GROUND WATER AND SOIL

POLLUTION REMEDIATION

(ESE161 / A1)

Case Study of Soil Contaminated Sites and Remediation

Jawahir A. Gomez

ESE – 3 / 2012105953

December 9, 2015

Engr. Wyndell A. Almenor

Adviser

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Table of Contents

Case Studies

Gunnar Uranium Mine 3

Saskatchewan, Canada

Subic Naval Base and Clark Air Base 9

Clark and Subic Bay, Philippines

Cedar Chemical Company 13

West Helena, Arkansas

References 16

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GUNNAR URANIUM MINE

SASKATCHEWAN, CANADA

Background

The Gunnar uranium deposit was discovered in July 1952; however, Gunnar Mining

Limited did not commence production until September 1955. Because of the remote and isolated

location, an on-site milling facility was constructed to extract and process the ore and produce

yellowcake. Numerous other support buildings and facilities were constructed at the site to serve

the mining and milling operations. A town site was also constructed to support mine workers and

their families.

Uranium ore was initially mined from an open pit from 1955 to 1961. Underground

operations, extending below the bottom of the pit, began in 1957 and ceased in 1963. It is

estimated that 5.5 million tonnes (T) of ore was mined during operation of the Gunnar site. The

mine officially closed in 1964, with little or no decommissioning of its facilities.

With cessation in mining activities, responsibility for the site fell to the Province of

Saskatchewan. In May 2000, the Nuclear Safety and Control Act (NCSA) came into effect and

the Canadian Nuclear Safety Commission (CNSC) requested that the Province license the site.

The site is currently under license exemption until April 30, 2013, pending approval of this EIS

and the licensing package that was submitted on January 4, 2013.

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In 2006, the Governments of Saskatchewan and Canada signed a memorandum of

agreement (MOA) to address the current environmental conditions at the abandoned uranium

mine sites in northern Saskatchewan, including the Gunnar site. Under the MOA, the

Saskatchewan Ministry of the Economy (ECON) is responsible for the remediation of the

Gunnar site on behalf of the two governments. The SRC was thereafter contracted by ECON to

act as Project manager, license applicant, and designated agent to manage and undertake the

environmental impact assessment, planning, and implementation of remedial activities. In June

2007, it was determined that, under CEAA, a comprehensive study (CS) was the appropriate

level of assessment for the Project.

As a result of the potential risk to public safety associated with the deterioration of

buildings and structures on the site since site abandonment, the CNSC issued Order 10-1 to

secure on-site hazardous substances and materials and take down buildings and structures that

failed a structural safety assessment. As a result of the imminence of these issues, the Provincial

and Federal regulators agreed to remove site demolition from the scope of the EIS. Disposal of

the demolition debris; however, is included.

Cause

The major sources of public safety and environmental risks at the site include waste rock

piles, Gunnar Main, Gunnar Central, and Langley Bay tailings, Gunnar pit, and demolition debris

from production buildings and other infrastructure in and around the former mine/mill site.

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The latter category includes a relatively large number of major (e.g., asbestos in the form

of fibre exposure) and more minor environmental issues such as possible residual soil

contamination in areas of former petroleum hydrocarbon (PHC) storage and use.

The various risks to humans, wildlife, plants, and aquatic life as a result of existing site

conditions fall into three major categories, based on physical hazards, exposure to radiation, and

exposure to chemical contamination.

Risk assessment has shown a need for radiological and toxicological risk reduction and

risk management, which is the focus of remediation activities, along with contaminant risk

reductions for plants and animals. The overall risk assessment confirms the need to reduce

contaminant concentrations in aquatic life in St. Mary’s Channel, Zeemel Bay, and Langley

Bay/Back Bay, especially in fish. The primary sources of contamination for aquatic life are from

water that flows through the waste rock piles and the discharge of surface water and groundwater

from the tailings deposits. A secondary source of contaminants to aquatic life and food webs are

the historic deposits of uranium in sediment.

