The Spurs Community Garden at the San Antonio Food bank is prepared for the next season's bounty. Photo by Iris Dimmick.
The Spurs Community Garden at the San Antonio Food bank is prepared for the next season's bounty. Photo by Iris Dimmick.

Two new chemical analyses of soil at the San Antonio Food Bank’s extensive outdoor fruit and vegetable gardens have confirmed the dirt is uncontaminated, both studies showing that trace minerals and heavy metals present are at natural or “background levels,” officials announced Friday at a City Hall press conference.

“I’m very proud that the Food Bank is in my district, and I am very pleased to tell you the soil there is safe and the food is safe,” said a relieved-sounding Councilmember Ray Lopez (D6). “It’s important for our city to know the Food Bank food is safe.”

Lopez recently called for third-party soil tests in the wake of news stories that questioned City staff’s handling of dirt removed from the Convention Center expansion site along the I-37 corridor. The dirt was moved between December and mid-February to City-owned undeveloped land at Hwy 151 and Old US Hwy 90 across from the Food Bank. 

The controversy arose over two conflicting prior studies of the soil made at the Convention Center expansion site last year. The first study, completed in September for the Design-Build Contractor Hunt-Zachry by Geo Strata Environmental Engineering, concluded the soil in question was contaminated. A more comprehensive study ordered by the City of San Antonio and completed by Raba Kistner concluded the soil was safe and suitable for reuse.

In July 2013, Hunt-Zachry removed 150 yards of the soil to a depth of five feet on the eastern side of the Henry B. Gonzalez Convention Center where the new extension is under construction, and replaced it with structurally enhanced soil, mostly crushed limestone, to bear the weight of the new building.

The excavated soil had to be removed from the site, either for reuse elsewhere if clean, or to a landfill if contaminated.

Graphic illustrating the Convention Center's move courtesy of HPARC.
Graphic illustrating the Convention Center’s move/construction courtesy of HPARC.


The latest chemical analysis of the Food Bank soil across the highway from the City commercial property was overseen by the City’s Metropolitan Health District and was conducted by the San Antonio-based Southwest Research Institute (SWRI), a highly-regarded applied research and development non-profit enterprise based in San Antonio. The report from SWRI with detailed soil sample analysis at the Food Bank should be available Tuesday, according to Deputy City Manager Peter Zanoni, who also attended Friday’s press conference.

Zanoni and other city officials are expected to deliver a briefing on the matter to the SAWS board of trustees Tuesday morning since the water utility had been in talks with the City about a possible land swap that would have given SAWS title to the 48-acre plot across from the Food Bank. The full City Council also will receive a briefing at the Wednesday B Session, Zanoni said, and representatives from the testing firms have been invited to attend and participate.

The Food Bank soil was testing to see if any wind-blown contaminants from the transferred soil had entered its garden soil. Another San Antonio firm, Weston Solutions, is currently conducting soil tests on the Convention Center dirt in its new location. Zanoni said Saturday that the work is being done on an accelerated basis and results should be available in four weeks or less. He noted that the same firm conducted soil samples there in the 1990s. The property formerly was part of the Van de Walle Farms , and Zanoni said cotton fields there likely were treated with fertilizers that included arsenic, so Weston Solutions and City officials will have to differentiate residual mineral levels at the site from levels attributed to the recently added dirt. The Food Bank soil analysis indicated only background levels of arsenic that pose no health threat.

An earlier version of this article incorrectly stated that SWRI was conducting the soil analysis on the City’s commercial property.

Dr. Vincent Nathan, the assistant director of Metro Health, said Friday that he prefers to describe the metals being tested as minerals, noting that at natural levels they serve as nutrients rather than contaminants, and are universally present in all soil. Such naturally occurring levels of  heavy metals are known as harmless “background levels,” while highly elevated levels of the eight heavy metals (lead, chromium, arsenic, zinc, cadmium, copper, mercury and nickel) pose health hazards to humans and animals. Acceptable elevated levels not considered a risk to humans or animals are categorized as falling within “regulatory levels.”

