Sludge Watch ==> Florida - chemical burns, stench, fumes - occupational hazards of sludge

[Maureen Reilly]

Sludgewatch Admin:

This plant looks like it may be out of compliance with occupational safety 
requirements.
In Ontario, Canada, the staff at the N-Viro sludge lime plants need to wear 
full respirators to prevent them breathing in the fumes from the reacting 
lime and sludge.

A lawsuit has been launched in Canada by a sewage treatment plant worker who 
became extremely ill from exposure to these kinds of chemicals and gases.  
Remember they are likely inhaling mercury and heavy metals, pathogens, 
endotoxins, mold and fungus as well as gases like hydrogen sulphide.

You might want to discuss the occupational risks  with the director of 
public works at Oldsmar:
jmulvihill at ci.oldsmar.fl.us
......................................................................................


Where it all goes after we flush
It takes a strong stomach to turn Oldsmar's wastewater into fertilizer. Face 
masks don't block the odor.
By TAMARA EL-KHOURY
Published April 24, 2007


[Times photo: Douglas R. Clifford]
Joshua Wolfe od Oldsmar's wastewater treatment plant prepares a sludge 
sample for a 217-degree oven. Later, he will measure the moisture loss. 
"This is definitely not for the squeamish of heart as far as working goes," 
he says.
--------------------------------------------------------------------------------


OLDSMAR - Their jobs, like those of their counterparts across Pinellas 
County, are not glamorous.

Seven days a week, the 13 men who work at the Oldsmar wastewater treatment 
plant deal with the waste Oldsmar residents flush down their toilets, push 
down their garbage disposals and rinse down their drains.

The stench has knocked the uninitiated on their rears. The chemicals needed 
to process the sludge can burn and scar.

But Joshua Wolfe, 37, just 15 months on the job, is already immune to the 
unpleasantries. On a recent Tuesday, he packed 10 grams of sludge into a 
foil dish with his bare hands to prepare it for testing.

"This is definitely not for the squeamish of heart as far as working goes," 
Wolfe said.

Waste management remains one of the core - if forgotten - functions of local 
government for sanitation. But the vital occupation could soon change 
significantly under a grand plan this small Pinellas County city has for 
changing how it and a host of regional neighbors deal with human waste.

Oldsmar wants Pinellas County, Dunedin, Tarpon Springs and Clearwater to 
join it in building a multimillion-dollar biosolids drying facility to 
produce a safe, organic pellet-shaped product that can be sold as 
fertilizer.

Economics, along with environmental issues, are forcing the newfangled 
proposal. The sod farms in Manatee, Citrus and Hardee counties that Oldsmar 
and other local cities have shipped their processed sludge to for decades 
are being snapped up for real estate development; those that remain demand 
higher environmental standards.

The new technology has other benefits as well, as it uses heat rather than a 
caustic chemical to neutralize the biohazards in sludge.

But until the new facility and its heat-drying technology is deployed, the 
messy and dangerous step that gets repeated every Tuesday night at the 
Oldsmar plant - lime stabilization - will continue.

On a recent rainy Tuesday, Wolfe, who hopes to get his operator's license, 
worked alongside Jim Hudgins, 56, an 18-year veteran of the industry.

"Just so you know, this is third-degree chemical burn," Wolfe said, lifting 
his calf and pointing to a scar caused when lime splashed into his boot and 
rubbed against his skin.

By the time Wolfe and Hudgins started work, the wastewater had already gone 
through multiple filtering and neutralizing processes, separating most of 
the water from solids and foreign objects such as adhesive bandages, shoes, 
sand and other things.

The resulting solid moved onto the gravity belt Tuesday, looking like muddy 
water, and was still just 1.2 percent solid.

Then the sludge is mixed with a polymer, causing the sludge and water to 
repeal from each other, creating a 7.9 percent solid.

The result is thick enough to make a mud ball. What started out as 35,000 
gallons of wastewater is reduced to 7,000 gallons of sludge by the time it 
leaves the gravity belt and is fed into one of four pits, each holding up to 
12,000 gallons of sludge.

Next, Hudgins and Wolfe don face masks to protect their skin as caustic 
granule lime is pulled down from a silo on the roof to mix with water. The 
liquid lime is then pumped into the four tanks holding the sludge.

The masks do nothing to block the stench as the sludge is blended with the 
lime. Hudgins and Wolfe don't flinch. A novice could faint.

For three hours, the mixture is churned until the sludge's biohazards are 
neutralized. Then it's held for an additional 22 hours before it's hauled 
once a week to sod farms.

On Thursday, a tanker hauls off only 35,000 gallons of sludge from the 
Oldsmar plant - the eventual byproduct of nearly 12-million gallons of 
wastewater that flows in weekly.

"When people go to the bathroom, they don't know where it goes," Hudgins 
said. "They just don't want it to come back at them."

[Last modified April 24, 2007, 00:07:01]
http://www.sptimes.com/2007/04/24/Northpinellas/Where_it_all_goes_aft.shtml