fAfter years of legal struggles, Gwinnett County officials turned the tap Wednesday on a wastewater treatment facility that has some of the strictest environmental requirements of any facility that releases wastewater into Lake Lanier.

With a permit to release 40 million gallons of treated wastewater each day, the F. Wayne Hill Water Resources Center in Buford is now responsible for the lake’s largest discharge of treated wastewater.

But the Gwinnett facility, thanks to a yearslong legal battle with lake advocacy groups, has the strictest permit requirements on phosphorus levels.

To keep from violating the county’s permit to discharge wastewater into the lake, each liter of water that flows from the plant must have no more than 0.08 milligrams of phosphorus in it, said Jane Hendricks, a manager for the Environmental Protection Division’s permitting compliance and enforcement program.

The standard is far and above the other six facilities that have discharge permits for Lake Lanier, which must keep phosphorus levels between 0.13 milligrams per liter to 0.5 milligrams per liter.

The standard in Gwinnett is the result of a struggle between the county and the Lake Lanier Association.

When Gwinnett initially received permission for the new discharge outlet in 2000, the association filed a lawsuit, objecting to such a high volume of wastewater being dumped into the lake.

After the case went to the Georgia Supreme Court, which ruled in favor of the advocacy group, Gwinnett officials agreed to make the plant’s discharges cleaner and to place the pipe that would discharge the water deeper into the lake.

Construction began on the $72 million pipeline in 2008 and the first discharge was made Wednesday.

Jackie Joseph, president of the Lake Lanier Association, recalled on Wednesday the legal battle with Gwinnett County over the pipeline.

“What our contention was, and what our source of litigation was, is that the parameters of the permit were not protective of the lake,” she said. “... The quality of the lake water was really going to be downgraded.”

The pipeline travels about 9.5 miles from the plant into Lake Lanier at a depth of 100 feet. About 1.2 miles into the lake, a diffuser at the end of the pipe mixes the treated wastewater with ambient lake water.

Joseph said advisers and engineers who helped the association during the legal battle told association officials that the impact of the treatment plant would not be detrimental if the pipe was 100 feet deep. Such a depth would allow the treated wastewater to cool to lake temperatures, she said.

“And therefore, there should be no negative effect to the lake itself. ... We’re having to suppose that this is going to be the case,” she said.

In a statement Wednesday, Gwinnett County’s chairman of the Board of Commissioners Charles Bannister said the new pipeline will help Gwinnett County’s downstream neighbors by returning the water to the source. Before Wednesday, Gwinnett County already had the ability to discharge 20 million gallons of treated wastewater per day into the Chattahoochee River below Lake Lanier’s Buford Dam.

“It has been a long journey to get to this point, but I believe that putting water back into the lake helps us secure a long-term water supply for our residents,” Bannister said in a statement.

Joseph isn’t sure whether Gwinnett’s new line will impress a federal judge who, in a July ruling, cut off Lake Lanier as a water supply to surrounding governments, scaling Gainesville back to 1970s levels.

“In my personal opinion, I don’t think you can come back (to the judge) and say, ‘OK, we’re going to add more water to the lake,’ ” she said. “(The ruling) never included anything about any discharges back into the lake.”

Kit Dunlap, president of the Greater Hall Chamber of Commerce, said it’s hard to second-guess the judge.

“... You’d hope it would make a difference, with returning highly, highly treated wastewater to its source.”

Dunlap said she believes Gwinnett “has done a good job in thinking outside of the box, doing some creative things and being on the edge of technology.”

Lisa Coghlan, spokeswoman for the U.S. Army Corps of Engineers, couldn’t immediately address the discharges’ impact on lake’s levels and how the corps might adjust for it.

The lake’s level Wednesday evening was 1,072.17 feet above sea level, with the full pool elevation at 1,071 feet. The lake peaked at 1,072.34 feet Tuesday morning, following heavy rainfall on Monday.