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Archive for Sunday, July 22, 1990

CITY WORKERS KEEP WATER FLOWING

July 22, 1990

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Lawrence water treatment plant operators might be likened to the fairytale elf Rumpelstiltskin. Just as he could spin straw into gold, Lawrence's water treatment operators turn murky, fishy, river water into sparkling clear drinking water perhaps better magic in a thirsty city than the elf's.

Ralph Gelvin Jr., water systems engineer for the city, said the nearly 75-year-old Kaw Water Treatment Plant at Third and Indiana streets the first built by M.T. Veach of Black and Veatch Consulting Engineers and the 12-year-old Clinton Water Treatment Plant, on Wakarusa south of 15th, "make" more than 20 million gallons of water each day.

They drink it, bathe in it, cook and launder clothing in it, and this time of year water lots and lots of grass with it.

The "worst day" on record in terms of usage, Gelvin noted, was June 28, 1988, when the two plants together pushed out 21 million gallons for users.

RIVER AND well water are processed at the Kaw plant, Gelvin explained, while Clinton Lake water is processed at the Clinton plant.

Both facilities are manned 24-hours a day, seven days a week, and certified operators perform process control tests every two hours to ensure compliance with state and federal safe drinking water laws.

Quality control tests at the Kaw plant are conducted in a lab just off the monitoring room, where technicians also are on duty seven days a week.

Lab technician Ed Haynes said he conducts tests every 24 hours on composite samples of water collected during process control tests, and Gelvin noted state regulators, with federal Environmental Protection Agency oversight, monitor those tests.

Haynes said he regularly checks hardness, Ph value, alkalinity, turbidity and, when needed, the levels of flouride, chloride, nitrates, phosphates and other materials.

GELVIN oversees the operations division, responsible for water treatment, in the city's utility department, which is directed by Roger Coffey. Four other divisions in the department are water distribution, waste water, sewer collections and the quality control laboratories.

Thanks to a network of water rights agreements, Gelvin said, Lawrence is "fairly certain of having water all the time" even in the event of drought.

Contracts with the Kansas Water Office, a state agency, guarantee 10 million gallons a day out of Clinton Reservoir, he explained. The Kansas Water Office in turn bought storage in Clinton from the U.S. Army Corps of Engineers.

The city also has water rights to the wells, situated under the eight "mushroom" shapes in Burcham Park.

"The majority of the year, we do run our wells," Gelvin said, noting the well water is treated just like surface water because of its close proximity to the river.

ONLY BOWERSOCK Mills and Power Co. has priority over the city on the river in terms of water use, he said, noting the water level at Burcham Park is dependent on what Bowersock is doing.

The city, happily, has a good working relationship with the small, private power company, he added.

Douglas County also belongs to the Kansas River Water Assurance District, an organization of Northeast Kansas entities, including cities and utilities, which aims to guarantee water coming downriver in times of drought.

The city built three intakes out in the river, about midstream in the Burcham Park area, but only one is now operational.

"We can pull 24 million gallons out of the one intake a day," Gelvin said. "It sure helps us when Bowersock backs up the pool.

"They can back it up almost to the KP&L plant."

RIVER WATER goes from the intake to two pump stations Low Service No. 1 and Low Service No. 2, which exist only to pump the water on up the hill to the plant.

No. 1 can pump 6 million gallons a day; No. 2, 20 million gallons.

At No. 1, built in the 1940s, river water goes into a wet well first so some of the sandy sediment can settle out before it hits the pumps, Gelvin said.

Every three years, the wet well is dredged down to about 20 feet to keep it functional.

No. 2 station, built in 1960, contains five pumps and has a giant sand screen rather than a wet well to help protect the pumps. No. 2 stands directly over a well, though, which receives river water through a 36-inch pipe some 35 to 40 feet down.

The screen in that station removes much of the sand from the water and returns it to the river, via a little tributary across the street and railroad tracks from the station, Gelvin said.

MAINTENANCE, he explained, is a primary concern because of the problems sand can cause in the pumps.

"They don't let them (the pumps) break," he said of the operators, adding that a working pump can be rebuilt at about half the cost of repairing a broken one.

