Water company goes high-tech to increase safety

It's not only state of the art, officials say, it's safer, too.

Georgetown Municipal Water and Sewer Service put the finishing touches last week on new technology for treating its water, and instead of dangerous chemicals stored on site, the process uses ordinary items that can be found in a grocery store.

The $1.3 million project, which includes two other new features, is almost completed, said Billy Jenkins, GMWSS general manager.

"All we've got left are some punch-list items," Jenkins said.

"The plant is shut down and we're purchasing today," Jim Long, GMWSS water treatment supervisor, said Tues_day. "We'll start filling Saturday morning, and by Saturday afternoon we'll be back in production. But before this we were in continuous production since Oct. 12."

The new technology will eliminate the utility's use of chlorine gas that has previously been stored on site.

"These loose cylinders will soon be a thing of the past," Long said, indicating two tanks of chlorine gas.

The location of the water plant, downtown on Water Street, and the use of the gas in treating the water, led to a potentially dangerous situation noted in a vulnerability assessment which every water company in the country underwent after the terrorist attacks of Sept. 11, 2001.

"The prevailing wind here is from the west," Long said, "right toward the center of town. If anything happened to one of these tanks, there would have to be an evacuation in a two-mile radius in the daytime and a five-mile radius at night."

But GMWSS is switching from chlorine gas to liquid bleach to purify its water, and the bleach will be manufactured on site.

"The bleach you buy at the grocery store is about 8 percent, and this is 12 percent," Long said. "But it's still basically the same."

Making the bleach, he said, involves another familiar household item - salt.

"It's food-grade salt and it's extremely pure," Long said.

The salt is mixed with water to create a brine.

"It goes from a solid to a liquid and then it goes through electrolysis," Long said. "The electric current goes through it and converts it into bleach."

GMWSS has installed two 1,000-gallon storage tanks to hold the bleach. While that may not seem like a lot, given the amount of water the utility treats each day when the plant is in operation, it's enough, Long said.

"Bleach has a short shelf life," he said. "In 30 days it loses all of its disinfectant qualities. So we make it as needed."

"It works great for us," Jenkins added. "We don't have to have all that storage."

Using bleach as opposed to chlorine gas is not only safer for the community; it's also safer for the workers.

"It's very easy to use compared to chlorine," Long said. "With chlorine we had to wear safety respirators and protective clothing. With the bleach all we need is rubber gloves and safety glasses."

After the bleach is used to disinfect the water, the water is pumped to the clear well, a 500,000-gallon storage tank. But there is one more step it goes through before it goes into the system and out to the customers.

"We disinfect the water against bacteria, but chlorine or bleach are not effective against viruses," Long said.

He said viruses cannot be killed, but they can be immobilized, and GMWSS has installed an ultraviolet system that treats the water in the final step before going into the system.

"Viruses are not alive," Long said. "But the ultraviolet treats them with intense irradiation, and that disrupts the RNA of the virus. It sterilizes the viruses and does not allow them to reproduce. That's the last step before the water goes out to our customers. We make sure the viruses are destroyed."

The ultraviolet uses so much electricity, and the computers that run it generate so much heat when they are in operation, the building they are housed in has to be kept air-conditioned all year long, even in the winter, Long said.

"If there's too much heat in there the system shuts down," he said.

The ultraviolet, Jenkins said, uses an extremely short wavelength.

"It can burn your skin like an arc welder," he said

The third part of the project was to build a dome over the utility's clarifier where the second step in treating the water, getting the dirt out, is done.

"The dome was constructed for two reasons," Jenkins said. "The vulnerability study we had to do after 9-11 pointed that with the clarifier open someone could come by and throw something in the water and contaminate it."

The second reason, he said, resulted in another plus.

"Algae has always been a problem," Jenkins said. "We were constantly taking the clarifier down and cleaning it. But with the dome the algae problem virtually went away and our use of chlorine decreased. So we limited our vulnerability, removed the algae and had savings in chemicals."

The project did three things for GMWSS, Jenkins said.

"We did maintenance, we made some replacements and we added new technology," he said. "And we were only down 30 days. The construction company, Her_rick of Lawrenceburg, did a great job to keep up with the pace. We gave them a 30-day window to get the project done, and they were down here working seven days a week."

And while the project was expensive, getting rid of the chlorine tanks was worth it, Long said.

"We will recoup our costs as we go along," he said, "but it's cheaper than body bags. We took a time bomb out of here."