barren to green technical paper

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-----------------------------------------------------------------------------------------------------------------------------------------------------Barren to Green, Briccio T. Abela, Coral Bay Nickel Corporation, October 31, 2012 Page 1 of 8

Reddish and Barren Tailings Landscape Transformed into a Green,

Productive and Functional Ecosystem - The Tailings Rehabilitation

Experience of Coral Bay Nickel Corporation

Engineer Briccio T. Abela

Coral Bay Nickel Corporation

Introduction

Coral Bay Nickel Corporation (CBNC) decommissioned its Tailings Storage Facility No.1 or

TSF-1 last June 2010. The tailings dam's rocky outside slope and the reddish tailings stored

inside the dam are barren and void of plants except for some scattered small patches of

grasses on the dam slope. The wide and ugly landscape is a loathsome picture to behold

especially on satellite images. We started rehabilitation works the moment the tailings soil

was stable and accessible and just after 16 months work that started last May 2011, the TSF-1

landscape can be likened to an ugly caterpillar that transformed into a beautiful butterfly.

Rehabilitation Objectives

We applied the planned decant system improvements last April-June 2011, we conducted

planting trials from December 2010 to March 2011, and we started massive planting works

last May 2011 with the following four main objectives:

1. Physical StabilityA tailings storage facility has an inherent risk of dam break and tailings spill specially during

stormy weather. The dam should be kept physically stable at all times. Potential cause of dam

break is overtopping of pond water. This is prevented by the TSF-1's effective decant system

that have the capacity to discharge pond water at all times. At TSF-1 the discharge channel is

two inclined underground concrete gutters with a channel opening of about 1 square meter

each located adjacent to the northwest dam where the channel exits at the dam s outside toe.

The spill level of the main spillway that is Gutter-A is at 65.0 meters above sea level (masl)

that has a free board of 3.2 m since the dam crest is at 68.2 masl. Gutter-B, the secondary

spillway, which is constructed parallel to Gutter-A and just 40 m distant has a spill level of

66.0 masl. After the decommissioning of TSF-1, an additional third emergency spillway at

elevation 66.0 masl was constructed at the northwest tip of the dam which is also adjacent to

the two inclined gutters. This is a horizontal concrete square culvert with 1 square meter

opening that will be the discharge channel of water in an emergency case that the gutter will

be clogged accidentally by debris or in extremely strong rains that the discharge water

volume can't be accommodated by the two inclined gutters.

Gutter-A (the main spillway) was provided with a settling sump 3 m wide at the base and 100

m long located upstream of the spill gate. The spill gate has 3 removable concrete planks,

each one is 30 cm in height that could be installed in order to control flow and create a deeper

pond in the settling sump. During heavy rains, 1 plank installed was found sufficient to effect

settling of silt and discharge clear pond water. An added factor to the clear water discharge is

the vegetation that covers most of the previously bare surface and the 50cm deep by 100cm

wide ditch network dug on the lower elevation of the tailings pond. The efficient decant


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filled with rice hull because of limited supply nearby and the difficulty of bringing it

to the middle portion of the tailings pond due to soft soil and surface cracks.

2.2 Fertile and nutrient-rich soil planting media containing a mixture of top soil,vermicompost and carbonized rice hull was used. This soil media was placed in

small (6 x 8 ) plastic pots where the plants were grown for 3-4 weeks into sturdy

condition prior to transplanting.

2.2.1 The top soil is sourced out from nearby farms where we literally buy theland or soil placed in bags.

2.2.2 The compost is produced in our vermicomposting facilities. We have atotal of 15 vermicomposting beds that can produce about 10 cubic meters

of humus-rich and microbe-rich compost every month. The main

composting materials are rice hay (i.e. dayami) which is abundant in

nearby rice farms and cow manure which is bought from the gatherers in

cow grazing lands nearby. The vermin utilized is the African night

crawlers species. We started with just 3 kg of vermin with 3 composting

beds last May 2007 and we have expanded at present to 15

vermicomposting beds, 1.8 cubic meters each in size (with dimensions 3 m

long, 1.5 m wide, and 0.4 m high). The quantity of available vermin forcomposting is now about 80 kg.

