There are engineering and design reasons why Columbia’s two water treatment plants aren’t fully connected, and a solution to that shortcoming is on the drawing board, the city’s former director of the water system said.
“People say, ‘Why can’t we solely supply water from the Lake Murray plant to the (downtown) Columbia plant or vice versa,’ ” Bud Summers, who retired last month after 33 years with the city’s water supply system, including as its superintendent, said Saturday. “There’s not enough of the correct diameter pipes to move enough to sustain either plant.”
Summers, who might know the water system better than anyone else, has been lending his help to the city during its worst water-supply crisis. The emergency began a week ago when the Columbia Canal dike was breached by a Congaree River that was flooded by historic rainfall.
The damage to the canal, the sole source of water for that plant, stressed the facility and city leaders, who scrambled to keep pumping raw and treated water from other places into the plant that serves about 188,000 of the city’s 375,000 customers. Repairs to the 60-foot gash in the canal will continue later this week.
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A vast network of lines connects the newer Lake Murray plant to the 2,500 miles of lines that distribute treated water throughout the system, Summers said. But there’s not a single, dedicated line between the plants sufficient to replace either plant for any length of time.
The largest line between connecting them is 2 feet across and can move as much as 12 million gallons daily when pushed to its safe capacity, he said. But that line also feeds other smaller and larger lines.
Still, the plant that abuts Riverfront Park downtown produces 60 million gallons when it’s operating normally, city officials have said.
That 24-inch line was used often last week to help sustain the downtown plant, Summers said. Treated water from the Lake Murray plant routinely is housed in two, roughly 2.5-million-gallon storage tanks at the downtown plant and then circulated to help serve customers in Columbia and southward into lower Richland County, he said.
That is an example of how the plants interconnect, among many smaller and larger lines that crisscross the vast network. The Lake Murray plant, which opened in 1983, generally serves customers north of I-20.
The deluge cut off water to some 130,000 customers of the canal plant, Columbia Mayor Steve Benjamin said last week.
The downtown plant’s canal was first used as a navigation route in the 1820s for cargo barges traveling between the Upstate and the Charleston port to get around dangerous rapids in rivers that combine to create the Congaree, Summers said. The canal, shortened from its original length to the current 3-mile stretch, was converted to that plant’s primary water source just before World War II, he said.
Part of the public’s confusion about how the plants tie together is fed by public pronouncements from the city. For example, a water quality report states, “The system is designed, however, so that sustainable water can be supplied to the entire service area by either plant.”
Summers said the term “sustainable” means the plants can handle minimal demand for a few days. Minimal demands include use restrictions such as not running washing machines, dishwashers, limiting baths and even how frequently toilets may be flushed.
The floods occurred at a time that a design consultant has been devising a plan to install a 60-inch line between the two plants, Summers said. City Hall has been considering such a plan for years, and the consultant began the work about a year ago, he said.
But council has authorized $27 million in upgrades to the downtown plant and $23 million in improvements to the Lake Murray facility, Summers said. The downtown plant upgrades have been completed and those at the lake are underway, he said.
“It’s going to be a very high-dollar project – way up there into the millions,” Summers said.
City Council has not approved money to build the line.
Still, the way city leaders were able to keep the downtown plant operating last week shows the system was able to endure a calamity, Summers said.
“We have done what we laid claim to do.”
Clif LeBlanc: 803-771-8664
THE COLUMBIA CANAL
A brief history
▪ The Columbia Canal dates to the 1820s, when it served as a way for cargo ships to bypass the rapids in the Broad and Saluda rivers that converge in downtown to become the Congaree River.
▪ Completion of a railway system connected to the Capital City during the 1840s devalued the canal’s importance to commerce.
▪ The canal was widened and deepened in the 1890s.
▪ In 1906, the city started using the canal’s water to drive water pumps at the plant, sort of ike a paddle wheel. The buildings that housed the pumps remain on the plant property but haven’t been used since in about four decades.
▪ Just before World War II, the canal became the only water source for the downtown plant that now abuts Riverfront Park.
SOURCE: Retired Columbia water system superintendent James “Bud” Summers.