Bioremediation
How this project was developed
Relevant aspects in the preparation of the project
Local Experts
In order to move towards the decision of which technology to use and which to discard, it was essential to advance studies that require greater specificity in the analysis. The first studies to obtain data regarding the effectiveness of the bioremediation alternative for Las Salinas soils began to be obtained in late 2015 and early 2016. The Universidad Técnica Federico Santa María was the expert organization in charge of the evaluation of the strategy through two experimental studies developed at the university premises: microcosm study and the analysis of aerobic pilots (bioaugmentation, biostimulation and enhanced bioremediation) and anaerobic pilots (bioaugmentation).
Subsequently, pilot studies were carried out on a semi-industrial scale, with research groups from the partner universities, Universidad Técnica Federico Santa María and Pontificia Universidad Católica de Valparaíso, in a gradual approach towards the real scale of the project.
Thus, the extraordinary technical support required to develop a project that integrates the scientific with the territorial and social, beyond the requirements of environmental institutions, was formed. This link would eventually shape the CES and the generation of collaboration agreements with both universities.
Strategic Sanitation Committee (CES)
- Marcel Szantó: PhD in Civil Engineering and Master in Environmental Contamination from Universidad Politécnica de Madrid; Construction Engineer from Pontificia Universidad Católica de Valparaíso.
- Roberto Orellana: PhD in Microbiology from the University of Massachusetts (UMASS); Agricultural Engineer from the University of Chile. Professor and researcher at Universidad de Playa Ancha.
- Salvador Donghi: Biologist and academic from the Pontificia Universidad Católica de Valparaíso. He has postgraduate studies in cell biology and biotechnology at the State University of New York and integrated environmental management at the European University Miguel de Cervantes. Owner of the environmental consulting firm Simbiosis SpA.
- Michael Seeger: Biochemist and Doctor of Science, Universidad de Chile. Professor of Biotechnology, Microbiology and Biochemistry at Universidad Técnica Federico Santa María in Valparaíso.
- Luis Álvarez: Master’s degree in Urban Planning from the Universidad de Chile and Bachelor’s degree in History from the Pontificia Universidad Católica de Valparaíso (PUCV).
All the work carried out by the CES, in conjunction with national and international professional experts and the company, was consolidated in December 2018 with the entry into the Environmental Impact Assessment System (SEIA) of the EIA of the “Sanitation for the Las Salinas Land” Project for its evaluation, which culminated favorably in 2020.
Sampling plan
After the withdrawal of the oil companies from the area and the final verification of the success of the first field remediation, as of 2015 a new and thorough field sampling process began, incorporating new technologies with respect to the first analyses performed by the oil companies between 2001 and 2013, in order to advance in the new required standards.
The 2015-2016 Sampling Plan was designed based on the guidelines and recommendations of the “Guía Metodologica para la Gestión de Suelos con Potencial Presencia de Contaminantes“, of the Ministry of the Environment (2012) and consisted of a complete characterization of the remaining traces of contamination after the initial remediation process of the land, a process that was supervised by the Universidad Técnica Federico Santa María.
Soil sampling plan
- Sampling grid of 33 x 33 meters (1,000 m2)
- Probes for each cell
- Sampling every 1 meter depth
- It considered all compounds of interest related to the industrial activity historically developed in the field.
Groundwater sampling
- 12 existing wells from previous studies + 59 new wells
- Samples were taken from drill holes and boreholes down to a depth of 8.5 nmeters.
Sampling in the beach area
- 36 new wells installed on a temporary basis.
- Characterization in 3 periods, since groundwater is subject to temporal changes due to both tides and winter-summer seasonality.
Soil gas sampling
- At 21 points in order to determine the concentrations of volatile organic compounds.
- The compounds of interest analyzed were BTEX, phenanthrene and naphthalene, and it was determined that only benzene, one of the BTEX compounds, requires remediation.
