Water wells still undergoing tests

Torus Tammer

The Orange County Water District is still conducting tests on two wells

it closed down last week after it found higher than expected levels of a

chemical called N-nitrosodimethylamine, commonly known as NDMA.

The district closed Well No. 98 in Huntington Beach and a well in Costa

Mesa after testing revealed the water had levels of of the chemical that

exceeded the legal limits. The chemical is a regulated carcinogen found

naturally in beverages such beer and milk and food such as processed

meats, as well as in the air and soil, said Rufus Howell, assistant chief

of the division of drinking water and environmental management for the

state Department of Health Services.

“NDMA is a relatively new contaminant that we’ve been aware of for two

years,” Howell said.

The chemical is produced as a byproduct of chlorine used as a

disinfectant in wells, water district officials said. The district uses

chlorine to purify waste water to use as a barrier between seawater and

freshwater.

According to the water district, the risk from the chemical is minute --

one part per trillion of the chemical is comparable to one second of

32,000 years.

Concern was raised when a water analysis of the two wells revealed levels

of the chemical that exceeded legal standards set by the state’s health

department, which is 20 parts per trillion. The Huntington Beach well had

a level of 32 parts per trillion, Howell said.

“To their credit, the Orange County Water District did the right thing in

this situation by notifying the city of Huntington Beach, as well as the

Department of Health Services, about the excessive levels discovered,”

Howell said.

The district will keep the two wells shut down until a solution can be

found to control the situation, officials said. Works is underway to

control or eliminate the high chemical levels by treating the water with

ultraviolet light, which may destroy the compounds that produce the

chemical.

Michael Wehner, associate general manager for water science and

technology at the water district, said he is pleased with the way the

district has handled the issue and said he believes there is nothing to

worry about.

The district “is a leader in the California water industry and the

pursuit to lower existing levels of NDMA,” Wehner said. “Our agency has

been very progressive in developing new procedures and are one of the

first cities to even monitor the NDMA levels of our wells.”

Howell said the chemical was first detected in 1998 at a Northern

California aerospace facility. It prompted investigations of chemicals in

nearby sources of drinking water. After discoveries of higher than

expected levels of the chemical in drinking wells in the San Gabriel

Basin, the state health department acknowledged that very low levels of

the chemical may have been present in treated drinking water. Technology

allowed the department to start regulating the chemical at the parts per

trillion level in March.