KAHULUI — Diversion of pineapple cannery wastewater from an injection well to cane fields is likely the reason that Kahului Harbor no longer experiences algae blooms, the County Council was told Monday as reported by The Maui News today.

Russell Sparks, education specialist with the Aquatic Resources Branch of the Department of Land and Natural Resources, said no controlled experiments were performed, so his explanation is just anecdotal. However, it seems to fit the facts. The council's Water Resources Committee was receiving a report on algae blooms and possible connections with wastewater injection, and Council Member Gladys Baisa recalled that the harbor used to experience smelly outbreaks of limu.

"It's gone," she said. "What happened?"

Sparks said the beginning of the end was probably when Maui Pineapple Co. stopped disposing of pineapple wash water in a well at Queen Ka'ahumanu Center a decade ago.

The water, about 2 million gallons a day, was highly diluted pineapple juice, containing sugar. Underground, the sugar was converted to methane. The methane leaked upward. Cannery mechanics used to pound pipes in the ground, collect the methane and light it to heat their coffee.

That ended when methane collected in an enclosed space within the cannery, exploded and knocked over a wall, injuring two workers.

Besides making methane, the wash water and its nutrients also made their way into the harbor, nourishing algae blooms that rotted and led to complaints from residents of the Harbor Lights condominium.

Maui Pine built a filter to strain the solids out of the wash water, and a pipeline to take the water to a Hawaiian Commercial & Sugar Co. field a couple of miles away.

By 2000, said Sparks, the volume of unwanted seaweed being scavenged from the harbor had dropped by half, and by 2001, "no more."

This experience, and others elsewhere, suggests that "it takes about three years to flush out" a groundwater source once a source of pollution is stopped, Sparks said.

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