Dr. Nathan said SWRI sampled for 23 different minerals, including the eight heavy metals, and all were within background levels except for a single metal, which was slightly elevated but still well below the regulatory level. In other words, the Food Bank is working with clean, safe dirt.

Food Bank President and CEO Eric Cooper also attended the press conference and said his organization had hired its own third-party firm, Virginia-based PSI, to conduct a study independent of the City-financed work.

“PSI did a very similar study to SWRI and they came back with pretty much the same results,” Cooper said. “Our food is safe. I’ve learned a lot about soil in the last few weeks.”

Digging Into the Dirt

The Rivard Report has been reviewing the originals reports, maps and interviewing city officials, environmental engineers and others over the past two weeks to gain an accurate understanding of how dirt removal became such a crisis at City Hall, even if the dirt proves to be uncontaminated. Clearly, a process that should have been conducted in a transparent fashion with ample public communication did not occur.

Hunt-Zachry determined as early as late 2012 that the new Convention Center extension would need greater support than existing soil could provide. That’s when the contractor made the decision to remove soil down to a depth of five feet over a broad area that would serve as the footprint for the newly expanded center. Crushed limestone was used to build a firmer base for the construction.

That probably would have been the ideal time for City staff to share developments with members of City Council and the public, particularly given the history surrounding the construction of the Alamodome across the very same freeway in the late 1980s and early 1990s at the former Alamo Iron Works site. City contractors removed the contaminated soil there and dispersed it elsewhere on the Eastside, and eventually were forced by court action to remove the soil, which had been buried, and incinerate it elsewhere at a cost to taxpayers of many millions of dollars.

The so-called “Dome Dirt” scandal antagonized an already deeply divided community at odds over the stadium construction and its intended purpose, and it demonstrated an appalling indifference to the well-being of the predominantly African-American and Latino families residing in the surrounding neighborhoods already disrupted by the project. Those neighbors have yet to see any of the promised economic development in the shadow of the Alamodome; the distrust in city government in still palpable on the Eastside more than 20 years later.

When construction on the new expansion site began in July 2013, Hunt-Zachry hired Geo Strata to conduct bore samples (see map) at three different locations at the Convention Center property:

Geo Strata Boring Map1
  • Area One runs parallel to South Alamo Street where the original Convention Center structure now stands and is slated for eventual demolition. The grounds will then be converted into a multi-acre green space, the so-called new “front porch” for Hemisfair Park.
  • Area Two is located in front of the Convention Center along East Market Street, which also will be redeveloped.
  • Area Three encompasses the sector now under construction that is visible to drivers along the freeway. Hunt-Zachry wanted Geo Strata to conduct bore samples in all three areas, including the dirt it was removing from Area 3. The study would guide its disposal of the Area 3 soil, and tell it what to expect when work begins on Areas One and Two in the future.

In its August 2014 report to Hunt-Zachry, Geo Strata reported elevated levels of heavy metals, including lead and arsenic, in Areas One and Two. That means when the original structure is demolished in a later phase on Hemisfair Park’s redevelopment, the soil under and around the building will have to be buried in a landfill. The high heavy metal readings in Areas One and Two, city officials say, are consistent with pre-1960s site activity, including the presence of underground fuel tanks and a service station before the area was cleared for Hemisfair ’68.

Geo Strata drilled nine bore holes in Area Three, a former residential neighborhood with no history of industrial use or known industrial spills. The firm’s engineers found slightly elevated metal levels in two of the nine bore holes, both well under the acceptable regulatory levels. In other words, Geo Strata’s chemical analysis showed the dirt being removed in this phase of the Convention Center expansion project safe for human use, including food production.

HBGCC Phase II ESA – Final-1.Compressed

The text of the Geo Strata report, however, contains two errors. In one place, the report states it found samples in Area Three that exceeded “regulatory levels.” The actual measurements in the same report contradict that statement and indicate the tests showed metals slightly above “background levels,”  well below regulatory levels set by the Texas Commission on Environmental Quality (TCEQ).

