I’m not really worried about the salt you consume but I am worried about the salt you may sprinkle onto the ground. According to the Minnesota Pollution Control Agency Minnesotan’s need to cut back on salt to help our water sources.
MPCA recommends low-salt diet for Minnesota waters
St. Paul, Minn. – For years, doctors have told people to stick to a low-salt diet. According to the Minnesota Pollution Control Agency (MPCA), our waters should follow the same advice.
Winters in Minnesota bring slippery roads, parking lots and sidewalks as well as the application of de-icing materials to keep these surfaces safe and ice-free. Road salt, which contains chloride, is the most commonly used de-icer. Chloride from road salt enters lakes, streams, and groundwater after snow melts. Once in the water, it becomes a permanent pollutant and is harmful to fish, insects and plants.
The chloride that enters surface water is eventually carried downward into the aquifers that provide the state’s drinking water, and it can even change the taste of tap water. Over the past five years, the MPCA has assessed the condition of Minnesota’s groundwater as part of the agency’s overall vision for clean water. Key findings of the Twin Cities Metro Area chloride project include:
One-third of wells across the state showed an increase in chloride concentrations.
Groundwater in the Twin Cities metropolitan area is impacted by high chloride concentrations.
27 percent of the metro-area monitoring wells in sand and gravel aquifers had chloride concentrations that were greater than drinking water guidelines set by the United States Environmental Protection Area.
The source of the high chloride concentrations in the Twin Cities and other urbanized areas comes primarily from winter de-icing chemicals.
“Salt is a real threat to water quality,” said Brooke Asleson, chloride project manager at the MPCA. “It only takes one teaspoon of road salt to pollute five gallons of water. If chloride continues to increase in groundwater, more waters will likely exceed drinking water and water-quality standards in the future. We are trying to spread the word that less is more when it comes to applying road salt because at high concentrations, chloride can harm the fish and plant life in our waters.”
Recently, the MPCA announced the draft 2014 Impaired Waters List. There are a total of 44 chloride impairments in the seven-county metro area. Thirty-five of those are new to the 2014 list. Many more waters may also have increasing chloride levels, but are not yet listed because of a lack of data to support the decision. All of the impairments in the metro area are being addressed through the Twin Cities Metro Area Chloride Project. The project also includes a chloride protection plan for all metro-area surface waters.
The MPCA remains concerned about the need to provide safe roads and paved areas, while also protecting water resources from contamination. The agency recommends the following tips for residents and individuals who are responsible for winter pavement maintenance:
Shovel first. The more snow and ice you remove manually, the less salt you will have to use and the more effective it can be. Then, break up ice with an ice scraper and decide if application of a de-icer or sand is even necessary to maintain traction.
Slow down. Drive for winter conditions, and be courteous to slow-moving plows. The slower they drive, the more salt will stay on the road where it’s needed.
More salt does not mean more melting. Use less than four pounds of salt per 1,000 square feet (an average parking space is about 150 square feet). One pound of salt is approximately a heaping 12-ounce coffee mug. And be patient: salt takes time to work. Applying more will lead to unnecessary contamination.
15 degrees is too cold for most salt to work. Most salts stop doing their job when the temperature is below 15 degrees. Instead, use sand for traction in frigid conditions.
Sweep up extra salt. If salt or sand is visible on dry pavement, it is no longer doing any work and will be washed away. The excess can be swept up and reused for the next snow or disposed of in the trash.
To learn more about the groundwater report, visit the MPCA’s website. For more on what you can do to reduce chloride in our waters, or to read more about MPCA’s role on this issue, visit the agency’s Twin Cities Metro Area Chloride Project web page.