Attacking Soil and Groundwater Contamination

CPC’s closed-down Kaohsiung refinery complex will be a test case for risk-based soil and groundwater remediation. Photo: Timothy Ferry

Taiwan has set admirable goals for cleaning up soil and groundwater pollution. But are overly rigorous standards actually inhibiting site remediation?

The CPC Corporation’s massive Kaohsiung refinery complex ceased operations in December 2015 as promised by the state-owned oil company in 1990 (when it was known as the Chinese Petroleum Corp.). Then Premier Hau Pei-tsun promised local residents who were protesting development of the Fifth Naphtha Cracker and its huge associated petrochemical complex that the entire operation would be closed in 25 years.

What remains today is one of Taiwan’s largest contaminated-waste removal projects. The refinery, which encompasses 273 hectares in downtown Kaohsiung, had a daily refining capacity of 200,000 barrels of crude oil and an annual production capacity of 50,000 metric tons of petroleum products and their derivatives. The Kaohsiung facility was the longest operating refinery in Taiwan, having begun in 1937 by supplying the Imperial Japanese Navy.

More than seven decades of continuous operation resulted in the refinery being more polluted than typical sites targeted for cleanup. “Some of those pollutants that have been there for a long time are not easily degraded,” says Tsai Meng-yu, director-general of the Kaohsiung City Government Environmental Protection Bureau (KEPB).

Unsurprisingly, the main contaminants on the site are TPH (total petroleum hydrocarbons) and BTEX – benzene, toluene, ethylene, and xylene – which also are petroleum derivatives. Many of these chemicals are known or suspected carcinogens, and heavier TPH with longer carbon chains, such as motor oil, fuel oils, and lubricants, are especially difficult to remove from the soil. Levels of BTEX are often found at refinery remediation sites, but the Kaohsiung refinery shows higher levels than is typical, according to the KEPB.

Restoring the soil and groundwater to minimum standards – known as “control levels” – is estimated to require at least 17 years and NT$10 billion. During that time these 273 hectares would be left unproductive.

To hasten the pace of the cleanup and return the site to productivity and public access, the Taiwan Environmental Protection Administration (EPA) and the local KEPB, along with CPC and other local and central government agencies, are teaming up to take a different approach to the refinery cleanup. This risk-based approach – what’s called “brownfield development” – has the potential to reduce costs and well as the time needed before at least parts of the site are able to be redeveloped

Currently Taiwan requires contaminated-waste sites to be remediated to high “control levels” similar to the U.S. Environmental Protection Agency’s Maximum Contamination Levels for pollutants in drinking water. Every site in Taiwan needs to be remediated as if it is in direct contact with drinking water.

“For the remediation site, we ask the polluter to clean up the soil and groundwater to the status below the control standard,” says Weber Chen, executive director-general of the Taiwan EPA’s Soil and Groundwater Remediation Fund Management Board. “Most members of the public aren’t satisfied with that,” he adds. “They want it cleaner, reducing the pollution standard to even below the monitoring standard.”

Critics say that such standards aren’t always necessary, and that each site should be dealt with according to the actual risks it presents to human health and the environment. In a risk-based approach, the evaluation of the site is based not simply on what contaminated materials are present in the soil and groundwater, but on where and how they are situated. Under this approach, EPB inspectors or environmental consulting firms consider three essential elements: the source, pathway, and receptor.

“You go through an analysis that asks; ‘Is there a source of contamination? Is there a pathway for it to get to a receptor? Is there a receptor?’” says Lance Robert, country head for ERM Environmental Consultants Taiwan, who has worked on remediation projects in the United States, Europe, Australia, and now Taiwan. “If you don’t have any one of those three, you don’t have a risk.”

Often hidden for decades

While air pollution is often apparent to the casual observer, soil and groundwater contamination is far more subtle, hiding beneath the surface and often detected only decades later when cancers and other diseases and birth defects begin to emerge in clusters among local residents.

In the United States, the infamous Love Canal case, in which a housing development was built adjacent to a chemical waste dump site, resulted in multiple birth defects decades later among children born to families in the area. In Taiwan, the former RCA factory site in Taoyuan is another example of a toxic waste site blamed for sickening hundreds and causing scores of early deaths.

The onetime RCA factory site in Taoyuan is still the subject of contentious lawsuits due to the effects of groundwater contamination. Photo: CNA

So it’s understandable that area residents and environmentalists take a hard line on soil and groundwater polluters, including the demand that remediated sites be returned to strict control levels before they are considered available for redevelopment.

The counter argument from many experts is that such an aggressive approach to soil and groundwater remediation is often unnecessary and may even be counterproductive to the goals of protecting the environment and human health. For example, if contaminated chemicals are in the ground but are isolated from the environment and from human contact, then pumping them out of the groundwater for treatment on the surface actually reintroduces them as health and environmental hazards.

