Saturday, October 23, 2004
Raw sewage spill was massive, reports say
Recent flooding shut down the regional wastewater treatment plant and released hundreds of millions of gallons of raw sewage.
More than 400 million gallons of raw sewage - and possibly as much as 750 million gallons - spilled into Roanoke's waterways, streets and back yards after recent floodwaters shut down the regional wastewater treatment plant, according to local and state estimates.
The spill, which was the largest since the 1985 record flood, was enough to fill 1,000 Olympic-size swimming pools or to bury the entire town of Vinton under more than a foot of sewage.
Although health authorities warned people to stay out of the Roanoke River because of the staggering volume of the spill, Western Virginia Water Authority officials said the risk to humans, wildlife and the environment was minor because the sewage was heavily diluted with storm water.
Plant officials also said the overflow was relatively insignificant given that Roanoke intentionally pumped all its sewage into the river until 1951, when the city's first treatment plant opened. Sewage spills during heavy rains have been a chronic problem ever since, prompting the ongoing multimillion-dollar effort to improve the system.
"The mental image of all that sewage going into the river is disgusting, but the fact is human waste is biodegradable ... and it's been going into the environment for centuries," said Rupert Cutler, a member of the Roanoke City Council and the board of the water authority, which operates the wastewater treatment plant. "It's just not as bad as an industrial or chemical spill that's toxic. I'm not trying to minimize this, but nature will take care of it."
Federal requirements are forcing localities nationwide to spend millions of dollars to upgrade their wastewater treatment plants and collection systems, a process that will take several more years - and water and sewer rate increases - to complete in the Roanoke Valley.
"Yes, it's a big number [in the recent spill], and it's not something we're proud of, but we're trying to address it as best we can," said Mike McEvoy, the executive director of wastewater services at the water authority.
In a Wednesday report, water authority officials estimated that 401.8 million gallons of untreated wastewater spilled out of the treatment plant in Southeast Roanoke and another 6.4 million gallons of sewage leaked out of manholes across the city after flooding by the remnants of Hurricane Jeanne shut down the plant.
Virginia Department of Environmental Quality officials said those figures were conservative and that the actual amount may be closer to 750 million gallons.
McEvoy said Friday that 90 percent of the overflow was rainwater.
Norman Auldridge, DEQ deputy regional director in Roanoke, said that although the sewage was diluted by storm water, it is still classified as raw sewage under state and federal regulations.
The sewage spills are caused by storm water overtaxing the sewage system, tree roots breaking aging pipelines, sporadic blockages, and homes' gutters being incorrectly hooked into the public wastewater system.
A $20 million upgrade to the wastewater treatment plant in 2000 failed to stop the spills, so a $50 million upgrade to improve the plant's capacity is under way.
Also, a plan to upgrade the system's 960 miles of collection pipes is due in 2006.
An earthen berm also is being constructed around the treatment plant in an effort to keep floodwaters out. McEvoy told water authority board members this week that the berm was three months from completion when the storm hit and that it probably would have prevented the plant from being flooded.
The sewage overflows were first reported Sept. 28 when floodwaters forced the closure of the wastewater treatment plant and collection system. The plant restarted Oct. 8, but the sewage spills continued until Monday, according to the water authority. No final cost estimate has been made for the plant's cleanup, equipment repair and replacement, or overtime pay for plant workers.
The water authority is required to notify the DEQ about every sewage spill.
According to water authority reports, one of the largest spills was at Tinker Creek, where sewage spilled out at an estimated 1,000 gallons a minute.
At that rate, as much as 13 million gallons of sewage - which gushed more than 10 feet into the air and left toilet paper hanging in the trees - went into the creek near its junction with the Roanoke River, which flows into Smith Mountain Lake.
Water authority reports also said sewage overflowed from more than 65 manholes across the city.
Among the biggest leaks were 1.5 million gallons in Garst Mill Park, 675,000 gallons at Hollins Road, 675,000 gallons at Edgewood Street, 451,500 gallons at Denniston and Memorial avenues and 360,000 gallons in Fishburn Park.
Officials said the overflow's exact amount could not be determined because flow monitors were not installed at every leak from start to finish.
The water authority's estimates also did not include spills caused by wet weather before Hurricane Jeanne, sewage spills outside Roanoke and sewage spills that were unreported.
Auldridge, McEvoy and Cutler praised treatment plant workers for restarting the facility so quickly. In 1985, the last time the whole plant was last shut down by flooding, the plant didn't restart for about three weeks.
Under a series of DEQ consent orders starting in the late 1980s, the water authority has been taking steps to increase the plant's capacity and stop the sewage leaks.
"We'd all like to see it happen tomorrow, but the reality is that's just not how these things happen" because of costs and the complexities of planning and construction, Auldridge said.