Samuel Baumgardner-Kranz, Senior Engineer with Sonoma County
By Lorella Angelini, Angelini Consulting Services, LLC
TSP2 is reaching out to local Agencies with the intent to better understand their bridge preservation needs and develop valuable tools that the Agencies can use. To reach this goal, TSP2 created the “Local Agency Outreach” National Working Group that is chaired by Gregg Freeman with KwikBond and Travis Kinney with David Evans and Associates.
The Working Group has already developed training modules on bridge preservation for local Agencies. The Group is also facilitating communication between local Agencies and the FHWA Bridge Preservation Expert Taskforce Group (BPETG) as well as the National Center for Pavement Preservation (NCPP). In addition, through the work of the “Local Agency Outreach” Working Group, local Agencies are getting an avenue to participate in the TSP2 Bridge Preservation regional meetings.
To learn about local Agencies and the challenges that they face addressing bridge preservation, I had an in-depth conversation with Samuel Baumgardner-Kranz, Senior Engineer with the Sonoma County in Northern California [https://sonomacounty.ca.gov/development-services/transportation-and-public-works/divisions/roads/services/bridges].
What are your main responsibilities with Sonoma County?
My role is primarily to oversee the bridge design group for our local Agency’s owned bridges. Sonoma County has 325 bridges in the National Bridge Inventory plus many other shorter structures. Generally, I work on the capital improvement design projects. I also assist our maintenance group with technical problems when it comes to bridge preservation. I serve as the subject matter specialist when it comes to transportation structures, which include retaining walls, bridges, and culverts.
Do you oversee a team at Sonoma County?
I personally oversee two staff primarily working with projects related to federally funded bridge replacement projects. On the maintenance end we have one full work crew, which is composed of four people. The crew is overseen by a construction engineer, who consults with me as we undertake bridge preservation activities.
How have you built your bridge preservation knowledge?
It can be a bit challenging to learn about bridge preservation. I’ve been trained since college with the purpose of learning about bridge design. Formal education is in fact primarily focused on new bridge design and there is not a lot of education out there for one to pursue concerning bridge preservation.
Manufacturers of preservation products often provide a very good source of learning. However, their information doesn’t always translate well in activities because of procurement requirements.
As I said before, I am always on the lookout for learning opportunities, but I personally haven’t found great single sources for building my knowledge about bridge preservation if you exclude the TSP2 web site. I often look for state Agency’s published knowledge and practices. Unfortunately, many of them keep that expertise internally.
You said that you get valuable information from the manufacturers, but then you can have issues with procurement. Can you explain?
In California you cannot just source a single product. To procure work or products, we need to set up a competitive bid, or issue a statement of public interested that says that no other product can provide a solution to the specific application pertaining to the project. In essence, we cannot choose to spend a lot of money with a single manufacturer without a competitive bid unless there is a very good reason to do it. For example, this is the case of the crash barrier systems. Some counties only procure one manufacturer’s system, so as to make parts’ replacement and maintenance simpler and cheaper.
The solution that we prefer is when we have a general specification that can be fulfilled by multiple manufacturers, so that the work can be competitively bid. However, this solution does not really work for new, innovative products that have a few, or no, competitors. It is true that we can push a new product through and get it used even if it is single source, but the process is not easy and takes extra work to prove that it is a responsible and ethical use of public money.
Do you support the bridge preservation concept?
Bridge preservation is important first and foremost for the environment. Keeping bridges in service as long as you can instead of replacing them is a good environmental practice. It takes a lot of material, disposal, and carbon emissions to produce a new bridge, far less to preserve one.
There may be a few caveats to this preservation concept though. In our County, we have a lot of bridges over waterways. It is not unusual for these bridges to be designed with old practices that have negative features for fish passage, fish habitat, or other natural habitats. So, it can be a good solution to build new bridges that can have a restorative benefit for the natural habitat when the old bridges deteriorate to the point that they are suitable for replacement. Bridge replacement for habitat restoration is not usually something our transportation Agency will plan though. It can be considered as an added benefit when we plan the replacement of old bridges over waterways.
