By ROBERT A. DEFRANK

Times Leader Staff Writer

ST. CLAIRSVILLE — Wastewater treatment methods are on the minds of many after recent leaks at St. Clairsville’s plant, where the city uses a chlorine disinfection system.

The Times Leader reached out to several local communities to learn more about their processes, safety factors and options for possible uprgrades.

While plant operators agreed that there are several advantages to the ultraviolet light method of treatment, in terms of safety and fewer regulatory restrictions, the cost of the process and the necessary upgrades to use it is a factor in choosing the best method for each plant.

According to a study by the University of Texas, there are several possible methods of water disinfection. In addition to chlorine and UV light, they include ozone gas, membrane disinfection, gamma irradiation, ultrasonic and electrochemical methods, as well as the use of chemicals such as bromine, peracetic acid and potassium ferrate. That study also estimates that the cost of UV treatment is about double the cost of using chlorine.

Ron Pacifico, manger at the Belmont County wastewater treatment plant, said chlorine is used there. He said the method has been largely safe, with only one small leak several years ago. The cylinders that hold the chlorine are housed in separate rooms in two parts of the plant. Gas meters in each room will detect any leak and sound an alarm, he said.

Pacifico noted chlorine and sulfur dioxide are only used from May through November, when warm conditions allow bacteria to grow.

Jeff Vaughn, consulting engineer and technical adviser for the Eastern Ohio Regional Wastewater Authority treatment plant in Bellaire, said the ultraviolet disinfection method has been used there since 1996 — a change that was made in the wake of a serious chlorine leak. The plant serves Martins Ferry, Bellaire, Bridgeport, Brookside, the Ohio Valley Mall and the Ohio Valley Plaza.

“They used to use chlorine up to 1995. They used chlorine in 1-ton cylinders, since the plant is fairly large,” Vaughn said.

“They had a massive chlorine leak at that time, due to old equipment. The board elected to move to ultraviolet disinfection rather than replace the chlorination system with a new one.”

He said ultraviolet was the best option due to the plant’s large size. Costs of operation include about $6,000 a year on UV bulbs and $3,000-$4,000 for electricity.

“When you use chlorine and sulfur dioxide as a dechlorinating agent, it’s probably the most inexpensive way to disinfect the wastewater effluent at a wastewater plant,” he said.

He then pointed out advantages of the ultraviolet method.

“It’s very safe for the operators, and they don’t have to work with a compressed, toxic gas,” he said. “As far as economics, you’re running a lot of electricity through all these lamps, and then the lamps, the bulbs themselves only last for so many hours, in the order of a year.”

Don Villani, superintendent at the Water Pollution Control Division in Wheeling, said both methods are utilized at that plant.

“We actually use UV the majority of the time during normal flows, and when we have increased flows during times of precipitation … we actually have a combination where we can go to UV plus chlorine, or just all chlorine if we have a problem with the UV,” Villani said, adding that the city had used just chlorine until 2006 and that system experienced some minor problems before the upgrade. He said liability was one factor that prompted the change. “We actually used to use 30- to 50-ton tank cars at one time. We would have two of those cars on site at the wastewater treatment plant.

“The advantage of ultraviolet is there’s no contaminants put into the receiving waters. There’s no chemicals, there’s no residue,” he said. “It uses ultraviolet light at a certain wavelength, and at that wavelength all the microorganisms in your wastewater are either sterilized or neutralized.”

He said UV is more costly, but it is also a simpler way to meet U.S. Environmental Protection Agency requirements.

Although the city continues to use chlorine as a supplement, Villani said officials are considering eliminating it entirely in the near future. He said one drawback to UV is that with chlorine workers could more easily test for disease-indicator organisms.

Harrison County Engineer Robert Sterling said his county utilizes a zero-discharge facility that does not release water back into a creek after UV treatment.

“After we treat it, we spray it on the land,” he said, citing several advantages. “For one thing, EPA doesn’t come around since you’re not discharging anything.”

Sterling said the process has been in use since 2001 and there have been no issues with it.

“We have seven spray zones. It automatically switches from one to the other after we put 28,000 gallons on it. It’s worked out really well. … We just have a couple of earthen lagoons, and we circulate water through them,” he said, adding that devices suck out the air as it circulates the water. “Aside from a couple pumps and the ultraviolet, we didn’t have that much in it as far as equipment’s concerned.”

Sterling added that the majority of Harrison County’s communities use the chlorine method to disinfect their wastewater.

Larry Bonar runs the Moundsville wastewater treatment plant. He said the ultraviolet method has served the city well for more than 20 years. He said the expense is balanced by the ease of complying with regulations.

David Green, water and sewer operator in Bethesda, said the village recently changed from using chlorine to the UV method after experiencing numerous problems.

“We had a lot of problems with leaks, shutting down and starting up, and went to an ultraviolet light system,” he said, noting the village was able to retrofit its existing system.

Roger Deal, Barnesville village administrator, prefers the ultraviolet method and gives unqualified approval of its performance for the village. It has used the method for close to 25 years.

John Blair, chairman of the sewerage district for Marshall County, said the county operates eight small package treatment plants at Pin Oak Hill, Williamsburg Farm, Fort Clark Estates, Pine Knoll Acres, Rustic Hills, Washington Lands and Sunnyside Greenbriar. Six of the sites use chlorine tablets to treat wastewater. The Sunnyside Greenbriar plant uses UV, while the Washington Lands site uses a hypochlorite solution. He said the county has had no issues with the current system and has had no discussion about changing methods.

The leak that occurred Monday in St. Clairsville involved chlorine, one of two chemicals used in the end process of treating water; sulfur dioxide is used to remove the chlorine from the water before it is released into a stream. On Aug. 4, a sulfur dioxide leak occurred at the plant. No one was injured in either incident.

The city has returned its chlorine cylinders to the manufacturer and is not currently using chlorine in its treatment process.