Colorado DOT Helping Reduce Impact of Firefighting Foam

The Colorado Department of Transportation’s Division of Aeronautics recently wrapped up a two-year effort to help certified commercial service airports statewide acquire equipment to minimize the environmental impact of aircraft firefighting foam containing toxic chemicals known as per- and polyfluoroalkyl substances or PFAS.

[Above photo by the Colorado DOT]

The Colorado Aeronautical Board, which oversees the Colorado DOT’s Division of Aeronautics, approved $400,000 in state aviation funding to assist with this equipment swap effort – only the second such program in the nation – in collaboration with state airports and the Colorado Department of Public Health and Environment.

This effort comes amid an increasing environmental focus on PFAS chemicals, which pose challenges to drinking water reserves.

For example, the Senate Committee on Environment and Public Works held a hearing in October to assess ongoing and proposed responses to the presence of PFAS chemicals in the environment, particularly in U.S. waters, by the Environmental Protection Agency.

Radhika Fox, the EPA’s assistant administrator for water, noted in her testimony at that hearing that a “growing body of scientific evidence” shows that exposure at certain levels to specific PFAS can adversely affect human and ecological health. Studies indicate that two common

PFAS – perfluorooctanoic acid and perfluorooctane sulfonate – can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals also caused tumors in animal studies, she said. Fox added that the most consistent findings from human epidemiology studies are increased cholesterol levels among exposed populations as well as some cases where that chemical family affected birth weights, the immune system, caused cancers, and thyroid hormone disruption.

Currently, commercial service airports certified under Federal Aviation Administration regulations are required to use PFAS-based foam and to annually test and certify aircraft rescue firefighting equipment and the foam utilized.

Under the provisions of this new statewide aviation initiative, however, the Colorado Division of Aeronautics said in a statement that it provided 100 percent funding for the acquisition of specialized testing and containment equipment designed to allow FAA-compliant firefighting foam testing to take place without the need for regular foam discharges. 

In total, 12 eligible airports participated in the division’s program, with the exception of Denver International Airport, as it already had the equipment, and Colorado Springs Airport, where the U.S. Air Force provides aircraft rescue and firefighting services.

MnDOT Trying to Cut Back on Its Salt

When it snows in Minnesota, drivers want the roads and bridges cleared – now.

However, simply dumping mass amounts of salt on the roads is an outdated practice for the Minnesota Department of Transportation. Today, the agency is taking a new strategic – and more environmentally friendly – approach to how it removes snow and ice.

[Above photo by the Minnesota DOT]

“We want to minimize what we use,” explained Sue Lodahl, Minnesota DOT’s acting state maintenance engineer. “It’s about using the right chemical at the right time in the right location.”

During the 2020-2021 winter season, the agency spent $116 million and used more than 800 plow trucks and 354 million pounds of salt to combat 53 inches of snowfall, according to the department’s Annual Winter Maintenance Report. The salt usage was down about 15 percent from the previous year.

[To learn more about snow and ice fighting tactics, check out the winter operations podcast put together by the American Association of State Highway and Transportation Officials Snow and Ice Pooled Fund Cooperative Program, known as “SICOP.”]

The Minnesota DOT has also published “Winter Maintenance Best Practices,” a guide for using salt, with an emphasis on sustainable practices. “MnDOT seeks to reduce the use of salt on roadways while maintaining a high level of performance with regard to level of service recovery in winter operations,” the guide states.

The department’s Salt Solutions Program helps operations personnel make good decisions about selecting the best and safest materials for clearing the roads. As a result, the Minnesota DOT’s maintenance crews now have an arsenal of tools to fight snow and ice – including salt, potassium acetate, calcium chloride, sodium acetate and even beet juice.

[Editor’s note: The Minnesota DOT also began testing the technology on 10 of its snowplows in January that allows operators to activate digital highway signs to warn motorists when slow-moving vehicles are ahead on the road. That technology activates digital message signs to display certain messages as they pass, such as “Snowplow ahead, use caution” or “Maintenance vehicle ahead, use caution” during non-snow events. The message stays activated for several minutes after the snowplow passes the sign.]

[Above photo by the Minnesota DOT]

Even with all the chemical options available, plain road salt – sodium chloride – is still the “go-to” material, yet it has its limitations. Salt is not effective if the temperature drops below 15 degrees Fahrenheit.

Moreover, if salt washes off the road, it can harm water, vegetation, and wildlife.

“We’re always going to use granular salt, but we’re trying to keep it on the road,” Lodahl said. “You can’t just put down salt. Otherwise, it will go into the environment.”

The Minnesota DOT also “pre-wets” the salt with truck sprayers just as it hits the road. The water helps the salt stay on the roadway, where it reacts to the heat from vehicle tires. “But if the temperature is less than 15 degrees, that’s when we move into calcium chloride,” Lodahl pointed out.