As I said before, generally speaking, the better environmental choice is to keep bridges in service for as long as possible rather than seeking to replace them.
Could you expand about the benefits of replacing old bridges that go over waterways?
Sometimes when the span isn’t long enough, it can constrict the channel. This constriction increases velocity of water on the downstream edge of the bridge, which causes an increase of foundation scour. Upstream, it impounds sediment, which changes the sediment load in the stream and effects the streambed and the water quality. All of this, in general, negatively impacts the natural habitat.
By replacing an under-length bridge with a new bridge that fully clears the channel and allows a natural waterway, we can improve the habitat of the species living within it as well as protect the foundations of the bridge in the long term. This is something we are focusing on in our bridge replacement projects and that has been found to be highly desirable by our various environmental protection Agencies like the California Department of Fish and Wildlife, the NOAA National Marine Fisheries Service, and various others like the Army Corps of Engineers.
As an example, we are currently replacing a bridge whose span is about 40 feet long, while the natural channel requires a bridge about 200 feet long. There is a substantial buildup of sediment behind the bridge that has covered the natural riverbed, which is a fish spawning habitat, and has blocked water passage. We’re designing the geometrics of the new bridge to reduce this problem and improve the situation over the existing condition. The new bridge will not be impacted by the river, and vice-versa. In the end, bridge replacement can be a good environmental choice, even though, as I said before, in general it is better to keep the current bridges in place for as long as it can serve.
Could you speak of the bridge preservation activities that are currently implemented by Sonoma County?
We have limited funding available for bridge preservation activities, which are selected based on their value for the public. We consequently focus on actions that provide immediate safety, which is top priority, then drivability such as repair of barrier rails, deck cleaning, patching, and resurfacing.
We don’t have the funding or staff available to implement larger scale or more labor-intensive bridge preservation activities, such as bearing replacement and painting. Even a joint replacement project can be a challenge to get done because of lack of the funding availability.
Our political leaders are often calling on us to define a dollar value for a preservation work. Unfortunately, this is a quite difficult evaluation. It entails the financial quantification of the damage that will likely result over time from preservation work that does not get done. It is a challenge to quantify this potential damage in a way that can satisfying political leaders who are trying to make difficult financial decisions.
The truth is that unless there is an emergency situation, we do not get funding for major preservation work.
It is definitively easier to calculate the value of work that gets done rather than the potential damage that results from the work that is not done. Communicating the value of bridge preservation can be challenging.
If I can say to our political leaders that $10,000 spent today will save $100,000 down the line, then I would have a lot easier time making the argument and getting funding for bridge preservation. However, I have not found the tools that allows me to make that argument.
It is also not up to me to create such tools. I have limited expertise with bridge preservation and there are no other bridge specialists in my department. My staff is not formally trained in bridges or structures, but their expertise is in the federal aid procurement process. So, the only other sources of expertise I can rely on a day-to-day basis are colleagues outside of my department and consultants. However, consultants are typically trained in bridge replacement or new design rather than in bridge preservation.
I am not aware of AASHTO publications for bridge preservation. Having an authority providing guidance and standards about bridge preservation could be extremely helpful for local Agencies.
AASHTO released a bridge preservation guide in 2021. Are you familiar with it?
Yes, I am familiar with this guide. It is high level and does not actually provide practical information that I can take far.
What bridge preservation action do you do more frequently?
We do deck washing pretty regularly.
Having so many bridges over water, do you encounter any environmental issues with deck washing?
We do not have any environmental issue with deck washing, which is not different from rain washing off the bridge. We do not use any solvents, but we simply scrape the deck, sweep dirt and debris, and rinse the deck off. We do not always rinse the deck after cleaning.
