FAIRFIELD -- The 197-unit apartment building that Blackrock Realty LLC wants to build on a site near the Fairfield Metro train station -- instead of the retail pavilion proposed previously -- is still blocked by concerns over a sewer line.

John Fallon, Blackrock's lawyer, told the Inland Wetlands Commission Thursday night that the apartment building would be consistent with the commission's 2003 approval of nearly 1 million square feet of commercial development on the Fairfield Metro 35.5-acre site, because it is more than 700 feet away from wetlands and wouldn't involve regulated activities not already approved by the commission.

He also told the panel the five-story apartment building would be farther from a conservation easement area than the proposed retail pavilion, adding that the wetlands board has no jurisdiction over the proposed building's use or height.

On Thursday, Fallon asked the commission to determine that the proposed apartments don't require a new inland wetlands permit.

"You don't approve uses. You approve regulated activities," he said.

But the extra 32,500 gallons a day of wastewater that the apartment building would generate compared to the retail building -- an issue which put the apartment building plan on hold last October -- continued to be a hurdle Thursday night. The apartment building is estimated to produce 40,000 gallons of wastewater a day, compared to 7,500 gallons a day under the retail plan.

Tony Margiotta and Richard Pettinelli, engineers with Parsons Brinckerhoff in Glastonbury, responded Thursday night to a town consultant who questioned the accuracy of a report that said the 33-inch sewer line could handle the extra flow after the Fairfield Metro Center development is fully built. The private development also is slated to include a hotel and five office buildings, although no plans for any those buildings have been filed by Blackrock Realty.

"It is our opinion the system can handle this," Margiotta said of the extra 32,500 gallons a day. "On any given day, that pipe is one-third full -- or two-thirds empty."

GHD Inc., of Middletown, the town's consultant, had questioned in a July 1 report how Parsons Brinckerhoff found 500,000 gallons less per day in the pipe in 2012 compared to the latter company's report in 2004, but Pettinelli said he stood by that finding. He attributed the reduction to fewer commercial tenants after the economic crash in 2008, measures taken by the town to limit groundwater flowing into the pipe, changes in industrial practices to limit water use, and water-saving fixtures in residential properties.

"I believe it's been a combination of those things," he said. "I stand by the data."

GHD also had questioned how the same peak flow of 5 million gallons a day in the pipe was five inches higher in 2012 compared to 2004. Pettinelli attributed that to the flow's speed, which his Sept. 4 report indicated was due to the town replacing sections of the 33-inch pipe with a 36-inch pipe that had a decreased slope.

Pettinelli said the 33-inch pipe has a capacity of 8.2 million to 8.4 million gallons a day, while the 36-inch pipe has a capacity of 10.4 million gallons a day.

Kathryn Braun, a lawyer and Representative Town Meeting member from District 8, noting that the commission had "competing reports" from Parsons Brinckerhoff and GHD, wanted to hear what GHD and Joseph Michelangelo, director of the town's Department of Public Works, had to say about Brinckerhoff's latest report. "I would suggest this commission table any action on consideration of the sewer line," she said.

Annette Jacobson, administrator of the town's Conservation Department, said information in Pettinelli's Sept. 4 report hadn't been evaluated by town officials. She said a sewer capacity for the Fairfield Metro Center development was established in 2003 and Blackrock Realty seemed to be using a lot of that capacity for the proposed apartment building. She said the effect on the rest of the proposed development should be considered.

Michelangelo said in a July 19 report that the flow rate originally approved for the entire development totals 114,500 gallons a day.

Jacobson said she spoke with Michelangelo on Thursday and that he believes he could respond to Brinckerhoff's latest report by the commission's next meeting on Oct. 3.

The commission then voted to continue the hearing on whether Blackrock Realty's proposal needs an inland wetlands permit so it could get more information on Oct. 3.

Blackrock Realty also wanted permission to close and disturb part of a 10.9-acre conservation open space and public access easement area for a year during construction of the apartments.

, and use part of it for construction or staging of construction equipment. Fallon said the request to close and disturb the easement area would be necessary regardless of whether the proposed building was used for retail or apartments.

Blackrock also wanted to modify the requirement that a stone wall be built around the conservation easement area before construction. Fallon didn't object, but said it ought to be built after construction.

"It wasn't built because of the town's belief it couldn't be built until the building was built," he said.

If the Inland Wetlands Commission decides the proposed apartment building doesn't require a new permit, Blackrock's request to change use of that building from retail to residential would head to review by the Town Plan and Zoning Commission.