The aim of this research paper was to
identify whether the water quality had been influenced either by the natural environment
or by anthropogenic activities or both in the municipality of Linares, the
second largest city of the State of Nuevo Leon, NE Mexico. The superficial
water (Pablillo River) and the groundwater quality (from a fractured and a
porous aquifers hydraulically interconnected) were determined by comparing their chemical
composition with maximum permissible limits for water consumption and
irrigation use. A hydrogeochemical modeling was performed to identify the
distribution of aqueous species responsible for the presence of some dissolved
or precipitated mineral species, as well as an identification of geochemical
factors responsible of superficial and groundwater quality. A canonical
correspondence analysis was allowed to determine if the natural environment and/or anthropogenic
activities were responsible for water quality. The parameters analysed in both aquifers, as well
as in the Pablillo River, were total solids, suspended solids, nitrate, and
chloride; barium and mercury were present in both aquifers. As a natural influence,
the predominant mineral species are as following: under-saturated anhydrite (porous aquifer),
over-saturated aragonite, calcite, dolomite, and gypsum (both aquifers and
Pablillo River), barite and whiterite (only in fractured aquifer). The geochemical
factors responsible for natural contamination were rock dominance (fractured
aquifer), and evaporation dominance (porous aquifer, Pablillo River). On the
other hand, anthropogenic activities such as changes in soil use and the
presence of point (old municipal landfill, pig farms, barite deposit), and diffuse
(agricultural areas, septic tanks and latrines) pollution sources had influence
in the presence of contaminants such as total and fecal coliforms, nitrates,
chlorides, mercury and barium. Several control and remediation strategies
should be taken into account to prevent this pollution in the future.