Sludge Watch ==> sludge on Vermont field

[maureen.reilly at sympatico.ca]

Sludgewatch Admin:

In this story they say land application is cheaper than incineration.  But 
with the higher prices for trucking sludge, high fuel prices, and fewer farm 
fields, increasingly using sludge for fuel in a biomass plant is the 
cheapest route.  Interesting that St Paul's found that their gassification / 
incineration plant is the cheapest venue for managing sludge. And Milwaukee 
found that making Milorganite is the most expensive way to manage sludge.

................................................................

Rutland County , Vermont


http://www.rutlandherald.com/apps/pbcs.dll/article?AID=/20060824/NEWS/608240378/1002/NEWS01



100,000 gallons of sludge spread on Benson field

August 24, 2006

By Tom Mitchell Herald Staff



Sludge is pumped from a truck on to a 10-acre hayfield in Benson on 
Wednesday.
Photo: VYTO STARINSKAS / RUTLAND HERALD
BENSON — The messy burden created by a 25-year accumulation of sludge in two 
small lagoons at Benson's sewer plant was alleviated Wednesday when 100,000 
gallons of sludge was spread on a resident's 10-acre hayfield.

The one-day spreading was part of a plan intended to end a number of 
scattered violations of the town's sewer plant discharge permit over the 
past year.

Legal notices were posted in late July about the sludge application. And 
apparently no objections were noted.

The clogging of the two lagoons apparently has played a part in some 
elevated biochemical oxygen demand (BOD) readings in a discharge near a 
local creek, according to Suzanne Pickett, an environmental analyst. "It's 
been very sporadic," she said.

Malfunctions in Benson's aging reef aerators, which were supposed to have 
been sending many more bubbles of oxygen into the pond than they had been 
recently, contributed to malfunctions in the lagoons bound up with sludge.

"It's very hard to keep the (sewer and lagoon) system functioning when you 
have so much sludge in there," Pickett said prior to the spreading 
operation.

To remove the overload at the plant, Wednesday's operation involved the use 
of a tractor to pump sludge to a transport truck that made frequent trips 
down a long farm lane, across meadows, then south onto Stage Road to a farm 
road leading to a parcel of land owned by resident Jeffrey Noble.

A fire truck was parked across from the Wheel in Restaurant near the center 
of town on Wednesday, ready to wash any sludge from the road in the event of 
a spill.

Assuring smooth flow of traffic during the spreading operation, a local flag 
man was stationed where the sludge transport came out onto Stage Road and up 
to the farmland.

The sludge was pumped from the truck to a tank hooked to the tractor.

Once filled, the farm tractor pulled the tank across a limited section of 
the field where the sludge was sprayed out in a matter of minutes. The 
sludge-spraying tanker was visible to motorists on Route 22A who might have 
been looking to the west.

The town's current discharge permit, meanwhile, allows the plant to 
discharge effluent with readings of no more than 50 milligrams per liter, 
according to the permit. A year ago, during a week- to two-week period, 
there were violations well over that limit, officials said.

There were additional violations this spring, Pickett said, adding, "They 
met the permit limit in June and July."

A longtime buildup of sludge in two lagoons apparently played a part in 
hampering operation of the aeration system, Pickett said. The effluent 
discharge from the plan emptied into an unnamed tributary of the Hubbardton 
River to the west of the plant. The tributary eventually connects with the 
Hubbardton River, more than a mile to the southwest.

When the BOD in the effluent gets high enough, it can remove enough oxygen 
in a stream to be detrimental to aquatic life and has the potential to kill 
fish.

"It was serious enough for us to get involved," said Brian Kooiker, chief of 
the operations and management section in the Wastewater Management division, 
when asked about the severity of effluent violations.

Officials in Benson now are hoping those violations are in the past.

Ed Tracey, who was hired earlier this year as a part-time chief operator of 
the plant, said that in terms of the spring violations, he was aware of only 
BOD violation that was just over the permit limit.

Working at the plant Wednesday, Selectman Charles Kellogg showed the old 
aerators that had been removed from the pond. Plates containing tiny holes 
were torn, preventing proper operation of the units; new ones use an 
aeration design using long tubes with more capacity.

The presence of more holes along a rubber section of the new aerator should 
greatly enhance that amount of oxygen that goes into the pond from aerated 
water pump through them, said Paul Olander, a process specialist from the 
Department of Environmental Conservation.

"The efficiency of the aeration was very low," Olander said of the work 
being done by the plates in the old aeration system.

At this time year, flow from the plant is low, about 5,500 gallons a day, he 
said.

The town recently received a biosolids permit, allowing it to spread sludge 
on farmland located at the south end of the Stage Road, said Ernest Kelley, 
an environmental analyst in the residuals management section of the 
Department of Environemtnal Conservation.

Kelley was on the farm site Wednesday to ensure the spreading went smoothly.

As they prepared for the spreading, town workers in recent days emptied one 
of the lagoons and found the aerator units that were not working, Kellogg 
said.

They ordered new units at a cost of about $4,000 and got them within three 
days, Kellogg said.

Using the application method, the town hopes to keep the cost o the 
sludge-spreading project at $10,000 or less, according to Kellogg, who took 
a number of weeks off from work to keep the sludge spreading operation on 
track.

To keep the right pH or alkalinity in the sludge in the lagoon, the process 
leading up the land application involved applying quicklime to kill 
pathogens, Kelley said.

As well, there is a dose of agricultural lime added on the farmfield to keep 
the pH around 7 (neutral), he said.

The farm site receiving the sludge is a considerable distance to the nearest 
residence, potentially making it a positive one in terms of effects on 
neighbors, Kelley said.

"This is probably, one of the (more) remote sites I have ever dealt with," 
he said.

Up to 20 percent of sewer plant biosolids (sludge) is land applied, Kelley 
said. Twenty six municipalities in Vermont are certified to manage their 
sludge by land application, he said.

More than a year ago, the issue of spreading of sludge on land in Benson 
came up when the town officials said they would like to consider spreading 
sludge on part of 50-acre parcel that they proposed purchasing.

At the time, M. Guy Charlton, Select Board chairman, said sending 
accumulated sludge to an incinerator would cost up to $35,000.

Early in the day Wednesday, Charlton, who also is the assistant plant 
operator, said the town didn't expect any surprises with the sludge removal 
operation.

Contact Tom Mitchell tom.mitchell at rutlandherald.com.