilities, a field representative with a question can show the site to project engineers no matter where the engineer is. This is more informative than a phone call. Plus, work can progress with minimal delay.

6. Quality Assurance

We can require fields in electronic forms to be filled in and time stamps automatically applied. Drop-down lists can limit potential input errors.

7. Access to Information in the Field

Tablets allow a new plan set to be sent to the field rep in real time–at a size that can be reasonably viewed.

8. Real Time Data Delivery

Our projects are often under a tight schedule. Getting data from the field as it’s collected allows us to better direct the field representatives, and begin making our designs and recommendations sooner.

9. Fewer Trips Back to the Office

Returning to the office at rush hour to get that piece of paper back to the office can add cost to the project. Plus, after a long day of work in the field, it’s nice that an employee can go directly home.

10. Automatic Backups

Automatic backups make sure that information isn’t lost if a tablet is damaged. However, we don’t expect much damage, because our tablets are dressed in invisible rain gear and they wear nearly as much armor as this guy.

505 First1

Bathtubs and Floating Buildings

You wouldn’t think that a building built on solid ground would be in danger of floating upwards. In fact, building where the water table is close to the surface can make this a concern. Dewatering the soil can keep floating buildings from being a problem, but some areas can’t be dewatered.

Here’s one example. Back when Seattle was just a pioneer town, the 505 First Avenue Building property was part of the waterfront. It had a wharf on pilings for timber mill-related businesses.  In the late 1880s and early 1890s, the area was filled in with, among other things, sawdust and wood debris from sawmills, wood planks and pilings, ship ballast, and burn debris from the Great Seattle Fire of 1889. This all meant that the soil where Starbucks now wanted to put up an office building was very soft and contained wood debris, abandoned timber piling foundations, and many other obstructions.

For this and other reasons, engineers couldn’t pump out the groundwater during or after construction. The four-level deep excavation had to be water-tight (think bathtub, but with the water on the outside). And this could lead to “an unbalanced hydrostatic uplift force in excess of the building weight acting on the foundation.” In other words, the seven-story building would float upwards.

How do you restrain such a building? In this case, engineers tied it down with 360 micropiles below the five-foot thick structural mat foundation.

Seattle Children’s Hospital Rain Gardens


In an earlier post (Infiltration and Laboratory Testing Support Green Design), we described how rain gardens and bio-filtration swales are important to sustainability. The Seattle Children’s Hospital main campus expanded through the Building Hope program to meet the growing need in our region. Please enjoy these photos of the rain gardens when they were newly planted outside the new construction.




Wetland Banking 101

Edmonds Wetland 033

When the EPA and Army Corps of Engineers released their final rule on Compensatory Mitigation for Losses of Aquatic Resources in 2008 (2008 Rules), compensatory mitigation became as easy as going to the bank. A mitigation bank, that is. The 2008 Rules set out a hierarchy for mitigation that gives preference to larger-scale wetland restoration in a watershed context. Mitigation banks provide this ecological framework. Before 2008, mitigation banking was more expensive and riskier than concurrent mitigation. Cheaper, smaller-scale permittee-responsible mitigation was preferred even if it wasn’t the most ecologically beneficial.

A mitigation bank is a wetland, stream or other aquatic resource area that has been restored, established, enhanced, or preserved. This resource area is then set aside to compensate for future impacts to aquatic resources resulting from permitted activities. The value of a bank is determined by adding up the aquatic resource functions restored, established, enhanced, and/or preserved in terms of “credits.” Permittees who want to develop property get approval of regulatory agencies, to buy these credits to compensate for unavoidable wetland impacts.  Individual projects must still avoid and minimize impacts to wetlands before using a mitigation bank.

Many mitigation banks have been developed or are in process in Washington, Oregon, and other areas in the United States. So how’s the 2008 Rule being implemented and how is mitigation banking performing? There hasn’t been a national analysis of mitigation banking since the 2008 Rule, but expect another blog post when any analysis of the 2008 Rule or mitigation banking is released.

For more information, contact Jim Shannon, 425.775.4682.