Objective

The primary objective of this report is to present remediation designs for the exposed

tailings deposits at the Site. As recommended in SRC (2013), the preferred option is to remediate

the tailings in-place. Given the radiological and geochemical characteristics of the tailings, an

earthen or soil cover system, at least 0.6 m thick, is required to remediate the tailings in-place to

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mitigate ecological and human health risks to acceptable levels post-reclamation. A fundamental

component to the long-term integrity and performance of soil cover systems is design of a final

landform that takes into consideration the cover system design objectives as well as local

conditions of rainfall, soil type, and vegetation cover. This report presents the preferred final

landform design for each of the primary tailings deposits as well as the proposed borrow

materials and sources. A field investigation was completed at the Site in June 2015, which will

confirm the characteristics and volumes of borrow sources for remediation of the tailings

deposits. Final detailed design information as well as a construction plan for remediation of the

tailings deposits will be documented in a report prior to the construction phase of the project.

The following tasks were completed to address the objectives of this report:

Review of available background information to support a data gaps analysis and

recommended actions to reduce uncertainties in the final remediation designs;

Development and review of various options for remediation of the primary and secondary

tailings deposits;

Review / refinement of existing conceptual models related to geochemical behaviour of

the tailings and performance of the base case tailings cover system (a 0.5 to 1.0 m thick

layer of local till material);

Preliminary assessment of loadings for constituents of potential concern (COPC) to

Langley Bay for the various tailings remediation options;

Development of preliminary cost estimates to support a multiple accounts analysis

(MAA) of the various tailings remediation options;

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Selection of the preferred remediation option for each tailings area including

identification of key construction elements and potential failure modes as well as an

assessment of potential effects of tailings remediation plans on other site aspects; and

Development of preliminary plans for revegetation, surface water management, and

performance monitoring of the remediated tailings areas.

Remediation Process

The remediation process used was different for every site residues. Tailings, for example,

were removed or remediated using re-vegetation and water/rock cover/borrow material cover. As

for waste rocks, excavating the contaminated rocks and using a cleaner rocks or soil was done

for remediation. Gunmar Pit was also one of the problems for remediation. Stabilizing the sides

of the pit was done.

Gunmar Pit BEFORE Gunmar Pit AFTER

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Effect

Based on the effects assessment, no significant adverse residual impacts have been

identified for any aspect of the Project. This pertains to both the closure and post-closure phases.

Throughout the closure phase of the Project, the SRC will actively monitor and record data such

as worker exposures, airborne dust levels, surface water, groundwater, and sediment quality, and

duck tissue concentrations of mine-related constituents.

Following site remediation, this monitoring will continue. In addition, there will also be

an ongoing monitoring program for fish tissue and on-site vegetation, such as berries, medicinal

plants, and possibly mushrooms.

Monitoring data will be used to help determine if impacts beyond those that have been

predicted are occurring and what further actions would need to be implemented as part of the

Project. These measures will assure the long-term safety of the area and healthy environment for

living things.

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SUBIC NAVAL BASE AND CLARK AIR BASE

CLARK AND SUBIC BAY, PHILIPPINES

Background

The Subic Naval Base is located some 120 km north of Manila, directly in the path of

international shipping lanes. Since 1990, NGOs both inside and outside of the Philippines have

reported that military activity in both locations had been contributing to extensive pollution of

the Subic Bay. Both the Subic Naval Base and Clark Air Force Base were abandoned in 1992,

leaving all the preexisting pollution untreated and uncovered in the environment. The Naval

facility had no comprehensive sewage system or sewage treatment, instead dumping all waste

directly into Subic Bay. Lead and heavy metals from the ship repair facility were also similarly

dumped into the Bay.

The Clark Air Base was evacuated following a volcanic eruption in September of 1991.

