Mapping of Nitrate Contamination (NO3-) in an Urban Area on the Brazil/Bolivia Border

Abstract

The objective of this research was to map and evaluate nitrate contamination in an urban area on the Brazil / Bolivia border. The evaluation of the groundwater table occurred in the water of cacimbas wells or Amazonian wells with an average depth of 10 meters in the city of Nova Mamoré, in the State of Rondônia, located in the southern region of Western Amazonia bordering the Republic of Bolivia. METHODS: Eighty (80) water samples were collected in the city's urban center, defined and evaluated for nitrate (NO3 -) in a proportion above or below the values defined by Ministry of Health Ordinance No. 2.914/2011, which governs standards of water standardization and potability in Brazil. From the data obtained, maps with georeferenced information were made to locate the areas with the highest and lowest contamination potential. The use of geostatistics assisted in the accomplishment of the spatialization of the samples and in the analysis of the spatial patterns allowing a higher quality of the generated data. Results: Sixty-two and a half percent

Nitrate Concentration (NO3-) in Groundwater of the Urban Area of Nova Mamoré - Rondônia in the Brazil / Bolivia Border

“…A study by Paraguassú-Chaves et al [14] in the region of the Brazil / Bolivia border had already found that in the first large pre-flood / flooding area of the Madeira River and its tributaries in 50% of samples, high levels of N nitrate (NO3-), above 10 mg/L, characteristic of waters with high degree of impaction. Water not suitable for human consumption.…”

“…In 70% of the samples, a content higher than 3 mg/L was detected, which characterizes water with a high degree of impaction, although it is not close to the results found in the areas of situation I, an area impacted by flooding / flooding of the Madeira River. [14]. The precarious infrastructure conditions, the use of Amazonian well water and tubular wells without maintenance and close to the septic and black wells are conditioning and / or determinant for this scenario [14].…”

“…[14]. The precarious infrastructure conditions, the use of Amazonian well water and tubular wells without maintenance and close to the septic and black wells are conditioning and / or determinant for this scenario [14]. In Rondônia, Brazilian Amazonia, other researches have presented results that demonstrate elevated levels of nitrate in urban and rural groundwater.…”

“…The main constraints are as sources of contamination to the anthropic and multi-point action of the in situ sanitation system, type septic tank and black cesspits, exposure and precariousness of the wells, exposure of solid waste, sewage discharge of all nature. Thus nitrate (NO3-) contamination occurs in urban areas in the Amazon region and on the border with Bolivia [14]. Allied to all these conditions the flooding / flooding of the abundant water courses in the region are determinant to aggravate the contamination of the water table.…”

“…The population is consuming water with a high degree of nitrate contamination. It alerts itself to a public health issue [14]. According to Barata [15] the municipality of Nova Mamoré lies between the parallels 09º 30 'S and 11º00' S, and Meridians 63º30'W and 65º30'W, located about 270 km southwest of the capital of Porto Velho, State of Rondônia.…”