In many cases, “monitored natural attenuation” – in which the site is monitored but is not actively remediated, allowing natural processes to act on the pollutants – is sufficient. In other cases, slower, less aggressive approaches are used, such as bioremediation in which microorganisms, either naturally occurring or introduced to the site, are cultivated to consume the pollutants. This approach takes more time, but uses less energy and chemicals. Meanwhile, the land can be put back into productive use.

Robert says that based on sheer necessity, most advanced countries follow the risk-based approach. Noting how horrified the world was by the discovery of the tragic contamination and birth defects seen in Love Canal, he says the U.S. EPA’s first impulse was to demand the complete cleanup of the site.

“But over time, when you discover how much contamination there really is, you start to realize that you have to prioritize how to spend your money, focusing on what actually presents a risk of people being exposed,” he says. “As the thinking has progressed, we’ve come [in the United States] to a more risk-based program using strict guidelines for how you evaluate the relative risk of something. What cleanup is required is then based upon the amount and type of risk present in that particular site.”

The risk-based approach to soil and groundwater remediation has since gone global, with most major markets following this option. Taiwan has so far remained an exception.

Under the Soil and Groundwater Remediation Act first implemented in 2000 and later amended in 2010, the Taiwan EPA authorizes local EPBs to take responsibility for checking on any suspected cases of soil and groundwater pollution, homing in on certain industries such as petrochemicals. If a site is tested and reveals some evidence of contamination, it is placed on a list of monitored sites and will be subject to further regular checks.

When pollution is found that reaches or is at risk of reaching control standards, the site is considered a “Control Site” and is subject to further in-depth investigation. If the site shows higher than control levels of contamination, it is listed for remediation and must submit a cleanup plan for approval by the local EPB.

Framework but little adoption

The Act does allow for a risk-based approach to soil and groundwater remediation. “We have the framework there but it hasn’t been widely adopted,” says Huang Chih, general manager of InnoFusion Environmental Management Co., Ltd., a remediation consultancy. Huang, who has been actively engaged in the industry for decades, wrote the risk-based approach guidelines for the EPA.

He describes the crux of the issue as a difference in levels of risk perception. “People usually look for zero risk, which is impossible,” he observes. “Industry is reluctant to go through the process of proposing a risk-based approach because that involves engaging with the public directly.” Further, even if a site is successfully remediated, it will remain on the control list and will continue to be monitored for years or even decades, “so the stigma is still there.”

“Although our law includes a mechanism for risk assessment, under previous Director Generals we did not have a successful case to determine a risk-based goal – so people and especially environmental NGOs lack confidence about risk assessment,” says Weber Chen. “Because of the lack of successful risk-based cases, environmental NGOs suspect that whenever someone proposes a risk assessment, the purpose is just to enable big enterprises to reduce the time and money required to do the cleanup.”

Chen has set the goal of changing this situation, introducing the risk-based approach to enable sites that are not heavily polluted or where the risk is low to be returned to public use before they meet control standards. In order to ensure fairness and support from the community, he says that the government will take the heat of communicating with the public on the issue. “We will seek to educate the public that the risk-based approach is a common practice internationally.”

The Kaohsiung refinery complex will be the first case.

According to the Act, polluters wishing to use a risk-based approach to remediation need to have a redevelopment plan already approved. This step is crucial, as the intensiveness of use – will the site be developed into a park or a housing development? – will dictate how aggressively and rigorously cleaned the site will need to be.

The plan for the Kaohsiung refinery divides the complex into different zones depending on such factors as the types of pollutants, their locations, and the geological conditions.

“If the future land usage is good for the community, then risk-based remediation is better so the land can be accessible earlier than by the current standards,” says KEPB’s Tsai. “But we want to make sure that the risk is acceptable to the community.”

Members of the EPA and KEPB note that the Kaohsiung refinery project will proceed in two stages. “In the first stage we really want some land to be available for public use,” says Tsai. “Depending on the remediation goal and usage, we can apply the risk-based approach and release the land for development earlier.”

Tsai concedes that a gap remains between the remediation goal and control standards, and that even sites that meet a risk-based goal will continue to be remediated even as they are being used under the watchful eye of environmentalists and citizen groups. “We will invite the NGO people and the community to form a panel to supervise the cleanup, and we will continuously do the cleanup until it reaches control standards,” says Tsai. “The bottom line is to get it to a control level.”

“By inviting the community to participate, we can exchange views, have a discussion, and reduce the conflict between the two sides,” says the EPA’s Chen.

Although the number of contaminated waste sites in Kaohsiung exceed those of all other cities and counties, Kaohsiung’s EPB is correspondingly experienced and well equipped to implement this test case, notes Chen. “We want to set a good example in Kaohsiung so that people all over Taiwan will have confidence in this system.”

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