In another place in the Geo Strata report’s text, the author describes the soil on the western side of the Convention Center along South Alamo Street in Area Three as contaminated, another error since the writer was describing Area One. That error made it into local news accounts with the South Alamo Street reference omitted and, until now, as far as I know, neither Geo Strata nor local media have corrected the errors.

Geo Strata in its report recommended that Hunt-Zachry deposit the soil in a landfill at a cost of $6 million, or that it be reused on site, an inexplicable suggestion if the firm’s environmental engineers believed it was unsafe for humans. The $6 million, of course, represented an unanticipated cost and Hunt-Zachry went to City officials in September with the report and the problem.

Mike Frisbee, the City’s director of Transportation and Capital Improvements, reviewed the report prepared for the contractors and determined the bore samples were insufficient to make such a determination. He noted the inconsistencies in the report’s data and its narrative.

“You don’t just spend $6 million of taxpayer money to make a potential problem go away,” Frisbee said. “We should have done a better job with our communications, but at the time we were trying to get an accurate assessment of the situation.”

The City hired Raba Kistner, one of the most established engineering consulting firms in San Antonio, to conduct a more in-depth soil study of Area Three. Where Geo Strata took nine bore samples in Area Three, Raba Kistner took 32, and sampled the dirt at the surface level, at five feet and at 10 feet in each sample.

Raba Kistner Boring Map2

“The area was far too big to make any accurate determinations with only nine samples,” one of the firm’s engineers said. Raba Kistner delivered its chemical analysis to the City in November, advising officials that the dirt met “residential standards and could be reused at another site.”

Raba Kistner Final BEA Report (R)

Trusting the Raba Kistner report over the one prepared for Hunt-Zachry, the City authorized Hunt-Zachry to transport the dirt to its commercial property at Hwy 151 and US Old Hwy 90. The City had been intermittently discussing a land swap with SAWS that was going nowhere and preparing for the eventual marketing of the property as an industrial park or for sale to an interested buyer. The City saved the $6 million landfill charge, and paid $432,000 to have the dirt graded and leveled on its commercial property.

In hindsight, City officials agree it was naive to think the media and public wouldn’t learn of the contradictory environmental assessments, and put the City in a position where it appeared it was withholding information that should have been disclosed. City officials never challenged Geo Strata’s report because it was prepared for a private contractor, but that contractor, Hunt-Zachry, was engaged in a very public project and with public health concerns at stake and Dome Dirt memories still fresh in many memories, the matter belonged in the public arena.

In that regard, the Food Bank’s Eric Cooper thanked the Express-News at the Friday press conference for surfacing the issue, while city officials confirmed the errors in the Gee Strata report that have not been acknowledged by other media in its coverage.

The press conference provided good news for more than Councilmember Ray Lopez, District 6, and the Food Bank, but the matter is bound to stay in the news with the Tuesday briefing at SAWS and the Wednesday briefing at City Council, while city officials, the media, and the public await the results of the Weston Solutions report analyzing the soil at the City’s commercial site. San Antonio doesn’t need another distracting contaminated soil  controversy dominating the headlines for months to come.

Area Three dirt might be suitable for tomatoes and chili peppers, but all indications are the City won’t be so fortunate when work progresses on the Convention Center project and Area One and Two come under construction. That gives plenty of time for everyone at City Hall to figure out what to do with that contaminated soil and how to keep the public informed once the digging begins.

Correction and Amplification: The body of this article contains updated information about planned briefings at SAWS and City Council, and the hiring of Weston Solutions to test soil at the City’s commercial property where the Convention Center dirt was deposited. An earlier version of this article incorrectly stated that the testing there was being done by SWRI. An editing error mistakenly changed “10 feet” to “10 inches” in describing Raba Kistner’s bore samples at Area Three. That also has been corrected.

*Featured/top image: The Spurs Community Garden at the San Antonio Food bank is prepared for the next season’s bounty. Photo by Iris Dimmick. 

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Robert Rivard

Robert Rivard is co-founder and columnist at the San Antonio Report.