UCI professor has new way to ID waste

Deirdre Newman

A UC Irvine professor is part of a research team that has

developed a systematic approach to identifying bacterial ocean

pollution.

Engineering professor Stanley Grant and two other researchers

conducted their work in Avalon Bay off Catalina Island to help

officials there determine the cause of a water quality problem on

their beach.

An account of their research was posted Thursday on a Web site for

the journal of Environmental Science and Technology.

The team’s ultimate goal was to determine whether the sources of

pollution represented human fecal material. This would be a

significant finding, Grant said, since if the pollution is caused by

human bacteria, there is usually an easy fix to the problem.

He added that he would like to see the team’s three-tiered

approach be modified to work in other areas of Southern California,

since ocean pollution is a pesky problem up and down the coast.

“My hope is that people will look at what we did at Avalon when

they are trying to solve problems in their own back yard,” Grant

said. “It is a case where through systematic answering of a set of

questions, we got to a point where we could say definitively that we

identified a number of [pollution] sources and we know what those

sources were, and the city was able to fix them.”

Grant was invited by the Avalon officials to help solve their

water quality problem, along with Jed Fuhrman from the University of

Southern California and Alexandria Boehm from Stanford University. In

the past, Grant has led major studies on whether boats have been

dumping sewage into Newport Harbor and an analysis of wetlands as a

contributor to ocean pollution.

Grant said the Avalon team used a common-sense approach similar to

how a doctor diagnoses a patient’s ailments.

First, they isolated the physical source of the pollution, then

they analyzed what the source was and then tried to assess whether

the source represented human fecal material.

They also tried to take into account all the variables that could

affect the concentration of bacteria, such as exposure to sunlight

and the tides.

“What happens frequently is people say, ‘Let’s just go out and

take a bunch of samples, and you get samples affected by the

variability and you don’t necessarily understand the results,” Grant

said.

The research at Avalon Bay turned up multiple sources of human

bacteria. One of those sources was traced to a leaky sewer trunk

line, which was eventually fixed, Grant said.

Larry Honeybourne, the county’s program chief of water quality,

said the Avalon study will be an asset to the county’s efforts in

tackling ocean pollution.

“I think it was an excellent piece of work,” Honeybourne said. “I

think it helps move us along in putting more tools in what we call

our tool box.”