An integrated chemical and biological approach for the quality assessment of freshwater resources in a vineyard area of the ‘Alentejo’ region (South Portugal) is presented. This includes analysis to 11 pesticide compounds and whole toxicity testing on algae and crustaceans. Simazine, terbuthylazine, terbutryn, desethylatrazine and chlorpyrifos were the most frequently detected pesticides in water collected from wells and drainage channels. Mixtures of up to three compounds in different qualitative combinations were also found. The quality standards for individual pesticides (0.1 μg L − 1) and pesticides-total (0.5 μg L − 1) were exceeded in some samples. However, their maximum concentrations were lower than the WHO guidelines, the USEPA health advisory values and the environmental quality standards for priority substances applicable to surface water. In five samples, the herbicides terbuthylazine and terbutryn and the insecticide chlorpyrifos did not pass the toxicity exposure ratio (TER) trigger values specified for aquatic organisms (algae, Daphnia and fish). Maximum toxic effects on Daphnia magna (100%) and Pseudokirchneriella subcapitata (82.56%) were determined in groundwater samples, while in surface water, no toxicity was observed. Concerning effects on Heterocypris incongruens in sediment samples collected at the drainage channels, mortality and growth inhibition values were below 38%. Pro-active management of the use of pesticides is recommended for implementing at the farm and catchment level to reduce inputs into ground- and surface water.

Taking in account the hydrogeologic characteristics and the intensive agricultural occupation, on 3rd September of 2004, through Portaria 1100/2004, the Northern Tagus alluvium was defined vulnerable zone to diffuse pollution with nitrates from agricultural source (ZVT). This region enclosing Golega, Alpiarca, Santarem, Chamusca, Vila Nova da Barquinha, Constância and Torres Novas councils, has an approach area of 19124 ha not integrating the Paul de Boquilobo protection area. Currently, ZVT is to be studied in the scope of the project AGRO 530 entitled “Intervention Plan and Support Decision System Development for the Northern Tagus Alluvium”. With the beginning in July of 2004, the institutions “Instituto Superior de Agronomia” (ISA) (Coordination), “Instituto Superior Tecnico” (IST) and “Direccao Regional de Agricultura do Ribatejo e Oeste” (DRARO) participate in this project. From the moment that an area is designed as vulnerable zone, one of the procedural obligations is the elaboration of an action plan (according to the Decree-Law 235/97, article 7o). One of the objectives of this project is to contribute for one correct implementation of the plan towards a sustainable and socially acceptable agriculture. The work, that now is presented, intends to divulge the outlines of this project. The results already obtained on the groundwater quality in the vulnerable zone, mainly concerning nitrates and pesticides contamination, show that in the involving areas of Golega, Azinhaga and Chamusca occur nitrates levels much higher than parametric value of 50 mg/ l of NO 3-, and that in a total of 89 groundwater samples, collected in 2004, in 27% were detected at least one of the pesticides and/or metabolites, being that, in 146 groundwater samples collected in 2005, the detection frequency of, at least, on pesticide and/or metabolite, it was of 38%. These results reinforce the development need of support decision systems, particularly for the sustainable nitrogen fertilizer and pesticide use in the main cultures of the ZVT.

