Urban Runoff and the Unseen

LynnkubLynnkub Charter Mem​ber
edited April 2012 in General Discussion
I have lots of friends that are afraid of sharks but the thing that freaks me out are the things that can make us really sick! Bacteria, pathogens, etc.
We have a rule of thumb not to swim for 72 hours after a "first-flush" rain event and that seems to get shortened as the rains are more frequent (thus less street-snot gets blown into the ocean).
Someone posted this today on our open water group about a "fresh water swimming" hazard. I have never heard of this but it sounds pretty scary:


I wonder what other swimmers do to protect themselves?
Avoid the open water?
Get shots?
Close your eyes and swim really really fast?


  • AquaRobAquaRob Humboldt Bay, CACharter Member
    I'm with you on this Lynn! Bacteria is way scarier than Sharks because one is more likely to actually harm me in real life!

    What we do in Avila is watch for rainfall. Then based on how much there is and how long it's been since it last rained, we guess. It's impressively scientific. Unfortunately the county only tests the water once a week, on Monday, which is amazingly unhelpful for weekend swimmers.

    The good news is our local Surfrider group is working on doing their own testing which will supplement that and give us a better idea of what we're in for for the weekend. Hopefully that gets under way in the next month or so. I's recommend people out there find their nearest Surfrider chapter and inquire about their Blue Water Task Force and see if they have additional water quality data that you can check out.
  • LynnkubLynnkub Charter Mem​ber
    We are pretty lucky in Orange County, CA. I am not sure of the frequency of their testing but the website is updated pretty frequently:

    But better yet is the Twitter which I have on RSS feed.

    One of my swimming buddies, formerly from Santa Cruz will go in no matter what and I have yet to see him get sick. I managed to pull a 6-month downer so am not eager to repeat that.

    Still would be interested to know how swimmers in different coasts fare?
  • Leonard_JansenLeonard_Jansen Charter Member
    It poured during parts of the 2006 MIMS race and I picked up the Bug From Heck - 3 days of having every molecule of water trying to escape my body and taking any exit it could. It did, however, get my wife out of a speeding ticket, but that's a different story...


    “Moderation is a fatal thing. Nothing succeeds like excess.” - Oscar Wilde

  • evmoevmo SydneyAdmin
    edited March 2012
    I live just up the coast from Lynn and just down the coast from Rob, so I'm in pretty much the same boat. However, I lived in Chicago for a year, two blocks from the lake, so I can report on that experience.

    Thanks to the reversal of the Chicago River in 1900, the water quality on the lakefront is generally quite good - especially given the proximity of the dense metropolis. The Chicago Park District measures E. coli levels at each beach every weekday during swim season (Memorial Day to Labor Day). When bacteria readings exceed certain thresholds, the CPD uses a color-coded flag notification system for swim warnings or bans - which are routinely ignored by some of the more grizzled veterans at Promontory Point.

    Chicago is topographically flat, and the rivers flow away from the lake, so runoff isn't a problem like in California. However, a particularly torrential downpour can overwhelm the sewer system, releasing raw sewage into the Chicago River. If the rain continues, the river can reach capacity and the MWRD is forced to open one or more of the locks - thus releasing raw sewage into the lake.

    I am kind of a p*ssy about water-borne pathogens (even more than I am about sharks), so I always stayed out of the water at least five days after a CSO event.

    Open Water Chicago has wonderful post on the subject:
  • loneswimmerloneswimmer IrelandCharter Member
    Seems there's an advantage to having it rain most of the time as here in Ireland after all. And of course lower density population.

    I remember looking at perfect surf in San Diego a few years and being told to stay out of the water due to runoff. The danger would never have occurred to me. (Though we have problems in some lakes & rivers here also and a couple of coastal sites).


  • nvr2latenvr2late Central VirginiaCharter Member
    I will be swimming the Chesapeake Bay Swim in June. In preparation, I took a deep breath and googled "water quality in the Chespeake Bay" (do I really want to know, I am committed to this swim, I have heard that it can be quite variable, and at times quite bad) It was suggested that one avoid swimming for a period of time after a rainfall, as suggested above. I wonder...would they call of the entire race due to a heavy rain the day before? Will I swim if there is rain and the race is not called off? Although I have read that water samples are taken in different locations on a regular basis, I don't believe that this event has ever been called off due to a rain before the race. Is ignorance bliss, would I opt out? I think that in every walk of life, we assume certain levels of risk, and certainly swimming in open water carries its share of them - and after all, we have immune systems which hopefully offer a degree of protection from the millions of bacteria we encounter every day.
  • GordsGords Syracuse, UTCharter Member
    Hi Lynn,

    I heard about the Naegleria last year when I was swimming at Bountiful Lake. Bountiful Lake is within 1/2 mile of both the county landfill, and the county sewer treatment plant. Also all the runoff from the city gutters goes right into it. During the summer months the algae would get pretty bad, so I quit swimming there and started swimming in Great Salt Lake.

    Whew! This thing doesn't like sea water (or GSL water).
  • IronMikeIronMike Northern VirginiaCharter Member
    Wow. Thanks a lot @Gords for that link. Now I want to swim in salt water only.

    We're all just carbon, water, starlight, oxygen and dreams

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