We do not use salts in Sonoma County since we do not have snow and ice. We have just one bridge where it may snow every few years. So, our deck washing is just about making the deck drivable and keeping the drainage clean rather than implementing actions to prevent corrosion from de-icing salts.
You spoke earlier about lack of funding to implement bridge preservation activities regularly. Could you go more in-depth?
At Sonoma County we have local funding for small and basic preservation activities, as I mentioned earlier. To implement the more complex and expensive bridge preservation activities, our primary funding source relies on the FHWA funding, is administered through Caltrans. Federal Highways participates financially in bridge preservation activities as much as they have funding available. However, there is a cost associated with gaining access to federal funding. It involves complying with a number of reporting requirements, including compliance with National Environmental Policy Act (NEPA). So, there is a certain threshold cost that we evaluate before we are willing to take on a federally funded project. Right now, our policy is that we’re not going to consider federal money for projects with a construction cost less than one million dollars. Our management is discussing whether we’re going to increase this threshold, since we are finding that even a one million-dollar project is no longer providing the additional value required to dedicate staff time. We also consider the staff costs in order to manage compliance with federal standards, the impact schedules, and delays associated with federal funding procedures.
For example, we currently have a 24-bridge project where methacrylate is specified as deck treatment. The treatment is time-dependent since the methacrylate doesn’t work as effectively when cracks get too large. This will likely happen if the treatment is applied too late in the maintenance cycle, since cyclical traffic loading increases the size of cracks over time, if they are not properly treated. We have been prepared to bid this methacrylate project for about three years now. Unfortunately, the federal funding hasn’t been available, and so they haven’t authorized us to proceed with the methacrylate deck treatment. These are the kind of considerations that make taking federal money for bridge preservation actions less attractive.
When the Federal Highway is not meeting expectations, for whatever reason, such as staffing or funding availability, it can get incredibly challenging for our County to meet our obligation to implement a project. The issue becomes more complicated when standards for design and construction change or time-out during the delays. When this happens, we have to employ people to update the projects and then we have to reapply for additional funding to cover overages incurred to update the standards implemented during the delay. Then the project very likely gets delayed again while we wait for funding approval, which could trigger another update, review and wait cycle. Sometimes working on a federally funded project feels like being stuck in a hamster wheel. It can last forever since there are so many levels of approval, review, and funding procurement that happens with it. It seems as if everybody’s solution to these sorts of deadlock problems is to add another level of reporting and oversight which compounds the problem rather than solving it.
Another issue to be considered is the inconsistency of funding availability. Now that the transportation bill, [the Bipartisan Infrastructure Law – Ed Note], went through, there’s going to be more money available to California for transportation. At this point, we do not know how much money the State is going to make available to Local Agencies, but, for sure, it will be a one-time deal. Local Agencies will have to hire people to manage projects. However, it will be difficult to convince the board of supervisors that it’s justified to hire four or five more people for a source of funding that’s only going to last for limited number of years.
It’s not easy for Sonoma County to staff up and then reduce staffing after the need is gone. It takes staff to put the funding to good use since you cannot consult everything out. Even if we consult most of the technical work out, we still need people to manage the consultants and set their priorities. What we need is a permanent source of funding that allows hiring of permanent, expert staff, who can make the best use of the money.
I think that consistency of funding is a very important topic. It is evident that you cannot build a solid team based on temporary funding. Is this a reoccurring issue?
I have been personally dealing with the problem of consistency of funding to this day. A lot of my projects are legacies stemming from a funding influx after the great recession of 2008. The projects were authorized around 2012 when Sonoma County was offered funding and accepted it. Unfortunately, the County didn’t actually have the staff to properly manage and execute the projects, which consisted of almost 20 bridge replacements. With only two or three people available to work on the projects, the projects couldn’t progress individually as much they needed to per the federal funding requirements. This is despite the fact that the staff worked very hard, to the point of burnout. Several people quit due to overwork and frustration with the process. Over time, as Agencies were completing their projects, the funding source dried up while many projects were still in progress.
