Warmer weather this week may be a good opportunity to help curb the salt running into our streams and lakes. The Minnesota Pollution Control Agency says just shoveling and chipping away ice is the best way avoid resorting to the chemical that is building up in Twin Cities waters.
"Currently we have 44 waters in the seven-county metro area that are higher than the state water quality standards for chloride," said Brooke Asleson, chloride project manager at the MPCA. That includes 35 waters new to the list for 2014. The chloride contamination comes from salt Minnesotans spread on their roads, driveways and sidewalks in the winter to keep them from getting slippery.
"There's really no other source of salt to our waters than road salt. So it's mostly an urban, very high road density problem where we see these higher chloride concentrations in our waters," said Asleson.
And unlike other contaminants, it shows no signs of going away. Chloride doesn't degrade over time, and it isn't taken up by plants or other organisms, Asleson said. It will continue to build up over time.
Here are four tips the MPCA has for keeping salt use down:
1) 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.
2) 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.
3) Use sparingly. 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.
4) Wait for warm weather. 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.