Salt Testing Shows Toxic Levels Continue into Spring

Snow plow painted by LFWA volunteers to raise public awareness of the threat road salt presents to aquatic life. Plow designed by Toby Kathan.

Volunteers testing creeks in the Little Falls watershed found that salt readings in area creeks spiked to toxic levels after snow storms, but they did not always return to safe levels after the events. April readings showed that chronic toxicity (over 230 parts per million) remains in 3 locations on the Little Falls Branch - by the Somerset Pool, by the Willard Avenue Neighborhood Park, and by Westbrook Elementary School. Chronic toxicity means that the habitat of the aquatic life that depends on fresh water is compromised to the point where they cannot survive.

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Results from April 2025 Salt testing show chronic toxicity is still a problem at three locations along the Little Falls Branch despite the fact that the last snow event was over a month ago.

Since December 2024, trained LFWA volunteers have tested 8 sites along the Minnehaha, Little Falls and Willett Branch creeks before and after snow storms as well as once a month in the warmer months. The data shows that we have a serious salt pollution problem in the watershed. Most of our sites experienced spikes to levels of over 860 PPM after snow events. Chloride is naturally present in the environment. Chloride concentrations between 1 and 100 ppm (mg/L) are “normal” in most freshwater waterways. But levels over 230 PPM are considered chronic toxicity as aquatic organisms cannot tolerance this much salt for more than a few days. Levels over 860 are considered acute toxicity as the organisms can only survive for several hours at this level.

Read our report on the state of Salt in the watershed HERE.

Problems with Salt Pollution

High levels of salt also have inverse impact on human health, contamination our drinking water. And there are costs to infrastructure. Chloride can corrode metal, concrete, bridges, vehicles, drainage systems, highway fixtures and drinking water pipes. Izaak Walton league estimates that the long term costs associated with salt pollution effects on the infrastructure will cost between $16 - $66 billion a year, if we continue to use salt at the current rate.

There is also a concern about salt in the water comes from local waterways. WSSC, which treats drinking water for Montgomery County has seen an alarming rise in the salinity of the Potomac River - a 41% increase in the past 30 years. “WSSC Water closely monitors the water entering our Potomac and Patuxent Water Filtration Plants. Over the past 30 years, the average salt levels (sodium and chloride are the two components of salt) have been steadily increasing. The levels peak in the winter months and are higher in years where we experience more winter weather events. Because there is no economically feasible way to remove salt during filtration, higher levels end up in the drinking water.” https://www.wsscwater.com/saltwise

For an excellent review of the concerns about salt pollution, there is this article from the Izaak Walton Salt Watch program.

LFWA Salt testing program

Salt testing sites in the Little Falls watershed.

LFWA has been testing four streams in our watershed for salt pollution since 2021. We have one site on the Glenbrook tributary, one site on the Willett Branch, one site on the Minnehaha creek and 5 sites long the Little Falls Branch.

The most up-to-date readings can be found HERE along with information about our salt testing program.

thank you

Thank you to Woody Stanley and our salt volunteers for their hard work on documenting the problem of road salt in the watershed.

This program is run in partnership with Izaak Walton Salt Watch.

No Snow Yet, but Salt Levels are High in the Watershed

LFWA citizen scientists are busy at work again, this time testing for salt pollution in our creeks. While the 3 inches of rain last weekend washed away much of the salt pollution, the baseline tests taken in mid-December showed high levels of salt - almost to the chronic level.  This is alarming as the freshwater organisms who live in the creek, cannot survive when the salinity of the water gets too high.   The saline levels are caused by road salt which makes its way into the creek through run-off when the salt melts.  

Baseline results from December 16.

These high levels at the beginning of winter are a reminder of long lasting effects of road salt.

Just a sprinkle will do.

High baseline levels are also a reminder to keep salting to minimum on your sidewalks and driveways. We want people to be safe, but we also want healthy creeks.  So read the instructions on the salt containers carefully and remember more is not better.  A 12 ounce coffee cup holds enough salt to treat a 20 foot driveway! And if there is salt still on the pavement after the storm - you can sweep it up and save it for another storm.

call 311 to report salt spills

Montgomery County is committed to responsible salt treatment of public roads and sidewalks. This means removing piles of excess salt. Please, if you see piles of salt on your street or other public areas, call 311 to report. They will come out and clean it up.

More information about the LFWA Salt Watch program and Salt Wise winters HERE.

Montgomery County maintenance crew cleaning up excess salt in the Westbrook neighborhood after receiving a 311 call from a resident.

Woody Stanley Named Winter Salt Watcher of the Month

Congratulations to Woody Stanley, LFWA Salt Watch Team Leader, for being named the Izaak Walton League Winter Salt Watch monitor of the Month, February 2022. LFWA is proud to partner with Izaak Walton in their winter salt watch program.

From the Izaak Walton Website:

Woody Stanley is the Salt Watch coordinator for the Little Falls Watershed Alliance in Bethesda, MD. While LFWA had a Salt Watch team, Woody took the program up a notch this year and recruited, organized and trained 16 volunteers to monitor three streams in the watershed at seven locations.

The volunteers test monthly (since November) to establish baseline readings and before and after snowstorms with Woody’s support at every step. He’s always available to answer questions, clarify the reading procedure and even meet volunteers creek-side to walk them through the app and testing procedure. Further, Woody is the inventor of the Tomato Stake Scooper – a really handy way to take a sample while safely standing on the creek bank, eliminating the risk of falling into the creek.

Woody also maintains our database, compiling all the information and producing graphics that are posted on our website and on community listservs.

Because of Woody’s efforts in organizing this initiative, LFWA now has a good idea of how much salt is being used during storms and how it is affecting the creeks. We have already used the data in our advocacy for more judicious salt application. And at least one local municipality is seriously rethinking their salt policy because of this increased data. Further, because Woody presents the information in a clear graphic form, public awareness of the problems with salt has increased and we are hearing from people who want to know who they can call to clean up excess salt. 

Learn about the LFWA Salt Watch Program HERE.