Where does your water come from?

Thursday, May 10th, 2012
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North Hawaii News

On a steep, windy road about 500 feet above Waimea, water is captured from Kohakohau and Waikoloa streams, made safe for drinking and sent to local tanks to be distributed from Kawaihae to Ahualoa.

The about 2.5 million gallon per day process is made possible by the Waimea Water Treatment Plant through the County of Hawaii Department of Water Supply.

“We capture it high and store it high to use gravity,” said Kanani Aton Keliikoa, public information and education specialist for the Department of Water Supply.

Keliikoa recently brought a group of eighth grade students from Waimea Middle School to visit the plant with their science teacher, Naui Murphy.

“We want them to feel the sense of responsibility and ownership for what it takes to produce water,” Murphy said.

There are three reservoirs above the plant that hold 50 million gallons each. One was damaged during the 2006 earthquake and had to be emptied. It was repaired and refilled last year. A second reservoir was also damaged and is now being repaired.

According to Anthony Tanodra, before the water is treated, it has a reddish color. Tanodra is the water treatment plant operator, level four; only one of five on the island. He said that “Waimea” means “reddish water.” To demonstrate, Tanodra filled a pitcher-sized beaker with red, murky untreated water from the stream and clean, clear water from a tap.

“For your parents and grandparents in early 70s, that is what the water was like,” Tanodra said, pointing to the tinted beaker.

According to Tanodra, the Army Corps of Engineers staying at the military camp in Waimea built the original water system. The plant was upgraded and the water purification process was added in the 1970s. The plant is also operated using a hydro generator to produce electricity, so it is its own renewable source of energy.

The water first goes through a flocculation process that removes organic and inorganic material. It next goes to a sedimentation bed, where the floc settles to the bottom, leaving clear water. After, it passes through a sand and charcoal filter, to further remove impurities. The water then goes through a disinfection process.

Tanodra said the water must pass stringent state and federal tests for cleanliness mandated by the Environmental Protection Agency and the State Department of Health. Tanodra said that at many points during the process, the water is tested and constantly monitored with analyzers 24 hours a day, seven days a week.

All of the byproduct removed from the treatment process flows into a “sludge lagoon.” Any extra water is recycled back into the plant. The sludge is pumped out of the 19-foot deep lagoon back up to a solar sludge drying facility and the dried product is used as landfill.

“We don’t waste any of the water,” Keliikoa said.

The finished water remains in a four million gallon holding reservoir until it flows out through a pipe system to tanks throughout the area, and then sent to homes. Tanodra said that the plant is always operating, so there must always be someone either on site or on call. Despite the responsibility, Tanodra said he enjoys his work. He encouraged students who are interested in his job to work hard in science and math.

“I like the gratification that I drink the water I help keep clean,” Tanodra said. “There is a satisfaction there.”

Keliikoa said it’s important for the students to understand the water cycle.

“We like to bring kids to this area to feel a deeper appreciation and enhance their understanding of what it takes to produce water that is safe to drink on demand,” Keliikoa said.