Triathlon Cancels Swimming Portion Because Hudson River Bacteria ‘9 Times Higher Than What is Deemed Safe’

The Hudson River. Photo by Bette Kerr.

Bacteria levels in the Hudson River were so high on Saturday that organizers of the triathlon canceled the swimming portion of the race on Sunday.

“In partnership with local health experts and, following repeated water quality tests, due to the recent heavy rainfall, bacteria levels in the Hudson River have been found to be nine times higher than what is deemed safe,” the race website says.

The triathlon now has a 1-mile run portion in place of the swimming event. There will still be a 24.8-mile bike and an additional 6.4-mile run after that.

“We apologize for the late notice, however, lab results were sent to us late in the day at which time we awaited further guidance and recommendations from officials,” the site says. “We recognize for some this is disappointing news but, as we hope you can understand and appreciate, the health and safety for all participants is our top priority.”

NEWS, OUTDOORS | 27 comments | permalink
    1. B.B. says:

      Heavy rains cause sewage overflows to run into NYC waterways, then you also have runoff as well. Thus not surprising bacteria count are elevated, happens each time there are major rainfall events.

    2. I asked the the NYC Triathlon these questions.
      “You reported that the lab said water quality was nine times worse than legal. What was it? What lab? I assume the sample was taken on Saturday. At what time? What location?”
      Water sampling typically takes a day to get a result. Date, time, location really matter. There is a citizen water quality testing program in NYC and their website is and the results are at

    3. Carlos says:

      That’s scary. Glad they figured it out. I know they are theoretically different bodies of water but are similar tests run at nearby beaches?

      It is particularly unfortunate as this year the weather is closer to decent Triathlon weather than normal – I recall a few recent years where it was 90+ degrees.

      • Josh says:

        There are signs on many beaches not to swim after heavy rains. I would not go to a NYC beach for a few days after a heavy rain storm. Especially if it is near a CSO.

    4. JS says:

      Did not see any signage or any notice about the triathalon- and given the Covid situation there was no reason to think it would be happening.

      Wondering why no notice?
      Nor signs at bus stops, buses impacted.

      A neighbor was to drive a frail elderly friend to see her relatives, first time since preCovid.
      Had no idea of triathalon street and highway closure.

      • lynn says:

        I didn’t see anything posted either, but Channel 1 News had coverage of the event in Central Park and mentioned that it was a no spectator event. I’m assuming that means no crowds and no traffic disruptions.

        • JS says:

          Some City and express buses were re-routed and not stopping at bus stops – but bus riders would only find out when they got to the bus stop on Sunday.
          (And that just added to the difficulties as the M11 is now regularly rerouted on weekends for “street dining” on blocks of Amsterdam and Columbus)

          West Side highway uptown was closed too

        • Tom says:

          The West Side Highway northbound was closed all the way to Yonkers without any signage. From 106th to 110th, the WSH, Riverside Drive, Amsterdam and Columbus were all closed, I think. No signs anywhere about the triathlon for motorists. Traffic cops on every single block of Riverside, West End and Broadway, though. For a triathlon that canceled one of the three events. Hey, remember when the swimmers all got stung by jellyfish?

      • Crankypants says:

        There has been tons of signage along the bike/running path on the river all week. So sad that it has now been rendered moot.

        • robert says:

          The BIG problem is that Mayor’s office of street activity did not give final sign off until Thrus pm and signs did not go up on 96 river to CPW till 5:30 pm Fri night, that there was no parking on sun. Long after alternate parking was done. Towing started at 02.00 on those blocks Lots of folks are going to be looking for their cars and the merchants that had their stores walled off on the southside of 96 lost most of their biz. And then came the sinkhole at 10.30 of Sun that ate some cars on RSD

          • JS says:

            Thanks for the information.
            City’s last minute action and lack of notification truly egregious.
            Let’s hope no disabled, no one needing to get to work with a long commute, no doctors needing to do surgery Monday morning etc did not get cars towed.

