Quantifying the pollutant load into the Southern California Bight from Mexican sewage discharges from 2011 to 2020

Sewage discharges into the ocean are one of main sources pollutant load on coasts, resulting in health risks and ecological deterioration. The Southern California Bight runs from Point Conception (USA) to Punta Colonet Baja (Mexico). impact U.S. sewage bay is well-documented, much less exist about Mexican discharges. Official wastewater quality results for 17 treatment plants (WWTP) Tijuana-Rosarito, 2011 2020 presented first time. average flow during these years was 3,421 L s −1 , covering discharge 2,049,413 people. Water compared with current Norm ocean. It found that only 53% samples complied all normed parameters, while 88% specifically trace metal concentrations. Among parameters above norm were fecal coliforms, total suspended solids, chemical biochemical oxygen demand (COD BOD). San Antonio de Los Buenos WWTP accounts 80% BOD Tijuana-Rosarito WWTPs, 76% COD, 84% solids (TSS), 54% nitrogen (TN), 55% phosphorous (TP) These represent mean yearly 150 tons TN, 27 TP, 528 TSS, 401 1,191 COD. Immediate action needed stop high loads Pacific coast.