Posted at 08.10.2018
Aznalcollar, a town in the region of Andalusia, is found in the the west of Spain. The region of Andalusia is the second largest region of Spain, and it is the country's highest populated region. Andalusia may be an financially poor region with nearly all progress in its industry and service areas. The region can be divided into two major sub areas; in the north, the Sierra Morena Mountains are available and below this in the south is the valley of the Guadalquivir. This valley is home to the region's most fertile land, which is found along the bankers of the river Guadalquivir and its tributaries. Among these tributaries is the river Guadiamar which flows through the city of Aznalcollar. The move of the Guadiamar River is very seasonal; however it still sustains agricultural activity throughout the area.
45 percent of the Andalusia region is in charge of agriculture. Agriculture is mainly located surrounding the fertile bankers of the parts Rivers such as the river Guadiamar. The main agriculture in this area is composed dried land farming of cereals such as barley and oats. Other cereals grown in the area use irrigation. These cereals include maize, cotton, olives and rice. Only 17 percent of Spain's cultivated land is irrigated, proving that this region is of great importance to Spain's most important sector. Taking the kind of crop into account, this land could also allow for the harvest of two successive vegetation in the same year proving its advantages to the region.
Other primary sectors in the region include: fishing and mining which are all located across the Guadiamar River. The Guadiamar River is a valuable source to the populace of Aznalcollar, providing a source of food, materials and work. Fish is the key source of protein in the Spanish diet which is commonly found in traditional Spanish meals. Angling not only offers a source of food to the area but also employment due to its demands.
Mining still keeps a great level of importance to the Andalusia region. The region is responsible for producing 50 % of Spain's mining product by value. The merchandise comes from different provinces of the spot including Seville, where various metals are extracted from the mine at Aznalcollar. The Los Frailes mine at Aznalcollar produces around 125000 a great deal of zinc and 2. 9 million ounces of led per calendar year. This mine offers a great source of job and income to the region from raw materials which are exported.
Tourism is also a significant beneficial source to the tertiary sector of the region. The seacoast of Andalusia offers a very obvious source of tourism however The Donana National Recreation area located along the lender of the Guadiamar River, is regarded as a Mecca for parrot watchers. The national Park covers 543km†(337. 41 mi†) which 135 km† (83. 89 mi†) is a secured area. It is composed of marsh, shallow streams and fine sand dunes. In 1963 the recreation area was proven as a character reserve when the planet Wildlife Fund became a member of with the Spanish federal government and purchased a portion of marshes to protect it. Donana Country wide Park is one of European countries most significant wetland reserves and a major site for migrating parrots. The area itself is internationally identified for its great ecological riches and has become a key center in the world of tourism. It is becoming very popular due to its substantial variety of parrot species, everlasting residents, winter site visitors from north and central European countries or summer site visitors from Africa, such as its numerous types of geese and vibrant colonies of flamingo. The playground is also home to one of the world's most significant colonies of Spanish imperial eagles. As a whole, the area offers three specific types of ecosystems: the marismas, the Mediterranean scrublands and the seaside mobile dunes with their beaches. The playground attracts a huge amount of travelers annually, which in turn benefit the market of the area. The playground is also used by pilgrims getting involved in the Romeria de El Rocio. This event together can attract up to 1 million pilgrims each year.
It is obvious from the information above that the area bordering the Guadiamar River is extremely dependent on its sourrouding natural sources. The city of Aznalcollar is reliant on the next; agriculture, sportfishing, mining and tourism. However in Apr 1998 when the dam of the mining residual tank of any pyrite mine in the vicinity ruptured, liberating sludge and contaminated waste drinking water. The wastewater joined the Agrio River and the Guadiamar River. Both these waterways had low water levels due to a planting season drought. Subsequently the rivers flooded nearby - cultivated areas and threatened to flood the Donana Country wide Playground further downstream.
