Cover Sheet - All Documents | The World Bank · 2016. 7. 8. · Matanza-Riachuelo and the Río de la Plata (Modelacion Matematica de la Cuenca Matanza-Riachuelo para el Estudio de

Environmental Assessment of the Matanza-Riachuelo Basin Sustainable Development Project, Executive Summary – Page 1

REPUBLIC OF ARGENTINA

ENVIRONMENTAL ASSESSMENT MATANZA RIACHUELO BASIN SUSTAINABLE DEVELOPMENT

PROJECT

EXECUTIVE SUMMARY

August 18, 2008

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ENVIRONMENTAL ASSESSMENT OF THE THE MATANZA-RIACHUELO BASIN SUSTAINABLE DEVELOPMENT PROJECT EXECUTIVE SUMMARY1 Table of Contents 1. Introduction 3 2. Legal and Institutional Framework 4 3. The Project’s Area of Influence 8 4. Environmental Baseline Setting 9 5. Analysis of Alternatives 16 6. The Selected Alternative 21 7. Environmental Impacts 27 8. Public Consultation and Social Aspects 35 9. Environmental Management Plan 37

1 This Executive Summary is based in the following documents: ACUMAR. (Agosto, 2008) Borrador Avanzado Evaluacion Ambiental Integral del proyecto Desarrollo sustentable de la Cuenca Matanza Riachuelo. Available online: http://www.ambiente.gov.ar/?idseccion=239 AySA. (Agosto, 2008) Borrador Avanzado Estudio de Impacto Ambiental del Plan Director de Saneamiento Obras Basicas en la Cuenca Matanza-Riachuelo.


1. Introduction 1- The present document presents a summary of the most relevant aspects of the Comprehensive Environmental Assessment (EAI) of the Matanza-Riachuelo Basin Sustainable Development Project (PDSCMR), focusing on the current environmental setting of the Matanza-Riachuelo (MR) basin, the environmental impacts stemming from project execution and operation, and the recommendations arising from the environmemtal assessment of the project. 2- To assist the Government of Argentina in addressing the problems related to water pollution in the MR basin and in the city of Buenos Aires, the project will develop a cost-effective approach to comprehensive wastewater management in the MR basin and other parts of Buenos Aires, the capital of Argentina, as well as water pollution control in the MR River and its tributaries and the La Plata River. The project will include investments for the collection, treatment and final disposal of domestic and industrial sewage, as well as for territoria development. The communities living in the MR basin will benefit from the proposed investments in sewage collection, while the investments in sewage treatment and final disposal will benefit most of the population of Buenos Aires. 3- When completed, the proposed project will have: (i) improved the quality of life of the 3.5 million inhabitants of the MR basin; (ii) improved sewerage and drainage services in the MR basin and other parts of Buenos Aires by expanding the coverage of the sewerage network (up to about 80%), especially in poor marginal areas; (iii) contributed to environmental cleanup and protection in the MR basin and Buenos Aires by providing installations for controlling pollution of rivers and tributaries crossing the urban area and the pollution of the La Plata River; and (iv) contributed to territorial development and reduce flooding in the MR basin. 4- The PDSCMR deals with the objectives and expected results that are carried out in two key initiatives: a) on the one hand, stemming from the Comprehensive Environmental Sanitation Plan for the Matanza-Riachuelo Basin (Plan Integral de Saneamiento Ambiental de la Cuenca MR – PISA) promoted by the National Secretariat of Environment and Sustainable Development (SAyDSN) through the Matanza-Riachuelo Basin Authority (ACuMaR), whose key objectives are the recovery and preservation of the quality of bodies of surface water in the Matanza-Riachuelo Basin and in the Río de la Plata, in terms of the uses and objectives of water quality to be proposed, agreed, and allocated for the various sections and zones of said basin and river; and b) on the other hand, the Master Plan (Plan Director) approved for AySA in accordance with the regulation established in the Regulatory Framework of the Public Service under its responsibility (Law 26221), which is fully incorporated in the PDSCMR and whose stated basic objectives are to ensure the expansion of sewer services, in accordance with the rules that regulate the provision of the service and its approved plan.


Altough the proposed project forms an important part of the PISA, it does not constitute the entire PISA but rather only a part of it. 5- Due to the scale, cost, and complexity of the project, its will be carried out with financing under the Adaptable Program Lending (APL) modality, so its different components will be carried out in sequential stages. The project’s main objective is to improve the quality of life and the sanitation services in the Matanza-Riachuelo Basin, as well as to improve water quality of the main water courses crossing it. It would consist of 4 components: (i) Sanitation; (ii) Industrial Pollution Abatement; (iii) Urban Rehabilitation; and (iv) Technical Assistance and project Management. 6- The Sanitation component is designed to eliminate sewage discharges into the Matanza Riachuelo River through the provision of infrastructure works such as collectors, preliminary tratment plants, and sub-aquatic outfalls wich will discharge effluents to the La Plata River. The Industrial pollution abatement component is designed to reduce industrial pollutant discharges into the Matanza Riachuelo River and the environment. This component includes monitoring and compliance improvement policies. The Urban Rehabilitation component is designed to address urban land use and flood management problems. Finally, the technical assistance and project management component will finance additional studies and overall project management. 7- Although this Executive Summary of the Environmental Assessment is a self-contained document, its objective is to orient the reader on issues of major relevance, mainly referencing the Integrated Environmental Assessment document and the references indicated in it, in particular those referring to the results of the numerical modeling of water quality for Matanza-Riachuelo and the Río de la Plata (Modelacion Matematica de la Cuenca Matanza-Riachuelo para el Estudio de Alternativas de Saneamiento , Informe Integrador, Junio 2008, carried out by the Universidad Tecnológica Nacional under the Direction of Dr. Angel Menendez), as well as the Environmental Impact Studies on specific works of the Plan Director conducted by AySA. 2. Legal and Institutional Framework 8- 17 jurisdictions and 29 relevant agencies coexist in the Matanza-Riachuelo Basin. 9- All of them have jurisdiction over and/or responsibility for water resources and/or their areas of influence. Therefore, there is a risk that regulations may clash among themselves and not respond to an integrated management focus on water resources, making it impossible to achieve the objective of reversing the basin’s polluted status. For these reasons, it is necessary to adjust the regulations, taking into consideration the basin’s receiving capacity and its areas of influence.


10-This stemmed from the need to create an environment of coordination that would allow legal-institutional consistency in order to implement the integrated management of water resources. Thus, on November 15, 2006, Law 26.168 was approved, creating the Matanza-Riachuelo Basin Authority (ACuMaR) as an interjurisdictional public agency under the scope of SAyDS in the Office of the Cabinet of Ministers. The duties of the Authority may be grouped as follows: Coordination: -principle of subsidiarity, -preeminence over local authorities. Execution: -authority to adopt any measure necessary or relevant for the basin’s sanitation, -execute the budget of the Basin Authority. Regulation and control responsibilities: -unify schemes dealing with liquid effluents and gas emissions, -conduct environmental land use planning, -create rates for services, -issue the Basin Authority’s organizational bylaws, -establish a special administrative procedure, -implement preventive measures, -intervene on allocations, audits, monitoring, environmental impact assessments, sanctions, -issue warnings, writs, and inspections, -order closures, seizures, and cessation of activities. 11- According to Article 2, the Authority is composed of 8 members: the head of the Secretariat who acts as president, 3 representatives of the National Executive Authority, 2 from the Province of Buenos Aires and 2 from the Autonomous City of Buenos Aires. The Authority issues its organizational and operational bylaws. Likewise, Article 3 creates a Municipal Council composed of one representative of each municipality in the jurisdictions, whose objective is to cooperate, assist, and advise the entity. Article 4 creates a Social Participation Commission with consultative functions, composed of representatives of organizations with interests in the area. Finally, Article 5 states the the Matanza-Riachuelo Basin Authority has the duties of regulation, control, and promotion regarding industrial activities, the provision of public services and any other activity having an environmental impact on the basin. It may administratively intervene on matters of prevention, sanitation, recomposition, and rational use of natural resources. 12- Two aspects of Law 26.168 need to be highlighted:


