July 30, 2020

cyanobacteria updateWe Have Met Our Goal of Raising $10,000 for a Water Quality Plan!

Thanks to your generosity, the Herring Ponds Watershed is able to commit to pay its share of the cost of the Water Quality Plan. 

Hopefully the “After” picture (2020) with the green water will morph back to the “Before” picture with the blue, cyanobacteria-free water. 

We have some good news in our battle against cyanobacteria blooms. The Herring Ponds Watershed Association share of $10,000 for the $80,000 Water Quality Plan has been raised. This plan will identify the origins of the phosphorus pollutant that enables the fast growth of the bloom, and suggest measures that will substantially reduce this pollution. We are optimistic that Town Meeting will approve Plymouth’s $70,000 expenditure for this plan with our good faith contribution. We will do our best to make sure that fall Town Meeting representatives know that this expenditure will help all ponds in Plymouth to better prevent harmful blooms. We are optimistic that we will find a way to control these blooms in the future using the results of this plan. We are optimistic that enough of you out there care about clean water to take on any other watershed problem that may arise.  We are grateful for your contributions, your patience and your love for this special place.

What can we do now to hasten the demise of the cyanobacteria in Great Herring Pond? 

  • Pump out your septic tank. If you can’t remember the last time it was done, it’s probably time to do it.
  • Don’t throw yard waste into the pond. Compost it instead.  Yard waste requires oxygen to decompose.  Lower oxygen levels in the pond encourage release of phosphorus pollutant from the pond sediment.
  • Pick up after your pets so their waste doesn’t wash into the pond during a rain storm.
  • If you have a yard service, ask them not to use phosphorus-containing fertilizer. There is plenty of phosphorus in the soil so it is not necessary to add any more.  Professional landscapers are the only ones permitted to use phosphorus-containing fertilizer. 
  • If you do your own lawn work, don’t fertilize near the pond even if your fertilizer is phosphorus-free.
  • Finally, and perhaps most important, don’t clear-cut your pond front land just to get a better view, especially if you’re property is sloped. Trees and shrubs hold the soil during torrential rainstorms and prevent runoff that physically transports soil and its phosphorus into the pond.

How else can you help?

Although we have reached our Water Quality Plan fundraising goal, we encourage you to contribute if you can ( you can donate on our website). Your donation will be designated for water quality improvement expenses and will be much appreciated when the plan tells us what must be done.

We have more good news:

  • Hilary Snook, head of the regional EPA and cyanobacteria expert, has agreed to give a ZOOM presentation in August or early September to share his knowledge and answer your questions. Stay tuned for a date and time.
  • We have tested the homeowner association beaches around Great Herring Pond for E.coli and the results of 11 tests show very low E. coli bacteria levels. Unlike cyanobacteria, these E. coli do not produce a powerful toxin but they will cause significant gastrointestinal stress if present.  Why did we do this when no one should be swimming?  The test also can detect septic system problem if an unanticipated spike in E. coli is observed in a usually clean area.

Don Williams, President
Herring Ponds Watershed Association

July 28, 2020

cyanobacteria updateTo my patient neighbors, the latest update.

The condition of the pond seems to be improving!

Today, there were no “sworls,” “slicks” or “mats” of cyanobacteria cells.

Thank you for your patience waiting for the long-anticipated testing results.  The sample, taken by Envirotech at the Boat Ramp and tested by them showed no cyanobacteria cells!  Before you start jumping in the pond and drinking the water to celebrate, the advice of Plymouth’s Department of Marine and Environmental Affairs is to continue our current cautious behavior.

There are very good reasons for this approach:

  1. The tested sample was taken at the Boat Ramp and the sampler clearly stated that “there was no bloom visible when the sample was taken.” So, they happened to take a sample at one of the few places where there was no bloom!
  2. Blooms are still visible (as of today when Geri and I checked) although not in “sworls” or “slicks” or “mats” that had previously been seen. The blooms are less common near the shore and more prevalent farther out. 
  3. We need two weeks in a row of zero cyanobacteria before we can re-open Great Herring Pond.
  4. We have had 3 dogs and 1 person (that I know of) with clear cyanobacteria reactions.


