Since the early 1990s, RGISC has actively worked with officials in Nuevo Laredo and the United States to decrease the amount of untreated wastewater that is discharged into the Rio Grande.

Construction of the binationally-funded Nuevo Laredo International Wastewater Treatment Plant in 1996 has reduced that amount from 25 million gallons per day (MGD) to 5 MGD.

RGISC continues to advocate on behalf of the river to end the remaining discharges, because of how it contributes to significantly high bacteria levels, namely E-coli and fecal coliforms.