a) The explicit indication that ACuMaR should be an agency that executes international loans. b) The preeminence of ACuMaR in the case of conflict with other jurisdictions. 13- Point a) is first contemplated in Article 5, clause e), which expresses that ACuMaR has the authority to “Manage and administer, as a Central Executing Unit, the funds needed to carry out the Integrated Plan for Pollution Control and Environmental Recomposition.” Moreover, Chapter III, “Financing – Environmental Compensation,” Article 9, makes explicit the “creation of an Environmental Compensation Fund that will be administered by ACuMaR and will be mainly aimed at the protection of human rights and the prevention, mitigation, and recomposition of environmental damages.” Thus, clause f) of said article refers to International Credits as one of the possible elements of the Fund. Point b), dealing with the regulation’s preeminence, is addressed in Article 6, which explains that “the faculties, powers, and duties of ACuMaR on environmental issues prevail over any others that are concurrent in the basin, and its linkage and harmonization with local authorities should be established”. To date, ACuMaR has issued the following eight resolutions: Resolution Nº 1: Permissible Limits for the Dumping of Liquid Effluents (8/31/2007); Resolution Nº 2: Parameters for the Measurement of Air Quality (8/31/2007); Resolution Nº 3: Operational Regulation of the Basin’s Social Participation Commission (8/31/2007); Resolution Nº 4: Operational Regulation on Access to Information and Receipt of Complaints (8/31/2007); Resolution Nº 5: Internal Bylaws of the Matanza-Riachuelo Basin Authority (9/12/2007); Resolution Nº 6: Appointment of the General Secretary of the Matanza-Riachuelo Basin Authority (10/25/2007); Resolution Nº 7: Organizational structure of the General Secretariat of the Matanza Basin Authority (11/22/2007); Resolution Nº 8: Approval of the Executive Summary of the Integrated Environmental Sanitation Plan (PISA) of the Matanza-Riachuelo Basin (11/22/2007).


14- Of the eight resolutions, numbers 1, 2, and 8 are directly related to the PISA. In fact, the latter is the one that approves the PISA and contains significant definitions regarding the objectives of the recomposition plan. 15- In particular, Resolution Nº 1, which unifies regulations for the control of liquid effluent dumping throughout the entire basin, assumes the displacement of old laws which now have a unified reading. This does not imply that the application of these regulations is the responsibility of ACuMaR, but rather that the latter has unified regulations under the scope of the basin for a subject specifically contemplated in the law that created it and adhered to by the three jurisdictions. Nevertheless, in a second stage, the dumping of effluents will not only consider the standards established in the unified regulation, but it will also consider the conditions of volume and concentration of polluting substances in dumping, with the uses and quality objectives established for waters in receiving bodies. 16- This is in line with the objectives of PISA, one of whose key targets is to recover and preserve the quality of bodies of surface water in the Matanza-Riachuelo Basin and in the Río de la Plata, in terms of uses and water quality objectives to be proposed, agreed, and allocated in the various sections and zones of the basin and river, in the short, medium, and long terms. 17- The strategy contained in PISA consists of proposing and reaching agreement on the uses and quality objectives for receiving bodies in the short, medium, and long terms, evaluating their implications and correlation with the AySA Sanitation Management Plan for raw sewage of domestic and industrial origin, through the application of water quality models, verifying the baseline of water bodies and the implications of sanitation efforts and works that are carried out, with the development of monitoring programs under execution with the collaboration of INA, SHN, and ILPLA in the Matanza-Riachuelo Basin and the Río de la Plata, as well as the implications of the AySA Sanitation Management Plan on the basin’s aquifers, based on the results of the study of hydrogeological conditions and groundwater quality in the MR basin that are under execution with the collaboration of UNLP. 18- Thus, ACUMAR Resolution Nº 1/2007, established for the purpose of addressing control efforts based on common limits, constitutes a transitional stage (phase 1) in a process of migration toward the new regulation (phase 2), based on a rational, coherent methodology with a comprehensive basin-level focus that considers a key element for evaluating the permissibility of dumping to be the mass load of pollutants dumped into the receiving body, together with its capacity to receive polluting substances in terms of the uses assigned or to be assigned to it. 19- ACUMAR Resolution No 1/2007 is not currently for application to the system operated by AySA and is not being applied in the evaluations of the implications of the AySA Sanitation Management Plan for raw sewage on water bodies in the Matanza-Riachuelo Basin and in the Río de la Plata.


What are applicable are the provisions contained in the AySA Regulatory Framework, together with the contemplation of mass loads of polluting sources and on the uses and quality objectives proposed for receiving bodies in the Matanza-Riachuelo Basin and in the Río de la Plata. 20- Thus, the significant authority over environmental management of the Matanza-Riachuelo Basin has simplified the basin’s management, considering that ACuMaR brings national and provincial jurisdictions (PBA and CABA) together in a single Basin Authority. 21- It is worth noting that the Basin Authority model does not assume an exercise of environmental functions “despite” jurisdictions but rather “in favor” of their interests, cooperating and overcoming the barriers that have historically hindered addressing the causes and consequences of pollution. 22- Although the above considers the central aspect of the regulatory-institutional framework, it should be remembered that there is a large amount of legislation, ranging from international to municipal levels and in national and provincial jurisdictions, which are applicable and deal with environmental aspects. For this purpose, these regulations and several aspects of interpretation are attached to Chapter 2 of the complete document of the Environmental Assessment of the Project for the Sustainable Development of the Matanza-Riachuelo Basin and its annexes. 3. The Project’s Area of Influence 23- Due to the comprehensive nature of the EIA, the definition of the area of influence has been conceived using wide-ranging criteria, using as a basis the entire Matanza-Riachuelo Basin, the area that is the subject of this project, and incorporating the different zones of direct influence of complementary works that in one way or another affect the environmental quality of the basin in general and of its surface and ground water resources in particular. As an example and for purposes of better understanding, sections of the AySA concession are included that do not belong to the same basin but whose sewer and industrial effluents are conveyed through it or dumped into it. Likewise, both sub-aquatic outfalls are located outside the basin area but are the final receptors of wastewater discharges conveyed from it. The Area of Influence for the EAI is considered to be that involving the following areas (see Fig. 3.1): The entire Matanza-Riachuelo Basin. The entire AySA concession area. The fluvial sector of the Luján River, from the mouth of the Reconquista River until its confluence into the Río de la Plata.


The sector of the Río de la Plata between the coast and the outer limit of the so-called “Paraná de las Palmas Flow Corridor,”2 to the height of the channel entering the Port of La Plata. The coastal sector between the coast of the Río de La Plata, the neighborhood access road to the river at approximately 14,000 m southeast of the boundary of the General Belgrano plant site, the Roca railroad, and the boundary between the districts of Quilmes and Berazategui. 24- The justification of the adopted boundaries is contained in Chapter 7, Numeral 2, of the EIA Report. Fig. 3.1—Area of Influence of the Project—shows the magnitude of the area involved. Fig. 3.1: Area of Influence of the Project

Source: Componente Cuerpo de Agua, ACuMaR, SAyDS. 2008 4. Environmental Baseline Setting

2 Jaime, P., Menéndez, A.N., Natale, O.E. Balance and Dinámica de Nutrientes Principales en el Río de la Plata Interior, Informe INA 10.4-01, setiembre de 2001