What are the next steps?

  1. Today, Kim Tower of the Plymouth Department of Marine and Environmental Affairs, has had another sample taken at the Boat Ramp to look for cyanobacteria.
  2. I suggested that an additional sample be taken that had the commonly observed, omnipresent (except at the Boat Ramp!) light green/yellow suspended particulate matter. Kim actually took 2 samples (one at Pond Road and the other at Great Herring Pond outlet) that clearly had this particulate matter. We will find out what the particulate matter is.
  3. Kim hopes to have analysis results by Friday.


Where does this leave us?

  1. Identification of the particulate matter is critical to ensure that reopening the pond is safe.
  2. A second zero cyanobacteria reading may lead to reopening of the pond if the particulate matter is definitely not cyanobacteria.
  3. If dogs and people get sick from drinking the water and swimming in the pond respectively, we need to find out why.


Kim just sent me another email.

  • As long as there is a visual like today’s picture that I sent her, the advisory should remain based on the visual.
  • She would be really surprised if the Pond Road sample came back “non-detect” since she “could see the cyanobacteria cells.”
  • She will take a sample next week and I will take her out to look for the most concentrated bloom area.


We do not want a repeat of the past 10 days.  We will, with your help, work to learn more about this incident and what we need to do to prevent it from happening again.  Without doubt, the cloudiness and green color in the water caused by the particulate matter is the result of some form of pollution.  Knowing what the pollutant is will help us to deal with it.  Unfortunately, cyanobacteria is still likely to be present. 

In the meantime, keep safe.  The noticeable improvement in water color and the lack of large “sworls,” “slicks” or “mats” give us hope that the bloom is clearing.  Please, however, let’s not make the mistake of “opening up too soon.”  

Don Williams, President
Herring Ponds Watershed Association

July 26, 2020

To all of you who have read our posts, asked questions and sent contributions:

Thanks so much for your support!

To summarize the Great Herring Pond situation:

  • There are still a lot of cyanobacteria in Great Herring Pond.
  • Those not aware of the cyanobacteria bloom invariably have come in from the boat ramp.
  • One more dog has taken ill from drinking the water.
  • We still do not have testing results.
  • Your donations toward the Water Quality Plan are making a huge difference.
  • Response to the new, larger signs was very positive.

Hilary Snook, Head of the regional EPA and cyanobacteria expert, is working tonight and has answered some of your questions that I forwarded on to him:

Question:  Will we have to replace the noodles, ropes and buoys that mark the swimming areas?

Answer:  No, you won’t need to replace any swimming area equipment.

Question:  Will we contaminate other ponds if we take our boat there?

Answer:  The likelihood of “seeding” another lake is small as it doesn’t work the same as say invasive Eurasian milfoil. If one was worried, I would say just keep the boat out of the water for a day or two before going to another lake.

Question:  Are there ways to speed up the disappearance of the bloom?

Answer: There are a lot of technologies out there and some work better than others depending on the algae/cyanobacteria, lake morphology and size, hydrology, etc. I am not an expert in all of the various types of treatment, but I have been on a working group compiling all of the known technologies and treatments and summarizing their efficacy, cost, etc. The site is not quite ready for prime time, but it is getting close. I wouldn’t jump at a quick remedy at this point. It usually takes some work to understand the system and know what will be the best strategy.

Be well, be safe and keep your thoughts, ideas and questions coming in!

Don Williams, President
Herring Ponds Watershed Association

July 24, 2020

To all of our loyal followers,

Jerry Levine (Board of Directors, Invasives Committee Chair, Plymouth Board of Health) and I posted 2 new, large (14″ x 22″) signs at the boat ramp (permission granted by Bourne) and 6 at home owner association beaches around Great Herring Pond.  It is our hope that these signs will be more visible than the the previous signs and prevent illness and discomfort.  Thanks to Jerry for getting the signs made and for making sure they were delivered before what promises to be another hot weekend.