No. 1 and No. 2 stations pump to No. 1 basin, at the top of the hill on the west edge of the plant. A series of basins, numbered 1 to 9, stairstep down the hill, holding progressively more drinkable water.

At No. 1 basin, which holds 1 million gallons, Gelvin noted, "The more (debris) we can remove here, the better we are.

"Once (water is) pumped to this level, the only time we pump again is after it's treated into the distribution system."

Water curls over the lip of basin No. 1, headed for No. 2, where plant operators start the treatment process.

THEIR ADDITIVIES "knock out the pathogens, basically anything that can cause disease," Gelvin said, and make the water visually more acceptable to consumers.

Occasionally, he added, the water will develop off tastes and odors, thanks to a strange breed of algae that sometimes grows in the river.

When that happens, the additive levels must be adjusted again.

"It's been hitting about every August," he said, noting the troublesome algae prefers water warm.

Gelvin said the technology of treating water hasn't changed appreciably since 1917, when the oldest section of the Kaw plant was built, so the entire operation there remains state of the art.

Certified operators man the monitoring room, where banks of gauges measure the balance of such additives as activated carbon, potassium permanganate and aqua ammonia, as well as water levels in storage wells and towers at both plants and around town, and pressure in the lines.

"THEY MAKE the water; they run the show," engineer Gelvin said of the monitoring room operators. "The rest of the staff are support."

The additives do different things to the water, he said. Activated carbon takes out the fishy taste and odor and potassium permanganate any residue of iron or manganese. Aqua ammonia combines with chlorine to make a dissinfectant called chloramine.

Carbon dioxide is added to control the water's pH, he said, noting that it forms a weak acid when added to water. That, in turn, is balanced with lime.

All the additives are potentially dangerous, Gelvin said. "We've been real fortunate. There have been no accidents but the danger is always here.

"This stuff is very unforgiving so when we hire people, we don't hide anything from them."

ON DOWN THE line in a huge room, 150,000-pound color-coded bins hold lime, soda ash and alum, which are added to the water as a slurry as it passes down a winding concrete trough.

Lime and soda ash fight hardness, Gelvin said, and the alum and a polymer, which he described as a generic name for a variety of chemicals that coagulate water, combine with electric charges on silts and clays in the water. As a consequence of that addition, silts and clays attract each other, get heavier and sink, leaving cleaner water.

From the troughs, water passes into twin basins, built so half the plant can be shut down at a time for cleaning with no sacrifice to residents' water supply.

As water begins its passage through the twin basin complex, operators can watch the sediments begin to coagulate as a consequence of the alum and polymer.

BIG ROTATING paddle wheels gently encourage coagulation in the first 20 feet of the basins because, as Gelvin explained, "The bigger they are, the faster they fall."

Then, as the water passes through a board fence and concrete baffle wall, it leaves the sinking silts behind and begins to look like drinking water.

In the next basin, only the top -inch of water, because "it's the cleanest," is skimmed off to move forward in the process.

Both chlorine gas and carbon dioxide, compressed to liquid forms, can be added to the water at different stages, to provide operators with a measure of flexibility in adjusting the additives.

At the west end of the twin basins, Gelvin said, the water finally meets primary standards for drinking water, although it gets one last cleaning before going into the distribution system.

THE FINAL touch is percolation through an eight-foot deep bed of sand topped by a layer of hard carbon called anthrocite. This process takes place inside the plant and removes the lightest sediments.

Gelvin said after about 100 or so hours of operation, the sand bed must be backwashed to clean it of debris, which ultimately is returned to the river from whence it came.

"We need 50,000 gallons to backwash about six months of use at your house," Gelvin said, noting the plant uses 10 percent of its total output inside the plant.

After water passes through the sand beds, it either goes directly into the distribution system or into an elaborate storage network that includes huge wells under the plant and towers at strategic points citywide.

THE STORED water can be distributed in concert with water coming directly from the plants, Gelvin said, through control mechanisms in the Kaw plant's monitoring room.

A 150,000 gallon well holds water under the Kaw plant's lunchroom and a million gallon well sits under the front yard.

The tanks at various locations throughout the city also help equalize water pressure, Gelvin explained, noting eventually another tower will be needed on the west side.

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