By Racquel Palmese
In the 1980s, when the Los Angeles Unified School District acquired the 36 acres that now houses South Region High School No. 9, also called South Gate High School, it could never have imagined that it would cost some $22 million, and take over a decade, to clean up the toxic chemicals that had saturated the soil throughout the property.
That was before much thought was given to building schools on acreage that had been used by industry, from electroplating to pesticide manufacturing, releasing an alphabet soup of toxics that ended up in the air, soil and groundwater. At the time, there was an extreme shortage of seats for students, and most LAUSD schools were operating with huge class sizes on year-round schedules. The District was looking in every corner for available properties that could be acquired for new schools.
South Gate gave up some $200,000 in tax revenues from these industries, according to an article in the Los Angeles Times, to provide the land to the school district, but it was up to LAUSD to clean it up. This has entailed removing some 112,000 cubic yards of soil and cleaning onsite another 12,000 cubic yards. In the end, a shiny new campus has emerged comprised of three energy efficient and otherwise green high schools – a Science, Technology, Engineering, Arts and Math school, the Visual and Performing Arts High School and the International Studies Learning Center.
A Massive Cleanup
What it took to remediate the site is a story of technology and dedication. Pat Shannon, environmental program manager for LAUSD, manages the District's environmental functions. When he joined the District in 2001, the land had already been acquired. “Regardless of whether or not we were going to build a school,” he said, “we were required by the regulatory agencies to do some sort of a cleanup.” With that in mind, building a school made sense.
“The property consists of a series of parcels that included metal foundries and fabricators, plating shops, pesticide formulators, automotive repair, truck shipping and storage and recycling businesses,” said Ed Morelan, site assessment program administrator for the Office of Environmental Health and Safety for the District.
These endeavors yielded a variety of contaminants buried in the soils and in the groundwater. A large majority were volatile organic compounds (VOC's) – things like trichloroethylene, used for cleaning metal parts; polychlorinated biphenyls (PCB's), no longer used in the United States but still prevalent in the environment, which are mixtures of up to 209 individual chlorinated compounds used as coolants and lubricants especially for electric devices and lighting. They found hexavalent chromium, cadmium and arsenic. “Pretty much the cross section of pollutants because of past industrial uses,” he said.
It took more than a decade to determine the scope of the contamination, which was found in both the soil and groundwater. A strategy was developed to clean the northern half of the property first because that’s where the school itself would be built. This was done under the direction of the Department of Toxic Substances Control (DTSC), the state regulating agency for all new school development in California.
Cleaning the soil was an epic project. Some 47,000 cubic yards required treatment or removal on the northern half of the property alone. There were three main cleanup options that were chosen by the District. “We were required to do the cleanup in a very accelerated time frame,” said Morelan, “so we could actually get to construction of the school. A large part of our cleanups involve excavation and offsite removal. We try our best to recycle contaminated soils. VOC-impacted soils were taken to a treatment facility where the chemicals are removed and those soils can ultimately be reused again.”
Getting the VOCs out of the soil usually involved thermal treatment, passing the contaminated soil through a high-temperature burner that volatizes and destroys it. The soil comes out the other side of the burner clean and potentially ready for reuse.
New Technological Approaches
A different technology is being utilized on the southern half of the property, which will be turned into community playfields and parks. Instead of hauling tons of soil offsite, the VOC laden soil is treated where it is. Avoiding transporting the soil has saved the District between $1-3 million. The soil is stockpiled onsite for out of the ground treatment by soil vapor extraction.
Morelan explains: “What that process involves is putting the soil that contains VOCs onto plastic, inserting extraction piping within the pile of soil and then sealing the pile with plastic. At that point we have a blower that pulls air through the soil, and by doing that the VOCs are actually removed from the soil and treated through a carbon unit that scrubs the air containing the VOC vapors. When we’re done with that vapor extraction process, those stockpiled soils are clean and can actually be reused as backfill at the site itself.”
“We’re very excited about that particular process,” said John Sterritt, director of the Office of Health and Safety for LAUSD. He is an environmental engineer who has been with District for three years. “It’s only the second time in the entire construction program that we’ve utilized that approach. It has saved the district a significant amount of money, and we also have a significant risk avoidance because of the number of trucks that would have had to take that dirt and move it to other places. So Ed and his team came up with this approach, this option. It provided less impact on the city down there with the big trucks coming and going at all hours.”