This had an enormous affects on the populace of Aznalcollar. In the beginning families living near to the river were bodily threatened. That they had to flee their homes immediately, not only due to rising overflow levels, however the fact that this particular had been polluted with toxic heavy metals. These individuals lost vast amounts of their stuff in the flood and the polluted water threatened their health. Fortunately there were no preliminary fatalities, just a small number of individuals injured. However it was not noted but these households were at the best risk of contacting terminal disease from the toxic water. DEVOTE WHAT AOIFE SAID
http://fuentesdeciencia. documents. wordpress. com/2010/10/hungria-aznalcollar. jpg?w=480&h=268
Initial influences to the area encompassing the Guadiamar River.
The cultivated lands across the bankers of the River Guadiamar were also demolished. As the poisonous waste water came into the river the level increased and flooded the cultivated land across the river banks. Not merely were the plants harmed by the polluted water but by the rest of the mud. The crops that acquired little water damage and mold still could not be harvest due to anxieties of toxic contaminants, so all harvest needed to be destroyed. This incident lead to a great economic loss, believed to estimate at $10million. Not only is this an extremely large amount of cash for a poor region, but it was disperse mainly among 2, 000 small farmers who acquired a great dependence on agriculture. Therefore also increased the price of rice, organic cotton and olives (main vegetation expanded) in the area as they had to be bought and transported from other areas. However not only were harvest effected in 1998, because of the pollution of soils, plants cannot be harvested for a least another five years, until analysis had considered the land safe for cultivation. This triggered great damage for the farming community in the region as that they had to give up farming for this period and discover another source of employment.
Pasture farmers were also damaged in a similar way. When the area flooded speedily farmers had to forego their farms, without the time for you to bring their pets to higher earth. These pets or animals either drowned from high flood levels or were poisoned from consuming the contaminated normal water. When farmers could return to the region, their herds have been killed no vegetation would grow for a long time after anticipated to level of pollution in the land. These farmers also experienced to seek different types of employment, which regarded very difficult in this poor region.
Fishing in the region was a great source of income for the city as there was a great demand. However once the contaminated wastewater inserted the river all fish stocks were killed by the contaminants. Fears also continued to be within the community years following the occurrence of how clean the river actually was and was it safe to consume fish from the river.
Mining was another great income source for Aznalcollar, as a poor region it depended greatly on its natural resources. But when the incident happened at the Los Frailes Mine, the mine was sealed down instantly scheduled to further threat of contamination to the region. This impacted the region greatly as the mine applied 500 people and an estimated 1800 people indirectly. The work of the area possessed a great dependency on the mine. Once the mine closed there were more that 2000 people in the region left unemployed. Also the materials extracted from the mine when sold brought a income source to the region, which was lost due to the closure of the mine.
As obvious from above the Donana Country wide Recreation area is Aznalcollar main source of tourism and bring in a great source income to the region. The park was not directly affected by the occurrence nonetheless it was under danger from the toxic flood water coming into the website. The fine sand and mud dikes which were constructed to control the move of the contaminated water avoided the park from begin affected. Nevertheless the surrounding areas were covered in a solid dangerous sludge. This area was then covered with dead fish, frogs, crabs etc which had been wiped out by the contaminated drinking water in the river and were then cleaned up in this area of sludge. Although the park had not been directly infected, the parrots in the playground were attracted to these poisoned pets on the sludge. If the bird consumed these poisons creatures they were poisoned themselves. The number of parrots in the recreation area decreased greatly. Also these wild birds propagate disease from these lifeless creatures to other animals inside the recreation area, building a continuoue negative have an effect on within the park. The nationwide parks main normal water source was take off as it was sourced from the polluted river - Guadiamar. This also created difficulty in the running to the park as a new water supply had to be sourced immediately. The area was closed for a brief occasion; so that staff could help assist in the cleanup operation outside the recreation area and so a new water source could be sourced. When the park have reopen there was a report in a drop of numbers of tourist browsing the park. The local association for travel and leisure ACETA reported that in 1998 about 40 percent of reservations for holiday visits were terminated, within the national park which determined to a loss of roughly 480, 000. This is possibly anticipated to health worries in the areas.