The eruption put a massive amount of ash into the air, as well as decimated a large portion of

land and residential areas. The fallout from the volcanic eruption left several groundwater

drinking wells contaminated. At the initial stages of this project, the Subic Bay housed 14

identified contaminated sites, as well as 12 potentially contaminated sites.

The local community is acutely aware of the deteriorating environment and drinking

water contamination in the area. Polychlorinated phenyl (PCBs) have infected the water as well

as the soil, making the situation more urgent, as the contamination now has a much higher

potential to freely spread throughout the environment through soil siccation.

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Cause

The Philippine government which has undertaken extensive efforts to convert the former

bases into flagship economic centers, commissioned environmental baseline studies in Clark and

Subic to assess the actual extent of contamination. The Clark study, conducted by Weston

International2, found, among other things, that:

High levels of the persistent toxic pesticide dieldrin in four operational wells and six

back-up wells inside Clark, fueling fears that the underground aquifers that supply

drinking water in and around the base are contaminated. The wells are all located near or

down-gradient of the golf course. The dieldrin found in the wells may be the breakdown

product of aldrin, a pesticide which may have been used in the golf course;

High levels of aldrin, dieldrin, lindane , chlordane, heptachlor, and HCB were also found

in the soil samples from several sites. The sample sites include a municipal landfill near a

residential area in the town of Mabalacat, an abandoned motor pool now used as a

relocation site for evacuees of the Mt. Pinatubo volcanic eruption, the old fire training

area , and the Civil Engineering Entomology center;

Elevated levels of PCB in soil were detected in the decommissioned power plant and

transformer sites, with one site recording a high of 7,800 parts per million (ppm).

Solution Implemented

Blacksmith is spearheading the formation of a local stakeholder group, including the

local population, redevelopment authorities, and governmental bodies. The goals of this project

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are to assist the remediation of former US military operations in Subic Bay, as well as to improve

the health of the inhabitants of the area that could have been negatively impacted by the

environmental pollution. Specifically, Blacksmith has outlined four specific objectives. First,

Blacksmith plans to assess the extent of contamination at the former US Naval Base Subic Bay

and the former US Air Force Base Clark. Second, Blacksmith, along with partner institutions,

plans to assist in the remediation of previously identified PCB contaminated soils at the former

US Air Force Base. Third, this project sets out to raise awareness of people directly and

indirectly affected by the contamination. Lastly, Blacksmith and the stakeholder group plan to

assist in the effective and efficient project management and sustainable operations.

Effect

In 1994, health problems were beginning to be monitored in certain communities around

Clark, particularly in CABCOM, a government evacuation center for people displaced by the

explosion of Mt Pinatubo. The center was located atop a contaminated motor pool of the former

air base. People in CABCOM described the water as having a funny smell or an oily sheen. They

also complained of skin irritation after bathing or washing, stomachs bloating to the size of a

basketball, and unusual numbers of miscarriages and spontaneous abortions. In one small

neighborhood, nine children were born with central nervous system problems; only one survived.

In response to these problems local comunity groups in 1994 initiated a health survey of 761

households in 13 communites around Clark. The results revealed that:

Certain communities around Clark Air Force Base report conspicuously high levels of

kidney, urinary, nervous and female system health problems.

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The weight and height of older children were abnormally low despite adequate nutritional

status.

Respiratory problems in children were at high rates ranging from 23 to 31 percent in each

of the 13 communities surveyed.

According to local people, nearly 100 people from communities around Clark are thought to

have died due to ailments caused by the toxics contamination. At least 63 people report a number

of unusual ailments, including cancer, leukemia, and skin problems. At the Subic Naval base, a

high incidence of leukemia cases is reported. More than 1000 former base-workers were

diagnosed with asbestosis a type of lung cancer contracted due to exposure (usually

occupational) to asbestos.

