LONG BEACH (CBSLA.com) — A stretch of coastline in Seal Beach was reopened Thursday to swimmers and surfers after a roughly three-day closure due to a sewage spill near downtown Los Angeles, but all beaches in Long Beach remained closed.

The ocean in Seal Beach between the mouth of the San Gabriel River and Anaheim Bay had been closed in response to the 2.4 million-gallon spill that happened about 2 p.m. Monday at Sixth Street and Mission Road in Boyle Heights, sending sewage into the Los Angeles River.

READ MORE: Enrollment Down 6% At LAUSD Schools

The Orange County Health Care Agency said Thursday that water testing showed bacteria levels were within acceptable health standards.

Water tests were still pending in Long Beach, but as of about midday, all coastal beaches in the city were still closed. Health officials said Wednesday that an initial round of testing came back mostly clean, but an additional test would still be needed to confirm that bacterial levels had dropped enough for the beaches to be reopened.

The flow of sewage from the ruptured pipe was stopped Tuesday afternoon, but not before sewage spilled onto area streets and into the L.A. River. Officials with the Los Angeles Department of Public Works said about 750,000 gallons of the spilled sewage had been recaptured.

Crews were performing environmental cleanup work Wednesday to sanitize the streets affected by the spill. The cleanup work was done between Mission Road and Clarence Street, between Fifth and Jesse streets.

READ MORE: 'Banksy: Genius Or Vandal' Exhibit To Open In Early October

“The streets and sidewalks within those boundaries, as well as the impacted storm drains and channels to the Los Angeles River, are being pressure-washed and sanitized,” according to the Department of Public Works.

The pipe that failed was installed in 1929.

“This is an old sewer, an aging sewer that was planned to be repaired,” Adel Hagekhalil, assistant director of city sanitation, said Tuesday. “… This one, we had a plan and it did not wait for us, it collapsed. Our record is very good in the city of Los Angeles. … We spent over $2 billion in the last 10 years in (upgrading) our sewers.”

He said there are about 6,700 miles of sewer lines across the city, and “we haven’t had a major collapse for a long, long time.”

MORE NEWS: Latino Restaurant Association Kicks Off DINE LATINO Restaurant Week

(©2016 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Wire services contributed to this report.)