Buffalo Niagara Waterkeeper is sampling chloride levels to get a better sense of waterway health and to study the impacts of road salt in the Niagara River/Lake Erie Watershed.
Background
While chloride is naturally found in freshwater systems, levels can become elevated due to runoff containing road salt (deicer). Studies have shown negative impacts of high levels of chloride on aquatic life and drinking water.
Sampling Locations and Schedule
In November 2024, BNW began sampling a select group of local waterways for chloride to better understand waterway health and explore the impacts of road salt in the Niagara River/Lake Erie Watershed.
A sample was collected from each site before the first snowfall and before any road salt was applied, during dry conditions in November 2024. These sampling results served as a baseline for the waterway. Additional samples were taken in March and April 2025, after the heaviest snowfall months, once the waterways were safely accessible.
| Waterway and sampling location | Latitude | Longitude |
| Crooked Brook @ West Lake Shore Rd. | 42.48259 | -79.35581 |
| Eighteenmile Creek @ Anna Mae Bacon Bird Sanctuary | 42.715107 | -78.82726 |
| Rush Creek @ Milestrip | 42.790254 | -78.836995 |
| Buffalo River @ Thomas Higgins Park | 42.861937 | -78.825436 |
| Scajaquada Creek @ West Avenue Bridge | 42.92982 | -78.89598 |
Map
Sampling Analysis
Samples were analyzed by the Erie County Department of Health Laboratory utilizing method EPA 300.1 REV 1.0. While this method is primarily used to analyze chloride in drinking water, it can also be used for surface and groundwater samples.
Our data set is compared to the U.S. Environmental Protection Agency’s recommended chronic aquatic life criteria for chloride, which is 230 mg/L.
A chronic limit refers to the highest concentration of a substance that is not expected to harm most aquatic life over long-term exposure.
Results
We acknowledge that our sample size was limited, with only three samples collected at each of the five locations. Additionally, this marks the first year that BNW has collected chloride data, establishing a baseline for future comparisons.
The dataset is displayed in two different ways in the two charts below.
As seen in Chart 1, the two highest readings were in March, after the winter months when road salt is applied.
Chart 2, below, displays chloride concentrations across the monitored waterways. The highest levels were recorded in March at Rush Creek and Scajaquada Creek.
These locations are downstream of busy urban roadways, where higher amounts of road salt are likely to be applied. The Rush Creek sample was collected downstream of Milestrip Highway (Route 179), and the Scajaquada Creek sample was collected downstream of many stormwater inputs from the Scajaquada Expressway (Route 198).
Both waterways’ chloride concentrations decreased from March to April, which could be due to reduced road salt usage due to warmer weather and decreased snowfall.