One of the very most prominent human effects from the disaster was its have an impact on on human being health. Short-term health problems resulted in a small number of minor casualties recorded. However the long-term health results were most feared. The contaminants found in the consisted of heavy metals such as lead, zinc, arsenic, cyanide and other heavy metals from the mines reservoir. Worries was that these toxic metals could be used by humans through drinking water. Even following the area was cleaned out, trace components of these metals could still stay in water pipes etc. Also the land which might also contain trace elements of these waste could copy the poisons from the land into crops and contaminate the meals chain. The fear behind permanent human health effects is the high dangers of cancers and neurological disease which can be caused by these contaminants.
The final individual impact induced by the catastrophe at Aznalcollar was the large scale cost involved. It is estimated that over all cost for the Boliden company came to 89 million, we were holding figures given out by the Boliden. This number included the cost of clearing up the northern sector of the Guadiamar - 27 million, the acquisition of the harvest of 1998 - 11 million, the businesses of decommissioning of the tailings lagoon - 41 million and losing because of the stop of the mining activity in 1998. The local administration of Andalusia provided 145 million for the disaster remediation. This budget was mainly utilized for cleaning up procedures, the acquisition of the polluted land - 48 million and recovery - 90 million. The Ministry for Environment provided a budget of 136. 7 million. 13 million was found in the removal of the tailings; 15 million was used for the treating toxic water deposition in the marshlands. The Ministry for Environment in addition has approved to provide 93. 7 million for a hydric regeneration arrange for Donana National Area and the Guadiamar riverbed. The overall cost of the whole devastation amounted to 377. 7 million, which impacted humans as this was mainly funded by duty payers money.
http://awsassets. wwf. es/downloads/mining_in_donana_english. pdf
http://www. fhs. se/Documents/Externwebben/forskning/centrumbildningar/Crismart/Forskning/Fallbanken/BOLIDEN_. PDF
http://countrystudies. us/spain/57. htm
http://www. slideshare. net/limitsspain/aznalcollars-spilling
Although the disaster resulted in great negative influences for the spot, positivity can be taken from the tragedy by learning from flaws and placing systems in spot to prevent a poisonous spill of such size from developing again. There have been four main lessons discovered:
Need to learn the possible environmental threats from mining lagoons in further fine detail and the post execution to avoid these actions.
Nessesity to fortify the mine legistration because of the improper environmental management of Aznalcollar mine before and following the incident.
The good routines in cleaning up activities techniques of the sludge have reduced the pollution degrees of the damaged area.
Oppurtunity to produce new restoration assignments and to put into action the Ramsar Convention advice.
Need to know the possible environmental dangers from mining lagoons in further information and the post implementation to avoid these actions.
The good techniques in clearing up activities techniques of the sludge have reduced the pollution degrees of the affected area.
The cleanup activities of the disaster were immediate and efficient since the area was flooded by polluted wastewater.
On the 25th of April 1998 in Aznalcollar, Spain, the Los Frailes tailings dam, ruptured. It comprised tailings from the mining of arsenic, silver, cadmium, copper, zinc and lead. The Los Frailes mine possessed a mining rate of around 4 million shades per 12 months. The ruptured dam released about 5-7 million cubic meters of harmful tailings sludge and polluted wastewater into Agrio River, which really is a tributary to Guadiamar River.
The actual cause of the Los Frailes tailings dam failing is still to this day exactly 100% clear as the ultimate report has yet to be posted and released. The regulators blamed the Swedish-Canadian operator of the mine, Boliden Ltd, and Boliden Ltd claimed instantaneously following this terrible incident took place that they were not at fault. Immediately after the accident happened it was suspected a foundation failure took place in the parting dam that's located between two elements of the impoundments, e. g. : the garden soil underneath the foot of the Los Frailes dam lost its mechanical strength. The separation dam is put among the basins, which can be filled up with tailings from pyroclastic rock and roll and pyritic rock and roll and the foundation failure of this business lead to the breaking of the main dam.