25- The deterioration of water quality in the principal course and in most of the tributaries in the middle and upper parts of the MR basin a result of the fact that the pollutant load dumped into the water courses greatly exceeds the capacity for dilution and self-purification. These water courses receive organic discharges, mineral and inorganic substances, heavy metals, pesticides, fungicides, herbicides, and sediments. 26- The groundwater resources related to the basin are also affected by this problem. In zones lacking sewerage, pollution may be related to water from domestic septic tanks that reaches the water table. Impacts on aquifers are also the result of the inadequate dumping of industrial wastes. 27- In the Matanza-Riachuelo Basin there are frequent floods that produce considerable losses and damage to goods and to people. Flood risks in all urban zones are a consequence of the low-lying natural terrain, insufficient rainwater drainage and deficient discharge from main pipelines, and unplanned urbanization that overtook natural drainage areas. 28- The settlement of the population in the basin responds to a progressive evolution of the location and not to a logical distribution of urban space. The social sections of the population of the highest socioeconomic level occupy the northern zone of Buenos Aires, while those with a lower economic level are located in the southern zone. 29- The basin includes the territories of 14 municipalities and of the Autonomous City of Buenos Aires, with an estimated population according to the latest Population and Housing Census (in 2001) of over 3,320,000 residents, with a forecast for 2008 of slightly more than 3,500,000 residents. 30- With regard to sanitation, the company Aguas Argentinas S.A., former concessionaire of water and sewer services in the city of Buenos Aires and 17 nearby urban districts, under a Public Services Concession Contract that became effective on May 1, 1993, signed in February 1997 an agreement on the Integrated Sanitation Plan (PSI), whose priority objective was to provide drinking water and sewerage services in the concession area. Of the total committed investment, as of March 2003 the concessionaire had only executed 24% of the works. This situation obliged the national government to rescind, through Decree 303 of March 21, 2006, the concession contract due to contract noncompliance. A new state enterprise (AySA) took over the responsibility for unmet obligations for the period of 10 years. According to information available in ACuMaR, of the basin’s total population, 60% lack sewers and 35% lack drinking water. 31- The Matanza-Riachuelo Basin zone has a historically industrial profile with over 3,600 companies located in it. The establishment of industries on the banks of water courses in the basin has a direct relationship with the possibility that the companies have had to dispose liquid effluents in it. The industrial sector is highly concentrated in the lower Riachuelo Basin where


the Dock Sud Petrochemical Hub is also located. These industries have different types of activities, but those with greater relevance due to their environmental impact are activities of the chemical, petrochemical, food, tanning, cold storage, and electrometallurgical sectors. Many industries use arsenic and heavy metals such as chromium, mercury, and lead for their production processes, all of which have been found in the waters of the Matanza or Riachuelo River in concentrations that exceed the levels permitted by relevant regulations. 32- Fig. 4.1 shows the location of 3,602 industries surveyed in August 2008 in the Matanza-Riachuelo Basin, with an indication of those that are already connected to the AySA network and those that dump their effluents into Matanza-Riachuelo Basin. Fig 4.1: The Location of 3,602 Industries Surveyed in August 2008 in the Matanza-Riachuelo Basin

33- The original concept of the management of the wastewater of the city of Buenos Aires consisted of intercepting the wastewater, conveying it to the the Berazategui District at the southwest, treating it at that point in a treatment plant and discharging the effluent into the Río de La Plata through a sub-aquatic outfall. On the basis of this program three main sewers were constructed, which convey an average flow of around 18 m3/s of wastewater to the existing outfall located in Berazategui. The Berazategui outfall, 4 meters in diameter and 2.5 km long discharges the wastewater, without prior treatment, into the Río de La Plata. The plan to construct a fourth main sewer to Berazategui, construct a treatment plant in


Berazategui, and a longer outfall at this site, with the capacity to discharge the entire wastewater flow of the Buenos Aires metropolitan zone, was never completed. 34- It is clear that the existing metropolitan area wastewater evacuation system is inadequate, since a significant portion of raw wastewater is being discharged into the rivers and tributaries that cross the metropolitan area (principally to the Matanza-Riachuelo and Reconquista Rivers) or directly in the coastal zone of the Río de La Plata. Consequently, the rivers and tributaries, as well as the coastal strip of the Río de La Plata, are highly polluted. Moreover, the length and configuration (absence of diffusers) of the existing outfall at Berazategui do not allow adequate discharge into the Río de La Plata. 35- On the basis water sampling at various point along the MR River and its tributaries and along the costasl strip of the La Plata River, and analyzing the water quality paramenters of the samples withdrawn, mathematical models for simulating the water quality of these rivers were developed, using the water quality data for calibrating of the models. Mathematical models simulate the processes of transport, dilution and transformation of pollutants in the receiving water body system. From a practical standpoint, the mathematical model has been used as a virtual laboratory, with which it is possible to evaluate the water body system’s response (distributions of the concentrations of pollutants within the water body) to the discharge of pollutants into it. 36- Mathematical models were used to in this study as the methodology for assessing the current state of contamination of the water bodies in the MR and La Plata rivers and for assessing the project’s environmental impact. Following are various numerical and graphical results of pollutant loads and responses of the system in terms of the availability of oxygen (in Matanza–Riachuelo and tributaries system) and restriction of use (in the Río de La Plata system). These results emerge from the calculation of concentration distributions of the various contaminants in the systems, conducted through water quality mathematical modeling. 37- The consequences of discharging industrial effluents to the MR system, added to those of diffused discharges (domestic sources) and point source discharges of effluents from treatment plants in operation in the MR basin, lead to the response of the MR receiving body presented in Fig. 4.2. The conditions presented in Fig. 4.2 correspond to minimum flows in the river. Anoxic conditions in the river are considered to occur when the Dissolved Oxygen (DO) concentration in the water is below 2 mg/l. 38- Fig. 4.2 shows that under the current conditions in the MR basin, during the low flow season, the MR River and most of its large tributaries are heavily polluted by organic matter and as a result suffer anoxic conditions i.e. are void of oxygen. That means objectionable appearance, generation of odor and pathogenic contamination in the river water. The river water is


also contaminated by toxic organics and heavy metals (that is not shown in Fig. 4.2). Fig. 4.2: Dissolved Oxygen Concentration in the Matanzas-Riachelo System during the Low Flow Period

39- With regard to the consequences of the current situation of discharge of wastewater to Rio de La Plata, the criterion of restriction of use as function of water quality has been applied for various types of use. In Figures 4.3 to 4.7 zones with restrictions of use due to various types of contaminants are presented. These results were also generated by the water quality mathematical model, which considers the cumulative effects of the contributions of discharges on the Southern Coastal Strip caused by the point source discharges and by the Luján River and the Paraná de las Palmas. These Figures show that currently the Southern Coastal Strip of Rio de La Plata is seriously contaminated. However, the Chromium and Lead contamination source is not the MR or basin or the city of Buenos Aires, but rather the upper basin of the La Plata River (the Parana River).


Fig 4.3: La Plata River Zone Inadequate as a Water Source for Human Consumption

Fig 4.4: La Plata River Zone Inadequate for Direct Contact Recreation


Fig 4.5: La Plata River Zone Inadequate for Indirect Contact Recreation

Fig 4.6: La Plata River Zone Inadequate for Maintaining Aquatic Life due to Chronic Toxicity


Fig 4.7: La Plata River Zone Inadequate for Maintaining Aquatic Life due to Acute Toxicity

40- The MR basin’s physical and socioeconomic features, as well as a more detailed environmental diagnostic of the basin, are presented in Chapter 5 of the EAI report. 5. Analysis of Alternatives 5.1. Conceptual framework for the development of alternatives 41- As mentioned, the original plan of transporting all the wastewater of the Metropolitan Buenos Aires to the Berazategui area was never completed. AySA (the current concessionaire of water and sewerage services for the city of Buenos Aires and 17 nearby urban districts) needs to comply with its commitment to extend the scope of its services. For that purpose it has developed a Sanitation Management Plan for its concession area, the Plan Director. 42- This concession area, which does not cover the entire area of the Matanza-Riachuelo Basin, but covers most of its urbanized area, also covers other areas of the city that are further to the north of the Matanza-Riachuelo Basin. 43- The AySA Management Plan modified the original concept of conveying all wastewater from the concession zone toward Berazategui, however, it maintains the principle of intercepting the rest of the wastewater in the


