Winter weather can wreak havoc on area roadways and on utility systems, particularly water and electric companies. The freeze-and-thaw cycle can lead to water main breaks and freezing temperatures can cause indoor plumbing and service lines to freeze, leading to service interruptions and broken pipes inside the home. Frost in the ground, which penetrates deeper when there is no snow cover or when moisture gets in the ground, will add an enormous downward load on pipes causing them to crack; and if shallow enough, to freeze. Ice on tree limbs can create unbearable weight, which can cause them to breach power lines, leading to service outages. And we all know the potential hazard of driving on roadways that have not been treated for ice.
Municipalities and state highway departments use various forms of salt to keep highways from freezing so vehicles can drive safely. Road salt is commonly made up of some combination of sodium, chloride and calcium, all of which are naturally occurring and can be found in drinking water on any given day. They are not removed through the conventional drinking water treatment process.
When runoff occurs, as a result of thawing or rain, road salts are washed from the roadways into the ground and surface waters, like rivers, streams and reservoirs. When runoff occurs as a result of a heavy rain, the impact of the salts on the waterways are dissipated by the dilution of the large volume of rain water. The impact of the runoff may also differ based on the size of the watershed area and the size of the affected body of surface water, such as the Delaware River compared to a local stream.
Usually, the impact of the road salts on the drinking water is minimal, with just a few customers who can taste the difference calling the utility. However, if the runoff occurs after a series of road saltings due to multiple storms and the ground remains frozen for an extended period of time, which prevents the percolation of the salt into the ground, the high concentrations of salt running into a small local stream can result in a salty taste to the drinking water.
The Environmental Protection Agency (EPA) and the many state environmental regulatory agencies—including the Pennsylvania Department of Environmental Protection (PA DEP)—have no regulatory standards for either sodium or calcium in drinking water.
EPA and many state environmental regulatory agencies—such as PA DEP— have secondary (aesthetic) regulatory standards for chloride. Secondary standards are not considered to have any public health risks.
Primary and secondary drinking water standards are set with the general public in mind. If any customer feels they are an exception to the general public and have a concern about their drinking water, they should contact their primary health care provider for counsel.