What comes in must go out

Henderson utility service manager Kurt Segler likes to think of water use as a cycle.

"You can bring it into the valley, but you also have to get rid of it," he said. "You can't hit a home run in water and strike out in waste water and still win the ball game."

The point is that the Las Vegas Valley could not have planned to bring in more water without also increasing the capacity of its treatment plants for waste water.

Compared to the water project, the costs associated with improving the handling of waste water are far more difficult to predict.

That's because of unknowns such as the future of the Las Vegas Wash, which deposits treated waste water into the northwestern edge of Lake Mead known as Las Vegas Bay. There is also potential for tougher federal and state treatment standards.

The cheapest alternative so far for waste water is to continue to use the wash at an estimated cost of $3.19 billion through 2027.

The wash, an unpaved natural drain that begins near Vegas Valley Drive and Stephanie Street on the east side of the valley, extends about 10 miles in a southeasterly direction to the lake.

Along the way, waste water from the valley's three treatment plants is piped to the wash. Storm water and contaminated ground water that bypass those plants also spill into the wash.

In order to continue using the wash so that it can handle nearly twice as much waste water to meet population estimates over the next quarter-century, planners believe they'll need $1.2 billion to upgrade the treatment plants.

Most of that money would come from the quarter-cent sales tax increase that takes effect on April 1 in Clark County.

The balance of those costs, along with nearly $2 billion in operational expenses, would come from one-time hookup charges for new construction paid by developers and annual sewer fees paid by consumers.

What has planners worried is that the cost could skyrocket if the eroding wash is deemed unfit to handle additional flow of waste water, forcing them to look elsewhere. Two alternatives are on the table, but both would cost far more.

One would require spending $4.25 billion to discharge treated waste water deep into Lake Mead, downstream from the site at Saddle Island where drinking water is taken from the lake to serve the valley.

The other alternative, at a price tag of $6.42 billion, would create even greater separation from the water intake site by discharging waste water into the lake's Virgin Basin several miles to the east.

The money for waste water improvements will be spent by the cities of Las Vegas and Henderson and the Clark County Sanitation District to upgrade their treatment plants, all of which are nearing capacity because of the valley's population explosion.

The county's facility, for instance, would reach its capacity of 80 million gallons a day by 2003 without expansion.

With the sanitation district already handling 72 million gallons a day at its East Flamingo plant, technical services manager Wayne Fisher said expansion is the only option.

"The plant on average is taking in 2 million more gallons per day each year," Fisher said. "For us the clock ticks."

The current plan is for the valley's three treatment plants, now permitted to handle a combined 165 million gallons of waste water a day, to be expanded on a graduated basis to a capacity of 282 million gallons by 2027.

The plants use screens and other filtration processes so that solid wastes can be separated from the water and taken to landfills. The disinfected liquid is then diverted to the wash.

Henderson and Las Vegas also would duplicate the sanitation district's practice of removing phosphorus through biological rather than chemical means to enhance the quality of treated waste water.

Left unchecked, phosphorus deposits can promote unwanted algae growth in Lake Mead, decreasing the lake's clarity.

"The real reason to remove phosphorous is to promote better water quality in the Las Vegas Bay," Segler said.

Las Vegas, which also treats waste water for North Las Vegas, and the county plan to open separate facilities that each would process 10 million gallons of waste water a day for reuse by parks and golf courses, a combined 20 million gallons a day that wouldn't have to be diverted down the wash.

Expanding treatment capacity is just part of the solution.

Practically everyone associated with local water issues agrees that the deteriorating wash presents one of the valley's greatest dilemmas.

Las Vegas Public Works Director Richard Goecke said it would be foolhardy not to preserve and improve the wash, the main drain for the valley's 1,600 square miles of watershed.

"We believe that the wash is a unique feature in this desert climate," Goecke said.

"It behooves those of us who are caretakers of the wash to look out for it. If we don't, it would be a huge mistake for the valley."

Retired UNLV biology professor Larry Paulson said floods exacerbated by development over the past 20 years have destroyed most of the marshy wetlands that helped cleanse the waste water moving through the wash. Because of development, storm water that otherwise would have seeped into the ground has been channeled instead into the wash, increasing flows and the pace of erosion.

The long-leafed cattail plant and other vegetation served to trap nutrients, bacteria and other organisms, which helped to purify the water as it moved down the wash.

What once was about 2,000 acres of wetlands in the wash basin has been reduced to about 100 acres. Paulson said the floods and erosion they have caused have also made parts of the wash much wider and deeper. That has led to more rapid flows, making it more difficult for wetlands vegetation to survive.

Paulson said that if the wash did a better job purifying waste water flowing into the lake, it would be much easier to treat the water piped from the lake back to the valley.

"It's like having another layer of defense between our waste water treatment plants and our drinking water," Paulson said.

The county is working on a wetlands restoration plan, but it could take several years to implement. Meantime, many of the ducks and birds that once waded in the wetland ponds have flocked elsewhere.

"We are getting a significant amount of sediment that moves through the wash and empties out into Las Vegas Bay in Lake Mead," Segler said.

"We have lost habitat for a variety of species."

The wash also is the recipient of pollutants, such as fertilizer runoff, dirty ground water and animal feces that bypass the treatment plants.

"The wash has become a major urban stream and therefore you have both water quantity and quality problems," Fisher said.

This has presented a daunting task for the Las Vegas Wash Coordinating Committee, made up of various government agency representatives and other users of the wash who are seeking remedies.

There are fears that the valley will never be able to take more than its current share of Colorado River water from Lake Mead unless it cleans up the wash or finds an alternative drainage system.

In addition to wetlands restoration, water authorities are exploring the possible need for better land-use planning along the wash, said Doug Karafa, utilities manager for the sanitation district.

"You have so many agencies with so many conflicting missions," Karafa said.

"How to bring them all together to one solution is the situation we're facing. The solution will have to be an answer the community can live with."

Segler said engineers usually cannot make sound predictions about the needs of a waste water system more than five to 10 years into the future. But planners are confident they've identified any current problems with the valley's system.

"I believe we've prepared ourselves in such a way where there aren't any surprises out there," Goecke said.

"I would say that 50 to 100 years out there may be a problem none of us have looked at, but there's also flexibility to deal with these things."

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