The initial estimate of 5,000 gallons reported to the San Francisco Bay Regional Water Quality Control Board on Wednesday was based on the board's requirement that notification of a spill be made within two hours, Redwood City spokesman Malcolm Smith said.
"The actual quantity will be much higher," Smith said.
He said a more accurate estimate is about 48,000 gallons.
The pipe ruptured near Davit Lane and Anchor Circle at about 3 p.m. Wednesday and was not repaired until around 10 p.m. Thursday, though sewage flowing from the pipe into the lagoon was halted hours before that. Runoff was being pumped into tanker trucks and taken to a sewage plant by Thursday afternoon.
Cleanup of about six residential garages and assessment of the environmental impact of the spill continued over the weekend and today, Smith said.
Smith said the city is working with the San Mateo County Health Department on options for treating the sewage in the lagoon in an environmentally friendly manner. He said sunlight will result in natural degradation of the sewage, causing it to dilute.
An estimate of cleanup costs and repairs has not been made.
ABC7 contirbuted to this report