Em virtude das características hidrogeológicas e da ocupação agrícola intensiva, no dia 3 de Setembro de 2004, através da Portaria 1100/2004, o sector norte da zona aluvionar do Tejo foi designado zona vulnerável à poluição difusa de nitratos de origem agrícola (ZVT). Esta região abrangendo os concelhos da Golegã, Alpiarça, Santarém, Chamusca, Vila Nova da Barquinha, Constância e Torres Novas tem uma área aproximada de 19.124ha não estando contudo integrada a área protegida do Paúl de Boquilobo. Actualmente, a ZVT está a ser estudada no âmbito do projecto AGRO 530 intitulado “Plano de Intervenção e Desenvolvimento de um Sistema de Apoio à Decisão para o Norte da Zona Aluvionar do Tejo”. Com início em Julho de 2004, participam neste projecto, o Instituto Superior de Agronomia (ISA), que coordena, o Instituto Superior Técnico (IST) e a Direcção Regional de Agricultura do Ribatejo e Oeste (DRARO). A partir do momento em que se designa uma área como zona vulnerável uma das obrigações processuais é a elaboração de um plano de acção (segundo o Decreto-Lei 235/ 97, artigo 7º). Um dos objectivos deste projecto é contribuir para uma correcta implementação daquele plano de maneira a que nessa zona se pratique uma agricultura sustentável e social-mente aceitável. O trabalho, que agora se apresenta, pretende divulgar as principais linhas de força desse projecto. Os resultados já obtidos sobre a qualidade da água subterrânea naquela zona vulnerável, principalmente no que respeita à contaminação por nitratos e pesticidas, mostram que nas áreas envolventes da Golegã, da Azinhaga e da Chamusca ocorrem teores de nitratos muito acima do valor legal de 50 mg/l de NO3, e que num total de 89 amostras de água subterrânea, colhidas em 2004, em 27% foram detectados pelo menos, um dos pesticidas e/ou metabolitos analisados, sendo que, em 146 amostras de água subterrânea colhidas em 2005, a frequência de detecção de, pelo menos, um pesticida e/ou metabolito, foi de 38% Estes resultados reforçam a necessidade do desenvolvimento de sistemas de apoio à decisão, particularmente para o uso sustentável de fertilizantes azotados e de pesticidas nas principais culturas da ZVT.Taking in account the hydrogeologic characteristics and the intensive agricultural occupation, on 3rd September of 2004, through Portaria 1100/2004, the Northern Tagus alluvium was defined vulnerable zone to diffuse pollution with nitrates from agricultural source (ZVT). This region enclosing Golegã, Alpiarça, Santarém, Chamusca, Vila Nova da Barquinha, Constância and Torres Novas councils, has an approach area of 19124 ha not integrating the Paúl de Boquilobo protection area. Currently, ZVT is to be studied in the scope of the project AGRO 530 entitled “Intervention Plan and Support Decision System Development for the Northern Tagus Alluvium”. With the beginning in July of 2004, the institutions “Instituto Superior de Agronomia” (ISA) (Coordination), “Instituto Superior Técnico” (IST) and “Direcção Regional de Agricultura do Ribatejo e Oeste” (DRARO) participate in this project. From the moment that an area is designed as vulnerable zone, one of the procedural obligations is the elaboration of an action plan (according to the Decree-Law 235/97, article 7º). One of the objectives of this project is to contribute for one correct implementation of the plan towards a sustainable and socially acceptable agriculture. The work, that now is presented, intends to divulge the outlines of this project. The results already obtained on the groundwater quality in the vulnerable zone, mainly concerning nitrates and pesticides contamination, show that in the involving areas of Golegã, Azinhaga and Chamusca occur nitrates levels much higher than parametric value of 50 mg/ l of NO 3-, and that in a total of 89 groundwater samples, collected in 2004, in 27% were detected at least one of the pesticides and/or metabolites, being that, in 146 groundwater samples collected in 2005, the detection frequency of, at least, on pesticide and/or metabolite, it was of 38%. These results reinforce the development need of support decision systems, particularly for the sustainable nitrogen fertilizer and pesticide use in the main cultures of the ZVT.

Maria Paula MENDES Eng.a dos Recursos Hidricos, Mestre de Georrecursos, CVRMIST, Av. Rovisco Pais, 1049-001 Lisboa, +351 21 8417830 Luis RIBEIRO Eng.o de Minas, Professor Auxiliar do IST, CVRMIST, Av. Rovisco Pais ,1049-001 Lisboa,+351.21.8417247, nlrib@alfa.ist.utl.pt Eduardo PARALTA Geologo, Mestre de Georrecursos, CVRMIST, Av. Rovisco Pais, 1049-001 Lisboa,+351.21.8417247, eduardo.paralta@ineti.pt Sofia BATISTA Eng.a Agronoma, Professora Auxiliar do ISA, DPPF/SAPIISA, Tapada da Ajuda, 1349-017 Lisboa, +351 21 3653221, sofiabatista@isa.utl.pt Emilia SILVA Eng.a Agronoma, Mestre em Quimica Analitica Aplicada, DPPF/SAPIISA, Tapada da Ajuda, 1349-017 Lisboa, +351 21 3653221, emiliasilva@isa.utl.pt Maria Jose CEREJEIRA Eng.a Agronoma, Professora Associada do ISA, DPPF/SAPIISA, Tapada da Ajuda, 1349-017 Lisboa, +351 21 3653221, mcerejeira@isa.utl.pt Pedro LEAO DE SOUSA Eng.a Agronomo, Professor Catedratico do ISA, Tapada da Ajuda, 1349-017 Lisboa, +351 21 3653221, pleao@isa.utl.pt

The aim of this study was the groundwater evaluation to pesticide compounds and nitrates in oriziculture areas of the 'Baixo Sado' region ( Portugal), based on their use, predictive approaches, and field and laboratory work. One or more of the pesticide compounds analysed (chlorfenvinphos, cycloxydim, 3,4-dichloroaniline, endosulphan, MCPA, molinate, oxadiazon, profoxydim, propanil) were detected in 62% of 171 water samples collected from 22 wells used for public supply, domestic supply, and irrigation, during 2002 and 2003. From the total samples, 6% presented maximum concentration levels of at least one of the compounds above 0.1 mu g L-1. Mixtures of pesticide compounds were observed in 25% of the total groundwater samples, with up to five substances being detected in each one. The concentration sum of all was above 0.5 mu g L-1 in four water samples. All the analysed compounds, with the exception of the insecticide chlorfenvinphos, occurred in groundwater. Molinate was the most frequently detected (55%), particularly with maximum concentration levels above 0.1 mu g L-1. Detection frequencies were higher in water samples collected from irrigation wells (78%). Groundwater exposure to total pesticides and nitrates was analysed. Maximum concentration levels were 59.6 mu g L-1 and 183 mg L-1 NO3-, respectively. A seasonal variation pattern could be observed for both parameters in water samples collected from some wells. The results from this study show that sustainable use of pesticides and nitrogen fertilizers is required in order to achieve an overall contamination reduction from these compounds in the aquatic environment.

