Road Salt is Imperiling Aquatic Ecosystems. It Doesn’t Have to.

ISTOCK.COM/WILLOWPIX

 

Connecting state and local government leaders

COMMENTARY | A pilot project in upstate New York shows how we can balance our need for safe roads with our duty to protect nature.

During this unusually snowy year, the rumble of snowplows and salt trucks has become a familiar — and comforting — winter soundtrack across the northern U.S. In southern Vermont, where I live, we received more than 100 inches of snow through February, about twice the typical snowfall for that time of year. Undoubtedly, de-icing salts have prevented numerous accidents on otherwise slick roads.

Although salt contributes to road safety, it racks up high hidden costs. In the U.S., salt damage to infrastructure and the economy is estimated to total between $19.8 billion and $45 billion annually. That includes damage to roadways, bridges, vehicles, tourism, and property values. For example, salt can leach calcium out of concrete and rust steel rebar, a process sometimes known as “concrete cancer” that rots bridges from the inside with few outward warning signs.

For all their economic costs, road salts may take an even steeper toll on the environment. As salty runoff infiltrates streams and lakes, it can upset freshwater ecosystems. Authors of a 2017 study estimated that 7,770 North American lakes — about 20 percent of those in the study region — may have elevated chloride concentrations. And this number may be an underestimate, say the authors.

If trends continue, the study concludes, many of these lakes will be too salty to support life within 50 years. Lakes with roads and parking lots nearby are most at risk; 70 percent of these lakes are likely to have elevated chloride levels, based on the study’s sample.

Excess salt can damage entire aquatic food chains, including zooplankton, salamanders and frogs, fish, shellfish, and aquatic plants. At high concentrations, salt can stunt the growth of some fish, making them more vulnerable to predators. It can tilt male-to-female ratios of amphibian populations out of balance. And it can kill off algae-eating zooplankton, allowing algae to grow unchecked into smelly, goopy, hazardous blooms.

Even organic additives made from natural substances like beet juice and molasses, used to improve salt’s melting power, can have unintended consequences. One study found that two common additives, GeoMelt and Magic Salt, caused mosquito larvae to mature and hatch earlier than usual.

Flora Krivak-Tetley, an ecologist at Dartmouth College who co-authored the 2017 study, says that salt concentrations in most lakes have not reached the threshold the Environmental Protection Agency’s deems lethal for aquatic life. But salt can throw an ecosystem out of balance well before that happens, she notes.

And this is to say nothing of the enormous carbon footprint associated with transporting and distributing the salt, much of which arrives on barges from countries such as Chile and Egypt.

How, then, can we balance our need for safe roads with our duty to protect the environment?

In 2015, the not-for-profit FUND for Lake George, in upstate New York, launched an effort to answer that question. They started by working with towns around Lake George to determine just how much salt they used. Maintenance managers deployed GPS to track trucks’ speed and position, and used sensors to measure how fast salt was being released. This feedback allowed road crews to calibrate their distribution rates, saving money, salt, and effort.

Next, leaders in the Lake George region experimented with ways to keep the roads clear using less salt. They found it worked well to pretreat roads with salt brine before winter storms. The liquid prevents snow and ice from bonding with the asphalt, making it easier to scrape roads clean. Unlike grains of rock salt, which often bounce onto road shoulders, brine largely adheres to its target.

Area officials found that, pound for pound, brine was far more efficient than traditional rock salt. They could protect a lane-mile of road with a solution containing under 100 pounds of salt, roughly one third the amount used by rock-salt trucks.

Last, the towns switched to live-edge plows, which have flexible blades made up of multiple, independently moving sections mounted on springs. These state-of-the-art blades are more thorough than conventional ones. And starting with brine makes the plows even more efficient, says Eric Siy, executive director of The FUND for Lake George. If live-edge snowplows are like razors that hug the curves, brine is like shaving cream.

The sweeping changes to road care required a culture shift within the towns’ maintenance departments. But black roads and shortened plowing times ultimately convinced road crews near Lake George to embrace sustainable winter management. Over two years of using brine and live-blade plows, these communities cut their salt usage in half, a drop that maintenance officials say can’t be explained by weather variations.

The changes also saved the municipalities time and money. Siy says that the town of Hague, New York, saved $66,000 of its $150,000 winter maintenance budget last winter. If just half the towns in New York achieved results like Hague’s, Siy says, taxpayers’ annual savings would be more than $30 million.

The Lake George area’s project is one of many efforts to create a more sustainable paradigm of winter road maintenance. Road salt use is also starting to decline in other communities around the nation as maintenance chiefs exchange best practices. More cities have incorporated brine pretreatments, flexible plow blades, and truck-level monitoring into their road maintenance regimes.

“There’s no trade-off, there’s no compromise,” says Rick Relyea, an ecologist at Rensselaer Polytechnic Institute who has partnered with The FUND for Lake George on a multi-year research project studying the lake’s water quality. “It’s not the environment versus safety. You can have both.”

As America thaws out from one of its snowiest winters in recent memory, the lessons of Lake George are timely. The U.S. applies about 24 million tons of salt to its roads each year. If salt use continues unabated, the environmental costs may be even higher than we can imagine. Experts say we’re only just starting to learn about the unintended impacts road salt has on ecosystems.

A nationwide effort to move toward sustainable winter road maintenance is long overdue — and it would be well worth the investment.

This article was originally published on Undark. Read the original article.

Anne N. Connor is a solution-focused science writer living in Vermont.

NEXT STORY: With Covid Aid Approved, Counties Will Look to Infrastructure

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.