2.2.3 The carbonized rice hull was sourced out from a rice mill operator thatagreed to supply it as needed. We provided the carbonizing equipment

which is made of a one-third metal drum cut crosswise with holes and

chimney to the rice mill operator and conducted training to the rice mill

workers on how to do carbonization. We then buy the produced

carbonized rice hull at a reasonable price.

2.3 We planted locally growing surface cover crops composed mainly of fast growingvines, grasses, and herbs that are forage species as well. Locally growing herbs with

wide green leaves were also planted.

Prior to massive planting, we first conducted planting trials. Three trial plots wereestablished in different locations both on the dam slope and on the tailings surface

soil. Coco-coir net was used to cover the dam slopes prior to planting. The coco-coir

net served to stabilize the slope and also served as an organic matter that the plant s

roots can hold on as it grows. The following vines and herbs listed below that were

proven suitable for planting based on trial plots were planted. Humidicola, stylo and

centrosema were used for slope stabilization while all plants described below were

used as tailings soil cover crops:

2.3.1 Brachiaria Humidicola a strong creeping perennial grass which forms adense matted sward that grows well in infertile soils and full sunlight. Its

main use is as a permanent pasture for grazing, particularly in wet areas. Itestablishes reliably and spreads rapidly from stem cuttings. At TSF-1, it was

planted at 0.3 m x 0.3 m spacing on dam slopes and at 0.5 m x 0.5 m spacing

on tailings soil (Please see Figure 3). After just two months, the planted

humidicola already densely crept and covered its immediate vicinity.

Humidicola is the main grass use as cover crop in greening the TSF-1

landscape.


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2.3.2 Stylosanthes seabrana an erect, branching, green, bushy, 40-70 cm tallperennial legume with woody base. It is tolerant to prolonged dry season. It

is suitable in clay soils. Use widely as grazed pasture legume. At TSF-1, this

was planted at 0.3 m x 0.3 m spacing on slopes and 0.5 m x 0.5 m spacing

on tailings soil (Please see Figure 3). It was planted in rows between

humidicola for the purpose of plant diversity.

2.3.3 Centrosema pubescens - a perennial, twining, and trailing legume which willclimb associated grasses and plants. Individual plants can spread 1-2 m from

the strong taproot. Used as a permanent pasture for cattle, this legume

improves soil fertility by adding nitrogen into the soil. At TSF-1, centrosema

is planted at 0.3 m x 0.3 m spacing on slopes and 0.5 m x 0.5 m spacing on

tailings soil (Please see Figure 3). It is planted in rows between humidicola

for the purpose of plant diversity and additionally as a biological nitrogen

fixer.

2.3.4 Wild sugar cane (Saccharum spontaneum) and Napier grass (Pennistumpurpurium) - a tall grass that can grow as much as 3 m high. This plant is

tolerant to many soil textures and moisture levels. It produces a lot of

biomass and its potential as a source of bio-fuel is being discovered. It growsso well in infertile soil that it needs just about 500 cc of fertile soil input to

grow in the tailings soil of TSF-1. It was planted at 2.5 m x 2.5 m spacing

(Please see Figure 4). Wild sugar cane and Napier grass are use as

permanent pasture for cattle.

2.3.5 Banana the species planted was mostly the saba" variety. It was chosen asone of the plants because it has wide leaves that could help in quickly

greening the tailings landscape and it can also produce a large amount of

biomass. Banana leaves are food for cattle and of course its fruit is food for

humans. At TSF-1, banana is planted at 5 m x 5 m spacing (Please see

Figure 4). The bananas grow well especially in areas where the raw rice hull

was introduced. After 18 months the bananas that were first planted in the

tailings surface trial plots already bear fruit.

2.3.6 Elephant ear plant, locally called badyang (Xanthosoma robustum) thisplant can be found in the wild and is usually abundant in the lowlands. It

was chosen as a rehabilitation plant because of its wide leaves that can grow

as much as 3 feet long and 2 feet wide that could contribute much in fast

greening the tailings soil landscape. Additionally, it also has the capacity to

produce large amount of biomass. At TSF-1, elephant ear is planted at 2.5 m

x 2.5 m spacing (Please see Figure 4).

