Copalo Chalco Wastewater Treatment Plant, Zojualo, San Luis Potosí

Copalo Chalco is a municipal wastewater treatment plant located in Zojualo, within the municipality of Axtla de Terrazas, San Luis Potosí, Mexico. The plant serves a small population of 1,825 residents, reflecting its role in a rural or peri-urban community. Its location in the Huasteca region places it within a tropical climate zone with significant seasonal rainfall. The plant provides secondary treatment, which is the standard biological treatment level for municipal wastewater in Mexico under NOM-001-SEMARNAT-1996 regulations. With a designed capacity of 172.80 cubic meters per day and a matching discharge volume, the plant operates at full capacity. For small agglomerations like this, secondary treatment is typically sufficient to meet environmental standards for discharge into inland water bodies. The treated effluent from Copalo Chalco likely discharges into a local stream or river that forms part of the Pánuco River basin, which drains into the Gulf of Mexico. The plant helps protect downstream water quality in a region known for its diverse aquatic ecosystems and agricultural activities. Proper wastewater management is critical to prevent nutrient pollution and safeguard both human health and the environment.

The plant's treated effluent likely enters a tributary of the Pánuco River, one of Mexico's largest river systems, which flows into the Gulf of Mexico. This watershed supports diverse aquatic life, including fish and migratory species, and is used for irrigation and recreation. The region's tropical climate and seasonal rains can increase runoff and pollution risks, making effective wastewater treatment essential for maintaining water quality in downstream ecosystems.