Supporters and opponents of the $220 million pump station proposed to cap off the decades-old Yazoo Backwater Project showed no sign of emotional letup Thursday as 520 packed the Vicksburg Convention Center to comment on its likely path to a veto by the Environmental Protection Agency.

South Delta residents and public officials from across the region voiced vigorous support of the project as they addressed wetlands and legal staff with the federal agency, which called the hearing as part of a veto process under provisions of the Clean Water Act.

Recent flooding along the Mississippi River up and down the Delta region only amplified the tone of their emotional appeals during the four-hour session.

“When you tell us flooding is good for the South Delta, we begin to question your science and motivation,” Rolling Fork resident and Mississippi Levee Board member Laurance Carter said. “Please take your veto back where it came from and let us get on with our pump project.”

Authorized by Congress in 1941, the overall project has undergone several revisions in scope and environmental impact since the Yazoo Backwater Levee was completed in 1978.

Its latest version calls for a facility with per-second pumping capacity at 14,000 cubic feet to remove some of the water that becomes trapped inside levees during flood years. Pumps would be built just west of the Steele Bayou Control Structure north of Vicksburg on Mississippi 465. They would not be turned on until the water reaches 87 feet above sea level inside the levees. About 55,000 acres would be reforested as part of the Army Corps’ plan, which the Corps has said is a balance between flood protection and habitat conservation.

Those statistics were spun in differing ways by those who spoke publicly, about 40 by the hearing’s fourth hour.

Gary Young, chief of the Corps’ Environmental Economic Section, said water levels behind the Steele Bayou Control Structure are now at 91 feet and rising.

Another 3 feet, predicted before the closed gates are opened — forecast for mid- to late May — will make up two-thirds of the 100-year flood event, Young said.

Changes in the project since the early 1980s have resulted in an 80 percent reduction in adverse effects on wetlands and have included 15 consultations with EPA since 2000, Young said, adding the wetland acreage affected is closer to 3,600 and not, as opposition states, more than 26,000 because it’s either cleared or private.

“There’s a huge misconception it will drain the Yazoo Backwater area,” Young said. “It’s not.”

Ruby Johnson of Sharkey County said she felt like a “backstabbing” had taken place on the part of EPA officials who took part in earlier deliberations on pump proposals.

“All you have is federal people fighting each other,” she said.

Most opposition present at Thursday’s hearing — part of a multilayered process culminating in a decision expected from EPA by the end of May — was from environmental and wildlife preservation groups, including American Rivers and the National Audubon Society.

“It is time to halt this environmentally destructive project once and for all,” said George Sorvalis of the National Wildlife Federation, which, along with Mississippi Riverkeeper, formed an aggressive “Dump The Pumps” media campaign, for which some supporters hung a sign in a window overlooking the podium as the hearing began.

EPA’s interpretation of its legal authority to step in and stop the project was called into question.

Under Section 404(c) of the federal Clean Water Act, passed in 1977, the EPA can restrict, prohibit, deny or withdraw an area as a site for disposing of dredge or fill material if the discharge is deemed harmful to natural resources. Since it and other provisions were added, only 11 projects have been vetoed and none since 1990.

Despite an ongoing project by EPA, the Lower Yazoo River Economic and Environmental Initiative, that would emphasize “non-structural” flood solutions, the agency retains the federally-derived veto power.

A statement read on behalf of Rolling Fork attorney Charles Weissinger called the agency’s premise “preposterous.” On the opposing side, environmental advocates contended nitrate deposited in the river from the pumps will contribute to oxygen-depleted “dead zones” in the Gulf of Mexico off coastal Louisiana.

“Nitrate is not a friend of creating new wetlands. It’s a foe,” said Jay Turner, one of 500 scientists to sign a letter to EPA expressing opposition to the pump station.

Success of other pump stations and projects built and maintained by the Corps came up on both sides.

Stations at River Styx Bayou in north-central Louisiana, inside Vicksburg District jurisdiction, and at Lake Chicot in southern Arkansas did not face a veto from the EPA and have turned into successes, Young said.

Those with Mississippi ties opposing the pumps also focused on the cost of the pumps in relation to other needs in the Delta.

“The powerful few stand to benefit from the taxpayers and will promote farming on marginal farmland,” said Avery Rollins, a Madison resident and sixth-generation Mississippi farmer.

“This is nothing but a welfare program for wealthy landowners who already get (assistance) from ASCS,” said Emma Cooper Harris of Sharkey County, referring to the Agricultural Stabilization and Conservation Service of the U.S. Department of Agriculture. “(The project) is $220 million? Just give me $100,000 and I’ll go create some jobs.”

Comments and questions about the pumps will be fielded by EPA officials and sent to the agency’s regional office in Atlanta for review. Public comments can be submitted by mail or online until May 5.

A recommended determination by Region 4 Administrator J.I. Palmer Jr. is expected by May 20. The decision also faces review by water management and administrative offices at EPA headquarters in Washington, D.C.