So if even the Romans thought salt was the ultimate environmental insult, shouldn’t we be concerned today when we see trucks spreading tons of salt after snowstorms like the ones we just endured?
This fear of salt was behind an email that Bay Daily reader Jeff Benson wrote to me during the height of the storm: “WHY ARE WE LETTING BALTIMORE CITY DUMP TONS OF CONTAMINATED SNOW INTO THE HARBOR?”
As it turns out, people who live next to the harbor or the Chesapeake Bay shouldn’t be worried about salt running into these waterways, because they’re already brackish -- a mixture of salty and fresh water. But folks who live inland, near freshwater streams and rivers, should try to minimize their use of salt, because adding excessive amounts of salt to these bodies of water can kill fish and the insect larvae that fish eat.
And, under no circumstances, should people use lawn or garden fertilizer as an ice-melting substitute for spreading salt on their sidewalks and driveways.
This sounds goofy, but apparently a Washington DC television station was advising that people spread fertilizer as a “concrete-friendly” alternative to salt. The problem with spreading fertilizer is that it is not Bay friendly. Most fertilizers contain nitrogen and/or phosphorus, which stimulate excessive algal growth and low-oxygen “dead zones.”
These conclusions come from Chesapeake Bay Foundation senior scientist Dr. Beth McGee, a biologist who knows all about how nitrogen and salts affect aquatic life.
“Although road salt does contain some impurities, the main concern is within the salt itself, which is not hurting the Bay,” Dr. McGee said. “The concern is freshwater systems – ponds, lakes and streams. There have been studies done that show that elevated chloride (salt) concentration, from applying salt to streets, can be toxic to freshwater organisms.”
The challenge in avoiding the use of salt on roads, is that more environmentally friendly alternatives –- such as calcium magnesium acetate –- can cost up to 20 times more, according to a report by Tom Schuler of the Center for Watershed Protection. This substitute also melts ice and is less toxic. But in this economic climate, it is hard to imagine local governments being able to afford this kind of expense.
Also, Dr. McGee said, while it is good to minimize the use of salt near freshwater streams, it is also important to consider other issues during a storm emergency. “You need to balance public safety with the environment,” she said.
We also need to keep this snowmageddon in perspective. Dr. McGee said it is not clear that this melting snow will create much more runoff pollution than a rainstorm.
“Is it any worse than a thunderstorm in the middle of the summer? It’s not any worse than that,” Dr. McGee said. “We need to do a better job with storm water management, period.”
(Photo of snowplow from the city of Frederick, Maryland)