The department’s top priority is to achieve what it calls “bare lanes,” a condition in which 95 percent of the lane between the wheel tracks is free of snow and ice and travel speeds are not impacted. Last winter, the Minnesota DOT saw bare lanes 87 percent of the time. The Salt Solutions Program’s goal is to strike a balance between achieving bare lanes and protecting the environment.

In 2020, the agency also studied using potassium acetate almost exclusively on roads in Duluth, where the average daily winter temperature is 23 degrees. The study showed promise, but there are still some environmental unknowns about the long-time use of potassium acetate, Lodahl said.

“Salt is still our biggest tool, our best tool,” she explained. “Everything is going to have some environmental factor. If salt scatters, it’s not doing us any good, and it harms the environment.”

Lodahl added that salt sustainability “is very important to MnDOT. We cherish the environment and try to keep the roads safe.”

Utah DOT Protects Reservoir as it Rebuilds Bridge

The Utah Department of Transportation is taking what it calls “significant steps” to protect the waters of the Starvation Reservoir during a U.S. 40 bridge renovation project in Duchesne County.

[Above photo by the Utah DOT]

The agency noted in a statement that the project’s contractor designed special “catch buckets” to capture demolition debris from the bridge to prevent them from entering the reservoir’s waters.

Excavators lower those 16-foot catch buckets, which are then affixed to the backside of the bridge’s barrier or parapet walls. Outfitted with rubber bumpers to provide a secure seal to the wall and to protect against damage to the existing infrastructure, the bottom of the bucket extends to fit under the bridge deck to capture bridge demolition debris.

The Utah DOT noted that the pan located on the bottom of the bucket is watertight and provides connections to a vacuum port, which pumps out the captured water and slurry materials into a vacuum trailer without any of it leaking into the waterway below.

All demolished materials are transported offsite to be recycled or disposed of in the landfill, the agency said. Duchesne County also plans to recycle the demolished bridge concrete for use as base material for future road projects.

In addition to capturing construction debris, Utah is using other procedures to protect both the project’s workers and the surrounding area. For example, crews working near or around the edge of the bridge are required to be in a harness and tethered to the bridge to prevent falling. That includes their tool and equipment as well – especially concrete saws – to prevent them from dropping into the waterway below. Finally, in case of unforeseen emergencies, the Utah DOT developed a water rescue plan for the project that includes life-preserving flotation devices and a rescue boat.

Tennessee DOT Helps Fund Two Trash Exhibits at Aquarium

A pair of new exhibits at the Tennessee Aquarium funded by the grants from the Tennessee Department of Transportation illustrate how microplastics and other roadside trash can negatively affect the health of the ocean as well as rivers, lakes, and streams.

[Above photo by the Tennessee Aquarium]

The new exhibits – housed in the Aquarium’s “River Journey” and supporting the Tennessee DOT’s “Nobody Trashes Tennessee” litter reduction campaign – includes actual debris taken from the banks of the Tennessee River

The exhibits demonstrate the connection between land-based pollution and aquatic ecosystems through “touchless” interactive elements, informative videos, and an exhibition of invasive aquatic wildlife such as a Northern Snakehead and Grass Carp. Those non-native fish are housed in one of the exhibits, swimming alongside examples — some of them 3D-printed — of common roadside debris such as tires and car batteries, which can wreak havoc on aquatic systems.

“The connections between roadside litter, water quality and aquatic systems cannot be understated,” said Shawn Bible, Tennessee DOT’s beautification office manager, in a statement.

“The ‘Nobody Trashes Tennessee’ campaign aims to educate citizens on the impact of what may be perceived as a minor issue for the state,” Bible added. “In reality, the state spends more than $19 million each year to clean up the more than 100 million pieces of litter on our roadways. We are pleased to partner with the Tennessee Aquarium on these interactive exhibits.”

The exhibits help visitors visualize how trash can imperil aquatic ecosystems and impact waterways that millions rely on for recreation and drinking water, while also demonstrating how changes in behavior on land can benefit the health of nearby waterways, explained Dr. Anna George, the Aquarium’s vice president of conservation science and education.

“Anything that is on land moves into our waterways,” Dr. George said. “If a piece of litter is thrown onto a street, wind might carry it to a stream or river. It might get washed or blown into storm drains and deposited in the nearest body of water. It is a safe assumption that any debris on land has a good chance of winding up in our water.”

According to the National Oceanic and Atmospheric Administration, 80 percent of garbage found in the ocean comes from inland sources, such as leaked automotive fluids and littering. “So even though the [Tennessee] Department of Transportation might seem like an odd partner for an aquarium, there’s a fundamental connection between activity on land and the health of waterways,” Dr. George noted.

