Sarnia's winter maintenance season has begun, and with it the city has written plans for balancing road safety with keeping salt use in check.

Recommended by Environment Canada for municipalities using more than 500 metric tonnes of salt annually, the city's new salt management and winter operation plans detail how crews monitor the weather, patrol roads, and clear slippery conditions when needed.

“It's really putting down on paper what we're already doing, but this is the first time we've put together plans like this,” said city engineering and operations general manager David Jackson.

According to the plans, approved by council this week, Sarnia maintains more than 900 kilometres of roadways along 11 routes, and 168 kilometres of sidewalks, using a combination of local staff and contracted services.

Minimum standards for snow clearance on highways range from four to 24 hours, depending on how well used roadways are, and their speed limits.

Salt and sand-salt mixes are applied between 70 and 160 kilograms per kilometre, depending on snowfall, the plans say.

And the city monitors ground water, catch basin outlets and other areas, while keeping in touch with local water agencies, to monitor the impact of salt use, the plans say.

“We are exploring groundwater monitoring but do not have a program in place for that yet,” Jackson said.

Winters lately have been milder, meaning less salt, Jackson said.

About $1.1 million is budgeted for winter maintenance in the city's 2025 draft budget.

“Always hard to predict,” Jackson said.

“One large winter storm can come up and then we'd be right back on track for what the budget was.”

Switching to mostly pre-treated salt has also reduced salt use, saving Sarnia money and mitigating environmental impact, Jackson said.

“Generally that treated salt will stick to the road a bit better and it leaves a residual on the road, which helps start the melting cycle the next time,” he said.

The city's winter maintenance season is flexible, but generally runs Nov. 15 to April 15, the plans say.

Sarnia uses about 2,100 tonnes of the pre-treated salt on average per winter maintenance season, based on the last five, Jackson said.

Last winter maintenance season, 2,265 tonnes were used, he said.

“It is the best product to help keep the roads clear in the winter, so we do have to use it,” Jackson said.

The reason for the plans is “to analyze the whole process and to minimize the use as much as possible,” he said.

The plans will be reviewed annually, city officials said in a report, noting changes may include route updates or technological upgrades as needed.