The Delaware County Council on Friday unveiled a detailed timeline for the establishment of a county health department, aiming to have one fully operational by the end of 2021.

The densely populated suburb is the only county in the Philadelphia region that does not have a health department, and with about 565,000 residents, it is the most populous county in Pennsylvania without one.

This absence affected local leaders’ initial response to the coronavirus pandemic, forcing them to rely on the overtaxed state Department of Health, which was slow to provide information about local cases. In March, the Chester County Health Department agreed to provide services for Delaware County through an arrangement approved by Gov. Tom Wolf.

But the offer by Chester County was temporary, and Delaware County leaders have been working to establish a department of their own. It was under discussion months before the first COVID-19 cases were identified. The Democrats who took control of the county’s ruling board in a historic election last year frequently discussed it on the campaign trail, and promised to make it a priority once in office.

They did not know how little time they had, according to Council Member Monica Taylor, who is leading the effort.

“Our working group already knew how badly we needed a health department, but with the pandemic coming, it became more of, how can we make these adjustments now and how can we speed it up?” she said. “We have been able to continue to push this ball forward, because we have to hit these timelines in play, to make sure we can get it online by a certain day.”

For months, Taylor and her colleagues have estimated that starting a county health department would take up to 24 months. In a meeting May 20, the five-member, all-Democratic council voted to contract with Gorenflo Consulting Inc., a strategic planning firm based in State College, Pa., that specializes in helping municipalities establish health departments.

In the timeline released Friday, the council updated the deadline and elaborated on the steps needed to secure approval from the state to create the department.

The first is a health study from Johns Hopkins University expected to be completed in July, followed by an economic feasibility study, which will determine how much operating the department will cost the county.

Both studies will then be discussed at community town halls this summer, with a strategic plan to follow in December. Key staff, including a director and Board of Health members, would be appointed early next year.

“I think now more than ever, because we’re currently in a pandemic, it helps to have a health department, and thankfully Chester County has been willing to help,” Taylor said. “But in general, our health department, like any health department, will focus beyond that, on protecting community well-being. It can help with child wellness, disaster relief, and even access to clean water.”

Compared with its neighbors, Delaware County has been particularly hard-hit by the virus. It has competed closely with Philadelphia for the highest 14-day per capita rate of new confirmed coronavirus cases in the region, a key metric that Wolf has been using to determine when counties are ready to being reopening.

Still, Jeanne Casner, the head of the Chester County Health Department, said this week that she was confident in Delaware County’s ability to move into the loose “yellow” stage of coronavirus restrictions.

Casner said Delaware County has made “steady progress” in boosting testing capacity and contact tracing. But the efforts have to be maintained, she said, even as some signs of normalcy return.

“You can’t pop a pill and make this go away,” she said. “There are public health practices that take time and dedication, and that’s what both counties are demonstrating.”