Behind the scenes of a city necessity
It is a part of living we all take for granted–until something clogs, cracks, leaks or backs up.
At a recent meeting of the Estherville City Council, Paul Barnes of the Wastewater Treatment Plant shared his annual report for 2007.
“The collection system is our first line of defense or the plant won’t work like it is supposed to. Jeff Kautz and his crew do a very good job,” Barnes said.
This system includes 66 miles of sanitary sewer main and has been divided in four sections for cleaning and inspection.
On tap for the latest go-around was section three which encompasses the northeast side of the city from the former railroad right-of-way east and south to Central Avenue.
Another 1,150 feet of sanitary sewer main was lined from the east bank of the river near the power plant to the river lift station on Second Avenue South.
Another 600 feet in the 400 block of South Ninth Street was also lined.
Repair work was conducted on the section under the bridge that spans School Creek on West South First Street.
Crews took time to rebuild a manhole and install two manholes on West South First Street near the tennis courts.
In 12 months’ time, employees answered 30 sewer calls with 21 being attributed to property owner sewer problems. The remainder were problems on the city’s side.
Grease and tree roots again are the main source of plugged-up sewers. Barnes noted over 1,000 feet of roots were stripped from the sanitary sewer.
Working in good repair and functioning properly are the three sewage lift stations.
The plant itself received a new operating permit in 2007. Some major changes affecting the cost of operation include:
n Ammonia limits were changed from a constant small concentration to more reasonable “flow-variable” limits. Barnes noted it took the city 10 years and $50,000 in engineering fees to convince the Iowa Department of Natural Resources that this was the right thing to do.
n A limit for Total Dissolved Solids was added. The superintendent stated this is a very unreasonable limit as the TDS level in the city’s drinking water is higher than the amount of TDS the Wastewater Treatment Plant is allowed to discharge. There is 1,200-1,300 milligrams per liter of TDS and the limit on the plant discharge is 1,068 mg/l.
n A Dissolved Oxygen limit is included on the permit.
n The WWT Plant is now responsible for disinfecting the effluent before discharging into the West Fork of the Des Moines River. The new demand is to protect people who swim, dive, water ski or canoe.
“Now that we protect the people in the river by adding chlorine, we will have to protect the aquatic life by “de-chlorinating.“
Barnes added, “This requirement was placed on Estherville to protect the fathead minnow and the water flea.”
Officials from the Environmental Protection Agency and the Department of Natural Resources jointly inspected the plant which received a very favorable rating from the EPA.
Other WWTP statistics are:
n 480.5 million gallons of sewage were treated in 2007 and reflects a decrease of 39 million from the previous year.
n 4.7 million gallons of sewage sludge with 349 tons of sewage solids were processed through the dewatering system.
n The cost to dewater the sludge was $.003 per gallon of sludge or $152 per ton of solids.
n Once the solids are stabilized, they are disposed of through land application. A total of 117 tons of stabilized sludge were removed with this method at a cost of $349 per ton.
Barnes noted the cost to dispose sludge in the future is expected to nearly triple and is due to new Department of Transportation regulations that limit the amount of sludge that can be hauled by our sludge truck.
In previous years, the city hauled 3,000 gallons per load. That amount has been cut in half which doubles the number of trips, fuel costs, maintenance and personnel costs.
It was noted the city and Estherville Foods signed a new treatment agreement. The company will now be billed a 20 percent penalty fee each month they exceed the limits in the agreement.
Estherville Foods had three agreement violations in 2007 when oil and gas limits were exceeded in July and Total Suspended Solids in August and September.
In addition to Barnes, staff includes Duane Dahna, laboratory technician, grade II; Jeff Kautz, plant operator, grade IV; Dean Murray, plant operator, grade II; Bernie Meyer, plant operator, grade II; Gary Enderson, plant operator, grade II; and Ian Schmitz, plant operator, grade II.