The Westchester County Department of Health has asked to be dropped from a lawsuit brought by a property owner who accuses it and several other defendants of botching contamination cleanup decades ago tied to the Mount Kisco property’s former role in atomic bomb development.

In court documents, the health department seeks dismissal, arguing it was not negligent because it was not involved in the 1960s demolition of a refinery on Kisco Road in Mount Kisco or the disposal of waste from it.

The health department also contends the statute of limitations ran out decades ago on the suit’s claims. And it asserts it acted as an arm of the county and therefore can not be sued in the matter, and has immunity because its actions were under the state’s direction.

The suit “fails to allege that the [county health department] was negligent, grossly negligent, or engaged in conduct that was reckless, willful, or wanton in performing its surveying role in the removal and/or remediation of the premises,” the health department says in the April court filing.

But plaintiffs’ lawyers reject the health department’s arguments and counter the suit should not be dismissed against it.

“There is no doubt that the [county department of health’s] intimate involvement with the property began as early as 1966, when it coordinated with the Village of Mt. Kisco in a botched clean-up attempt,” lawyers for Mark Stagg, majority owner of 105 Kisco Ave., contend in court documents. The health department hopes to “unfairly pin the full bill for the remediation on the plaintiffs” even though the plaintiffs have only recently owned the property, the filing argues.

The suit, filed last year in White Plains federal court, names multiple defendants, including the village, the U.S. government and Stagg’s former business partner, and seeks more than $3.2 million in all for recovery of costs, damages and lawyer’s fees.

Stagg acquired the 105 Kisco Road property through limited liability companies, which are also named as plaintiffs, and paid hundreds of thousands of dollars to clear the former business owner’s financial debts, only to learn of the history of contamination that the suit alleges the former owner/business partner allegedly kept from him. Stagg personally loaned almost $3 million to make improvements and renovations to start a new business there, which is no longer operating, called NY Stone & Masonry Supply.

The health department is one of several defendants accused of spreading or worsening contamination on 103 and 105 Kisco Ave., during the course of the site’s history. Various defendants are expected to seek dismissal of the suit as well.

The site’s history dates to the 1940s. According to court documents, New York City-based Canadian Radium and Uranium Corporation, known as Canrad and founded by brothers Boris and Alexander Pregel, put a refinery at what is now the intersection of Kisco and Railroad avenues: a two-story concrete building and two one-story concrete buildings at 103 and 105 Kisco Ave.

Today, Metro North tracks and Kisco Avenue border the property.

The U.S. asked the refinery to participate in the Manhattan Engineering District, popularly known as the Manhattan Project, which developed the atomic bomb, due to the brothers’ international uranium trade connections, court documents say. The U.S. contracted with Canrad, which extracted radium and polonium and supplied those to the project.

After the war, the company changed to commercial uses. In 1966, an urban-renewal agency bought the property and the refinery was demolished and efforts to clean up/do remediation began.