concession area and providing adequate disposal to the entire wastewater flow. 44- The AySA Management Plan did not provide for the evacuation of all wastewater from the Matanza-Riachuelo Basin toward La Plata River outfalls, but instead contemplates that part of the middle and upper basin located in the concession area would divert its wastewater to various in land wastewater treatment plants to be constructed or expanded, such as the Southeast, El Jagüel, Laferrere and Fiorito, with their effluents discharged into the Matanza-Riachuelo River. 45- In addition to domestic wastewater, the basin has a large amount of liquid industrial wastes, most of which are currently not subjected to any type of treatment. Part of them is being discharged directly into the Matanza-Riachuelo River and its tributaries, and part to the existing sewerage network. The AySA Management Plan did not take into account the comprehensive solution of the problem of basin, and therefore to achieve the basin’s effective sanitation, a broader program than the AySA Management Plan is required. 46- To understand the magnitude of this difference, the estimated future flow of wastewater in the entire Matanza-Riachuelo Basin, which according to AySA Management Plan will not reach the outlet system, is around 13.5 m3/s. All previously mentioned flows already include the contributions of industrial liquid wastes. 47- Due to the original concept of the management of the metropolitan area wastewater, and taking into account the the existing system of main conveyance of wastewater toward Berazategui, it has been necessary to seek solutions to the problem of the Matanza-Riachuelo Basin that are compatible with the existing system. This means that in terms of the treatment and disposal of wastewater to obtain environmental improvements in the Matanza-Riachuelo Basin, the sanitation of the entire AySA concession area (i.e., most of the metropolitan area of the city of Buenos Aires and the all of the city itself) should be included in this project, since the contribution or influence on the Matanza-Riachuelo Basin of raw wastewater coming from the northern parts of the city and nearby districts cannot be ignored, although geographically these northern parts are not part of the MR basin. 48- Taking into account that the Project of the Sustainable Development of the Matanza-Riachuelo Basin is aimed at achieving the comprehensive sustainable development of the entire MR basin and not only at sanitation in a part of it, the solution proposed in the AySA Management Plan is insufficient and therefore an analysis was made of alternatives that cover not only the entire basin area but a broader area (also the entire AySA concession area) and broader aspects than just the management of wastewater.


5.2. Alternatives Studied 49- To meet the requirements presented in Section 5.1, a series of viable project alternatives have been developed, each aimed at avoiding environmental damage such as the contaminating the drinking water intakes in the Río de La Plata (San Martín and Bernal plants) and supporting the environmental recovery of the Matanza-Riachuelo Basin without causing other negative effects on receiving water bodies: The alternatives developed for analysis were: 50- 1) Decentralized treatment with various plants and different levels of treatment, with effluents discharged into the Matanza-Riachuelo River, its tributaries, and the Río de La Plata. This alternative is referred to as Partially Centralized Scenario (EPC). 51- 2) Centralized treatment with a single treatment plant in Berazategui and one sub-aquatic outfall at this site. This is the original alternative that was proposed for the sanitation of the city of Buenos Aires. 52- 3) Centralized treatment with various points of discharge into the Río de la Plata. Although from a theoretical standpoint a solution with several discharge points can be adopted, in reality the number of discharge points is restricted to only two, due to the difficulty of obtaining additional treatment sites, over and above two, for such large-scale plants on the banks of the Río de La Plata. From the analysis of the coastal land strip within the city of Buenos Aires and between the mouth of the Matanza-Riachuelo and the current Berazategui Outfall, considering the location of the intake of the Bernal drinking water purification plant, the recreational sector on the Quilmes coast, and the CEAMSE sanitary landfill sector in Villa Domínico, there are no other locations for siting a wastewater treatment plant in addition to the two already.selected, with large enough areas necessary for a treatement Plant. This alternative is referred to as Totally Centralized Scenario (ETC). 53- 4) Alternatives based on different levels of treatment prior to discharge into the Río de La Plata. These alternatives involve determination of the lengths of the outfall as function of the treatment levels, since higher levels of treatment may require shorter outfalls. The outfalls lengths was determined using for the La Plata river water quality simulation model. During the development of these alternatives, their impact on the uses of the river water (source of water supply for human consumption with conventional treatment, recreational uses with and without direct contact, preservation of aquatic life, impact on navigation, etc.) was taken into account, as well as the environmental and social impact of the operation of different treatment systems (odor control, amounts of sludge generated in the various alternatives, truck traffic for sludge removal, necessary space for the plants, etc.).


54- 5). Secondary treatment followed by chlorination of the effluent and discharge of the effluent to the La Plata river using a short outfall. 55- 6) Alternatives of the main wastewater conveyance system in order to ensure the collection of the entire wastewater of the basin and of the entire AySA concession area. Among the conveyance alternatives analyzed was one with a single Left Bank Collector with the capacity to also convey all wastewater from the middle and upper basin of the Matanza-Riachuelo River toward the Riachuelo treatment plant, and another with two collectors: (i) the separate Left Bank Collector, and (ii) the Right Bank Collector with the capacity to convey all wastewater from the middle and upper basin of the Matanza-Riachuelo River to the Riachuelo pretreatment plant. 5.3 Comparison of alternatives 56- Based on the information developed for each of the alternatives, these were compared using technical, economic, environmental, and social criteria. As a result of this comparison, the most favorable alternative and its stages of execution were selected. 57- The most suitable alternative which, from a combined standpoint, offers: lower cost, technical advantages, simple operation and maintenance, greater positive environmental impacts, lesser negative impacts, and minimum negative social impacts was found to be Alternative 3, consisting of distributing the total collected wastewater flow to two sub-aquatic outfalls one located in Berazategui and the other at the southern bank of the MR river at its confluence to the La Plata River. The disadvantages of the alternatives that were not adopted are: 58- Alternative 1. Decentralized treatment, i.e., a variety of treatment plants with different levels of treatment that discharge their treated effluents into the Matanza-Riachuelos River, its tributaries, and the Río de La Plata. It was rejected due to technical reasons, based on the modeling results of the Matanza-Riachuelo River, which demonstrated that the river has a low capacity to receive large amounts of organic loads. That means that the MR River will remain anoxic even if treated effluent will be discharged to it. 59- Alternative 2. Centralized treatment with a single treatment plant and a single outfall in Berazategui. This alternative has environmental and economic disadvantages in relation to the alternative of two outfalls, and is also unviable due to legal, social and political reasons, because it discharges all the wastewater of the Buenos Aires metropolitan area in the jurisdiction of a downstream municipality and this is no longer unaccaptable. 60- Alternative 4. This is in fact a series of alternatives of different levels of treatment prior to effluents discharge into the Río de La Plata. These alternatives involve the establishment of the lengths of the outfalls as


function of the level of treatment, using for this purpose the water quality simulation model developed for Río La Plata. Simulation results demonstrate that treatment to a level higher than preliminary does not provide advantage in terms of water quality. This is compatible with the recommendation of the World Health Organization (WHO)3 which provides that from the public health standpoint of human exposure to wastewater, for discharge of wastewater to the sea through effective outfalls, additional treatment higher than preliminary prior to the discharge does not reduce risk, that is to say, the risk of a system comprised of preliminary treatment followed by an effective outfall is identical to the risk of a system comprised of secondary treatment followed by an effective outfall. The WHO report refers to risk related to human exposure through bathing, which is not exactly the risk in the case of discharge to the La Plata River. However, also in the La Plata river system, the main risk of effluent discharge is imposed by pathogenic organisms, so that the exposure risk referred to in the WHO report is a good proxy to the risk in the La Plata River. Higher than preliminary treatment levels also imply enormous additional investment costs, as well as high operation and maintenance costs, which are practically unaffordable given the large population to be serves and large wastewater flows to be treated. Higher treatment level plants also create a major problem of generating very large quantities of biological sludges. Thus, the concept of preliminary treatment plants followed by long and effective outfalls was selected as the preferred solution for the project, because it is considered a scientifically solid and economically favorable solution. However, sufficient area was reserved in the sites of the location of the Riachuelo and Berazategui treatment plants, to enable expanding the treatment plants and increasing the level of treatment, should it be required. 61- Alternative 5. Secondary treatment followed by chlorination of the effluent and its discharge into the Río de La Plata through a short outlet is a very costly alternative, much more than the one selected, and environmentally very risky because of the need to handle enormous amounts of chlorine in the middle of the city, and with a negative impact on aquatic life due to the effect of the chlorine and its byproducts. It is not reliable because it fully depends on the provision of chlorine (since the effluent can be discharged to the river only if chlorinated, otherwise it will cuase heavy pathogenic contamination thereby constituting a risk to the water supply intakes) while the continuous provision of such large amounts of chlorine cannot be assured.

