Stormwater tanks prep work turns up landfill, fire waste

There’s an old landfill on East Sprague Avenue that used to be set on fire whenever its piles grew too high. After a massive fire ravaged downtown Spokane and destroyed 300 buildings in 1889, the charred debris was pushed into a ravine that cut toward Peaceful Valley.

These early wanton disposals of waste have made a headache for the city as it continues work to solve a modern waste conundrum. Both old waste sites are in the way of the construction of massive tanks the city will build to capture sewage so that it can be properly treated instead of released untreated in the river.

Not even 20 years ago, the city dumped an average of 570 million gallons of sewage into the Spokane River every year.

In much of the city, sanitary sewers and storm sewers are one-in-the-same. In those locations, the system gets overwhelmed and untreated wastewater gets diverted to the river. But by the end of 2017, thanks to demands from state and federal regulatory agencies, Spokane will have turned a virtual spigot of sewage into the occasional drip.

The city sewage system has its roots in the great rebuild of downtown that took place after the fire of 1889. Before then, the only sewer ran along Howard Street from First Avenue to the river, where it was relieved of its burden. After the fire, the city built a network of sewers, which first connected downtown and the lower South Hill. As the decades progressed, sewers followed the city’s population to Corbin Park, 29th Avenue and beyond.

Through all of this, the city’s sewage dumped untreated into the river. It wasn’t until 1958 that the Riverside State Park Reclamation Facility went online. In 1972, the federal Clean Water Act was passed, creating strict standards for what was allowed in water, one of the first steps in national rules to regulate pollution.

In 1994, the city created its Combined Sewer Overflow Reduction Plan, laying the groundwork for the cleanup happening today. In 1999, the city began implementing the plan.

“We were trying to test some of the concepts,” said Marlene Feist, city utilities spokeswoman, about the first, small storage tanks.

Now, as the city faces a three-year deadline to finish the majority of its $180 million sewer overflow plan, the tougher, much larger and more central projects remain. Eight tanks have been built; 17 projects remain, including a 4-million gallon storage tank near downtown.

“By the time we’re done, we’ll have taken (overflows into the river) down to less than 8 million gallons a year,” Feist said. “Back in the ’80s, we had thousands of overflows, so we’ve already taken it down 90 percent. Now we’re going to take it down 90 percent of the remaining. It’s an amazing reduction over time.”

The old landfill surfaced this winter when the city uncovered caches of industrial waste – the forgotten landfill on East Sprague.

The fire waste was anticipated, but the old landfill on Sprague near the Hamilton overpass was a surprise – and tacked on about $700,000 to the project for mitigation and redesign.

At a recent Public Works meeting, Rick Romero, who leads the city’s utilities department, asked members of the City Council to view the increased cost in context. In the scheme of things, he said, $700,000 is a drop in the bucket compared to the $300 million that will be spent to keep the river clean.

“I ask that we keep this a bit in perspective,” Romero said, pointing out that the $300,000 needed to clean up the forgotten landfill will largely come from state grants aimed at brownfields.

The old landfill on Sprague was unknown to city workers until they broke ground to build the 260,000-gallon tank, where they uncovered contaminated groundwater. When the city investigated more, a landfill was discovered. At some point in Spokane’s past, people would fill the lot with waste, burn it down to make room, and more garbage was delivered. The city confirmed the lot’s use when a historic photo surfaced, but it’s still unclear when and for how long the dump existed.

Because of the landfill, the city had to redesign the project for a cost of $380,000, rotating the tank and moving it away from the accumulated waste to stable bedrock.

Romero told the Public Works committee that the work site had been analyzed, but the analysis missed the waste. The city is now investigating other means to correctly identify potential hazards below ground.

The project that is contending with the fire waste is across West Main Avenue from Glover Field, where the city will build a 4-million gallon tank, the largest it will construct. Cost is estimated about $42 million.

“That’s where they pushed the debris from the fire, down Main,” said Marcia Davis, a senior engineer at the city. “That used to be a ravine. So we already know that it has fill. We already know its potential for hazard.”

When the fire broke out on an August evening in 1889, a gully stretched southeast from the river all the way to the block past Post Street south of Main. By the time the city had cleaned up the charred remains of its frontier downtown, the gully was gone.

Now, as the city prepares to move to a future with a cleaner river, the fire is being remembered, primarily because the city has to foot the bill to clean it up – again.

“We found some things. Petroleum products. Lead was a problem in the past,” Davis said of site investigations. “We’ll come up with a plan to dispose of that properly.”

The massive storage tank will hold stormwater from the west half of the South Hill and downtown, where most surfaces are paved and don’t allow for runoff to absorb into the earth. Construction on the project is scheduled to start early next year and take about two years to complete.

Feist, who has been working on the city’s effort to clean its central waterway for a few years, said the tanks are likely to go the way of the fire debris and forgotten landfill.

“Ten years from now, most people won’t even know there are these huge tanks underground,” Feist said. “But we want people to know about this. It’s costing them a lot of money and it’s pretty important. We want to people to know about it.”