The Swedish-Canadian operator of the mine, Boliden Ltd, has reassured the authorities and the people of Aznalcollar that there was no possible way of foreseeing the foundation failure. There have been many different reviews and thoughts given as to why the dam failing occurred. The business Boliden Ltd mentioned at the start, that the cause of the dam rupturing was a landslide, which resulted in the movement of a part of the wall. However, the specialists stated that the damn was not of adequate development and also that any signs or symptoms of a probable break were overlooked by the company in control. Three independent investigations were carried out into the reason behind the dam inability. One exploration was commissioned by Boliden Ltd and carried out by EPTISA, another was commissioned by the local authorities and completed by CEDEX and another research was commissioned by the judge who was in charge of leading the legal proceedings of the car accident and was completed by the College or university of Barcelona. From your results of the three investigations it was agreed that the cause of the dam failure was from the formation of sliding surfaces in the marl beneath the foundation. The foundation failure occurred due to chemical episode of the impounded acidic pyritic sludge on the marl. Marl contains calcium mineral carbonate and clay. The strike of acid on the marl decomposed the calcium mineral carbonate present, which resulted in the deterioration of the mechanised stableness of the land.
Fig 1: The breaking of the dam:
A large part of land, that was located underneath the dam, migrated towards Rio Agrio (approx. 1 metre). The front part of the moving land was approx. 20 metres wide and positioned where the junction of both impoundments.
This brought on the dam to crack and break all of a sudden causing the wall structure to collapse progress along the separation dam, between your two impoundments.
Approximately 5 million cubic metres of toxic tailings sludge and contaminated wastewater seeped through the beginning.
The bed of Rio Agrio increased by approximately 3 metres and evolved its course.
Fig 2: Detailed diagram showing before the displacement had happened and after the displacement had took place.
The Los Frailes dam is approximately 25 meters in height and is placed on 4 meters of alluvium, which is situated under 70 meters of blue marl. By overstressing of the blue marl, it led to the dam, alluvium and the marl to glide. This sliding caused the pyrite tailings to liquefy, which in turn led to increasing the loading on the dam as the foundation level of resistance was decreased. These various procedures were the consequence of the 60 meters of horizontal displacement of the Los Frailes dam. Several other factors were eliminated to be contributing factors to the failure of the dam, e. g. : blasting, earthquakes etc.
Fig 3: Real photo of the Los Frailes tailings dam failure showing a complete of approximately 60 meters of displacement.
In the beginning of November 1998, Boliden directed a written report to the judge who was simply responsible for the case. Within the report it stated a new displacement (3 millimetres) of the dam possessed taken place because the spill. The Government confronted the general public, as there was an increased threat of a fresh spill. Mid-November 1998, environmentally friendly Protection Division warned that there was still a higher amount of tailings than what was lost when the dam ruptured in April, in case it rains and the dam fills with the rainwater then it could apply even more pressure to the surfaces of the dam. In February 1999, Boliden Ltd finally admitted for the first time that the tailings dam was not properly designed. They aimed the blame totally on the company (Dragados y Construcciones) and both engineering firms used by them.
An emergency operation needed to be set up in order to minimize the damaged brought on by the spill. The Spanish Authorities, the Regional Administration of Andalusia and also Boliden Ltd (Apirsa) were mixed up in tidy up. On the 1st of May 1998, the several administrations created a Mixed Commission payment of Coordination. The 1st process that was completed was the immediate removal of the tailings, that have been bought at the old area of the mine. Getting rid of the tailings was disseminate over two operations, in 1998 and 1999. Roughly 99% of the tailings were recovered as a result. Based on the Regional Authorities of Andalusia, the collection of almost all the tailings means that around 7000 million litres of earth and tailings have been retrieved.
