As it turns out, Chipotle Mexican Grill Chief Executive Steve Ells waited at least five months to apologize for making some customers ill.

Chipotle CMG, +1.11% sickened scores of customers in Washington, California and Minnesota as far back as last summer — well before the E. coli outbreak in October and November that spread to nine states.

The earlier outbreaks received little notice beyond local media reports.

Related: 10 things Chipotle won’t tell you

The outbreak of sickened eaters appears to have started in July, when five people in Seattle contracted E. coli after eating at a local Chipotle, according to Public Health – Seattle & King County.

On Thursday, the Seattle agency closed a Chipotle location because of “repeated food safety violations.”

In August, more than 100 customers in Simi Valley, Calif., got sick with a norovirus after eating at the Chipotle at 1555 Simi Town Center Way.

In Minnesota, in August and September, more than 64 cases of salmonella were reported and linked to 22 Chipotle restaurants, according to published reports and lawsuits filed in the matter.

William Marler, a prominent Seattle lawyer who specializes in food safety, is representing 74 victims in Chipotle-related cases. Several Boston College students who contracted norovirus at a local Chipotle last weekend also retained him.

Marler, who has secured more than $600 million for victims of bad restaurant food at such chains as McDonald’s MCD, -0.66% , KFC YUM, -0.90% , Chili’s EAT, -2.26% and, most famously, Jack in the Box JACK, -2.83% in 1993 —when 732 people became ill with E. coli and four children died — said the recent cases could end up costing Chipotle more than $10 million.

Denver-based Chipotle, with a market cap of $17 billion, lost roughly $6 billion in value from Oct. 13 to Dec. 7.

As its E. coli nightmare appeared on Thursday to be fading, Chipotle shares surged 5.1 percent, to close at $576.02.

The number of Chipotle victims in the nine-state outbreak is likely much higher than the current 52 counted by the Centers for Disease Control and Prevention, Marler said.

“For every one person they count, there are about 10 people who go to the doctor and don’t get a stool culture,” which provides definitive evidence of E. coli, Marler noted.

Chipotle referred to the summer outbreaks as “a small number of isolated and unrelated incidents — in terms of geography and incident,” in an e-mail to The Post from spokesman Chris Arnold.

“There really wasn’t a pattern,” he added. “Since all of this began, we have completed a comprehensive reassessment of all of our food safety and handling practices … and we have begun implementing that program.”

On Thursday, Ells apologized to Chipotle customers on NBC’s “Today” and promised the chain “would be the safest place to eat” but made no mention of the company’s extensive rap sheet.

This article first appeared in the New York Post.