2.3.7 High value crops like vegetables, watermelon, cut flowers, sunflower,jasmine (sampaguita) as well as rice (palay) were planted and produced

good harvest. Sugarcane was also found to grow well. The purpose of

planting these crops is more of an experiment on the tailings soilsproductivity in addition to aesthetics value. Results proved that the soil can

be restored into a productive agricultural farm with inputs of carbonized rice

hull and vermicompost.

2.3.8 Diverse other grasses and vines whose seeds or roots were naturally presentin the soil purchased from nearby farms also sprouted and are growing

naturally. These added to the biodiversity of plants that now occupies the

tailings landscape.


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----------------------------------------------------Barren to Green, Briccio T. Abela, Coral B

Figure 3. TSF-1 Surface Planti

This planting design is intersper

Legend: - humi

- stylo

Figure 4. TSF-1 Surface Planti

ear and wild sugar cane:

Legend:

- Banana: 5 m- Wild sugar ca- Elephant ear (

----------------------------------------------------------------------------y Nickel Corporation, October 31, 2012

ng Plot Design; 1 m x 1 m area for Grassesed within the 10 m x 10 m plot design shown i

icola: 0.5 m x 0.5 m distance

santhes or centrosema: 0.5 m x 0.5 m distance

ng Plot Design; 10 m x 10 m area for Banana

5 m distance

ne: 2.5 m x 2.5 m distance

or wild sugar cane): 2.5 m x 2.5 m distance

--------------------Page 5 of 8

Vines:Figure 2.

, Elephant


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After the application of the greening strategies outlined above, the decommissioned TSF-1

was noticeably transformed from an ugly looking landscape into a vibrant green grass land.

After just sixteen (16) months of planting from May 2011 to August 2012, seventy (70)

hectares of the more or less ninety five (95) hectares of previously bare and rocky and

reddish brown landscape are now covered in green. This resulted in the following positive

impacts:

A. Negative TSF-1 landscape aesthetics were eliminated and converted into beautifulscenery.

B. Soil erosion during rains was drastically minimized resulting to clear pond waterdischarge. Conversely, the potential of dust generation from open areas during sunny

days was also averted.

C. Diverse fauna like insects, birds, rodents, snakes, monitor lizard and the like havenow started to come and occupy the area. A colony of wild honey bees was observed

to form a hive in an inverted metal drum near the sunflower garden starting last

August 2012.

D. The TSF-1 Rehabilitation project resulted in positive impact on the nearbycommunities by providing employment to about one hundred people composed oflocal indigenous people and indigents who served as workers.

Figure 5. TSF-1 Satellite Image before rehabilitation (April 2010)

Figure 6. TSF-1 Aerial Photograph after rehabilitation (October 29, 2012)

N

N


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3. ProductivityThe productivity of the decommissioned TSF-1 was well incorporated in the strategies

outlined for its rehabilitation. Five (5) species of grasses and vines planted were all forage

species. The planted area can served as a vast pasture land for cattle, goat, and other grazing

animals.

The success of cut flower plantation trials opens a potential as an alternative farm product for

supply for Puerto Princesa City which at present still acquires cut flowers from outside of

Palawan. In addition, the flowers are also a potential source of essential oils.

The wild sugar cane and the sugarcane itself as a potential resource for ethanol can be

explored.

Basing from the success of the vegetable garden trials and even the rice farm, the tailings soil

can be developed into a productive agricultural land. The needed inputs of carbonized rice

hull and vermicompost can be easily produced from abundantly available materials. The

experimental vegetable and rice farms using only organic inputs also serve as a model for

local farmers (who are working in this tailings dam rehab project) to improve their farmingmethods. For some parties that may have apprehension on the suitability of growing food

products in the tailings soil because of toxic elements, I would like to give assurance based

on laboratory results of the soil and the food products extract that the TSF-1 farm products

are safe for human consumption. I would even venture to advertise that TSF-1 farm products

are fortified with iron that is much needed by the human body since the tailings soil contains

about 35% iron.

