For the fourth time in a month, St. Tammany Parish residents packed a public meeting Monday night to express their opposition to a proposed oil well near Lakeshore High School. As at the previous meetings, many residents came carrying signs and wearing shirts stating their feelings about the subject.

Monday’s meeting, sponsored by Parish Councilman Jake Groby at Pelican Park’s Castine Center, drew several hundred people to hear a brief talk by Groby, a lengthy presentation by environmentalist Wilma Subra and a talk about coastal issues by John Barry.

As at the other meetings, Helis Oil & Gas, the company that plans to drill a hydraulic fracturing well north of Interstate 12 and east of La. 1088, was absent.

Much of the opposition has centered on Helis’ plans to use hydraulic fracturing, or fracking, a method in which water, sand and chemicals are injected into the ground to create fissures in rock more than two miles deep. Oil and natural gas can move through the fissures and then can be pumped out of the well.

The technology is relatively new, and even though several wells have been drilled in St. Tammany Parish over the past several decades, none employed fracking as the method of extraction.

In other parts of the country, however, fracking has been blamed for issues with drinking water, mini-earthquakes and other health, air and water quality problems. Subra recounted a number of these, telling the crowd that she personally studied health effects from fracking wells in Texas and Wyoming.

Problems there included numerous health issues such as chronic indigestion, forgetfulness, memory loss, mood swings and worse, she said. She also warned that processing facilities, pipelines and other hazards could be placed close to homes because there are no regulatory preventions in place.

“These things could be coming to your community,” Subra said.

The crowd — already on her side — gave her a long ovation when she concluded.

Many of Subra’s concerns have been echoed by St. Tammany residents at earlier meetings and on Facebook pages such as Fracking Free St. Tammany and Keep Your Fracking Drills Out of St. Tammany.

Much of the opposition has been focused on potential damage to the Southern Hills Aquifer, the underground source from which all of St. Tammany Parish draws its drinking water, and which Groby said could be at risk from a well.

Helis had been asked to send a representative to Monday’s meeting, Groby said, but the company instead sent a statement from President David Kerstein that read in part, “We will continue to communicate with the St. Tammany community through mechanisms and venues that do justice to this important subject in a way that is both respectful and cooperative.”

A May 1 statement from Helis also attempted to allay residents’ fears about the project, saying that several of the company’s employees reside in St. Tammany and that the company has safely drilled hundreds of wells in Louisiana and approximately 60 fracking wells to the same depth as the one planned for St. Tammany, with no “significant environmentally related incident.”

To many in the crowd, however, such assurances didn’t seem to matter. Hunter Montgomery and Stephanie Houston Grey, who started the two Facebook pages opposing the proposed well, said they felt the company isn’t being completely forthcoming.

“They are still only talking about one site,” Montgomery said — not the numerous additional wells that likely would follow if the first one proves productive.

Helis has applied to the state’s commissioner of conservation for a “unitization hearing,” a hearing that sets the boundaries of a drilling unit, a key step that must be taken before the company can apply for a permit to actually drill the well. The company has identified a 960-acre tract on which it wishes to put one well on a 10-acre site.

Helis originally asked for that hearing to be held Tuesday, but parish leaders asked for a delay. Last week, Parish President Pat Brister and Council Chairman Reid Falconer announced that the company had agreed to delay the hearing by 30 days.

That announcement capped a frenzied month in which residents and officials scrambled for ways to delay or stop Helis’ plans in the face of rising public discontent. On May 1, the Parish Council passed a resolution — sponsored by Groby — to hire an attorney to safeguard parish interests; it set a $25,000 spending cap for the first month.

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