Salt Lake County leaders gave the go-ahead for a new sewage treatment plant in Riverton on Tuesday, voting to amend its water management plan to accommodate new growth in the county's southern end.

Despite the 7-1 County Council vote to allow the new $30 million plant, the approval comes with conditions, including a requirement to increase wetlands around the plant and maintain a buffer of open space for public use.

Councilman Joe Hatch also tacked on a provision that any future expansion of the plant — near the river bottoms off 13500 South — must be part of a systemic review of sewage needs throughout the valley.

Though the decision clarifies the county's intent to build the Riverton plant, the facility is still not a done deal as its city conditional-use permit is tied up in court.

The county's existing water treatment plant in West Jordan processes about 38 million gallons per day and will soon be expanded to treat another 50 million. That falls below the estimated need for new development, which county engineers peg at around 80 million gallons per day.

The city's water management plan has not been updated since it was created in the late 1970s.

"Unless we stop flushing our toilets and using our disposals, something needs to be done," Councilwoman Jenny Wilson said.

South Valley Sewer District general manager Craig White said he was "very pleased" by the vote.

"After going through a very lengthy public hearing process, it was good to come to a formal vote," he said. "Most of the conditions are very manageable. There are a few challenges we will need to overcome. Most of them we were looking at working in the framework anyway."

The district is a part owner of South Valley Wastewater Treatment Facility in West Jordan, but because of recent rapid growth in the southern suburbs the district is dumping more sewage into the plant than it has contracted for. With growth projected to continue, district officials insist they need a new plant — and fast.

The Riverton site, they say, is the best available site because of the natural slope of the valley toward the river, and Riverton water officials say the proposed plant would be a boon to secondary water for irrigation.

Jeff Salt, head of the Great Salt Lakekeeper and a leader of the residents' group opposed to the Riverton site, decried the vote Tuesday.

"It's unfortunate that the county was pressured into making a rash decision and that the public has not been adequately involved in evaluating all of the reasonable alternatives, evaluating the environmental and community costs of this," he said.

He said the Great Salt Lakekeeper plans to appeal the decision.

Salt and other residents say there are plenty of other opportunities that won't bring the aesthetic and environmental blight they predict would be caused at the Riverton site.

Councilman Cort Ashton cast his vote against amending the plan, saying he would rather opt for a smaller fix to the piping system to stave off a new treatment plant.

That option, he said, would cost about $3 million but could give the county another three to five 3-5 years to decide how to approach sewage on a countywide basis instead of reacting to an urgent need in one region.

"Because of these little turf wars and parochial lines that have been drawn, we're not looking at the big picture," Ashton said. "I have the faith and the hope that we may come up with a better, different process"

Hatch said he too would like to buy some more time for more holistic planning but that putting off the Riverton plant may only mean paying more for the land in the future.

"Even if we buy the time and we do the due diligence, I am absolutely in my heart convinced that at the end of the process there will be a Riverton treatment plant," Hatch said.

Although the county gave the Riverton site the green light, concrete plans for the facility must still go through a city permit process.

Riverton city's planning commission and City Council city council have taken several votes on a conditional-use permit for the site and calling for more information and public hearings.

In November, the planning commission denied the district a conditional-use permit, but that decision has been appealed by the district. It is awaiting a hearing date in 3rd District Court.

White said there remain several issues for the district to overcome before the plant can be built, but he said the county vote was "by far the largest hurdle."