Keeping Groundwater Supplies Clean During the Winter Season

By Heather Voorman, The Groundwater Foundation

We all breathe a sigh of relief when we see the road maintenance crew salt, sand and shovel out the roads after a winter storm.  The truth is however, too much road salt can contaminate groundwater supplies.   So what can be done to make roads safe without harming the environment?

How do road salts contaminate groundwater?

First, it’s important to understand how road salts contaminate groundwater. When the snow melts and spring rains come, all the salt that accumulated over the winter ends up in storm water catch basins and streams.  The salt that is carried to surface water can harm fish and plants.  The salt can also damage vegetation and soil along the shoulders of roads, causing erosion issues. 

The salt can get into underground drinking water supplies by infiltrating the groundwater and contaminating wells.  Salt can remain in groundwater for decades.  If the salt does get into groundwater supplies used for drinking water it can affect the taste of the water, affect individuals with hypertension, and corrode plumbing infrastructure.  

Lowering salt applications make roadways safer.

Although salt is used because many municipalities believe it is one of the only ways to ensure roadways are safe, there are techniques, equipment and chemicals that require less salt to be used and actually make roads safer.  In Kamloops, BC, Canada following the change to a low-salt application technique, the city saw an 8% decrease in accidents.  Similarly, in Idaho transportation officials switched from heavy salt and sand applications to liquid magnesium chloride on one stretch of road and saw an 83% reduction in accidents in that area.  This sort of success story probably won’t happen in every case, but by utilizing lower salt application techniques, roadways become safer and the environment becomes healthier.

What can you do?

Here are some ideas you can recommend to your local municipality to protect groundwater supplies from salt contamination:

1.     Use the right amount: The most important factor to remember when applying salt is the surface temperature.  When roads are warmer, less salt is needed.  Municipalities might consider purchasing inexpensive infrared thermometers for spreading trucks.

2.     Only use it where it’s needed: Make sure salt is being used in areas where it is most needed.  Hills, curves, bridges, etc. need more salt than other areas of the road.  There are also times when salt won’t help melt ice on roads.  If the surface temperature is below ~10º F, a road won’t benefit from salt.  Instead, use another chemical suited for lower temperatures. 

3.     Apply early!: Don’t wait until the snow starts falling to apply salt.  It takes more salt to melt snow that has accumulated than it does to prevent the accumulation.  Brine can be applied days before a weather event in the right conditions. 

You can also use these techniques when you apply salt on your own driveway and sidewalks so you can stay safe while keeping groundwater supplies clean!

[source: www.epa.gov]

 

Water Wars: Are Groundwater and Surface Water One Resource?

By Ann Bleed, Groundwater Foundation Board Member

This is a story about Nebraska, but I have reason to believe, the lessons Nebraskans are learning are pertinent to all United States. In Nebraska, as in the rest of the United States, the use of surface water started early. It wasn’t long, particularly in the arid west, that the adage, “Whiskey’s for drinkin, water’s for fightin” became true. Yet, in time we developed rules and surface water storage reservoirs to tame, if not eliminate, the water wars.

Although the use of ground water for domestic wells and some irrigation along streams started early, it wasn’t until the middle of the twentieth century, with the invention of methods to drill and pump from deep wells and the innovative development of the center pivot, that ground water use began to develop. Again, in Nebraska as elsewhere, ground water helped slake our ever increasing demand for water and quell the water wars.

For a time, with large surface and ground water reservoirs at our disposal, we in Nebraska truly lived the good life. Even in the dry years of the 1970s, squabbles among water users were few. Many believed with our endless ground water supplies, we had solved our water problems. This myth was bolstered by the strong belief in people’s minds that surface water and ground water are connected. Even state law did not recognize a connection. Gradually, however, our streamflows, and worse yet the alluvial aquifers fed by stream flows, started to decline. Surface water users, with permitted water rights, environmentalists, started complaining that ground water pumping was drying up Nebraska’s surface water supplies.

With the threat of law suits, from both within and outside the state, slowly Nebraskans and Nebraska law began to take small steps toward recognizing that surface water and ground water are indeed connected. But the politics were, and still are, such that neither the courts nor the legislature seem inclined to tackle the problem. Hence the water wars have started again and seem to grow, in proportion to our growing water demands.

Yet, I see signs of hope. We are slowly starting to recognize that our surface water and ground water supplies are not only connected, but in many instances are simply different manifestations of a single resource. In addition, although in the early 1900s, Robert Willis, one of Nebraska’s early water engineers, recognized the importance of surface water irrigation for maintaining alluvial aquifers and streamflow during the irrigation season, we are just now starting to actively manage some of our surface water canals for ground water recharge. And, better yet, where these management schemes are being realized, the “fightin” words between surface water users and ground water users is beginning to disappear.

The importance of the realization that managing interconnected surface water and ground water as one resource was recently demonstrated at a water users task force, The Water Funding Task Force was established by the legislature to develop much needed funding for water research, management, and infrastructure. A battle between surface water users and ground water users over who should allocate the funds was widely expected to block any consensus on a recommendation for the legislature. That did not happen. Why? After much education and discussion among task force members, the task force recognized that ground water and surface water are not only connected, but where there are these connections are simply different manifestations of one resource. Also, and importantly, they came to understand that if we are to sustain the water uses that provide Nebraska with the good life, we must work together to manage this precious resource as one supply. With this understanding a consensus, which few expected, was achieved. Perhaps, the rest of the state can learn from the task force and instead of funding lawsuits, we can stop “fightin”, and use our resources to solve our mutual water resource problems.