Officials on Friday night doubled their estimate of how much raw sewage spilled from a pipeline near the Santa Barbara Airport into the Goleta Slough last weekend.

“The present estimate of the volume of the spill is now believed to have been approximately 1,025,000 gallons, based on current data and available information,” according to Brian McCarthy, general manager of the Goleta West Sanitary District.

The original estimate placed the amount of the spill last Saturday into Tecolotito Creek from the pipeline near the end of the north-south Runway 33 at 500,000 gallons.

The district notified the California Office of Emergency Services and the Santa Barbara County Public Health Department about the spill, which occurred during heavy rainstorms.

The incident prompted the Public Health Department to order the closure of parts of Goleta Beach Park to water contact on Thursday — from a mile east to a half-mile west of the mouth of the slough.

Access to the sandy beach remains open, although the east end of the park is closed for emergency operations related to disposal of silt from tributaries in the Goleta Valley.

The Goleta West Sanitary District, with the assistance of personnel from the Goleta Sanitary District and other agencies, was able to prevent the discharge of about 75,000 gallons into the slough, McCarthy said.

The cause of the spill remained under investigation.

“Goleta West Sanitary District is continuing to work closely with various agencies to ensure public and environmental health and safety are protected while diligent response efforts are underway, including monitoring of water quality in the affected area,” McCarthy said.

Public inquiries about the spill can be directed to McCarthy at 805.968.2617 or bmccarthy@goletawest.org.