A group of Democratic senators and San Diego County-based congressional representatives sent a letter to multiple federal agencies Tuesday urging them to address sewage runoff in the Tijuana River, which then flows into the Pacific Ocean. California Sens. Kamala Harris and Dianne Feinstein and Reps. Juan Vargas, D-San Diego, Scott Peters, D-San Diego, Susan Davis, D-San Diego, and Mike Levin, D-Dana Point, co-signed the letter addressed to the directors of the U.S. Department of State, Environmental Protection Agency, Customs and Border Protection, Army Corps of Engineers and the U.S. section of the International Boundary and Water Commission, which oversees bodies of water that traverse the U.S.-Mexico border.