The U.S. Army Corps of Engineers dealt a setback to opponents of a proposed St. Tammany Parish oil well Wednesday when it denied a request for a public hearing on the oil company’s application for a wetlands permit.

Attorneys for the group Concerned Citizens of St. Tammany and the town of Abita Springs — both of which have sued in state court to stop the well from being drilled — originally requested a public hearing in the fall but received no response from the Corps.

In December, the Corps and the Environmental Protection Agency requested more information on the project than was provided in Helis Oil and Gas Co.’s October application for a permit to drill in federally protected wetlands. Helis responded Jan. 2 with 500 pages of documents.

The voluminous new information was cause for a new public hearing, attorneys Lisa Jordan and Mariane Cufone argued in a Jan. 14 renewed request for such a hearing. The pair also requested that the Corps reopen the public comment period on the permit application, which the Corps also denied.

“The Corps cannot allow Helis to subvert the public’s due process right to comment by withholding previously produced or accessible information until after the comment period has closed,” the attorneys said in their letter.

Helis needs a wetlands permit because a portion of the site of its proposed 3.21-acre drilling pad has been designated as wetlands. The proposed drilling pad is big enough for only a vertical test well, which Helis has proposed as the first phase in what could be a two-phase process.

After the vertical well is drilled, the company plans to test samples collected from approximately 13,000 feet underground to see if the rock formation there could be a viable commercial source of crude oil.

If the test results are positive, the company will have to reapply to the Corps and the Louisiana commissioner of conservation for wetlands and drilling permits, respectively, to build a bigger drilling pad so that a horizontal shaft can be drilled and the well hydraulically fractured, or fracked.

In the Corps’ letter denying the request for a public hearing, Regulatory Branch Chief Martin Mayer said that if Helis “submits an application to install fracking production wells (based on information obtained from this exploratory well),” the Corps will publish a 30-day public notice “and you will have an opportunity to submit a public hearing request at that time.”

Helis has said the proposed drilling site — about a mile south of Lakeshore High School, northeast of Mandeville — sits atop a unique rock formation within the Tuscaloosa Marine Shale, a rock formation more than two miles deep.

Fracking wells are being drilled in the Tuscaloosa Marine Shale in Washington, Tangipahoa and St. Helena parishes, as well as the Feliciana parishes and southern Mississippi. Some have estimated that the Tuscaloosa Marine Shale may contain as much as seven billion barrels of oil. But because the formation it is looking at is unique to southern St. Tammany Parish, Helis has said it would be impossible for its well to be drilled in another area.

Although opponents have vehemently protested Helis’ plans to drill the exploratory well, it’s the possibility of fracking that has them most worried. Fracking, a process where water, sand and other chemicals are injected into rock to create tiny cracks through which oil and gas can be extracted, has been blamed for a litany of environmental problems, and some communities around the country have tried to ban it, with varying degrees of success.

In normally oil-industry-friendly St. Tammany, as soon as Helis’ plans became known, a strong opposition formed and has fought Helis every step of the way, including persuading state Commissioner of Conservation James Welsh to hold an unprecedented public hearing to discuss Helis’ request for a drilling permit before that permit was awarded in mid-December.

The only other permit needed by Helis is the Corps’ wetlands permit, but the company is faced with lawsuits filed in state court in both Baton Rouge and Covington to prevent the well from being drilled.

Follow Faimon A. Roberts III on Twitter, @faimon.