With this information, a geo-spatial modeling (3D) was developed, which allowed predicting the distribution of contaminants and the biogeochemical processes that take place in both matrices, soil and water.
Environmental Impact Study
In December 2018, Las Salinas submitted to the Environmental Evaluation Service (SEIA) the Environmental Impact Study “Sanitation of Las Salinas land”. After a 2-year process; 2 Consolidated Reports of Requests for Clarifications, Rectifications or Amplifications (ICSARA); and a complete citizen consultation process – which included an Anticipated Citizen Participation (PACA), carried out voluntarily by the company, and a Citizen Participation Process (PAC) established in the approval process – the Environmental Evaluation Commission (COEVA) of the Valparaíso Region resolved to approve it unanimously through the Environmental Qualification Resolution favorable to the year 2020, which was ratified in 2022 by the Committee of Ministers.
The remediation project uses the on-site bioremediation technique, i.e., the implementation of biopiles with soil removed from the Las Salinas site. In the same way, the groundwater will be bioremediated through the use of amendments that trigger biodegradable processes. This definition was made thanks to the incorporation of the local vision of research groups from the Universidad Técnica Federico Santa María and Pontificia Universidad Católica de Valparaíso, who reviewed the different techniques available, conducted studies, reviewed international experiences and laboratory tests before establishing bioremediation as the most appropriate technique for the remediation of the land.
Latest in Bioremediation
Check out the most recent activities we have carried out as part of our remediation work in Viña del Mar.
5 Frequently Asked Questions about Bioremediation
Why should it be remediated only in the deeper layers?
A: The oil companies that had stopped operating in Las Salinas submitted a first EIA called “Recuperación Terreno Las Salinas” on December 20, 2002, which obtained an Environmental Qualification Resolution (RCA) that was favorably qualified by the Regional Environmental Commission (COREMA) of Valparaíso (or regional CONAMA), through Exempt Resolution No. 203 of October 7, 2004.
The first stage of remediation of the Las Salinas site was carried out between 2009 and 2013, during which time 47 thousand tons of contaminated soil were removed and the surface and subsoil facilities of the fuel distribution companies that operated until 2000 were dismantled. This explains why the first meter of soil on the site has been completely remediated.
After the first phase of remediation, studies established that the major contamination of the soil is associated with hydrocarbon compounds, which are located between 5 and 8 meters deep.
Is it dangerous for bacteria to be so close to populations?
A: Bacteria are everywhere on a massive scale, in gardens, in parks, in our refrigerator, etc. So far, after more than 70 years of a naturally activated process, there is no record of them being a threat to populations, because they are bacteria adapted to surplus and remaining hydrocarbons, and not to human pathologies.
How do bacteria travel and can they reach our homes?
A: It is impossible for bacteria to travel to the surrounding dwellings or beyond, let alone in a non-homogeneous environment.
The movement of bacteria is on a microscopic scale, imperceptible to human measurement standards; their world (cosmos) is reduced to a dimension not perceptible to man. Moreover, bacteria cannot fly.
Why is phytoremediation not applied at the site?
A: Because there is no pre-existence in the place that we can take as a reference, the ruderal (colonizing species in uninhabited or abandoned sites) present do not do phytoextraction, fundamentally because the contaminants are below 6 to 7 meters in the subsoil, even if we bring them to the surface to force phytoremediation the species to be incorporated will change the matrix of the contaminants, that is to say, the contaminants are extracted by the plants that later would have to be eliminated in another way. In addition, there is no possibility of tree species for coastal soils where the substrate is mineral (sands), with brackish soils. Clearly a technique that does not apply to this type of site and soil type.
Why do they install the monitoring stations inside the field and not in the surroundings where people live?
A: Because the source of contamination to be monitored is the site itself, it is the closest location to a potential exposure and, therefore, where measurements will be highest. Monitoring within the contaminated site and not in the surrounding area helps to differentiate the contaminants coming from the site in question and not from other sources, such as local industry or traffic, and allows to evaluate the effectiveness of corrective measures in real time.
