Reverse Osmosis Used to Purify and De-nitrify Water in a Municipal Plant
Culligan International Company has been providing services to small municipalities since the 1970s, but in February of 1997 the company signed a $1.9 million contract with the city of Abilene, Kansas, to remove nitrates from the city's water system.
The overall cost of the project was estimated at $6 million. This marked the largest domestic municipal project for Culligan and led to the creation of a municipal markets division within the company.
Fertilizers used in this farming area raised nitrate levels in the water beyond those allowed by state law. The Kansas Department of Health and Environment enforced action against Abilene and the city searched for a solution.
Culligan used reverse osmosis (RO) to de-nitrify the water, a procedure that was common in the industrial market but was fairly new to municipalities.
"The method of using sand and chlorine to cleanse water requires a large amount of land and building space," said Tim Mahon, director of municipal markets for Culligan. "Start-up costs for RO can be more expensive, yet it is significantly more cost-effective in the long run. Square footage usage is reduced by 40 percent and labor and material costs go down within the first two years."
Research, testing, design and installation have been on-going since the contract was signed and the project has recently entered its start-up phase.
"This job is 100 percent customized," Mahon said. "As with many municipal water treatment systems, a solution can't be pulled off the shelf. Our equipment takes into account the site-specific variables that make Abilene unique."
Abilene is just one example of a water problem for which Culligan provided a solution. Using a variation of traditional water treatment processes, Culligan has developed the Multi-Tech System to treat surface water.
Culligan's proficiency was used in a water treatment project in the ex-Soviet Republic of Turkmenistan to provide safe drinking water for the capitol and its suburbs. The raw water from the country's basins was disinfected, coagulated and filtered with a Culligan system.
In 1996, Culligan-Enerserve was called on by the Island Government in St. Maarten to provide a more cost-effective sea water purification system. The company was able to complete the RO plant in Cay Bay in seven months, a job that would normally require 12 months.
"The scope of these projects is a clear indicator that Culligan has grown quite a bit since the home water tank delivery days," Mahon said.