Used condoms … hypodermic needles … stinky turds – all littering Santa Monica Bay. I’ve seen it all as longtime surfer and former Heal the Bay staffer. It’s not a pretty sight.

The Bay took another hit this week when a mechanical failure at the Hyperion Water Reclamation Plant led to 17 million-gallon sewage spill into the Bay. The nasty breakdown led to the closure of a 4-mile stretch of sand for four days.

Fortunately, these unsettling incidents at Hyperion don’t happen too often. The last major one occurred in 2015, when a 30 million-gallon discharge fouled shorelines with hygiene waste for a week. We got a lot of media attention at Heal the Bay by providing daily updates on a crisis we dubbed “Tampon-alooza.”

These outbreaks make headlines not only because of their icky nature, but because of their relative rarity. Most people are usually shocked to hear that Hyperion used to regularly dump billions of gallons of partially treated sewage into the Bay as a normal practice.

In the early 80s, years of accumulated sewage sludge had taken its toll. A huge dead zone sat in the middle of the Bay. Fin-rot decimated local species of fish. Strange tumors plagued the few dolphins that cruised local waters. Beach lifeguards suffered cancer rates at a disproportionately high rate.

A fed-up Dorothy Green co-founded Heal the Bay with a number of fellow activists in response. Armed with a bullhorn and a savvy media strategy, Green mobilized thousands to attend meetings and lean on regulators. Thanks to lawsuits and grassroots pressure, the EPA compelled Hyperion to move to secondary treatment of sewage.

Since that triumphant day in 1987, beach water quality has improved exponentially. During the summer – when most people swim at the beach – 94% of L.A. County Beaches got an A or B grade in Heal the Bay’s latest Beach Report Card. These grades are based on levels of harmful bacteria like E. coli measured at Bay beaches each week.

That doesn’t mean everything is hunky dory. Far from it. The Santa Monica Pier barely avoided this year’s dreaded Beach Bummer List – Heal the Bay’s ranking of the 10 most polluted sites in the state. But it still got a grade of D in the summer, meaning that anyone that swims in the popular spot faces a significantly greater risk of contracting gastro-intestinal illness, skin rashes and other unpleasant maladies.

I’ve been sickened terribly by polluted ocean water. One foolish surf session in the rain at El Porto left me crippled in the bathroom for three days with the worst stomach flu of my life. But illness isn’t limited to a small band of dumb surfers. At least 700,000 people in Southern California get sick each year from swimming in the ocean, according to one UCLA-Stanford study. Associated public health care costs hit at least $20 million.

Hundreds of thousands of people swim at the Pier each year. The overwhelming majority of these visitors are people of color, who travel on the 10 Freeway from heat-island neighborhoods to cool off at the beach. It bothers me to see these unsuspecting souls splashing around in one of the state’s most polluted beaches. To me, it’s another example of environmental injustice.

To be sure, the city has spent millions to try and fix the problem. I organized a press conference with then council-member Bobby Shriver about a decade ago. We proudly declared that Pier had gotten off the Beach Bummer List and had turned the corner on bacterial pollution.

The city built SMURRF, a water recycling plant that treats dry weather runoff – the inland slobber that carries bacteria and trash into the ocean. This concrete jungle-gym sits on Appian Way across the street from the Carousel. The city also recently completed work on a stormwater runoff storage tank north of the Pier. The project diverts 1.6 million gallons of polluted runoff from reaching the Bay each day.

Despite these efforts, problems persist at the Pier – as the recent D grade attests. Diagnosing the problem is no easy task. Many piers throughout California get bad water quality grades. Flowing stormdrains, faulty sewer lines servicing crowded facilities, dark areas of pooled water, and roosting birds make for an ideal Petri dish.

If you walk under the Pier during low-tide, you may feel like Tim Robbins’ character having a bad flashback in “Jacob’s Ladder.” It’s dark and creepy. Hundreds of dirty pigeons flutter around. You sense water dripping in ominous places. It smells funky.

The city deserves credit for the work it has done. But clearly more needs to be done.

Some 8 million people visit the Pier each year. For a city that prides itself on well-being and equity, it’s an embarrassment that we welcome guests to one of the dirtiest beaches in the state. Pier businesses and other stakeholders must encourage the City to prioritize basic public health at one of our crown jewels. Residents should email their councilmembers, reminding them that they voted to tax themselves to clean up local beaches (Measures V and W).

At minimum, the City should post permanent and highly visible warning signs near the Pier in Spanish and English. Ocean users need to know that the water consistently exceeds acceptable bacteria limits. A black eye for sure, but maybe it’d spur action. As we used to say at Heal the Bay: A day at the beach shouldn’t make anyone sick.

Matthew King grew up on the beaches of Santa Monica, where his father served as a County lifeguard for 30 years. He sneaks away from his communications and marketing consultancy as often as he can to surf Bay Street and other local breaks.