Water quality officials have notified Vista and Carlsbad that the two cities are facing a nearly $1.1 million fine for a sewer line rupture last spring that dumped 7.3 million gallons of waste into Buena Vista Lagoon.
The cities, which co-own the pipe, can either pay the fine or argue their case at a meeting on Dec. 12, according to the complaint issued Friday by the California Regional Water Quality Control Board.
Discovered by a private citizen on April 1, the spill was one of the largest in county history. About 1,700 fish were killed in the freshwater lagoon on the border of Oceanside and Carlsbad.
Water quality regulators reported spending 140 hours investigating the spill and preparing the complaint. In it, the board faults the cities for failing to effectively monitor the sewer line and for failing to perform preventative measures, such as replacing the sewer line or installing a backup system.
Because Vista owns about 90 percent of the pipe where the breach occurred, it is expected to pick up most of the tab.
Vista City Manager Rita Geldert said that a financial hit of that size could potentially lead to increased sewer rates or delays to future projects. Yet the fine could have been worse. For a spill of that size, the maximum penalty allowed by law was $73 million, according to the complaint.
When it ruptured in late March, the sewer main, which transports waste to a regional treatment plant, was only halfway through its estimated 50-year lifespan. Analysts determined that a tear in the protective liner encasing the pressurized sewer main allowed "highly corrosive" soil to eat a hole in the line.
For Vista, there may be another fine on the horizon. Shortly after the Buena Vista Lagoon spill, more than 400,000 gallons of sewage escaped from a separate, Vista-owned line near South Melrose Drive in Carlsbad. External corrosion was again pegged as the culprit.