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CEDAR CHEMICAL COMPANY

WEST HELENA, ARKANSAS

Background

Cedar Chemical Company (CCC), covering approximately 48 acres, is located in the

West Helena Industrial Park. The abandoned manufacturing facility consists of approximately 40

fenced acres. An additional eight acres contain the active wastewater treatment ponds, thought to

be constructed in 1977. The wastewater treatment ponds are permitted by ADEQ following state

and federal regulations and discharge into the Mississippi River.

This site is surrounded by other industrial companies, a rail road line, agricultural

property, and State Highway 242. Past plant operations at CCC resulted in off-site groundwater

contamination south of the facility. The contaminant of concern (COC) from this contamination

was identified as 1,2-dichloroethane (1,2-DCA). According to the current FIR, potential

contamination sources at the CCC site include: six former process units in the manufacturing

area, wastewater treatment facilities (both former and existing), and historical on-site waste

disposal areas. All may have contributed to past soil and groundwater contamination, both on-

and off-site at CCC.

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Cause

Hazardous substances detected in soils at concentrations greater than risk-based screening

criteria include Arsenic, Cadmium, Mercury, Aldrin, Dieldrin, Dinoseb, Heptachlor,

Methoxychlor, Toxaphene, 3,4-Dichloroaniline, Propanil, Chloroform, 1,2-Dichloroethane,

Methylene Chloride, and Pentachlorophenol.

Hazardous substances detected in groundwater at concentrations greater than risk-based

screening criteria and/or Maximum Contaminant Levels (MCLs) include Arsenic, Barium,

Cadmium, Chromium, Lead, 4,4’-DDT, Alpha BHC, Aniline, 4-Chloroaniline, Chlorobenzene,

1,2-Dichlorobenzene, 1,3-Dichlorobenzene, Chloroethane, 1,4-Dichlorobenzene, 2,6-

Dinitrotoluene, 3,4-Dichloroaniline, 4Chlorozniline, Dinoseb, bis(2-Chloroethyl)ether, bis(2-

Ethylhexyl) phthalate, 1,2-Dichloroethane, 4Methyl-2-Pentanone, 2Methylphenol, Acetone,

Benzene, Chloroform, Vinyl Chloride, Methylene Chloride, Trichloroethene,

1,1,2Trichloroethane, 1,2-Dichloropropane, Bromodichloromethane, Bromoform,

Dibromochloromethane, and Toluene.

Eighty (80) Solid Waste Management Units (SWMUs) (including approx. 30 sumps and

10 drum/drum storage/drum crushing areas) have been identified onsite to date that are deemed

areas of concern.

In summary, the surface soils and subsurface soils are contaminated with pesticides,

volatile organics, and heavy metals. The onsite surface water bodies and groundwater are

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contaminated with volatile organics and heavy metals. The sediments are contaminated with

pesticides and heavy metals.

Effect

Because of the site’s restricted access to the public, limited proximity to any residential

area, and public drinking water access, a pathway exposure for any child or adult (i.e., trespasser

or nearby resident) is eliminated.

ADH/ATSDR conclude that accidental ingestion or skin contact of subsurface soil or

groundwater at Cedar Chemical Company by a residential child or adult (and/or trespasser) is not

expected to harm people’s health because the exposure route has been eliminated due to no (or

very limited) contact with the site.

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References

http://www.src.sk.ca/resource%20files/gunnar%20tailings%20remediation%20plan%20re

port%20(aug%2017%202015).pdf

http://www.environment.gov.sk.ca/2007-068EISExecutiveSummary

http://www.greenpeace.org/seasia/ph/Global/seasia/report/2001/7/us-toxic-legacies-toxic-

hotsp.pdf

http://www.blacksmithinstitute.org/files/FileUpload/files/ClarkSubic%20Bay%20Update.p

df

http://www.atsdr.cdc.gov/HAC/pha/CedarChemicalCorporation/CedarChemicalCorpHC0

4022010.pdf

http://www2.adeq.state.ar.us/downloads/hw/PriorityList/pdf/Cedar%20SPL%20Site%20S

ummary.pdf