According to the group's 24th annual Beach Report Card released on Thursday, 90 percent of the county's beaches received "A" or "B" grades for the period between April and October 2013 -- that's up 6 percent from the previous year. The group says the severe drought has helped water quality along the coast. Less runoff has meant less pollution going into the beach water.
But the county still leads the state in the number of beaches with overall poor water quality. Ten percent of the county's beaches got a "C" or lower for pollution.
Mothers Beach in Marina del Rey, Cabrillo Beach in San Pedro and the beach at the Santa Monica Pier landed on this year's "Beach Bummer List," which ranks the most polluted beaches.
On the other hand, Avalon Beach has dropped off of the Beach Bummer List this year due to efforts to improve water quality.
Heal the Bay says Santa Monica's bad grade is due to deteriorating netting, which allowed for birds to roost there.
City News Service contributed to this report.