“We were able to actually treat 12,000 cubic yards of soil like that,” said Morelan, “and we can reuse all that soil onsite.” Even the carbon used to remove the vapors gets recycled and reused. While the extraction process has been around for a couple of decades, the LAUSD geologists said it is unusual to apply it to soil that has already removed from the ground. Part of the DTSC oversight process is a requirement that the District confirms the removal of soil contaminants, and testing is showing the method to be effective.
As for the inorganic chemicals at the site – arsenic and chromium for example - these can’t be cleaned up and reused. They require special treatment and stabilization and offsite disposal. But the VOC contamination is the largest type pollution.
What remains an issue is the polluted groundwater under the parcels. The District has started pilot testing for the groundwater cleanup as part of the excavations of the soil. “Right now we’re trying to identify the best way to clean up that groundwater,” said Sterritt. “We’re in the process of developing a remedial action plan.” The groundwater at the site is deep enough that it doesn’t have any impacts to any people on the surface, so the District was able to clean up the soils at the site and build the school. “The research will be concluded probably by the beginning of next year, and then we’ll go ahead and start implementation of the groundwater cleanup,” he said. The district will accept proposals for the cleanup after it has identified the right technology that to use. The team is looking for the right technology now.
All the Big Players
They agree that the length of this project and the research that has gone into it has enabled them to learn what it takes to expediently decontaminate an urban brownfield site to the point where it could safely house a school. “The nice thing about the District is we’ve been in this bond funded construction program for the last decade,” said Sterritt, “and I would say bar none between our district staff and our contract professionals and our network of contractors, you’re not going to find higher qualified, more skilled and experienced people to deal with this in the nation. Just the sheer number of projects we’ve done over the last decade. We’ve got a good leadership team here, but we’ve got literally all the big players that do this for a living . We’ve pretty much driven this industry for the last decade in Southern California. “
The industry Sterritt is referring to is site remediation and site assessment. Of the 129 new schools LAUSD has constructed in recent years, most have been in urban areas. Thus, there have been many projects that have required at least some extent of toxic remediation. “We have put tens, if not hundreds of millions of dollars into this particular business,” said Sterritt. Almost all of the properties had some environmental site assessment and required remediation from small to large scale on a tremendous amount of properties over the last decade.
“To give you a factoid in that regard,” said Morelan, “a calculation was done several years ago and it concluded that the Los Angeles Unified school building efforts was responsible for cleanup of over a square mile of land here in LA.” To put that in perspective, a square mile equals over 3 million square yards, or almost 28 million square feet.
More on the Way
LAUSD’s $19.5 billion new school construction program is winding down, but in November 2008 voters approved an additional school bond, Measure Q, which authorized LAUSD to issue $7 billion in bonds to continue repair and upgrade of aging classrooms. The District won’t state an exact date that it will issue the new bond for its modernization program, but it will probably begin sometime in the next couple of years. The environmental team doesn’t expect anywhere near the scope of environmental remediation to be needed, since these would be existing school campuses, but there will be some contamination to be cleaned up.
The school that adorns the newly decontaminated soil is itself a high performance school, meeting requirements, as all the new LAUSD schools do, for certification by the Collaborative for High Performance Schools (CHPS). Solar panels sit atop the parking structures, the school has energy efficient lighting, occupancy controls, energy monitoring systems, good indoor air quality with ventilation systems that ensure the continuous delivery of outside air. There is space provided for recycling, and other green aspects.
“Part of the bond funding is we have a pretty a good sustainability initiatives group in the district,” said Shannon, “and they establish design standards and manage projects. We try to make sure these schools are built with water conservation, utilities in mind, windows, HVAC systems. As we build these schools, we incorporate these things into the design specs in a reasonable and cost effective way to incorporate all the green design aspects we could.”
Would the District’s toxic cleanup team feel good about their own children attending South Gate High? “Absolutely,” said Morelan. “We’ve spent a long time getting to this point. We’ve done very thorough site investigations, we’ve gone through the whole remedial action planning process and with public input and oversight by DTSC, I think we’ve done a very good job at cleaning up these sites.”
The guiding force behind what they do, says Sterritt, are the student population and staff. “We’ve done sampling that has been approved by DTSC, we’ve gone in and done additional sampling for gases, so we’ve basically covered the safety of our students and staff. Obviously, there will be additional testing in the future.” Because toxins can migrate from groundwater to soil, there will be further monitoring on a regular basis. Surely this school campus lends new meaning to the term “clean and green.”