Our County ended up in a sort of a limbo that still lingers on. We are expected to deliver these replacement projects, but the funding sources are no longer there. I was hired and assigned staff to execute these backlog projects. Meanwhile, the County had to return a large amount of FHWA money from projects that failed to meet schedule requirements. And that’s again the consequence of one-time funding that did not make the County confident to keep enough staff on hand to manage the projects effectively. It is also the consequence of the fact that lower priority projects losing funding when others in the grant program go over budget.
Comparing with a number of local Agencies that I’m familiar with in California, Sonoma County is remarkably well staffed for bridges. I can think of only one other County that actually has a structural engineer with a background in bridges and transportation structures. I am privileged to have such background as well as a staff of two people, which, however, is still a small group for the scale of projects we manage. The expertise gap gets much wider when local Agencies are smaller than Sonoma County, such as cities with low population or lower population rural Counties. These local Agencies often have just one person who is doing both pavement and bridge preservation. Not having have in-house expertise of all preservation activities, these Agencies must rely on consultants that are hired on a project-by-project basis and supported by temporary funding. However, consultants are expensive, they lack local knowledge, and have the County’s best interest in mind only as far they are professionally obligated. There are pluses and minuses to consulting versus in-house expertise, but I think that the latter is always the desirable choice, when practicable.
Can you explain the process of giving money back because federal requirements were not met by the County?
It is not that Sonoma County had a pot of money and we gave that money back. We paid the consultants and specialists for the projects out of our own pocket. Then the County used the grant to reimburse the money that was spent. When some projects failed because they did not meet the federal schedule requirements, we had to pay back the money that was reimbursed, which was approximately three quarters of a million dollars. In our case, several contributing factors for not meeting schedule were outside of our control, and included delays from the Caltrans/FHWA oversite, who are also not appropriately staffed. Caltrans administers the program that allows Counties to receive grants from FHWA.
We failed to meet what is called the 10-year rule [CFR Title 23, § 630.112 (2), interpreted by FHWA Order 5020.1A – Ed Note]. Since we could not show substantial progress with the projects, the funding could not be extended. This is the way the highway program works for us. I must say that it was really painful to pay back the grant, which was money we spent on those projects. Accepting grant money actually ended up taking money away from our bridge program. We could have put that money to good use elsewhere.
So, at this point it may be challenging for your County to take on significant bridge projects.
Yes, it is unlikely that we’re going to take on much from the most recent transportation bill. As we discussed, we are still clearing out the backlog of projects that were initiated with funding from 2012. We are desperately fighting to meet our obligations so we do not to have to return more money. Most likely we will not start any projects as a result of new funding anytime soon. I am glad someone else is going to get the transportation bill funding so that they can start new projects and complete projects they have on hold.
It would be ideal if the transportation bill money could be used to fund existing programs, such as the Highway Bridge Program. However, it appears as if this money is dedicated to implement a new grant program, called the Bridge Investment Program. This may be frustrating for the local Agencies. It means that existing projects will not receive help, and the Counties will have to learn new grant rules to achieve funding in order to complete these projects.
You mentioned Caltrans. What is your relationship with Caltrans? Do you have any form of collaboration with them?
Caltrans has taken on the effort of inspecting every bridge in California in the national inventory. Therefore, they inspect all of our bridges, identify deficiencies and make recommendations for maintenance and repairs. This service is extremely valuable. We do not have in-house expertise or time for it.
As I briefly mentioned earlier, Caltrans has also been given delegated authority for federal grants by the Federal Highway Administration. Caltrans administers all the federal funding that comes to the State for the local Agencies and provides assistance to make sure that local Agencies meet the federal requirements. Caltrans also provides assistance in terms of procedures and manuals in order to meet these requirements. All of this is pretty helpful.
We also completely rely on the technical information published by Caltrans, such as amendments to the AASHTO LRFD Bridge Design Specification, seismic design manuals, construction manuals, and all sorts of bridge technical information. Caltrans is very good at bridge design, and we follow their lead.