Lastly, one of the intents of planting the different flowers in about one-half hectare tailings

soil area is to develop a butterfly garden without nets or enclosures. Part of the plans yet to be

implemented next year 2013 is to have a plantation of all locally known medicinal plants to

serve as a source of medicine for indigenous people and locals who still practice the use of

these plants for medicine. Another plan to be implemented in 2013 is the development ofwetlands in order to enhance further the biodiversity of the TSF-1 landscape. In the near

future, after all the planned rehabilitation works are completed, the TSF-1 rehabilitated

landscape will be an interesting site for students educational field trips and for tourists of

varied interests.

4. Self-sustainability.The end goal of the rehabilitation of the TSF-1 landscape is to re-create a functional

ecosystem. Towards this goal, our planting program widely applied principles of natural or

organic farming. Diverse plant species that included biological nitrogen fixers were

introduced. The tailings soil was void of nutrients and organic matter that will sustain plant

growth. This was remedied by our use of large amount of carbonized rice hull andvermicompost inputs. The carbonized rice hull is the main source of organic carbon that also

served to enhance microbial growth of the microbes present in the humus-rich and microbe-

rich vermicompost. In addition, the fertile soil coming from nearby farms also carries soil-

inherent nutrients and microorganisms that will enhance sustainability. The presence of

microorganisms and the diverse flora and fauna that already occupies the TSF-1 rehabilitated

landscape will enhance the nutrient cycle and keep the re-created grassland ecosystem

functional and sustainable.


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Concluding Remarks

Overall, the previously ugly and barren tailings dam landscape was successfully converted

into a beautiful, productive, sustainable and functional ecosystem with a very safe and stable

dam structure. The millions of pesos spent to accomplish the resourceful and innovative

efforts give proof to CBNC s commitment to be a responsible mineral processing company.

Acknowledgement

I am greatly indebted to the support given by CBNC Management in the TSF-1 rehabilitation

that needed millions of pesos for its realization. Please allow me to mention that the MGB-

IVB Regional Director Roland De Jesus supported the rehabilitation project and encouraged

CBNC Management to pursue the rehabilitation works in order to show proof that

responsible mining and mine rehabilitation are possible and can be done. Lastly, let me

express gratitude to the exceptional dedication of the whole EMQCS staff and tailings dam

workers who worked beyond the call of duty in order to achieve the very challenging TSF-1

rehabilitation objectives. Above all, to God be the glory that causes the grasses we planted to

grow.

References:

Prepared by BMP Environment & Community Care, Inc. for CBNC. Final MineRehabilitation and/or Decommissioning Plan for HPP Lines 1 & 2; (approved by CLRF

on December 14, 2009).

Munroe, Glenn. Manual of On-Farm Vermicomposting and Vermiculture, OrganicAgriculture Center of Canada

Tongway, David. The LFA Monitoring Procedure: A monitoring procedure to assessminesite rehabilitation success. Part 1: Introduction to the Field Procedure

Anuj K. Chandel, Om V. Singh, M. Lakshmi Narasu, L. Venkateswar Rao.Bioconversion ofSaccharum spontaneum (wild sugarcane) hemicellulosic hydrolysateinto ethanol by mono and co-cultures of Pichia stipitis NCIM3498 and thermotolerant

Saccharomyces cerevisiae-VS3. New Biotechnology, Volume 28, Issue 6, October 2011,

Pages 593-599.

http://www.tropicalforages.info/key/Forages/Media/Html/Stylosanthes_seabrana.htm http://www.tropicalforages.info/key/Forages/Media/Html/Centrosema_pubescens.htm http://www.pasturepicker.com.au/Html/Humidicola.htm http://www.ecosystems.ws/ecosystem_concept.htmAbout the Author:

Briccio T. Abela, a Chemical Engineer, is a farmer's son whose father's legacy included a

love of the land and pride in being a Palaweo. He passed these values on to his children and

to environmental science students in Palawan State University where he taught during a break

from working as a Grade Control Engineer for the Rio Tuba Nickel Mining Corporation. He

also served as Environmental Laboratory Manager and Environmental Monitoring Point

Person for the Palawan Council for Sustainable Development Staff. He joined Coral Bay

Nickel Corporation in 2006, where he is currently the Section Head of the Environmental

Management and Quality Control Section.

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