Salt is polluting our fresh water in Minnesota. It is not just the salt used on winter roads but also salt used in water softeners.
According to the Minnesota Pollution Control Agency, one teaspoon of road salt pollutes five gallons of water-forever. The only way to un-do the damage is through reverse osmosis which remains too expensive to implement on a large scale according to MPCA.
Minnesota dumps 730 million pounds of salt on roadways each winter and it’s posing a major risk to the environment. The MPCA has calculated that 50 bodies of water meet the one teaspoon per five-gallon threshold, which means they are impaired, and 75 more are considered high risk. Most of the impaired bodies of water are in the metro area, but the potential for damage is statewide.
The salt we dump into our water is permanent, whether it is put on our roads or in our water softeners, it will not breakdown and it will not go away. Albar Sohanghpurwala, an expert in the field of corrosion of metals in concrete, estimates that one ton of road salt does about $1,500 worth of corrosion damage to bridges, vehicles and the environment.
The Minnesota Department of Transportation is responsible for 12,000 miles of road in the state. The department has made reducing salt use a major effort across the state and the MPCA has launched a chloride management plan across the metro area that focuses on smart salting, which is using the minimum amount necessary. Cutting back on salt use is an important first step but it does not eliminate the problem. State agencies have experimented with other deicers but with little success.
Cheese brine, beet juice and sand have been used effectively is some areas but does not solve the problem statewide. MnDOT has been working at using more snow fencing is some areas and working with landowners to leave rows of corn standing to block snow from drifting across the highway thus reducing the amount of salt used.
Homeowners can also help address the problem. Using less salt on the driveway and even reusing salt that is swept up in the spring can cut down on salt runoff and shoveling snow to bare tar or concrete can greatly reduce the amount of salt used. Water softeners are a huge contributor to salt in ground water. Most of us do not consider the impact that the bags of salt we dump into our softener are going to end up in ground water over time.
There are other products that can soften water but they are not as effective as salt. A call to the local plumber for ideas on how to reduce salt consumption would be a call worth making. Of course, not having soft water is another option some folks might want to consider.
Using salt on roads makes winter driving much safer. The challenge is finding ways to reduce salt use or find other methods that can protect our rivers, lakes and groundwater and still keep our roads safe.