Heal the Bay released its 26th annual beach report card last week, and along with it came the environmental group’s top-10 “Beach Bummer” list.

Heal the Bay analysts assigned A-to-F letter grades to 456 beaches along the California coast for three reporting periods in 2015-2016, based on levels of weekly bacterial pollution. Some 95 percent of beaches received A or B grades during the high-traffic summer season (April-October 2015), slightly above the statewide five-year average.

But not all beaches faired so well on the grading scale.

According to Heal the Bay, of the state’s 10 most polluted beaches, split among beaches in Southern and Northern California, Cowell Beach in Santa Cruz topped the list for the third year in a row. New entrants this year include Shoreline Park at Shelter Island in San Diego and Monarch Beach near Salt Creek in Dana Point. The Santa Monica Pier hit the middle of the list at number 5, moving up two spots from where it stood on last year’s report.

Leslie Griffin, Heal the Bay’s chief water quality scientist and co-author of the report who delivered the findings in a speech Thursday, said it is tough for the Santa Monica-based organization to be so close to one of the “bummer” locations.

“It’s just really difficult with an area with so much infrastructure and so many people visiting the beach every year,” Griffin said. “There are so many different factors that affect it. And really our big thing is that people can come here and they can use the beach, it’s great. But you just want to stay at least 100 yards away from the pier. So go on the pier, enjoy the pier, but when you go in the water walk about a football field away and you’ll be fine.”

According to this year’s report, from 2011 to 2012, Heal the Bay partnered with the City of Santa Monica and the University of California at Los Angeles to conduct a Bacterial Source study. “The study results indicated that (1) conditions under the pier (moisture and lack of sunlight) promote bacterial persistence, (2) bird specific bacteria were detected, (3) human specific bacteria were undetected. The City continues to implement best management practices to improve beach water quality,” the report stated.

“Following past efforts to keep the beach water around Santa Monica Pier safe for swimming, the City was approved for a Clean Beaches Initiative (CBI) grant to build a regional, multi-benefit project that will capture the wet weather runoff from the sub-watershed that drains to the Santa Monica Pier storm drain,” the report continues. “The runoff will be stored in a tank to supply water to the nearby Santa Monica Urban Runoff Recycling Facility (SMURRF) during dry weather periods when there is greater capacity. Any runoff overflow will be directed to the sanitary sewer system. Once implemented, the project will treat both dry and wet weather runoff flows, which will greatly reduce the amount of stormwater that enters Santa Monica Bay from city streets and hopefully improve water quality at the pier.”

The full “Beach Bummer” rankings, beginning with the worst-ranked beach, are as follows: Cowell Beach, west of the wharf (Santa Cruz County); Clam Beach, near Strawberry Creek (Humboldt County); Shoreline Beach Park at Shelter Island (San Diego County); Monarch Beach, north at Salt Creek (Orange County); Santa Monica Pier (Los Angeles County); Marina del Rey Mother’s Beach (Los Angeles County); Redondo Municipal Pier (Los Angeles County); Candlestick Point/Sunnydale Cove (San Francisco County); Pillar Point, end of West Point Ave. (San Mateo County); Pismo Beach Pier, 40 feet south (San Luis Obispo County).

For more information on the report, go to beachreportcard.org.