ENGLEWOOD — One of Colorado’s most enduring firefighting forces — the Englewood Fire Department — ceased to exist Sunday as economic constraints and operational realities conspired to bring about a merger of the 108-year-old department with Denver fire.

The merger, which was hotly debated for months, will send 40 Englewood firefighters to the Denver Fire Academy on Monday to go through the ropes and come out as firefighters 1st grade — the highest level of firefighter in the Denver system.

For those like Englewood Deputy Chief Richard Petau, it means stepping down from his managerial duties and heading back out into the field for the first time in years. But the 40-year firefighting veteran doesn’t see the move as a demotion.

“That’s just fine,” he said last week at Englewood City Hall during a reception recognizing the department’s legacy.

Petau said there was initial grumbling among some Englewood fire personnel about having to start over with a new organization, but he said they grew to recognize they had little choice.

“At some point, reality starts to set in that keeping a stand-alone department is something the city couldn’t afford,” he said. “Englewood is just too small, and we’re surrounded by Denver.”

Petau said regionalization of firefighting resources is becoming a trend nationwide, including in and around the Denver metro area.

An analysis by Englewood concluded that maintaining its firefighting force would cost the city an initial $18 million — in addition to the department’s $9 million annual budget — to upgrade equipment and fire stations.

The Denver Fire Department, by contrast, will charge about $7.8 million in the first year and $5.4 million annually on a contract basis thereafter to provide fire and emergency medical services.

Englewood will spend another $600,000 a year to keep fire marshal duties in the hands of former Englewood Fire Chief Laura Herblan and her staff rather than confer those responsibilities to Denver.

Out of Englewood’s 58 firefighters, 40 are heading to Denver while the rest either chose to retire or move on to other things. Three members of the force didn’t meet Denver’s specifications for employment.

The city will pay a salary differential to its transitioning firefighters to keep their compensation equivalent to what they make now. That will cost Englewood $1.58 million over the next three years, said city manager Eric Keck.

“It’s my desire that these people are taken care of going forward,” he said.

Keck faced intense opposition from community members, including much of the department’s rank-and-file, as he pushed for the change. But Keck said understandable pride in a long-standing fire department steeped in history didn’t square with the economic realities of the day.

“It’s economies of scale that we just don’t have being the size of city we are,” Keck said.

Denver Deputy Chief Todd Bower said the nearly 32,000 residents of Englewood will be as safe as ever. This isn’t the first time the city has taken over firefighting and medical service functions for a neighboring municipality. The city plays that role in Glendale and Sheridan.

The Jefferson and Acoma stations, which will become Denver Fire Stations 37 and 38, respectively, will remain in service in Englewood while the Tejon Station will close, due to the fact that nearby Denver stations can provide coverage.

Bower said Denver fire is doing what it can to make the transition as smooth as possible. Firefighters moving over from Englewood will have to attend only a five- to six-week academy session, as opposed to the normal 17 weeks.

“They’re coming in with years of experience and not coming in from scratch,” he said.

Bower said with the addition of 40 firefighters from Englewood, who will be assigned to various stations throughout Denver, Denver fire’s head count will rise to nearly 1,000.

“I think all the stakeholders from both cities have looked at the totality of the process and see that it’s a win-win for everybody,” Bower said.

But that doesn’t make the end of an era in Englewood for a veteran like Petau any easier.

“My heart is telling me one thing,” he said, “and my head is telling me something else.”

John Aguilar: 303-954-1695, jaguilar@denverpost.com or twitter.com/abuvthefold