A Salt Assault. The use of salt on roads saves lives, and its use in water softeners improves water quality, but there is a down side, and a price to be paid for using all this salt. Salt deteriorates the country’s infrastructure and it is slowly contaminating the environment. Road salt, unlike organic compounds, never deteriorates and only a small portion returns through rivers and streams into the ocean. The rest remains in the soil and slowly migrates into the lakes and ground water (our drinking water).
The salt measurements of Geneva Lake taken by the Geneva Lake Environmental Agency (GLEA) show a slow but steady increase in salinity from 32 mg/L in 1997 to 48 mg/L in 2016. This 50% increase in less than 20 years is a significant increase, even though it is still below the federally designated danger threshold of 230 mg/L.
How serious is the rising salt level of Geneva Lake? There are both knowns and unknowns about the impact of salt on the lake. Here are a few of the knowns about salt:
1.) There is no health-based standard for sodium (salt) in drinking water in the U.S.
2.) Public drinking-water systems under the Safe Drinking Water Act are required to sample for sodium on a regular basis and report to the Medical Officer of Health when sodium levels exceed 20 mg/L. This information is made available to local physicians in order to help people on sodium-restricted diets control their sodium intake.
3.) If Geneva Lake were drinking water it would be at 2.4 times that 20 mg/L threshold for notification.
4.) The Canadian Drinking Water Guideline maximum for sodium is 200 mg/L. Sodium concentrations above 200 mg/L will make the water taste “salty,” and at 1000mg/L the lake would be classified as a salt water lake.
5.) At its current rate of increase in 200 to 250 years Geneva Lake would begin to taste salty, and another 1,000 years and it would be a salt lake.
6.) With the increasing number of roads, sidewalks and the use of salt on them, this trend is expected to increase and shorten the time unless offset by global warming and a corresponding reduced use of salt due to milder winters.
The short term effect of the increasing salt level in the lake is the real unknown, but some species, like some individuals, are less tolerant of salt. Those species that are less tolerant of higher levels of salt will slowly die off, and give way to those that are more tolerant. This will be a non-reversible event that will alter our lake and its future, and no one knows with certainty at what level this will occur or the magnitude of the impact. What is certain is that it will occur if salt levels continue to rise, and it will be devastating on the lake. For now the best thing that is practical is for us to use as little salt on our roads as road safety permits, while science continues to study the impact and hopefully finds a solution before time runs out for our lake. Currently, there is no way to get salt out of the lake, all we can do is to stop putting it in.