3 WHO (2003): Guidelines for Safe Recreational Water Environments. Volume 12, Coastal and Fresh Waters, World Health Organization, Geneva, Switzerland, p. 80 (http://www.who.int/water_sanitation_health/bathing/srwe1/en/)


6. The Selected Alternative 62- The alternative selected for the collection, treatment, and removal of wastewater of the MR basin along with the wastewater of the concession area of AySA makes it possible to comply with the dual objective of extending and improving the level of coverage and quality of sewerage services in the Matanza-Riachuelo Basin and in the entire AySA concession area, coupled with recovering and preserving the quality of water bodies in the entire Matanza-Riachuelo Basin and in Río de La Plata, in terms of uses and quality objectives to be achieved for their various sections and zones in the short, medium and long terms. 63- The sewerage works included in the alternative selected for the sanitation of the Matanza-Riachuelo basin are essential to improve the coverage and the quality of the sewerage services in the Matanza-Riachuelo basin and in the entire AySA concession area, and to improve water quality and potential uses of the water bodies in the Matanza-Riachuelo basin and of the southern coastal strip of the Río de La Plata. The alternative selected for the sanitation component (Component 1) provides the following substantial aspects: 64- -Making available the main wastewater collection system properly dimensioned, thereby enabling to limit discharges of wastewater and effluents into inland rivers such as the Matanza–Riachuelo and protect these receiving bodies, which have limited autopurification capacity, by diverting all collected wastewater to Río de La Plata, thus making use of its major autopurification capacity for such discharges. 65- -Distributing the flow initially allocated to the Berazategui plant between two plants (Riachuelo and Berazategui) in order to provide greater flexibility and security to the main conveyance and treatment systems. The incorporation of the Riachuelo system makes it possible to divide wastewater flows and perform treatment and effluents discharge independently through both systems, thereby achieving the system’s decentralization and a lesser impact of the effluents discharged into Río de La Plata. 66- -Intercepting major dry season rainwater flows in the area served by AySA’s existing sewerage network in order to substantially reduce the pollution of the La Plata and the MR rivers. This will be performed through the use of collectors scaled to provide the necessary flexibility of exchanging flows between the Riachuelo and the Berazategui systems. 67- -Allowing all industries located in the area served by AySA which pretreat their wastewater to the required level, to connect their effluents to the sewerage network, limiting thereby the level of in situe treatment to the level which allows for connecting the the sewerage network.


68- -Allowing the entire population and all industries located in the Matanza-Riachuelo basin to be connected to the sewerage network. 69- The selected alternative is thus based on intercepting most of the domestic and industrial wastewater in the AySA concession area (except those that are diverted to the North Treatment Plant which discharges its effluent into the Reconquista River), as well as the wastewater of the municipalities in the upper Matanza-Riachuelo Basin and diverting this entire wastewater flow to Río La Plata through two new sub-aquatic outfalls: (i) an outfall located on the left bank of Sarandí creek, denominated the Riachuelo outfall, 4.7 meter internal diameter, 11.5 km long, of which the final 4 km are the diffuser zone; and (ii) a new Berazategui outfall, 3.8 meter internal diameter 7.5 km long, of which the final 3.5 km are the diffuser zone. The maximum design flows of each outfall are 38 m3/s at the Riachuelo and 25 m3/s at Berazategui. 70- Prior to discharging the wastewater through each outlet into Río La Plata, it will be subjected to preliminary treatment in two plants, one located in an area within Río La Plata (requiring landfilling), near the left bank of Sarandí creek, and the other in Berazategui near the location of the inlet structure to the existing 2.5 km long outfall. The preliminary treatment plants consist of coarse screens to retain heavy material, followed by milliscreens with 6 mm opening for removal of finer material (the milliscreens opening in the Riachuelo treatment plant might be smaller that 6 mm), followed by aerated grit chambers to remove sand and floating material such as oil and grease. Each preliminary treatment plant will be equipped with two pumping stations, one lift station at the entrance to the treatment plant and one to discharge the effluent into the Río de La Plata through the respective outfall. 71- Although the removal level of solids by the preliminary treatment plants seems to be low, their function is important since they remove important segments of the solids contained in the raw sewage, i.e,: (i) the course solids like sand and grains which, if not removed tend to settle rapidly and accumulate around the outfalls discharge points without being carried away by the receiving body water flow; (ii) coarse floatable materials like plastic bags which, if not removed, float on the receiving body’s water surface and cause aesthetic problems; and (iii) oil and grease which, if not removed, floats on the water and causes an oil layer over the water surface, which prevents reaeration and oxygen transfer into the water and may result in oxygen depletion from the water. 72- The quantities of solids which will be generated in the Riachelo treatment plant at the first stage of its operation will be about: (i) 132 m3/day solid residues; (ii) 29 to 74 m3/day sand; and (iii) 48 to 96 m3/day oil and grease, totaling about 200 to 300 ton/day solids of various types. These quantities will grow with time. 73- The quantities of solids which will be generated in the Berazategui treatment plant at the first stage of its operation will be about: (i) 86


m3/day solid residues; (ii) 19 to 48 m3/day sand; and (iii) 31 to 70 m3/day oil and grease, totaling about 140 to 200 ton/day solids of various types. These quantities will grow with time. 74- The total quantity of solids of various types which will be genarted in both treatment plants during the initial years of their operation will oscillate in the range of 340-500 ton/day. These are considerable quantities. These solids will be removed by trucks and deposited in the sanitary landfill of CEAMSE (Coordinacion Ecologia Area Metropolitana Sociedad del Estado. CEAMSE is the public company in charge of the Solid Waste Management in the city of Buenos Aires and 34 Municipalities in the Buenos Aires Province). Installations for recovery of sand for reuse and generation of energy from the oil are considered to be included in the project; however, investigations are still required before taking actions. 75- The main wastewater collection system and its distribution between the two preliminsry tresatment plants consists of the Left Bank Collector (CMI) with an approximate length of 12.5 km and 2.9 meter diameter, the Baja Costanera Bypass collector with an approximate length of 15 km and 4.5 meter diameter, as well as complementary works such as the Baja Costanera Expansion Collector (Radio Antiguo section), the Baja Costanera Expansion Collector (Federal Capital – Vicente López section), the Right Bank Collector (CMD) with an approximate length of 42 km and varying diameters (smaller in the upper basin zone and up to 3.5 meter at the lower basin zone) and a capacity in its lower stretch of 13.5 m3/s, which will receive and transport wastewater collected in the coverage area of the Southwest, Jagüel, Fiorito, and Laferrere treatment plants, respectively, and that generated in the municipalities of the Matanza-Riachuelo upper basin located outside the AySA concession area, diverting it through the Berazategui treatment plant and pumping stations to the Berazategui outfall, for discharge into the Río de La Plata. 76- Component 1 also includes the construction of primary sewerage networks (in Lomas de Zamora, Lanús, and other neighborhoods), and secondary sewerage networks in Lomas de Zamora, Lanús, A. Brown, and other neighborhoods. 77- Component 2, the industrial pollution abatement component of the selected alternative, will incorporate activities related to the Industrial Pollution Reduction associated with the generation of databases on the contributions of industrial pollutants, definition of priorities and order of implementation of Industrial Reconversion Programs (PRI), definition of discharge conditions and setting of permissible limits of pollutants in the short, medium, and long terms, specific objectives or targets to be met in the PRIs of each industry, prioritized implementation of PRIs in industrial plants with higher pollutant loads and/or greater toxic effects, implementation of real-time systems to monitor water input flows, wastewater discharge flows and concentration of polluting substances in the industrial effluents.


