Challenges and Opportunities on Urban Water Quality in Mexico City
Por:
Mazari-Hiriart, Marisa, Tapia-Palacios, Marco A., Zarco-Arista, Alba E., Espinosa-Garcia, Ana C.
Publicada:
29 oct 2019
Categoría:
Environmental science (miscellaneous)
Resumen:
Mexico City has a population of 9 million inhabitants and was settled on
a lakebed with high seismic potential. It is currently embedded in the
Mexico City Metropolitan Area, which encompasses 22 million inhabitants
and which was self-sufficient in water in the past, but currently
extracts 70% from the regional aquifers and imports about 30% of the
water required by this megacity. Groundwater represents its main water
source but its water quality is increasingly threatened. The purpose of
this study was to determine the water quality in areas related to
seismic fractures, which may increase the vulnerability of water
provision, and to identify specific zones that could be affected.
Official water quality data from the period 2002 to 2017 was analyzed
and compared to recent data taken in wells in the city after the
September 2017 earthquake. Physicochemical parameters were determined
and compared to the existing data. Statistical and temporal analyses
were performed in order to understand the evolution and spatial
distribution of water quality. The results show that free chlorine was
below the limits according to the Mexican regulatory framework, while
the presence of fecal coliforms, aluminum, ammonia, iron, and manganese
exceeded the standards. The presence of arsenic, boron, and chrome was
detected in some areas. Clusters show specific parameters that increase
with time: turbidity, sulfates, nitrates, arsenic, manganese, lead, and
iron. These tendencies could imply the deterioration of groundwater
quality and a potential effect on the health of the exposed population.
Spatially, vulnerability was observed in lztapalapa, Tlahuac,
Xochimilco, and Coyoacan. Wells coincide spatially with some of the
geological damaged areas from the earthquakes in lztapalapa and
Xochimilco. In addition to water quantity, water quality represents a
challenge for the urban future, since water disinfection systems are
limited to treating the diversity of compounds detected. The water
quality-monitoring program must be changed to improve its capacities
within a framework of sustainable water management in different regions
of the city, and based on the season, considering the potential exposure
to the city's population. This represents an opportunity to propose a
strategic plan for the groundwater system in order to improve conditions
toward a more equitable and sustainable pathway for Mexico City.
Filiaciones:
Mazari-Hiriart, Marisa:
Univ Nacl Autonoma Mexico, Lab Nacl Ciencias Sostenibilidad, Inst Ecol, Mexico City, DF, Mexico
Tapia-Palacios, Marco A.:
Univ Nacl Autonoma Mexico, Lab Nacl Ciencias Sostenibilidad, Inst Ecol, Mexico City, DF, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencias Biol, Mexico City, DF, Mexico
Zarco-Arista, Alba E.:
Univ Nacl Autonoma Mexico, Lab Nacl Ciencias Sostenibilidad, Inst Ecol, Mexico City, DF, Mexico
Espinosa-Garcia, Ana C.:
Univ Nacl Autonoma Mexico, Lab Nacl Ciencias Sostenibilidad, Inst Ecol, Mexico City, DF, Mexico
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