Video: Caltrans Uses Boat Fleet to Clear Waterways of Trash

The California Department of Transportation recently put together a video highlighting how its boat fleet in the San Francisco Bay Area – typically used to transport engineers, biologists, and maintenance crews to the area’s seven bridges – also helps clean up trash from local waterways and areas that are hard to reach by land.

[Photo courtesy of the California Department of Transportation.]

Hawaii DOT Launches Storm Water Online Learning Series for Kids

Protecting the ocean, rivers, and streams from pollution is the focus of a new online learning series for kids launched by the Hawaii Department of Transportation’s Storm Water Management Program.

[Photo courtesy of Hawaii Department of Transportation.]

The Hawaii Storm Patrol Online Learning Series teaches children – known as “keiki” in Hawaiian – about storm drain systems, how they carry rainwater off roadways to prevent flooding, and why preventing litter, debris, chemicals, and other pollutants from entering storm drains helps preserve the environment.

Photo courtesy of Hawaii DOT

The free series is available at and can be viewed on a desktop, laptop, or mobile device.

The agency noted that this video series is comprised of four animated videos that explain the water cycle, how Hawaii’s storm drains work, different types of pollution, and the impact of storm water on our ocean and near shore waters. Characters from the popular Hawaii Storm Patrol: New Recruits booklet star in the series and offer tips to protect the environment.

Each video is followed by a short quiz to help young viewers retain information and students who complete the online learning series become an official recruit of the Hawaii Storm Patrol and can download a specially designed Zoom background to use for their virtual classes.

An instructor’s guide is included to help parents and teachers utilize the online learning series in a remote learning or classroom setting. “Our in-person, in-classroom storm water presentations were well received by students and teachers. Keiki now understand the importance of protecting the environment and are eager to learn how they can help,” explained Jade Butay, Hawaii DOT’s director, in a statement. “We wanted to build on the success of our in-classroom program and creating a remote learning version enables us to reach more students and expand the awareness of storm water pollution prevention.”

Filling Pavement Temperature Data Gaps to Prevent Overuse of Road Salt

Could more accurate and consistent pavement temperature data held reduce the overuse of salt and other ice-melting chemicals during winter operations? The Iowa Department of Transportation plans to find out via a new one-year pilot program it recently launched.

[Photo courtesy of the Iowa Department of Transportation.]

Road salt – also known as sodium chloride – is widely used as a pavement deicer in the United States and other countries, yet it is an increasing source of concern as it accumulates in lakes, streams, and other bodies of water. In 2017, the Minnesota Department of Transportation released a 128-page study that sodium chloride infiltrated pervious areas adjacent to the streets after being plowed or splashed over curbs by traffic. That report showed, in part, that reducing the amount of sodium chloride and other road-clearing chemicals deployed by snowplows depends on the broad availability and accuracy of road temperature data.

Tina Greenfield, who works in the Iowa DOT’s maintenance bureau, noted in a blog post that its highway maintenance supervisors rely on pavement temperature data to determine what treatment options to deploy during winter storms – such as granular salt or brine – and in what quantities to either pretreat the roads or break up snow and ice.

Currently, the Iowa DOT collects pavement temperature via more than 70 Roadway Weather Information System, or RWIS, stations positioned around the state – stations owned and maintained by the agency.

However, those stations cannot collect data on every stretch of highway maintained by the Iowa DOT – leaving a number of large “data gaps” throughout the system.

To close those gaps, the agency is conducting a pilot project to purchase “data as a service.” The project will collect data recorded by smaller, privately owned battery-operated units using infrared technology to sense pavement temperatures and relay the data over a cellular connection.

“This is very similar to the sensor technology we have in our snow plow trucks,” Greenfield explained “Since we’re just purchasing the data, we don’t incur any of the cellular or power costs,” she added. “By using infrared technology, there are no sensors in the pavement to install or maintain.”

[Want to know more about snow and ice fighting tactics? Check out the winter operations podcast put together by the American Association of State Highway and Transportation Officials Snow and Ice Pooled Fund Cooperative Program, known as “SICOP.”]

She noted that the pilot project also allows her agency to choose the vendors supplying and maintaining this data collecting and reporting equipment “We simply purchase that data that equipment gathers,” Greenfield emphasized. “If these work out, this can be a very affordable way to get the data. This allows us to gather more data without having to invest in hardware and technology.”

Video: WSDOT Makes Bridge Safer for Human Travelers & Fish Species

The Washington State Department of Transportation recently wrapped up a roughly $13 million fish barrier correction project – resulting in a new 440-foot bridge that spans Kilisut Harbor along State Route 116. The new bridge not only improves safety for human travelers but also is, in the words WSDOT Project Engineer Dan McKernan, a “huge win” for local salmon and other fish species in the area.