78- Component 3, the territorial development component, seeks to contribute to expanding appropriate urban development in the Matanza-Riachuelo river basin by improving the living conditions of the poor and the environmental quality in the territory. 79- The design of components 2 and 3 is currently limited to a conceptual level and will be further developed during project implementation. 80- Due to the scale, cost, and complexity of the project, its will be carried out with financing under the Adaptable Program Lending (APL) modality, so its different components will be carried out in sequential stages. The sanitation component will be implemented in two stages; however the EA refers to the impact of both stages. The first stage of Component 1, APL1, will consist of the following works: Left Bank Collector, the Baja Costanera Bypass Collector, the Riachuelo treatment plant, the two Riachuelo pumping stations and the Riachuelo outfall. The second stage of Component 1, APL2, will consists of the implementing following works: Right Bank Collector, Bajo Costanera aliviation collector, Berazategui pumping station, Berazategui treatment plant (not financed by the Bank), the Berazategui outfall and additional primary and secondary sewage networks. 81- Components 2, 3 will also be carried out in stages but the scope of APL2 activities will be determined at a later stage. 82- The location and staging of the works of Component 1 are presented in Fig. 6.1.


Fig. 6.1: Location and Staging of the Works of Component 1


83- Technical information regarding some works of Component 1, as well as the construction techniques and materials of construction that are expected to be used, are presented in Table 6.1. Table 6.1: Technical Information Regarding some Works of Component 1 Stage Work Section Length

(Km) Internal Diameter (m)

Construction Method

Material of construction

CMI

Aliviador Cildañes – Desvío Baja Costanera

12,50

2,9

Túnel con dovelas

Dovelas revestido con hormigón polimérico

Desvío Baja Costanera

CMI - Planta Riachuelo

7,00

5,00

Túnel con dovelas


APL1

Emisario Riachuelo

Parte sin difusor

7,50

4,70

Túnel con dovelas


Sudoeste – Desvío Baja Costanera

17,80

3,50

Túnel con dovelas


Ramal el Jagüel

11,24 2,3’0 Túnel – “Pipe Jacking”

Tubos de hormigón polimérico

Ramal Sudoeste

1,47 2,80 Túnel – “Pipe Jacking


CMD

Ramal Laferrere

11,40 2,20 Túnel – “Pipe Jacking


APL2

Emisario Berazategui

Parte sin difusor

4,00 3,80 Túnel con dovelas


84- For the method of pipe installation in a tunnel by pipe jacking, shafts are applied every 1 to 1.5 km, and for the method of pipe installation in a tunnel by segments, shafts are applied every 4 to 5 km.


7. Environmental Impacts 85- The assessment of the environmental impact of the project was prepared at two levels of disaggregation. The first corresponds to a macro-analysis of identified basic project actions that stem from a series of actions with environmental relevance which induce direct environmental effects. This first level has been used to interpret the project’s overall environmental viability. Later, based on the specific actions of the project’s different components, more specific evaluations have been made to assess particular impacts. At this second level, quantitative evaluations have been made when objective data were available (for example, the preparation of the river water quality simulation models based on data measured in the rivers) and quantitative evaluations were undertaken when data were not available. 86- The macro analysis showed that there is clear predominance of the projects positive effects over the negative effects, indicating the overall environmental viability of the project. With this in mind, specific project impacts were assessed, considearing separately impacts during the project construction stage and during its operation stage. Impacts During the Construction Stage 87- A thorough assessment of the project’s environment impact during the construction stage was carried out by AySA for the main wastewater collection system and for the two treatment and outfalls discharge systems (Riachuelo and Berazategui). The AySA EA studies form part of the EA assessment of the project. 88- The installation of main collectors and of the sub-aquatic outfalls will be done using trenchless technology methods, i.e., installing the pipes by tunneling (using pipe jacking for smaller diameter pipes of up to about 3 meter and segments installation for larger diameter pipes). The trenchless technology reduces significantly the negative environmental impacts of the works, in the sense that it concentrates the impacts to the limited areas of the attack shafts, which for pipe jacking are installed at distances of about 1 to 1.5 km along the pipe route and for segment tunneling at distances of about 5 km. 89- With regard to impacts during construction, regardless of the project components which is being evaluated, there are common impacts stemming from common construction activities (for example, transportation of sand, concrete and construction materials, earth compacting, concrete pouring, operation of construction equipment, etc.). Following are descriptions of some of these common impacts based on assessments made for the project by AySA in its “Environmental Impact Study—Preliminary tretament plant and pumping station”:


90- Air quality and odors: During the construction stage, air quality may be affected due to the increased concentration of particles and of carbon monoxide as a consequence of earth moving and machinery operation. It is to be expected that when dirt is removed as a product of excavations, there may be odors that can be considered bothersome. Another action that can generate odors is the temporary disposal of waste. These impacts were characterized as negative with a medium or moderate value. They will generally be of medium or low intensity, of brief duration, localized, appearing immediately and having a direct effect, ongoing while the operation that produces them lasts, and have a reversible effect. 91- Noise level: During the works, temporary or continuous elevation in noise levels in the area directly affected by the work may occur, resulting from the movement and operation of trucks and mechanical equipment. 92- The main sources of noise and vibrations will be: (i) manual tools; (ii) movement of personnel, light vehicles; and (iii) mobile equipment and machinery, electric generators, etc. noise impacts will be negative and have a medium or moderate effect, a low to medium intensity, an immediate effect of short duration, local scope, and intermittant occurrence while the works that generate them continue. 93- Soil quality: Soil quality may possibly be affected by leaching, dumping and hauling of solid or liquid materials that are in temporary use or are transported to their final disposal site (inputs and/or residues). The impacts that may be generated on soil quality in these cases will be moderate, of medium or high intensity depending on the type of material involved, of local scope, with a direct effect and an occasional nature, and the duration of their effects will be temporary. 94- Soil Compacting and settling: Aspects that may impact the compacting and/or settling of soils around the work site are: (i) excavations and movements of heavy machinery; (ii) temporary disposal of large volumes of materials, residues and/or debris; (iii) depression of the water table; (iv) Settling due to large-scale, heavy installations; and (v) demolition works. The impacts that may occur in these cases will be negative, of medium or high intensity, of local scope, with a direct effect and of an occasional nature; the duration of their effects will be temporary. 95- Soil Stability: During earth moving and/or excavations, the walls of ditches may cave in, thus causing the loss of soil stability, with the following potential risks: (i) risk of affecting the foundations of buildings and public facilities; and (ii) risk of affecting existing pipelines and underground infrastructure (water network, gas network, electrical a nd phone lines, etc.). The impacts that may occur in these cases will be negative, of medium or high intensity, of local scope, with direct effect and of an occasional nature, and the duration of their effects will be temporary or permanent. Although the occurrence of such impacts is highly unlikely if the works are properly designed, all necessary measures to avoid these risks must be taken into account.


96- Quality of surface and groundwater: The environmental aspects that may affect the quality of water resources during the construction stage are: (i) hauling of solids and/or liquids during the clearing of work sites; (ii) leaching, dumping, and/or hauling of solids that have been in temporary use or are transported to their final disposal site; and (iii) emission of particulate matter that may reach surface waters. The negative impacts that these activities may generate will be direct, of low to medium intensity, of short duration, of local scope, and of occasional occurrence. No negative impacts were identified in this aspect, taking into account the current baseline conditions of the water bodies in the project area. 97- Groundwater table: Available data on the relationship between the behavior of the groundwater table and the activities carried out during construction (depression of the water table, disposal of extracted water, etc.) do not make it possible to perform an evaluation of their effect. However, based on AySA’s experience in this type of works, the activities associated with the project are not expected to modify the aquifer’s behavior in the zone. 98- Resuspension of sediments during implementation of works and dredging in the rivers: One of the principal environmental impacts associated with dredging operations corresponds to the movement and resuspension of sediments that may contain significant concentrations of pollutants. In this regard, two types of impacts can be identified: (i) those caused by increased turbidity from the resuspension of solids and the increased concentration of suspended solids in the water body, with the consequent decrease in transparency, and (ii) those related to the transfer of polluting substances between solids in suspension and water, producing an increase in the concentrations of these contaminants in the aqueous phase. This impact was considered moderate to high, depending on the factor affected (especially turbidity) and the zone where dredging operations will be conducted. Of special importance will be the impact of works in the La Plate River and their potential impact on the tubidity of water in the intakes for the Buenos Aires water treatment plants. For that purpose, a mathematical simulation model for solids behaviour in the La Plata River was developed and its results are presented in the AySA EA study. This model takes into account extreme scenarios of current velocities and winds, identifies the risks and proposes mitigation measures. A mitigating effect is attributed to the fact that the outfalls will be constructed using trenchless technology, i.e., tunneling below the level of the bottom of the river. 99- Plant cover: Although it is unlikely that vegetation will be affected during the works, because since the design phase consideration and prioritization have been given so as not to affect it, accidents that damage public wooded areas or parks may occur during the construction stage. Plant cover and/or small shrubs may be affected by the installation of work sites and storage areas, the temporary disposal of surplus earth and/or work debris, and the movement of vehicles and heavy machinery. Special


