A new sewer district proposed for the south end of the parish could cost East Baton Rouge more than $50 million over the next 30 years in potential lost revenue, according to a study by the city-parish’s public works department.

But developers of the proposed district, called Harveston Baton Rouge, said the analysis fails to acknowledge the costs the city-parish would incur if it had to build the infrastructure necessary to collect and treat sewage generated by the development.

Harveston, which is being developed by Mike Wampold and John Fetzer, is a 1,400-acre planned development south of Bluebonnet Boulevard and Highland Road and east of Nicholson Drive.

The developers have asked the Metro Council to approve what they say would be an eco-friendly sewer system for the development, operating separately from the parish’s consolidated system.

If approved, the system would be built and paid for by the developers, which means that the district’s residents would not be on the hook for the parish’s sewer fees.

The financial impact study done by the city-parish projects the money that the city-parish would have otherwise received from the new construction if the houses and businesses were connected to the parish system and were subject to parish sewer fees.

The analysis, conducted by assistant DPW director Mark LeBlanc, assumes the district would build 2,500 homes over a 30-year period at an average of 83 to 84 homes per year.

Fetzer has said he envisions retail, office space, apartments and about 2,500 houses to be built in the development over the next 20 to 25 years.

The analysis projects a potential loss of $4.2 million in sewer user fee revenue over the next 10 years if developers build a separate sewer system. In 20 years, it projects a potential loss of $20.6 million, and in 30 years it projects a loss of $46.5 million.

Sewer user fees are used toward paying off the city-parish’s debt service on its $1.5 billion sewer system rehabilitation project and for maintaining the system.

If Harveston’s sewer user fees were collected by the city-parish, it could be used to help alleviate the outstanding debt.

The average sewer user fee for a homeowner, based on usage of 8,600 gallons of water, is $42.23 per month. The user fee increases 4 percent every year, and does not have a sunset.

LeBlanc’s analysis assumes the 4 percent annual increase will be in effect for all 30 years.

The report also estimates the city-parish could lose out on $2.2 million of sewer impact fees in the first 10 years. After 20 years, that number grows to $4.2 million and after 30 years it would be $5.6 million.

Sewer impact fees are one-time fees assessed for new construction that cover the cost of connecting into the parish sewer system. For a single family home, the fee is $2,150.

Fetzer called the report “misleading,” noting that the funds that would have been generated by sewer fees are only used toward the city-parish’s sewer program.

“Those funds don’t go into the general fund for just any parish projects,” Fetzer said. “It’s looking at a piece of the puzzle without looking at the whole thing.”

He noted that Harveston is being built in an area where there is no city-parish sewer infrastructure. He said some parts are as far as two miles away from the city-parish’s connections.

“If the system was there in place for us to use it, we would use it,” Fetzer said. “We’re having to do the best we can with what we got.”

Harveston District is proposing to use wetland assimilation, which is a waste water treatment technique that uses filtered waste water to enrich the wetlands.

Councilman Chandler Loupe, whose district encompasses Harveston, said he supports the project and applauds the developers’ decision to use eco-friendly treatment methods.

William Daniel, chief administrative officer for Mayor-President Kip Holden, declined to comment, saying only that, “We are formulating an official response.”

LeBlanc said he prepared the cost analysis at the request of Metro Councilman Ryan Heck.

Heck said he wanted to see the numbers before the council votes on the district at its June 12 meeting.