Major sewer spills can be caused by clogged pipes, vandalism, deteriorated or poorly maintained pipes, and power outages that cause sewer pumps to stop working. Clogged pipes are the main cause of sewer overflows. The most common culprits are:
Fat, oil and grease buildup
General household products, including rags, dental floss, disposable wipes (even flushable ones) and feminine hygiene products
Even with a vigilant prevention program, spills can still occur. When that happens, electronic alarms located throughout the city’s sewer system alert city staff when an overflow is detected. Calls received from the public who report a spill or detect a sewer smell are also very helpful.
In the event of a sewer spill emergency, city staff is on call 24 hours a day, seven days a week, including holidays, to implement its emergency response plan. Threats to public health, the environment and property are the top priority. Depending on the nature of the spill, the city might bring in large trucks with tanks and vacuum hoses and bring the contained sewage to be treated at a local plant. Sometimes the city can clear the blockage and flow returns to normal. Other times a bypass pipe needs to be installed until the main pipe can be repaired. The city sometimes needs to build temporary berms to divert the sewage away from possible public contact, gutters that lead to the ocean and property that could be damaged. It is possible the city will need to shut off the water in nearby neighborhoods or ask neighbors to reduce indoor water use (water that goes down the drain) during the repairs. Once the immediate fix is complete, the city works to clean up the affected area as quickly as possible.
The city works very hard to keep spilled sewage contained, but sometimes it’s not possible, and sewage enters creeks, lagoons or the beach. If there is even a possibility that some sewage has reached creeks, lagoons or the beach, the city coordinates with the San Diego County Department of Environmental Health to post signs in the affected areas advising the public to stay out of the water until water quality tests show the water is safe for human contact.
California Department of Fish and Game and U.S. Fish and Wildlife – These agencies maintain and oversee habitat protection to ensure the survival of all species and natural communities. The departments may monitor oxygen levels, temperature and bacteria levels, and install an aeration system in the lagoon to help protect fish and wildlife.
State and federal Environmental Protection Agency – The EPA has authority to regulate sewer spill pollution under the Clean Water Act, which regulates the discharges of pollutants into the waters of the U.S. and regulates surface water quality standards. In California, the EPA and state regulatory agencies, including the San Diego Water Quality Control Board, oversee municipal wastewater operations and have the ability to impose fines.
Sewer spill fines are paid for through money in the city’s sewer fund kept for emergencies. Typically fines for sewer spills are imposed by the San Diego Regional Water Quality Control Board. After an investigation, the board will take enforcement actions, which often include a fine. The City of Carlsbad can request that the board use the fined funds for a local mitigation project such as sand replenishment for Carlsbad’s beaches.