In 1999, Boliden Ltd was granted the licensing of stabilization works for the dam as it was discovered that there was a substantial movement following the first spill (17 centimeters) and was a cause for major matter.
Another campaign was then undertaken by the Mixed Commission of Coordination, which engaged treating the soil. The dirt was treated utilizing a chemical method, which would lead to immobilizing the many heavy metals that remained in the garden soil. The construction of the Entremuros dike triggered the retention of 2 billion litres of acid normal water. In order to permit the Guadalquivir River Basin Specialist to purify the dammed waters, a water treatment flower was constructed next to the Entremuros dike. Following the purification process, it could then release the purified normal water to the estuary of Guadalquivir.
Another drastic solution was set up in order to regulate the environmental quality in the top waters, mid-air, the subterranean waters, the estuary, and also a sanitary control program of people living in the surrounding area who had been influenced by the Aznalcollar spill.
The whole process was proven in some published laws, decrees and also purchases between May 5th 1998 and 1999. Also in May 1998, the Council of Ministers of the Regional Government of Andalusia got approved the many actions which were necessary for conducting a project of regeneration and adaption for public use. This was called the Guadiamar Green Corridor.
The Guadiamar Green Corridor project was developed in 1999. The reason it originated was to restore the Guadiamar basin and it's surrounding ecosystems. The plan of action of the job was defined in the Guadiamar Green Corridor Strategy, which was recognized by the International Seminary on Ecological Corridors in March 1999. The Guadiamar Green Corridor job is also reveled in the results of an investigation program, which is known as PICOVER. PICOVER originated between the years of 1998 and 2002. The Regional Authorities of Andalusia shared the conclusions found because of this of this program. The predicted total amount of the PICOVER was 5. 8 million. It was divided down into 2 different phases. The 1st level originated between 1998 and 2001. The effects of the Aznalcollar spill were analyzed (on microorganisms and ecosystems) and the required rules for the repair were set out. The 2nd level was developed between your many years of 2002 and 2003. The objective of the 2nd stage was to regulate the factors which were most effected by the spill, which were soil and water. Attention was also directed at the species that were considered to be the most important bio indications e. g. vegetation, fish, etc.
The Green Corridors objectives and the plan of action:
To decontaminate this, soil and also microorganisms of the riverbed. Also the decontamination of the flooded plains and the marsh that was broken by the acid normal water and tailings.
Water: The Green Corridor has a complex office, which had set up channels. These channels were put in place to control the surface water (17 stations). From all 17 channels, only one of which has had an increased value (El Guijo). A report that was carried out by the Guadalquivir River Basin Expert back in 2003 figured the El Guijo stop, which was situated in the Guadiamar River, possessed continued to present an increased level of zinc, cadmium and copper metals. The El Guijo stop, from the 17 channels, is one of the closest to the Los Frailes mine. It really is 2. 5 kilometres beneath water. All the remaining 16 channels are within the legal limits and fit for individuals consumption.
The Guadalquivir estuary was tested after the spill and it confirmed an increase in the level of contamination. This issue solved itself after having a few short weeks as the contaminants level returned to what it was before the spill happened.
Soil: Because the Aznalcollar spill, the procedure of decontaminating the land had been efficiently carried out for the most part. The monitoring of the dirt to ensure the contaminants level remains low has continuously been followed up, especially focusing on the main affected area (the Aznalcollar mine and the bridge of Doblas). The reason why this area was the primary affected area was due to its closeness to the devastating lagoon. This led to high levels of zinc, arsenic and business lead contamination. Since 2002, nearly all soil areas that were affected were cleansed. The cleaning process taken away central tips of contamination but in some particular staining of the land, minuet residual contamination still remains.
Fauna: Among the key populations influenced were fish and amphibians. Because the Aznalcollar spill, the riverbed has been recolonized with fish and amphibians plus they have survived without any problems. In 2004, it was discovered that 6 different species of fish had laid eggs. It had been the 1st yr since the spill that different varieties of fish laying eggs was recognized.
