With massive tax increases to ease the pension crisis behind him and Chicago homeowners and businesses already paying the price, Mayor Rahm Emanuel is expected to unveil a 2017 city budget Tuesday that goes light on new taxes and fees and heavy on public safety.

The cornerstone of the mayor’s budget is the promise to hire 970 Chicago Police officers over the next two years to combat a 50 percent surge in homicides and shootings.

The Chicago Sun-Times reported last week that Emanuel will open one or more auxiliary training facilities and build a new academy shared by police and fire to help deliver on that promise.

Half of the two-year, $133.8 million price tag for the new officers would be built into a 2017 budget that includes roughly $30 million in “targeted” taxes, fines and fees even as it closes loopholes and holds the line on property, sales and gasoline taxes, the newspaper reported.

The targeted taxes include a 7 cents-a-bag tax on paper and plastic bags to aimed at getting consumers to bring reusable bags on shopping trips.

The spending plan will also forge ahead with a previously shelved, $31 million plan to turn 311 non-emergency into a two-way communications system without the privatization that sparked a mini-rebellion in the City Council.

The overhaul will be bankrolled by the sale of 18 acres of prime riverfront property near Goose Island that houses the city’s largest vehicle maintenance facility. It will be sold to a developer after Fleet Management moves that facility to Chicago’s impoverished but rebounding Englewood community.

The bag tax might leave Chicago consumers feeling nickel and dimed because they will pay it every time they go to a grocery store or any other Chicago retailer without reusable bags.

The purpose is threefold: penalize consumers for using disposable bags that clog the city’s waste stream and drive up landfill costs; stop major retailers from getting around the city’s partial ban on disposable bags by using thicker plastic ones; and raise as much as $13 million a year for the city.

At a ribbon-cutting Monday for a Mariano’s store in Bronzeville, Ald. Pat Dowell (3rd) said she’s not “that concerned” about a consumer backlash.

“In this case, they have a choice . . . whether they want to pay this tax or not,” Dowell said. “People have the power to avoid that tax by taking recyclable bags to the store.”

“[If] it’s 7 cents a bag, that’ll encourage a lot of people to use recyclable bags. I know it’ll encourage me because I’m someone who carries bags in my car and sometimes forgets to take them in there. But if I have to pay 7 cents, I’m gonna remember.”

Ald. George Cardenas (12th), chairman of the City Council’s Committee on Health and Environmental Protection, said the bag tax might have to be higher.

“Seven cents [per bag] is probably not gonna cover it. I don’t know if that’s the right amount. It does seem too low. It may not be enough of an incentive,” Cardenas said Monday.

“We went through this exercise a couple of years ago. . . . We want to get it right — not be back to square one.”

Two years ago, the Illinois Retail Merchants Association pushed hard for a 10 cent tax on paper bags to allow retailers to recoup their costs.

Emanuel refused to go along. He said there was nothing stopping retailers from charging for disposable bags, but he was not about to do it for them.

But that was before the partial ban turned into something of a farce with giant retailers like Target and Jewel-Osco switching to thicker plastic bag capable of holding up to 22 pounds and being reused 125 times.

Emanuel refused Monday to say why he changed his mind about the bag tax.

He would only talk about his budget priorities and the investment he plans to make in mentoring, after-school programs and summer jobs that he views as every bit as important as the police hiring surge.

“Starting this November, 4,000 of our young men in neighborhoods will be in a mentoring program on our way to 7,200,” Emanuel said.

“I’m gonna add 2,000 [summer] jobs this year. But those jobs will be reserved for the young men [who] are part of our Becoming-A-Man program. Just for them. They have to get good grades, good attendance and stay out of trouble. If they do that, there’s a summer job waiting for them and a paycheck.”

Chicago taxpayers have paid a heavy price for easing the city’s $30 billion pension crisis.

They have been hit with $838 million in property tax increases for police, fire and teacher pensions; a 29.5 percent tax on water and sewer bills to save the Municipal Employees pension fund; and a 56 percent increase in the monthly tax on telephone bills — cellphones and land lines — for the Laborers Pension fund.

The heavy tax burden already imposed is why Emanuel’s sixth budget is his easiest: The tough stuff has already been done.

Still, there are warning signs ahead.

Contracts with the building trades and Chicago Police officers expire mid-year. Costly pay raises will be required after June 30 at a time when the city will be under pressure to satisfy salary demands of the Fraternal Order of Police to offset the city’s need to change how cops are disciplined.

And the U.S. Justice Department is likely to make costly demands for police hiring, training, supervision and equipment after completing a sweeping civil rights investigation of the Chicago Police Department triggered by the police shooting of Laquan McDonald.

With that in mind, Emanuel plans to thank aldermen for the difficult decisions they have already made, with a caveat: “Our work is not done.”