care will be taken to avoid spilling pollutants that may harm vegetation. The impacts resulting from such accidents, should they occur, will be negative, direct, of variable intensity, and localized; their effects will be temporary or permanent, depending on the damage and possible occurrence. 100- Wildlife and Fauna: No significant impacts on were identified in any of the project stages, except in the accidental case of fire, in which case impacts on wildlife present in the zone may be high. 101- Ocupational safety: Due to the magnitude and extent of civil and electromechanical works, a large number of skilled and unskilled workers will be employed during project construction. Strict occupational measyres will be applied to avoid accidents. Impacts During the Operation Stage 102- With regard to the impacts associated with the project’s operation, the main impacts that need to be assessed are those related to the water quality in the rivers, i.e., in the Matanza-Riachuelo basin itself and in the final receiving body of the effluents, the Río de La Plata. 103- Dissolved Oxygen concentrations in the Matanzas-Riachelo river system during the current low flow period (before project implementation) are presented in Fig. 4.2. Fig. 7.1 presents forecasted Dissolved Oxygen concentrations in the Matanzas-Riachelo river system during the low flow period after the completion of project implenetation. This figure shows the positive impact of the project on the recovery of the water quality of the Matanzas-Riachuelo river system as a result of the implementation of the project (project implementation refers to the implementation of stages 1 and 2). 104- With regard to Río de La Plata, Figures 7.2 to 7.4 show the improvement of its water quality after project implementation. Fig. 7.2 shows the La Plata River zones inadequate for serving as a water Source for human consumption under the current conditions, before project implementation. This figure is equivalent to Fig. 4.2. The forecasted situation in therms of water quality for human consumption is shown in Fig. 7.3. This figure shows the alleviation of the risk of inadequate water quality for human consumption occurance in the intake zones of Bernal and San Martin. Fig. 7.4 provides a breakdown of specific contaminants in the zones that restrict the use of water for human consumption as presented in Fig. 7.3. It shows that most of the inadequate zone is impacted by pathogenic organisms. 105- Figures 7.4 shows the major positive impact of the project in terms of reducing pathogenic contamination in the coastal strip of Rio La Plata. Pathogens constitute a critical pollutant of the river, because organic matter discharges do not significantly modify the La Plata river’s dissolved oxygen levels. Metals and toxic substances are also not the main problem, due to the preexisting load in the river, arriving from its upstream sections.


106- Fig. 7.1 Forecasted Dissolved Oxygen Concentrations in the Matanzas-Riachelo River System during the Low Flow Period after the Completion of Project Implementation


107- Fig. 7.2 La Plata River Zones Inadequate to serve as a Water Source for Human Consumption, Current Situation without Project

108- Fig. 7.3 La Plata River Zones Inadequate to serve as a Water Source for Human Consumption, Predicted Situation after Project Implementation


109- Fig. 7.4: Identification of the Specific Contaminants that Restrict the use of Certain Zones of the La Plata River as a Water Source for Human Consumption (Forecast Situation after Project Implementation)

110- After project implementation, there is also a redistribution of zones not suitable for recreation with direct contact, alleviating part of the coastal zone and permitting its use for recreation. Also, a significant part of the coastal zone is recovered for recreation without direct contact. There is no change in the unfavorable status of chronic toxicity for aquatic life in the La Plata River, because the contribution of pollutants from the Paraná de las Palmas River (upstream of Buenos Aires) continues and is independent of the project. The reduction in the zone not suitable for aquatic life due to acute toxicity is insignificant, because the contribution of chromium from Sarandí and Santo Domingo creeks continues to be significant. Cumulative Impacts 111- The Water quality simulation runs undertaken to evaluate the project’s impact on the La Plata River were based on wastewater flow values forecasted for the next 20 years. The simulations included the impact of


both outfalls, Berazategui and Riachuelo. No other wastewater projects or water pollution sources were identified. In this respect, the assessment carried out takes into account all potential cumulative aspects. Impact of operation of the Treatment Plants and Pumping Stations 112- The preliminary wastewater treatment plants may generate odor and noise problems. Fortunately, the plants are located in isolated areas, distant for residential zones, so potential negative impacts are small. Also, modern design takes care of noise and odor problems through the use of adequate technologies (collection and treatment of odor generating gases, isolation of noise generating equipment). The pumping stations which will be constructed under the project are located in the treatment plants sites and the problems of odors and noise will be taken care of as part of managing the treatment plants. Disposal of the Solids Generated in the Treatment Plants 113- The total quantity of solids of various types (grit and sand, oil and gris, solid residues) which will be genarted by both treatment plants during the initial years of their operation will oscillate in the range of 340-500 ton/day. These are considerable quantities. These solids will be removed by trucks and deposited in the sanitary landfill of CEAMSE. The handling and transportion of such quantities of solids present environmental risks. AySA is already handling the solids generated in its wastewater treatment plants in a similar manner and has experience in that matter. Precautions need to be taken to handle the preliminary treatment plant solids according to the existing standards and, as defined in the Environmenmtal Management Plan. 114- Installations for recovery of sand for reuse and generation of energy from the oil are considered to be included in the project; however, investigations are still required before taking actions. The impact of such installations will be assessed after having taken decisions. Environmental Impacts of Component 2 (Industrial Pollution Abatement) and Component 3 (Territorial Development) 115- Although these two components will include physical interventions, the scope of works under these components and their details has not yet been determined. Consequently, it is not possible at this stage to carry out and an assessment of the environmental impact of these components. Therefore, two environmental frameworks were developed, one for each component, and they will guide the preparation of the environmental assessment of each component, which will be carried out once decision on respective works will be taken.


8. Public Consultation and Social Aspects 8.1 Stakeholder Consultation 116- As part of the project preparation process, a series of public disclosures, workshops, and focal groups have been conducted and others are being planned in order to disseminate the information on the project; to solicit stakeholder concerns; and to ensure an open process of debate and discussion about project objectives and goals. 117- A major public consultation event, organized by ACUMAR and AySA, was held in July 10, 2008 in Buenos Aires. The objective of the workshop was to present and discuss the Terms of Reference of the Environmental Impact Assessments proposed for the project. This scoping workshop was attended by 140 participants, representative of a wide range of public and private stakeholders including representatives of the National Environment Secretariat, ACUMAR, AySA, Province of Buenos Aires, municipal governments, national and local environmental NGOs, national government agencies, community organizations and professional associations. At this workshop, the terms of reference and proposed scope of work for the Environmental Impact Studies were discussed and agreed upon by the workshop participants. 118- During the workshop many questions were raised by participants and answered by the organizers (ACUMAR and AySA). In addition to the public meeting, written comments were received after the workshop and were taken into account during project preparation activities. 119- During the preparation of the economic and social assessment studies, household and communities meetings have been conducted to collect information. Important project information was also shared with the meeting participants. 120- Additional consultations and information sharing workshops are currently being planned as part of the project communication strategy and will be conducted at different project stages. A second round of public discussion of the first draft EA report is planned for September 2008. The Draft EA report will soon be made available to the public through the internet and by posting a hard copy in ACUMAR as well as in the Infoshop.


