The Meaning of Hahamongna

The original settlers of the region were sometimes called the Hahamongna Indians. The word means "Flowing Waters, Fruitful Valley" in the native Tongva language.

Hahamongna News


NASA begins groundwater cleanup at its JPL campus





Lisa Faught , Staff Writer


Pasadena Star News


LA CANADA FLINTRIDGE -- NASA has started construction on its first treatment plant to clean groundwater contaminated with chemicals left over from testing rockets at the Jet Propulsion Laboratory decades ago.

The chemicals perchlorate and two volatile organic compounds, potentially a health risk, are concentrated in the groundwater at the heart of the JPL campus.

Starting in 1936, the U.S. Army Air Corps tested some of its first rockets at the site. The standard practice then was to dump the chemicals down the drain into pits, where they seeped slowly into the soil.

Over the years, the plume of contamination has drifted several thousand feet below Hahamongna Watershed Park toward Altadena, triggering the closure of nine water wells in Pasadena.

NASA has pledged to clean up the contamination to drinking water standards, but some questions still remain over the extent of the pollution.

The city of Pasadena has filed a $2 million claim against NASA seeking to recoup costs for shutting all nine water wells. However, NASA is calling for further testing on five of them.

Until further tests pinpoint the scope of the contamination, NASA is focusing on cleaning up the worst of the mess beneath JPL. Construction on the first of two water treatment plants to be built at the JPL campus kicked off in early February.

Right to the source

On this day, a drill rig is boring deep into the ground amid the buildings and parking lots on the JPL campus. The well, 13 inches in diameter and 315 feet deep, plunges directly into the hotspot of contamination.

The chemicals are most concentrated in about eight acres at the center of the campus, near the "Extraterrestrial Materials Simulation Laboratory.' This is where the chemicals were once discarded in pits.

The levels of perchlorate here have reached as high as 13,000 parts per billion (PPB), more than 3,000 times higher than the state guideline of 4 PPB.

The goal is to pump and treat the pollution at the source, to prevent the chemical plume from spreading further, said Steve Slaten, NASA project manager for the cleanup.

"We want to drill right into the heart of the highest levels of chemicals to control the source,' Slaten said.

Cleaning the water

Over the next few months, workers will drill three water wells and build the water treatment plant to clean the groundwater.

The system will pump 125 gallons of water per minute from one well, pipe it to the water treatment plant, then pump it back into the ground through two wells several hundred feet away.

Once the system is up and running, workers will drill another three water wells, doubling the capacity to 250 gallons of water per minute.

If the system pumps enough groundwater, it could actually pull the plume back toward JPL, Slaten said.

"It's like a tug of war. If there's strong enough suction going on here, it should make the water flow toward the well,' Slaten said.

Eventually, once the details are worked out with Pasadena Water & Power, the plan is to build a second water treatment plant nearby to clean the drinking water from wells in Pasadena.

The challenge

The first water treatment plant will clean the groundwater of perchlorate and volatile organic compounds.

The contaminated water will first pass through a carbon filter, similar to a home drinking- water purifier, to remove any VOCs.

The water will then pipe into a reactor where microbes activated by a corn syrup mixture will essentially eat and destroy the perchlorate.

It then runs through a filter to strain out the microbes before it is pumped back into the ground.

The technology for removing VOCs is fairly simple, but the methods for removing perchlorate are more involved, Slaten said.

"Perchlorate removal is the challenge,' Slaten said. "It's more difficult. The technology is far more advanced.'

Live microbes

The perchlorate removal hinges on a method steadily taking hold in the world of water cleanup.

Most water treatment plants remove perchlorate through a method called ion exchange, which captures perchlorate anions and replaces them with a harmless chloride ion. The method produces waste composed of concentrated perchlorate brine and spent resin.

But NASA officials opted to go with live microbes to break down the perchlorate, a method employed in only one other case in California.

The method is used to treat contaminated groundwater at the Aerojet site in Rancho Cordova near Sacramento, but it has yet to be used to treat drinking water.

The microbes, widely found in nature, feed on perchlorate and reduce it into oxygen and chloride.

The benefit of microbes over ion exchange is the absence of any waste product, which can be difficult to dispose of, Slaten said.

"Ion exchange grabs the perchlorate and concentrates it, a concentrated waste that must be destroyed,' Slaten said.

"The beauty of the biological (method) is the bacteria like to eat perchlorate as their food.'

Pasadena a first?

NASA officials are also considering the biological method for its second water treatment plant to clean contaminated drinking water from wells in Pasadena. If approved, it would be the first of its kind.

The state Department of Health Services has conditionally approved biological treatment for the project, but a decision has yet to be made on which technology to use, said Vera Melnyk-Vecchio, regional chief of the drinking water program for DHS.

The biological treatment eliminates the problem of waste disposal, but some residents may have a hard time swallowing the idea of microbes in their water, said Jeff O'Keefe, district engineer of the drinking water program for DHS.

"The fact that microorganisms are used in the treatment process scares some people, but it shouldn't be a concern because there are various post-treatment filtration and disinfection to remove them,' O'Keefe said.

"Every lake and river in California has active microorganisms as well.'

Contamination common

The Department of Health Services started monitoring for perchlorate contamination statewide in 1997, when it developed a more precise test for detecting the chemical.

It set a guideline recommending agencies not serve drinking water with levels of perchlorate higher than 18 PPB, which was later revised to 4 PPB. But state and federal agencies are still working to set enforceable levels for the chemical.

Since then, the chemical has been found at some 350 sites providing drinking water throughout the state, spurring the closure of water wells with high levels.

In the San Gabriel Valley, perchlorate has been detected in a number of drinking water wells, including Alhambra, Arcadia, Azusa, Baldwin Park, Duarte, Commerce, Covina, El Monte, Glendora, La Puente, La Verne, Monrovia, Pasadena, San Gabriel, San Marino and South Pasadena, according to a 2003 report from the California Regional Water Quality Control Board.

In Pasadena, the city has stopped pumping drinking water at nine of its wells because of perchlorate contamination. Four of the wells are believed contaminated by perchlorate from JPL, but NASA is still trying to determine if the contamination has spread to the other five, Slaten said.

Plans for a second water treatment plant to clean drinking water in the Pasadena water wells are expected to be finalized in coming months, Slaten said.

-- Lisa Faught can be reached at (626) 578-6300, Ext. 4496, or by e-mail at .