For locally funded projects, however, we are on our own. Caltrans is not really interested in providing us with technical assistance for our bridges. I think that’s a fair stance since they have their own bridges, but more active technical help from them would be welcome.
What do you mean when you say “more active technical help” from Caltrans?
Caltrans does not provide any training to the County or, as policy, make staff available to take technical calls. I do have some relationship with Caltrans people that I use informally. However, if I have questions, such as how to approach a joint seal project or a bearing replacement, I am essentially on my own. I need to figure it out.
I am a bridge engineer who knows how to design new bridges but I don’t necessarily know how to set up plans and specifications for a bearing or a joint seal replacement, or something like that, so as to contract it out correctly. To do so, I must develop a skill set in standard practices for bridge preservation. Unfortunately, there aren’t a ton of places for me to develop that skill set. The County does not necessarily have the resources to pay someone to train me in that either, if such a training exists.
My counterpart who manages pavement preservation gets more attention, support, staff, and funding than what I get managing bridge preservation. This is because the benefits of pavement preservation are easily perceived by the public and elected leaders. Their results are obvious and immediate. Everybody likes riding on a smooth road. So, it is politically popular to spend money on pavement preservation, which, to be clear, is very important. On the other hand, the benefits of bridge preservation are more difficult perceive. Unless you have a major disaster, such as the collapse of a bridge, it is a lot harder to convince people to invest in bridge preservation. Nobody gets excited by joint seal replacements, except for me and the bridge maintenance crew.
In Minneapolis, where I live, there was a major bridge failure in 2007. It was a tragedy. Thirteen people died, and many more were injured. Bridge collapse must be avoided at any cost.
We’ve been fortunate in Sonoma County to have not had any bridge collapses, only minor bridge problems and safe failures. Recently we had to close a couple of bridges because there was a condition that posed an immediate threat to safety. Thankfully, we were able to identify this condition before it caused harm.
If there is an issue that keeps me up at night, it is the scour, since in our County there are some bridges for which the scour is critical. Scour problems are probably the hardest ones for me to approach. Whereas the required scour countermeasures are pretty simple, the approach to a scour countermeasure project is complex. For each bridge we must produce detailed planning and design work to receive permits from four Agencies, which are the Department of Fish and Wildlife, the Army Corps of Engineers, the National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service, and the California Water Boards. A lot of documentation is required by these Agencies to get permits. This effort is very staff intensive even though the actual amount of construction work is small. The professional costs can actually match the cost of construction.
It can take two months of my time to get a permit for scour measures for an individual bridge. It is evidently more cost effective for the County to put this time towards the very high dollar value of capital improvement projects for which I was hired. So, it is almost inevitable for me to put off scour work.
I presume that the permitting effort requires structural engineering knowledge but also knowledge of hydraulics and environmental issues. It does appear to be quite a complex work to me.
Yes, obtaining scour permits is a complex work indeed. In several instances we do not have in-house expertise to do the work, which includes hydraulics, geomorphology design, structural design and environmental studies. In these instances, we give the work out to consultants, provided we reach a certain minimum dollar value that makes the work worth bidding on.
As I have already said, the scour on some of our bridges is critical. This actually keeps me up at night since a lot of the bridge failures that I’m familiar with in California have been from scour. We have rain that comes only at certain times of the year and all at once, we have mountainous terrain and we have a lot of alluvial soils. In our State we have all those conditions that can cause scour, such as rain that comes only at certain times of the year and all at once, mountainous terrain and a lot of alluvial soils.
Recently, in our County, a Caltrans bridge over the Russian River failed quietly. Caltrans closed the bridge when the fire department noticed that it was leaning over a little bit more than normal. Caltrans assessed the bridge and they were able to close it before it collapsed or caused harm. The replacement bridge was built in a hurry. Not having the time to plan properly and do all the necessary hydraulic studies, the new bridge is now having scour problems. Working in an emergency situation with limited time is never the best practice. Scour is definitively a big problem here in California.
