Guadalajara drinking water under alert for toxins from Lake Chapala.
Specialists warn that the water supplying the Guadalajara Metropolitan Area contains toxic microalgae without adequate monitoring.
A risky scenario is currently being presented in the drinking water supply in the Guadalajara Metropolitan Area (ZMG), where toxins emanating from Lake Chapala, as a result of a harmful algal bloom, are of growing concern.
The Intermunicipal System of Potable Water and Sewerage (SIAPA) is not carrying out systematic monitoring and specific treatment processes to mitigate the presence of these harmful substances in its water treatment facilities.
According to Eduardo Juárez Carrillo, director of the Institute of Limnology of the University Centre of Biological and Agricultural Sciences of the University of Guadalajara, the microalgae detected in the lake generate a toxin known as microsystin, which can pose a health risk to the inhabitants.
‘The 6.5 cubic metres that are taken per second from the lake to Guadalajara arrive in this area and go to the city’s treatment plants, there is no security, in fact, SIAPA does not do it, it is not measuring whether microsystins are arriving in Lake Chapala.”
“SIAPA’s water treatment processes are many, among them we find flocculation and oxidation, which greatly lowers the levels of Lake Chapala. However, with two thousand cells we can have problems if we have moments of around 30 million cells per litre,” he said in an interview with El Occidental.
Toxins enter directly into the treatment plants without effective supervision. According to Juárez Carrillo, SIAPA does not measure the levels of microsystins in the water extracted from Lake Chapala, which generates uncertainty about the quality of the liquid that reaches homes.
The specialist explained that, although treatment processes such as flocculation and oxidation can reduce contamination, the current levels of microalgae in the lake are worrying.
“Already with two thousand cells we can have problems, and we are at moments of up to 30 million cells per litre.”
In addition to pollution, Lake Chapala faces an ecological crisis due to the proliferation of water lilies and the presence of invasive species such as bass, tilapia and carp, which affects native species such as charales.
“We found that almost all the bass we tested had char in their stomachs. It has been documented that this species is a very active predator, not only of char, but also of tilapia and crustaceans that live on the bottom of the lake,” Juárez Carrillo explained.
Regarding water levels, the rainy season is expected to bring an additional 50 to 100 millimetres, which would allow the lake to reach 65% of its capacity. Although this represents an improvement, the optimum level should be around 75%, according to specialists.
Despite the increase in the volume of water, at the end of the low water level, the surface temperature of the lake could decrease by up to 48%, which would further affect the ecosystem and the stability of the species that inhabit it.
