Hazardous to Safe
(continued)

Groundwater: the remedial action chosen by L-P to address the PCP contamination was a combination of groundwater

  • extraction,
  • treatment,
  • reinjection,
  • and institutional controls.

The general idea is to pump out the contaminated water via extraction wells, run it through granular activated carbon, and discharge the treated water to an onsite dry well. The treated water would then slowly enter the water table by means of several infiltration galleries.

The extraction, treatment and discharge system was operational by April 1, 1997 and it is believed that it will be necessary to operate it for at least 10 years to meet the remedial action goal of less than one ppb of PCP.

The extraction well network consists of four wells near the concrete impoundment area. Monitoring Wells provide source control and were existing 4-inch diameter wells converted at the head to accommodate piping and an extraction pump. Extraction Wells are both six-inch diameter wells and were installed to provide hydraulic containment.

The treatment system is housed in a building built between the Engineering Building and Warehouse on site. The building was constructed of brick to match the appearance of the other onsite existing buildings and can act as a secondary containment vessel in the event of a tank or pipe rupture. The system can accommodate a flow rate of up to 40 gallons per minute and can easily be upgraded to accommodate a flow rate of 80 gallons per minute by adding two additional carbon vessels.

PCP is removed from the contaminated water by running it through two liquid phase carbon vessels. The entire system was designed to operate with little operator oversight and is equipped to shut down in an event of an emergency such as tank or pipe rupture, tank overflows, high pressure, or pump failures.

All instrumentation for the system is located inside the treatment building in an effort to easily monitor, sample and control both the extraction and discharge wells. Treated water re-enters the shallow groundwater aquifer through a series of four discharge wells, which are located down gradient of the contaminated plume near the property line. All four wells are eight feet in diameter, approximately 20 feet deep and are approximately 75 feet apart (from each other).

The water entering the dry wells is sampled by L-P on a monthly basis in accordance with the waste discharge permit issued by the Regional Water Quality Control Board, Central Valley Region.

2. REMOVE PATHWAY

Pathways were

  • ingestion,
  • dermal contact,
  • and inhalation.

The most widespread soil contaminate on the site is arsenic. Rail spur lines were the primary means for moving material throughout the site with approximately 5 miles of track that have been identified to exist on site throughout its history.

SOIL SCHEMATIC


Click for larger image
Soil Movement Schematic


HydroStratigraghic Cross Section

Approximately 32,500 cubic yards of soil, with arsenic concentrations in excess of the background level of 5.4 mg/kg, were removed by L-P from beneath the existing railroad tracks. This soil was then stockpiled on-site, and later placed under an on-site concrete cap.

To do the on-site remediation, approximately 46,000 cubic yards of on-site clean soil had to be excavated from a designated area. This clean soil, mixed with an additional 11,000 cubic yards of imported clean soil, was then used to backfill along the railroad tracks and to provide a buffer between the arsenic contaminated soil and the asphalt cap.

ASPHALT CAP


Aerial view

The two-acre on-site location is the final resting-place for the 32,500 cubic yards of arsenic contaminated soil. An asphalt cap placed on top of this soil will, "effectively control surface infiltration; inhibit long-term surface exposure and is fully protective of human health" (SHN 1996, 1-2).

The asphalt cap is inspected every year for possible cracks and debris or vegetation that may be obstructing the drainage ditches. Upon inspection, individual cracks are resealed or the entire cap is resurfaced and the drainage ditches are cleared. Additionally, the entire cap is re-sealed every five years.

3. REMOVE PEOPLE

Another way in which to eliminate the hazard is to remove the people from the site. As part of the remediation process, L-P placed a deed restriction around the area of the asphalt cap. The deed restrictions declare that "no portion of the capped area shall be used for residential purposes, and that the arsenic contaminated material removed from beneath the cap during site development must be used as backfill beneath the cap or transported offsite and disposed of at an approved facility" (SHN 1996, 4-1).

In other words, the cap must remain intact for perpetuity, or the 32,500 cubic yards of arsenic, contaminated soil beneath the cap must be removed off-site to a hazardous waste landfill. People have also been removed from other areas of the site. For instance, this site was never remediated for a school, or hospital. This site is safe only if we follow the deed restrictions.

So,

  • deed restrictions restricting future use of the site
  • remedial actions
  • toxicity assessments for arsenic and PCP
  • are the fundamental ingredients of the remediation.


