Evaluación de la Calidad del Agua de la Ciénaga Mallorquín y del Arroyo León, norte
de Colombia
Authors: Guzmán-Tordecilla Maria , Enamorado-Montes Germán , Elles-Pérez Cindy , Ramos De la Hoz Yuliceth , Castillo Ramírez Margarita , Medina-Altahona Jhorma , Díaz-Hernández Linda , Garzón Rodríguez Carolina , Burgos-Núñez Saudith , Paternina-Uribe Roberth 
Published: February 2025

The Mallorquín swamp is an ecologically significant area and a strategic
ecosystem, providing environmental goods and services to the surrounding communities.
However, it is subject to substantial pollutant loads that affect its water quality. The
objective of this study was to assess the current water quality of the Mallorquín swamp
and the León stream using physico- chemical, microbiological parameters, and water
quality indices. Three monitoring campaigns were conducted, representing the rainy,
transitional, and dry seasons. For the León stream, five monitoring sites were
established, while nine sites were defined for the Mallorquín swamp. Water sampling was
carried out fo- llowing Standard Methods in heavy metals, polycyclic aromatic
hydrocarbons (PAHs), and emerging contaminants (ECs) were analyzed. The results showed
that for the León stream, pH was influenced by the sampling season, with values ranging
from 6.6 to 7.5 during the rainy season, significantly lower than those in the
transitional and dry seasons (7.6 - 7.8). In the Mallorquín swamp, electrical
conductivity was significantly lower during the rainy season (33.4 mS/cm) compared to
the transitional (54.4 mS/cm) and dry seasons (51.8 mS/cm). Both water bodies were
dominated by total dissolved solids, with con- centrations ranging from 456 to 2755 mg/L
for the León stream and from 16286 to 97113 mg/L for the Mallorquín swamp. Se- ttleable
solids ranged between < 0.1 and 1.0 mL/L, while total suspended solids concentrations
ranged from 22 to 321 mg/L, with an overall average of 103 mg/L. Ammoniacal nitrogen and
Kjeldahl organic nitrogen were the dominant nitrogen species in the León stream, with
19.89 and 23.31 mg/L averages. At the same time, nitrates were dominant in the
Mallorquín swamp with a mean concentration of 4.31 mg/L. 23 Capítulo 1: Evaluación de la
Calisas del Agua de la Ciénaga Mallorquín y del Arroyo León, norte de Colombia The main
pollutants in the León stream were Biochemical Oxy- gen Demand (BOD5), Chemical Oxygen
Demand (COD), total coliforms, and Escherichia coli, with average concentrations of 103
± 54 mg/L, 150 ± 105 mg/L, 2.1x106 ± 2.3x106 MPN/mL, and 6.6x105 ± 6.8x105 MPN/mL,
respectively. In the Mallorquín swamp, the main pollutants were COD and total coliforms,
with average concentrations of 58 ± 58 mg/L and 6.6x105 ± 1.1x106 MPN/mL, respectively.
At some monitoring sites in the León stream and Mallorquín swamp, Cd concentrations were
found between 0.003 and 0.005 mg/L, only during the rainy season. Additionally, As was
detected at concentrations up to 1.6 mg/L in the León stream, exceeding the permissible
limits for livestock and agricultural use established in Colombian regulations. PAHs and
ECs such as methyl dihydrojasmonate, galaxolide, tonalide, and bisphenol A were not
detected in the water of either water body, while the detection frequencies for ECs such
as naproxen, ibuprofen, caffeine, and heptachlor were 15, 13, 8, and 5%, res- pectively.
The predominant categories for the ICA and ICOMO indices were “acceptable” and “good,”
while for the ICOSUS, the cate- gories “very poor” and “poor” prevailed. The results
demonstrate the organic and microbiological contamination of the Mallorquín swamp and
the León stream, and the data obtained in this study constitute the first report of
emerging contaminants in both water bodies.