March 3, 2014 Leave a comment
We posted previously about what it takes to keep Philadelphia’s streets clear and safe during winter weather. It turns out the story gets saltier— in a good way.
To reduce the amount of rock salt applied to roads while still effectively combating ice and snow, the Streets department applies brine. Just like the brine used for pickling and other culinary feats, the brine applied to roads is a solution of salt and water. Brine can be applied to roads up to two days before a snow event. As the water in the solution evaporates, a coating of salt remains on the asphalt. In contrast to dry rock salt, which is often swept from travel lanes to gutters by vehicular traffic, brine residue stays in travel lanes where it is applied. The Streets Department applies brine proactively to prevent ice or snow from adhering to road surfaces. Brine can melt up to the first two inches of snow that falls in a storm.
The Streets Department estimates that brining reduces total amount of salt required for wintry city streets by over 30%. Less salt used on roadways means less salt enters the urban ecosystem and area watershed. Less salt also means reduced corrosion and deterioration of the city’s bridges and streets, resulting in fewer potholes and needed repairs.
The City has been brining for about 15 years. To address challenges caused by aging brining equipment, Streets Department Commissioner Perri recently directed the Highway Division to revitalize the City’s brine operations. As a result, the Street Department’s Bridge Maintenance and Central Maintenance Units, along with Fleet Management, rehabilitated two brine stations. The Streets Department plans to expand brining operations as conditions permit. The primary focus for brine treatment at this time is roadways in elevated regions of the city and on Roosevelt Boulevard.
The challenge this year, of course, has been the intensity snow and icy conditions we’ve experienced, which mean brining can’t be the only solution deployed. Not including this year’s winter snowfall, 75% of the snow events in Philadelphia result in a snowfall accumulation of one inch or less. In the future, the Streets Department will continue to invest in this cost effective treatment technique for use in most storm events.
Thanks to the Streets Department for all of this information!