Air Photo of Diamond Match Area, 1965

Conclusion and Final Thoughts

This thesis used the Diamond Match/Louisiana-Pacific Wood Treatment Facility in Chico, CA., as an arena in which to evaluate social concerns associated with soil and groundwater contamination from past industrial pollution. The California Department of Toxic Substance Control (DTSC) declared the 133-acre Diamond industrial site "hazardous" in 1991 and then declared the same site "safe" in 2000.

Scientific processes, such as a risk assessment, determine hazardous and safe exposure levels to the chemical contamination of our air, water, and land. My thesis related these processes to the chemical contamination of soil and groundwater at the Diamond site. In doing so I hope you were informed about various social processes that influence scientific assessments of a pollution hazard and gained current information regarding the status of the site.

Bureaucratic agencies such as DTSC regulate hazardous and safe exposure levels through a scientific process called "risk assessment." Quality of life is directly influenced by the outcome of a risk assessment. Risk assessments direct future land use, industrial operations, and human health standards.

DTSC risk assessments for arsenic, pentachlorophenol, and other chemicals found at the Diamond site, determine the site hazardous and later safe. Characterizing hazardous and safe levels of chemical contamination is a complex, multi-disciplinary process.

Although DTSC declared the chemical contamination at the Diamond site safe, I believe that this site still poses a risk and is hazardous to human health.

The remedial actions taken by L-P at the site may not fall in line with what many people believe happens when we "clean up" contamination. Most often, we socially characterize clean, or safe, as a process in which the chemical contaminate has been removed from the environment.

L-P representative, Liz Smith was quoted in an early 1990's Enterprise Record article stating that L-P would "remove" every bit of contamination from the site." This action did not occur even though we would socially expect this action to occur if the site was to become clean. However, at the Diamond site, this cleaning action only occurred with some of the contaminants. Other contaminates were in a way, swept under a concrete rug, which I would not consider to be an acceptable action for cleaning.

Actually, these types of clean-up actions remind me of those I took as a child. Upon my mother asking me to cleanup my room, I merely pushed and hid everything under my bed, claiming that my room was clean. My mother did not consider my room clean, as I do not consider the Diamond site clean. Some of the on-site contaminants have not been cleaned-up; they have just been socially altered to fit into the definitions for safe chemical contamination.

The majority of the contamination on-site became safe by L-P eliminating the exposure routes, or pathways, not by eliminating the contamination. In remediating both the soils and groundwater contamination, deed restrictions placed on the contamination make it safe. The elimination of possible exposure routes is a socially negotiated remediation process, and not just a straightforward scientific process.

Another way in which the contamination at the site became safe was by removing the people from the area. Humans are, under the current deed, only able to live in certain areas of the site. Humans are not, for instance, allowed to live in the area of the arsenic contaminated soils. Though humans can live in certain areas, they may never be hospitalized or educated within the boundaries of the site.

In a way, we have socially made parts of this site fit into what are now called, "national sacrifice zones." These zones are highly toxic to human health and in order to ensure the public health and safety, government regulations have removed humans from the area. Chico, in a way, now has a national sacrifice zone within the city boundaries. As I mentioned, our toxic environment is growing, not contracting.

At the Diamond site, for instance, as L-P remediates for PCP they release another toxic substance, dioxin. Dioxin is a by-product of our industrial processes and is the most toxic chemical threatening human health (Gibbs 1995, 25).

Recent advances in technology have begun to offer science avenues for detecting dioxin in picograms, or parts-per-quadrillion. However, we still do not know how to remediate, eliminate, or assess risk for dioxin, yet we continue to allow it to contaminate the environment.

Along with threat of dioxin, toxicity evaluations have not been conducted for chemical synergistic, additive, potentiation or promotion toxicity effects. For instance, what kind of health hazard does arsenic combined with PCP pose, and at what level are these chemicals, when combined, safe?

It is essential that we understand the lifetime effects due to the accumulations of chemicals within the environment, because these chemicals wind up in our drinking water, in the air we breath, and food we eat. Why do we socially allow the continual contamination of the environment? Why do we allow ourselves to "run the rat race" of contaminating the environment to eventually clean it up later?

Corporate greed vs. quality of life? I believe that our faith in science and human intelligence allows us to accept a toxic environment, even though "the tools of science do not work well when everything is changing all at once" (Steingraber 2000, 29). This faith in science and human intelligence needs to be continually analyzed, questioned, and scrutinized by the social process.

The social processes of a toxic environment will one day, hopefully help to eliminate the health threats resulting from the toxic environment because, "the widespread introduction of suspected carcinogens into the human environment is itself a kind of uncontrolled experiment (Steingraber 2000, 29). And with that, I would like to thank you for listening.

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