    5. nemo paradise says:

      Just curious — why would heavy rains create such a large increase in river bacteria? Runoff from garbage dumps? Septic clouds? It seems counterintuitive.

      • Sharon E Lamberth says:

        Combined Sewer Overflow (CSO) which many cities including NYC have storm water and sewer water go into the same system. Yes sewer water includes flushed toliet water.

        During and after a heavy rain, there’s too much water for wastewater treatment plants to handle. So you have overflow, into the river.

        Untreated sewage leads to elevated bacteria. You don’t see actual poop floating in the river because there are screens that catch solids. But the poopy water goes directly into the river.

        • Naomi B Bishop says:

          What effect does this “poopy water” have on Hudson marine life (fish, plants, algae, etc)?

          • I’m not a scientist so I cannot say for sure and I’m sure they affect many critters differently but if its not too bad and too often, I think this may actually be beneficial. However, its a very complicated system and the critters we have a used to what the way things are and if you change it suddenly many will not be able to adapt. Eg. more poop may mean more algae, which means more food for algae consumers like mussels and oysters but if there’s too much algae the algae can suck up all the oxygen causing a die off which sucks up even more oxygen. Also its not just the poop. The runoff contains a host of other bad things.

          • robert says:

            Less 02 more N in the water

          • B.B. says:

            Within certain limits marine life can cope with increased bacteria levels.

            Long as a body of water isn’t stagnant things keep moving downstream from river to bay to ocean which helps dilute things.

            OTOH humans who come into contact with said water and or eat things from it (fish, shellfish, etc…) can become sick to violently ill.

            Typhoid,amoebic dysentery and some other diseases are transmitted by humans coming into contact and or consuming water fouled by sewage.

            Waters off NYC were once full of shellfish and fish that Indians routinely consumed with no problems. As did early arrivals to New York from Europe. But as city grew and waters became more polluted consuming anything caught from East, North rivers, harbor, or waters off Staten Island, Brooklyn or Queens became dicey.

          • Josh says:

            Not much. The Hudson River is not actually a river in NYC but a tidal estuary. This means that the water is really flowing both ways. In other words, the bacterial level is elevated after heavy rains and can cause human sickness, but it is very quickly diluted and washed away. In fact, depending on where you test the water in the Hudson, you can see very different levels of bacteria within just tens of feet, especially during an ebb tide.

        • Josh says:

          NYC’s sewage system can handle rain storms up to 1/4 inch of rain per hour, afterwards the CSO system kicks in and the storm water mixes with raw sewage to flow into the waterways.

      • Nick says:

        From a while ago, but shows the CSO outflow after heavy rain.

    6. A concerned UWSer says:

      You can find your neighborhood sewage discharge points, check out your water quality, and find practical suggestions & solutions here:

      Each year more than 20 billion gallons of New York City’s raw sewage pours into our waterways. That volume would fill 72 Empire State Buildings!

    7. PM says:

      To even contemplate swimming in that river…
      with that color and smell even in “normal” times… knowing that it goes thru one of the largest metro areas in the world with all its avenues for pollution… is beyond me.

      • Josh P. says:

        I run on the Riverside Park greenway almost every day and I don’t think I’ve ever noticed a smell coming from the river. High levels of bacteria are not great, but let’s not exaggerate the problem. New York’s air and water is cleaner today than it has been in decades.

    8. AC says:

      An overflow/effluent drain exists (or used to exist) at 72 street by the water’s edge. It was covered by a concrete structure, which has deteriorated over decades. As kids, we would throw rocks at the rats that would hang by the drain. The effluent looked like waste water. I believe such drains exists along the Hudson, but are primarily used during instances of heavy rainfall.

    9. Kate Asher says:

      JUST A REMINDER – on rainy days, it is a good time to limit your water usage

    10. Hudson says:

      Oh, and let’s not forget the great fish massacreast summer, which made the greenway unusable for a week or so

    11. BillW says:

      Watching them setup for the NYC Tri, I was starting to reconsider my phobia of swimming in the Hudson and sign up for next year’s race. Maaaaybe not.