W I S C O N S I N
P O W E R
P L A N T
Caustic and sulfuric tank
cleaning minimizes
environmental impact
and disposal costs
“Veolia was able to rapidly mobilize and provide our
customer with a cost-effective solution to clean their
tanks and neutralize and dispose of sulfuric sludge.”
– Julie Welch, Account Manager, Veolia North America
W I S C O N S I N
P O W E R
P L A N T
Scope
Contract Facts
9/15 -10/15
duration of project
six
veolia employees
$20,000
saved in waste disposal costs
three
weeks saved in project duration
zero
accidents or injuries
sludge needed to be neutralized with a large
As part of the decommissioning process of a
amount of soda ash to reach a pH of 7 in order
nuclear power plant that went offline in 2013,
for it to be safely disposed of off-site as nonthe customer needed to clean a caustic and a
hazardous waste.
sulfuric acid tank. Each tank had a capacity of
Veolia also needed to use a high pressure
5,000 gallons. Both tanks were empty, but the
water 3D spinning nozzle system to
sulfuric tank contained approximately one foot,
decontaminate both of the tanks, drain the
or 700 gallons, of hazardous sulfuric sludge.
wastewater, and manage the residual waste.
Veolia was challenged to construct a
temporary controlled
ventilation structure
Challenge
for the sulfuric tank
to prevent hazardous
Veolia was challenged to clean caustic and sulfuric
vapors from escaping
storage tanks and neutralize large volumes of sulfuric
from the work area.
acid sludge with chromium for non-hazardous landfill.
Additionally, the sulfuric
Solution
Veolia’s team of six crewmembers combined
high pressure water with 3D spinning nozzles
to clean the tanks. The sulfuric acid sludge was
diluted by the water and soda ash was added
to it to neutralize the pH and allow it to be
removed and disposed of as non-hazardous
waste to a regional off-site landfill.
The spinner nozzle system performed a full
360 degree rotation while spraying 1,500 gallons
of water per cycle in each tank. The nozzle was
fed by a 1.5’’ fire hose providing 80 GPM and
between 100 to 150 PSI of water pressure.
The cleaning process for the caustic tank
required two cycles, or 3,000 gallons, of water
for the tank to meet Veolia’s standard of
decontamination as determined by pH.
To begin cleaning the sulfuric tank, Veolia
constructed a temporary poly sheeting
enclosure around the manway area of the tank
to enhance worker safety and prevent odors
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from migrating to other plant areas.
Veolia removed the manway of the sulfuric
tank and cut two pipes that entered the tank
sludge. Two diaphragm pumps were used
to remove liquified sludge with the sludge
discharge being directed to temporary ground
level storage tanks. Veolia liquified the sludge
and it was continuously cooled by spraying
water from a 1.5’’ fire hose provided by the
customer to minimize its reactivity.
Soda ash was premixed in water and pumped
into the temporary tanks that contained the
sulfuric sludge. That mixture was recirculated
as needed to neutralize the pH of the sludge.
The contents of the temporary tanks were
transferred to a transport tanker or totes as
required for on-site disposal. These temporary
storage vessels were then flushed with a
high pressure water hose and the resulting
wastewater was collected for off-site disposal.
W I S C O N S I N
P O W E R
P L A N T
Result
Veolia’s turnkey tank cleaning and waste
disposal project was a success. Veolia was
able to expand the scale of work to provide a
complete turn-key service in a timely manner
to neutralize more waste material than was
originally anticipated. Veolia did so by acting
quickly to locate and arrange extra poly tanks
for temporary storage and neutralization of the
sludge and wastewater.
Veolia stabilized the reactive sulfuric acid to a
neutral pH of 7. Changing the classification of
the customer’s waste allowed Veolia to dispose
of it as non-hazardous material into a Wisconsin
landfill, which helped save the customer
$20,000 in disposal costs alone.
Because the waste was properly neutralized
and disposed of, the company also saved three
weeks of time that would have been required
for permitting, transportation and disposal of
the waste if it had remained untreated.
Veolia successfully contained the sulfuric
acid vapors that were present due to the 700
gallons of sulfuric acid sludge. By properly
sealing and ventilating the area, worker safety
was enhanced and the contained vapors were
scrubbed before they exited the containment
structure and entered the general atmosphere.
The sulfuric and caustic tanks were effectively
cleaned and all neutralized sludge and
wastewater was properly disposed of as nonhazardous waste off-site. In total, the project
was successfully completed in only three weeks
without any accidents or injuries.
Contact
Julie Welch
Account Manager
Veolia North America
Office: (262) 236-8130
[email protected]
“Veolia ensured that the sulfuric and caustic
tanks were effectively cleaned while our
employees and the environment were
protected. Our highly trained teams did the
job right by saving the customer money and
protecting them from hazardous liabilities.”
- Julie Welch, Account Manager, Veolia North America.
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Resourcing the world
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