Wetland mitigation bank guidance

Questions and Answers


What is Your Marketing Staff Saying behind Your Back?


You’ve just managed to land your firm a spot on a proposal team for a great project. The technical proposal manager from Company X tells you to send them some resumes and project descriptions. You rush back to your firm and inform your marketing staff.

Suddenly, your marketing staff is talking behind your back.

That is, if they’re smart. They’re calling the other firm’s marketing staff to ask, “What do you really want?” Because it’s almost never what the project manager from Company X asked you to provide.

The marketing staff members communicate about how many resumes and projects to prepare. They also communicate about other materials, length, formats, and win themes. That way your firm isn’t doing the work twice, and you give Company X materials they can actually use—that will help them win!

Next time, be sure to ask the technical proposal manager for the contact information of the marketing staff member who will be handling the proposal. Let your marketing staff talk behind your back.

Beyond the Go-To Microbe

Microbes Feeding on Petroleum

Microbes Feeding on Petroleum

Rapid, cost-effective complete genome sequencing (CGS) has opened a universe of possibilities.  New discoveries. A better understanding of life. New ways to solve modern problems.  The new advances could some day show the innovation of CGS technology to be as important as the discovery of fire.

One problem faster CGS is solving is confirming that the “right microbes” are present for environmental cleanup. Until CGS, scientists had only classified 10% of microbes in nature, guessing how the unculturable microbes related to each other.  Supercomputers are changing this limitation.

Over the past five to ten years, bioremediation practitioners have increasingly used specialized microbial strains to help them with environmental cleanup, termed “bio-augmentation.”  For example, various strains of Dehalococcoides ethenogenes have been the go-to microbe to treat chlorinated ethenes (at dry cleaning sites, for example).  This was largely because it was one of the first species to be successfully cultured and shared among researchers.  CGS and other genetic tools have revealed numerous additional microbes are able to perform some of the specialized reactions. We can now pick a sequenced gene, check for the simple presence of that gene, and then see if that gene is present in any microbes in a soil or groundwater sample.

While the newest tools have helped us, one critical fact remains the same. Give the microbes the food, nutrients, and growing conditions they need, and they will degrade contamination into something less dangerous to people and the environment.  We continue to work with nature to fix our transgressions against it.

Challenge to End Hunger

Food Frenzy Pet Contest

Our hallway is lined with photos of staff members’ pets. We vote with our change and small bills. The categories are cats, dogs, and “exotic” (which includes chickens, snakes, gerbils, or whatever doesn’t fit into the other two categories).

Food Frenzy books

Geochemist Anne Conrad looks to see what’s new in our book sale. Many employees collected books, CD, and DVDs to donate while spring cleaning at home. There’s a nice selection this year!

Food Frenzy, the two-week-long annual event sponsored by Food Lifeline, is going on right now. Hart Crowser is just one of many Seattle-area companies who are challenging each other in this competition to raise funds to help end hunger for children in Western Washington. This is our second year participating and we’re having a blast. So far we kicked off a book sale and launched a competition for the cutest pet. We are having bake sales and a silent auction this week. And we’ve had teams of volunteers working at Food Lifeline warehouses to earn even more points in the competition.

If your company wants to join the fun next year, contact Food Lifeline.

That’s Not Real Blood And Gore


Ward McDonald and Megan Higgins portray accident victims in a wilderness training class

Environmental scientists and engineers often go deep into the wilderness to sample surface water, sediment, soil, and groundwater.  Some sites may take hours to hike into, and others may only be accessible by helicopter.  Taking samples is not highly dangerous in itself, but a medical emergency in a remote and unpredictable environment requires a different level of first aid training.

With this in mind, some of our staff recently took an intensive two-day wilderness first aid introduction to remote medicine.  The course was led by paramedic and Mount Rainer guide, Carrie Parker of Remote Medical International.  The material was practical and hands-on: patient assessment, traumatic injuries, medical emergencies, environmental emergencies, lifting and moving patients, and medical kits.

Realistic practice helped participants learn to handle serious situations when they are an hour or more from professional help.  We hope they’ll never have to use these skills, but they’ll be ready if they do.