I think that climate change doesn’t help since it makes events more concentrated and dramatic. Do you see the impact of climate change on the bridges in Sonoma County?
My County has become famous for how heavily we have been impacted by the early effects of climate change. We’ve been on fire almost every year. We had huge, enormous wildfires that affected the bridges in many ways.
First, fires remove vegetation which controls erosion. This exacerbates the bridges’ scour issues.
Sometimes bridges actually burn. This can affect the strength of the concrete, which is really difficult to evaluate without taking cores and testing them. There is also the possibility that steel may have softened because of the heat, which can cause problems in the short and long term.
Falling trees are also a problem. When the root structure burns, trees can fall on bridges. This has happened a few times in our County.
Also, in order to fight these fires, we had particularly heavy equipment going over bridges that were not designed for that type of traffic, which was worrisome.
Wildfires driven by climate change are definitively a huge problem for our bridge system in Sonoma County. Safe, redundant crossings is important in our County because we never know when a route will become an evacuation one, or if a route will be cut off.
What are your goals with bridge preservation in the short and long term?
My vision for the short term is to make sure that everybody has at least one safe route to and from their destination. Sometimes a bridge is the only available way to destination. So, I want to make sure that if there’s no detour available, bridges stay open. That’s my short-term goal.
For the long term, I would love to see sufficiency ratings of my bridges go up. The ratings have been steadily dropping for Sonoma County and for the other local Agencies in California since the 1990s when funding available started to dry up. [Sufficiency ratings data for the National Bridge Inventory can be found in the FHWA LTBP Info Bridge website, see https://infobridge.fhwa.dot.gov/ Ed Note]. I am aware that reaching this long-term goal may be challenging. It may require convincing the public to fund bridge preservation, finding more sources of funding, or redirecting funding.
When sufficiency ratings go up, I can maintain bridges and keep them in service for longer, rather than having to replace them. One thing I’ve learned from my capital improvement projects is that our local communities love their bridges, even basic bridges that no one expects people to love. Replacements can upset the community. This is another reason for keeping bridges in service for as long as one possibly can.
The old design life for bridges was 50 years, the new design calls for 75 years. If I could keep bridges in service for 150 years, or indefinitely through maintenance, that would be awesome. This is my vision for the future.
Can you say something about you, such as your professional career and what you like to do in your free time?
I went to school for structural engineering focusing specifically on bridges and I am a licensed Structural Engineer in the state of California. Sonoma County is one of the very few Agencies that has a licensed Structural Engineer in their Transportation Department.
I have been practicing engineering for about ten years. In my early career I targeted inspection work and construction work because I wanted to learn the practical side of engineering. Later I joined a bridge design firm and spent a few years designing bridges, retaining walls, and culverts. When I found this opportunity with the County of Sonoma, I was fortunate to be selected. I’ve been with the County of Sonoma as the lead of their bridge division for four years now.
In my free time I like to garden, hike, build things, and play video games. Gardening, both vegetables and flowers, is perhaps my biggest hobby which I share with my wife.
You have been working on getting an additional Structural Engineering license. Have you achieved it?
Yes, I recently received a Structural Engineer license, which can be sought after gaining experience as a licensed Professional Engineer. A Structural Engineer license is required in California for certain life-safety critical infrastructure, such as schools, emergency shelters, police stations, and hospitals. I would argue that bridges are part of these structures even though State requirements do not necessarily agree with me.
Definitively, bridges are always on your mind.
I do love bridges, including bicycle and pedestrian bridges. I would like to see federal funding available for these types of bridges too. I think that increasing the number of pedestrian bridges and bike routes is an important step towards meeting climate change goals. It is surprisingly hard to get bike projects off the ground in our State. We cannot even add sidewalks or bike lanes on federally eligible bridges if the roadway approaching the bridge doesn’t have them. Without a doubt, we are very attached to our cars in California.