State water officials proposed a $50,000 fine on Friday against the San Diego Association of Governments for allowing sediment from a construction project in Rose Creek to flow into Mission Bay.
The San Diego Regional Water Quality Control Board complaint alleges that SANDAG failed to implement routine management practices to prevent the runoff in September.
"It's surprising that an organization with so much experience in linear construction projects would let this happen," said Chiara Clemente, the water board's enforcement coordinator. "The proposed penalty would have been much greater, had they not been responsive in implementing the necessary management measures."
The runoff was reported to the water board by a citizen, and SANDAG's contractor fixed the problem. The contractor was realigning railroad tracks near Regents Road, Jim Linthicum, SANDAG's director of mobility told City News Service.
"This is the first instance this has happened," Linthicum said about the fine. "We're trying to figure out the process and procedures."
He said the project involved grading work, and a rainstorm overwhelmed erosion barriers.
Water board officials said excess sediment can alter or obstruct flows, resulting in flooding, and it can damage local ecosystems.
Abnormally high levels of sediment in the water can smother aquatic animals and habitats, and it can reduce the clarity of water, which harms the ability of organisms to breath, find food and refuge, and reproduce, according to the water board.
Sediment can also act as a binder, carrying toxic constituents such as metals, pesticides and other synthetic organic chemicals into rivers, bays and the ocean.
With anticipated El Niño rains just around the corner, the water board has been urging construction site operators and others to take necessary precautions.
"We often hear about how exceptional a particular rain event was," said Clemente, referring to prior enforcement cases. "Between El Niño and climate change, extreme storms are the new norm. People need to adapt accordingly."
The San Diego water board scheduled a Feb. 10 hearing to consider the complaint.
SANDAG can pay the penalty, propose a settlement or supplemental environmental project, or contest the allegations.