Flora: The contaminants of metals in vegetation has decreased with time. 2. 5 million vegetation have been planted to be able to restore the affected area. Almost all were planted between the Entremuros marsh and the Los Frailes mine. The Entremuros area was restored by replanting in small plots. This technique allowed the ecosystem to improve naturally.
To repair the working of the terrestrial and aquatic ecosystems that have been damaged or ruined by the Aznalcollar spill.
The massive amount area that was influenced, from the mine to the entry to the Entremuros swamp, has now been restored. The aim is to produce a fluvial ecological corridor.
The gravel extractions, or the agricultural occupation has induced the Guadiamar riverbed to suffer from extreme transformations. If the riverbed was being restored it was thought that it was more critical to recuperate the procedures for fluvial dynamics, which had been modified, alternatively than recreate the initial morphology of the river. In 2004, it turned out known that the natural dynamic of the river, specially the flood plains, had been recuperated. Also, non-indigenous vegetation have been removed as instructed.
Since the spill, there used to be many gravel exploitations found on the foundation of the river of the Guadiamar, between your upper and middle branches. These were reformed serving two purposes. One use is environmental recuperation and the other is good for the use of the public.
Entremuros marshes: The primary reasoning behind the activities was to ensure the riverbed was recuperated by removing the effects that hindered the natural functioning. The results have shown to be considerably good. The fauna and flora have quickly colonized the area.
To promote a model for the management of the many uses of the spot so that ecological heterogeneity could be marketed to be able to reinstate different types and natural functions among the pile range and the seacoast.
Positive results were found on the motion of land pets through the Corridor, in the middle span of the Guadiamar River. There are plenty of communities that commenced to become set up in the Corridor, including the eagle, rabbit, and the lynx. Because of this it offers aided the purpose of the ecological corridor of the Guadiamar River. The Corridor has would have to be fastened through the northern part as this restored the river basin of the Guadiamar River and the mining region in its higher course. The recovery continues to be followed up, even today, as it ensures its work as a fluvial ecological corridor and the near future tendencies of the river.
To improve and promote the quality of life of the numerous people living in the region through the strategies of development fitted with the conservation of the functions with their natural systems.
Public use: The Green Corridor is now recognized as a tourist destination. It includes tails that can be used for walking, biking and horse riding. A number of infrastructures have been made including recreational areas, a botanical garden, visitor centers, etc. There has been sign posts put up of the area, and also the roads. There have also been tutorials produced on the infrastructures and programs in the Green Corridor (for public use).
Other uses: Within the Green Corridor there are numerous kind of functions prohibited which include hunting, angling, and bringing up livestock. Also, due to the old mine an environmental services site has been produced.
Relations with the surrounding inhabitants: Many environmental educational activities were developed to be able to educate the populace, but largely for schoolchildren. A lot of the people surviving in the surrounding area weren't aware of the countless activities in the Green Corridor and its own ideas. To make it clear to the populace, it was necessary to cover the animals values, historical, panorama etc of the Green Corridor.
To donate to the alteration of the Network of Protected Natural Areas of Andalusia as an arrangement of areas, which can be linked by ecological corridors and which fluvial ones stand out the most.
The Green Corridor needed to be declared as a 'Protected landscape' to be able to adhere to this aim. The Green Corridor will not reach up to the north of Aznalcollar therefore it is not connected as an ecological corridor with the shoreline and mountain range.
To operate as a model of integrated planning of an Mediterranean basin with could be extrapolated to other parts.
The WWF has acknowledged that the Guadiamar Green Corridor functions as a style of basin restoration. Any office for the Mediterranean chosen one of its projects to be a style of management and recovery of Mediterranean wetlands. The WWF gave the 'lessons discovered' of the Guadiamar to Romania to help them after the mine accident of Baia Mare.