8.2 Social Impacts 121- With regard to the social impact of the Project for the Sustainable Development of the Matanza-Riachuelo Basin, studies have been conducted that make it possible to conclude that the Project will have a positive impact on the population in this basin and in the Buenos Aires metropolitan area. 122- Although a social assessment of the Project is currently underway, the preliminary results of a recent study, in which nearly 1,000 households were interviewed about their perception of the current status of the Matanza-Riachuelo River and the Río de la Plata, indicate that the project will be contributing to the solution of problems expressed by the population. 123- In fact, according to this study, “…the pollution of both rivers affects people, mainly because of damage to the environment and risks of disease, and because space for recreation is lost.” 124- Considering that the Project for the Sustainable Development of the Matanza-Riachuelo Basin will contribute to restoring the condition of said basin, the improvement of the environmental situation will have a positive impact on the health of the affected population and on spatial use. 125- Several stakeholders may perceive that they might be negatively affected by the project, among them: groups that use the river for recreation (yachting), artisanal fishermen, La Plata river navigation authorities (due to potential interference with navigation) and municipalities located downstream of Buenos Aires. In reality, all these stakeholders will benefit from the project due to the improvement in the La Plata river water quality along the river shoreline, as a result of project implementation. The communication strategy which is being developed will include actions to convey this message to the referenced stakeholders. 126- In addition, no resettlement of population is foreseen under Component 1 of the project. Pipe routes were selected to be located in public areas and will not impact private property. During construction acess to some small extentions of public areas may be temporarily restrictes, however trenchkess methos to be used for pipe laying will minimize such restrictions. Maps, satellital photos and draft designs suggest that no resettlement will be needed. 127- Since the physical interventions of Components 2 and 3 of the project have not been determined yet, a Resettlement Framework has been prepared, to be implemented if and when warranted.


9. Environmental Management Plan 128- As part of the comprehensive EIA process, ACUMAR and AySA are finalizing detailed Environmental Management Plans (EMP) which includes measures for avoiding, minimizing, mitigating and monitoring of potential project impacts. The EIA carried out for the project identifies 6 primary impacts of concern which are outlined in Table 9.1. These are: (1) Construction Impacts; (2) Impacts from potential Re-suspension of Dredged Material; (3) Spoil disposal from tunneling; (4) Facilities operations (noise, odors, traffic, etc); (5) Related to the facilities operation the management of sludge from treatment plant operation; (6) Contamination of the Rio de la Plata resulting from outfalls;


129- Table 9.1: Primary Environmental Impacts and mitigation measures found for the Implementation of the Matanza-Riachuelo Basin Sustainable Development Project. Associated problems

Issue Risk Without Mitigation

Mitigation Measure Stage/location Responsible

Construction Impacts

Construction works are associated with generation of dust, noise, visual , traffic, and other network disturbances, as well as for handling of hazardous and non-hazardous construction material

Low Construction Manual: For all the construction works a construction manual will be designed. In this manual it will be defined for the contractor how to manage environmental aspects As well, in order to avoid resettlement for the sanitation works, public areas have been selected for the designed pipe courses. The selection of construction methods will also allow to only block small public areas.

Annex in to bidding documents

AySA Contractor

Construction Impacts / Re-suspension form dredging activities

During dredging activities for the outfall construction, settled sediments from La Plata River will be re-suspended. Sediments may carry pollutants that have been settled down from past pollution events and from diverse sources.

High Based on scientific support, models have been placed in order to minimize the possible dredging impact. As well a Dredging Manual will be designed previous effectiveness: Mitigation measures have been proposed in order to reduce the environmental impact. Some of which are:

Annex in dredging bidding documents

AySA Contractor


-No continuum dredging. - Stop dredging with winds velocities higher than 30 km/h in direction to the water intakes -Stop dredging with non usual metrological or fluvial activity that generates turbulence.

Construction Impacts / Spoil disposal from excavation and tunneling

Outfalls and associated collectors will be placed underground generating considerable amount of spoil material

Low According to normal practice, and normative, the construction manual will contain a specific segment in spoil material management to reduce the possible associated environmental impact. This material will be disposed in an appropriate form

Annex in to bidding documents

AySA Contractor

Operation Impacts / Pre treatment Plants – odors, noise, and visual impacts

Operation of waste water treatment plants have been largely associated with odors, visual, and noise disturbances

Medium Location and design. Pre-treatment plants will be located in a non-residential area. Equipment will be stored within sound proof infrastructure that will also reduce visual impacts. Air will be treated in order to reduce contaminant emissions and odors through biological filters and tower absorbing systems

Design and Technical specification in the bidding document

AySA

Operation Impacts/Pre

Pre-treatment plants will retain solids mainly sand,

Medium Disposal / Reuse. At a first stage, retained solids will be disposed in

Plants operational

AySA


treatment Plants – Solids

organic matter and grease. Solids have to be properly managed, disposed and/or reused in order to minimize, traffic impacts and environmental impacts.

the Villa Dominico Landfill managed by CEAMSE4. The transport from the Plants to the landfill will be done by trucks accordingly to the existing solid waste transport rules. Alternatives uses for the solids are being studied. Sands can be recovered using sand wash procedures and latter use in construction and/or landfill operations. Organic Matter and grease can be used for energy generation, through biodigesters and incineration.

Manual will be finished previous operation of the facilities.

Operation Impacts / Outfalls

Pre-treated sewage will be diluted through diffusion to La Plata River, affecting the water quality.

High Design parameters and Water Quality Monitoring: Length and location of the outfalls were designed in order to minimize the potential impacts on La Plata River in sensitive areas taken into account the water uses quality parameters. In order to verify the correct operation of the sub-fluvial

A monitoring manual will be finished before effectiveness

AySA

4 CEAMSE: Coordinacion Ecologia Area Metropolitana Sociedad del Estado. CEAMSE is the public company in charge of the Solid Waste Management in city of Buenos Aires and 34 Municipalities in the Buenos Aires Province.


outfalls, and correct any failure, a monitoring system will be installed, previous and after construction activities.


130- The EMP for the project is organized into 5 principle programs: Prevention; Monitoring; Contingencies; Mitigation; and Capacity Building. Each program is further sub-divided into specific sub-program addressing specific issues of concern. (i) Overall institutional responsibilities 131- ACUMAR will be responsible for overall project adherence to required environmental measures under all components of the project with particular emphasis on components 2 and 3. ACUMAR will assign specific qualified staff dedicated to the management and supervision of all aspects of the EMP during project implementation period. ACUMAR will also be responsible for ensuring that periodic audits and supervision of environmental performance are carried out and they will take the lead in coordinating information disclosure and consultations (see section ii below). 132- AySA will have specific institutional responsibilities to ensure that all construction contracts for works carried out under Component 1 will have explicit requirements to ensure the minimization and avoidance of all construction related impacts. AySA will establish a specific project unit with a competent core staff to supervise the implementation of environmental management measures directly under their control and to ensure compliance of contractual obligations of contractors. AySA will also have the responsibility to ensure that future operations of all facilities are done in adherence to agreed environmental management plans. 133- Construction contractors will be required to follow Site Specific Environmental Management Plans which describe various measures to be followed at each site. It is ensilaged that each contractor will assign an environmental engineer or other suitably qualified staff to oversee compliance with the Site-specific plan on a day to day basis. (ii) Monitoring 134- Environmental monitoring will be required for all three components both during project construction and operational phases. AySA will have the primary responsibility for establishing baselines and monitoring specific works and facilities operations under Component 1. Similarly ACUMAR will have the responsibility for establishing baseline and monitoring programs associated with components 2 and 3. Naturally, these monitoring programs are mutually supportive and a large degree of coordination and cooperation is expected between the various stakeholders. (iii) Disclosure of information 135- It is expected that there will be high degree of public interest in the progress of the project and the results of monitoring activities, especially during project operations. ACUMAR and AySA will work together to ensure a close collaboration related to public disclosure of monitoring reports and


data throughout the life of the project. Both ACUMAR and AySA will establish public web-sites where periodic status reports, monitoring data, and information will be available. Stakeholders will also be able to obtain information through the environment units of both AySA and ACUMAR. 136- To the greatest extent possible information will be made available to local government and local stakeholders through the development of a comprehensive communications and outreach strategy which aims at providing regular project updates, media events, and other information campaigns at the local level. Both ACUMAR and AySA will establish communications links with concern