Pesticides used in Portuguese agricultural areas have been found in surface and ground waters. In the surface water collected in three river basins from 1983 to 1999, insecticides and herbicides were detected from the monitored pesticides, particularly atrazine, chlorfenvinphos (Z+E), alpha- and beta-endosulfan, lindane, molinate and simazine, reaching the maximum values, respectively, of 0.63, 31.6, 0.18 microg/L (alpha-endosulfan), 0.18 microg/L (beta-endosulfan), 0.24, 48 and 0.3 microg/L. In the ground water collected from the wells of seven agricultural areas from 1991 to 1998, several monitored herbicides were detected: alachlor, atrazine, metolachlor, metribuzine and simazine, reaching the maximum concentration values of 13, 30, 56, 1.4 and 0.4 microg/L, respectively. The herbicides more frequently detected were atrazine (64%), simazine (45%) and alachlor (25%). Other than these, the monitored pesticides can be present in Portuguese surface and ground waters. Therefore, to improve the analytical conditions, the use of multiresidue methods and automated techniques are desirable in future work.

In two Portuguese agricultural areas, "Beira Litoral" and "Ribatejo e Oeste", several pesticides regularly applied in vineyards, maize, potato, tomato for industry, apple, pear and rice were detected in ground water.Atrazine was the most frequently detected, being found in 70% of the total of 79 sites selected in the year 2000, followed by its metabolites desethylatrazine and desisopropylatrazine with frequencies of detection, respectively, of 56% and 48% and by simazine (37%), alachlor (25%), metolachlor (24%) and metribuzin (15%). Other pesticides and metabolites i.e. 3,4-dichloroaniline, dimethoate, alpha and beta-endosulfan, lindane, molinate and prometryn were also detected but at lower occurrences. Pesticides were detected mainly in ground water wells used for irrigation purposes, although in some locations they were also found in water wells used for human consumption. In this study, it was also observed a seasonal variation of pesticide residues in ground water of shallow and deep wells.

In irrigated maize areas of an important Portuguese agricultural area, Ribatejo and Oeste Region, alachlor, atrazine and metolachlor were detected in ground water. During the study performed from 1996 to 1998 atrazine was the herbicide that showed the highest frequency of detection. In the 177 ground water samples collected 62% were contaminated with atrazine, 30% with alachlor and 12% with metolachlor. All these herbicides were detected both in ground water for human consumption and for irrigation, in some cases above 0.1 ug/L. The maximum levels quantified were 13μg/L for alachlor, 30μg/L for atrazine and 56 μg/L for metolachlor. Seasonal variation of residues in ground water it is also presented through several examples of studies performed during the period 1991–1999.

Resumo As potencialidades dos Sistemas de Informacao, ao nivel do processamento e analise de dados georeferenciados e da criacao de Sistemas de Apoio a Decisao, constituem modernas ferramentas de gestao e ordenamento do territorio com aplicacao crescente em todas as areas das Geociencias e do Ambiente. No seguimento de varios estudos, realizados entre 1991 e 2000, sobre contaminacao dos aquiferos por pesticidas e nitratos, na zona do Ribatejo, foram aplicadas metodologias apoiadas por suporte informatico para avaliacao da vulnerabilidade/susceptibilidade dos aquiferos a poluicao e apresentados os respectivos mapas de qualidade ambiental relativamente aos teores de nitratos e alguns herbicidas, particularmente de alacloro, atrazina, metolacloro, metribuzina e simazina na agua subterrânea. Os resultados obtidos constituem instrumentos fundamentais na gestao dos recursos hidricos subterrâneos e inclusivamente no estabelecimento de redes de monitorizacao adequadas em aquiferos vulneraveis.

From 1996 to 1998, residues of simazine, metribuzine and nitrates in ground water (irrigation and drinking) were monitored in wells of the main vineyard, apple and pear orchards, potato and tomato growing areas of "Ribatejo e Oeste";, an important agricultural region of Portugal. Of a total of 214 samples collected in nine different areas, simazine was the most frequently detected herbicide. It was measured in 96 water samples (44.9%) and reached a maximum concentration of 0.43 μg/L. Metribuzine was found in 15.4% of the samples with a maximum concentration of 1.45 ug/L. Levels of metribuzine and simazine above 0.1 ug/L were found respectively in 4.7% and 6.1% of the total number of analysed samples. Only residues of simazine were detected in ground water for human consumption. Nitrates were also analysed and levels above the maximum concentration of 50 mg/L were found in some areas, reaching a maximum concentration value of 276mg/L.