[Photo courtesy of Washington State Department of Transportation.]

“The work involved replacing two small culverts that were installed in the 1950s. The channel here now with the bridge was not here previously,” he said, adding that the new channel aids in the annual migration of salmon in the area.

This work is part of WSDOT’s Fish Barrier Removal Program, which identifies and removes barriers to fish caused by culverts under state highways. The agency noted in a statement that it worked with the North Olympic Salmon Coalition or NOSC to complete this specific bridge project while also continuing to work with the Washington State Department of Fish and Wildlife to identify locations where culvert replacement will increase fish habitat.

“The area between Indian and Marrowstone Islands was historically comprised of tidal channels and salt marsh,” NOSC noted in separate statement. “Tidal waters exchanged freely between Oak Bay and Kilisut Harbor, flushing cold water, moving sediment, and allowing juvenile salmon to migrate northward from Oak Bay into the shallow, productive waters of Kilisut Harbor. The installation of the causeway in between Kilisut Harbor and Oak Bay eased transportation between the Islands, but choked the flow of water and sediment, eventually creating an artificial beach berm, a filled channel, and increased water temperatures in Kilisut Harbor.”

The construction of the new bridge also resulted in the removal that land barrier, reconnecting the large numbers of Hood Canal and Puget Sound out-migrating juvenile salmon that converge at Oak Bay with immense foraging opportunities available within Kilisut Harbor while also restoring and enhance important staging and foraging habitat for multiple coastal dependent and migratory birds. “Clean, cold water is now flowing north into Kilisut Harbor/Scow Bay,” the organization noted. “This mixing on each tide cycle is expected to improve water quality in Kilisut Harbor over time.”

Video: Volunteers Help Oregon DOT with Wetland Renewal

Volunteers with Klamath Wingwatchers recently helped the Oregon Department of Transportation resettle “sedges” from the Lost River Wetlands to the Lake Ewauna Trail in Klamath Falls.

“Sedges” are grass-like plants with triangular stems and inconspicuous flowers that typically grow in moist, wet ground. They are a major – often the dominant – plant of many wetland ecosystems throughout the world and their long, strong densely tangled stems and roots can help with erosion control. They also help improve water quality by acting as filters to remove pollutants and sediments; demonstrating the ability to remove a large percentage of nitrogen and significantly sequester metals such as copper.

Moving sedges to the Lake Ewauna Trail – Oregon DOT

Maryland DOT Division Joins New Chesapeake Bay Restoration Effort

The Maryland Department of Transportation’s State Highway Administration is launching a pilot education program with Living Classrooms Foundation that will encourage activities to reduce pollution to Maryland waterways and the Chesapeake Bay, with the overall success of this endeavor to be measured under Maryland Department of the Environment (MDE).

“Working with Living Classrooms and other Bay partners, this program will help us empower one of our greatest resources in cleaning up the Chesapeake Bay – our young people,” explained Gregory Slater, Maryland’s transportation secretary, in a statement. “Together we will educate future stewards of the environment with a program that’s informative, innovative, and driven by data to achieve real progress in restoring the bay.”  

He said SHA is investing in the program as part of the agency’s commitment to pollution reduction goals under its municipal stormwater permit. Meanwhile, MDE will work with SHA and Living Classrooms to establish a scientific basis for credits SHA would receive toward its stormwater permit obligations; credits for “environmentally positive actions” resulting from this educational program.

Those “actions” might include reducing the use of fertilizer, building rain gardens, using rain barrels to reduce polluted stormwater runoff, or increasing the use of public transit to reduce emissions that can deposit nutrient pollution in the bay. 

The agency noted that this pilot project is designed to tie environmental education and pollutant reductions together through rigorous social and scientific monitoring. When students are moved to install rain gardens for capturing stormwater runoff or take mass transit for reducing harmful emissions, those actions can be tracked, pollutant reductions can be measured, and stormwater discharges can be reduced.

The scientific basis for crediting an educational best management practice supports the Chesapeake Bay Program’s Citizen Stewardship Outcome Management Strategy, which holds that the long-term success and sustainability of the Chesapeake Bay restoration effort will ultimately depend on the actions and support of the 17 million residents who call the watershed home.

Slater, who previously served as SHA’s administrator, said the partnership with Living Classrooms was sparked by ongoing concern with litter that affects the health of the bay – noting that in 2018, the Maryland DOT spent more than $9 million on litter abatement. 

“Maryland DOT’s environmental programs are a key part of our mission and we are continuously looking for innovative partnerships in yielding sustainable results,” said Secretary Slater. “This partnership recognizes that education is just as important as our physical efforts to tackle pollution.”