A summary reminder of “DON’Ts” is in order:

  1. Don’t drink the water.
  2. Don’t let your dog drink the water.
  3. Don’t swim in the water (especially children and dogs).
  4. Don’t eat the fish you catch; release them.
  5. Be careful to wash thoroughly if you have to walk in the water (especially children and dogs).

We are humbled by your response to our call for help to raise the Herring Pond Watershed’s share of $10,000 toward the $80,000 Water Quality Plan.  The WQP is the best way to determine the source of nutrients (phosphorus), the only cyanobacteria growth variable that is readily controllable.  The WQP will also suggest ways to limit phosphorus in our watershed ponds and prevent recurrences of these blooms in the future.  So far, we have raised $1410 on Facebook and have had additional WQP donations and pledges of $1100.  Our Board of Directors has pledged $1600, bringing the total thus far to $4110.  Adding in the match promise of $1 for every $2 raised brings the total up to $6165.  We are getting close and optimism is rising.  Your generosity has played a critical role in this process.  Thank you.  (Click here to go to the Donations page)

We have not yet received the testing results.  I will let you know when I find out.

You have asked if it is safe to sit out near the pond.  I have again approached my expert contact, Hilary Snook, head of the regional EPA and cyanobacteria authority. He said that he personally wouldn’t be too worried.  If it was happening all the time and you were exposed to long-term chronic exposure then he might be concerned.  He would just err on the side of caution; if it smells noxious, keep your distance and if it is choppy and a bloom is breaking up along the shoreline, just stay away until it dissipates.

The bloom is still very much with us but Little Herring Pond and Carters River still appear clear.  We are monitoring both visually.

Please take the time to warn those doing any of the “DON’Ts” above.  If they appear skeptical, advise them that one of our residents was in the hospital with welts and shingles-like rashes from swimming in the water and two dogs are still seriously ill.  I will be vigilant this weekend also.

Thanks for your support.

Don Williams, President
Herring Ponds Watershed Association 

July 22, 2020

We will be getting larger (14″ x 22″) two-sided signs with metal holders on Friday.  Jerry Levine and I will post them at the boat ramp and at the home owner’s association beaches.  The current signs are small and are not easily seen.  They are due to come in on Friday and will be up before the weekend.  The Town of Bourne has no problem with us putting a sign up at their boat ramp.

We have not received results from the testing lab on the concentration of the cyanobacteria.  We should hear soon or early next week, depending on who you believe.  This will provide a good baseline number for comparison of next week’s result and subsequent results.  As of this morning, there was still a lot of cyanobacteria present.

Some of went out this morning to collect samples for E. coli testing at the major swimming beaches on Great Herring Pond.  We learned more about the resident who was hospitalized from swimming last week in the pond.  Her allergic reaction was quite severe and required lengthy hospitalization.  She is now resting at home. 

The toxins produced by cyanobacteria produce allergic reactions in some people upon contact.  Not all react in the same way and to the same degree, typical of allergic responses.  However, ingestion of this cyanobacteria-containing water would make most adults and all children and dogs very ill.

Fish eat the cyanobacteria and are NOT safe to eat.  The birds that eat fish (herons, terns) are at risk.  In my travels, though, I have not seen any dead fish.

We have results on the temperatures of Great and Little Herring (thanks Lee Pulis and Jim Smith) Ponds.  Great Herring Pond varied from 78 – 84 F, with 80.3 F being the average of 13 readings.  Little Herring Pond was 52.7 F at the spring and went up to 77.7 F and averaged 70.7 F (8 readings).  At the very least, we can conclude that Great Herring Pond, being 10 F warmer than Little Herring Pond, provides a better environment for cyanobacteria.  Little Herring Pond, as of Monday at least, had no visible cyanobacteria.

At present, we have raised $925!  Thanks to all of you for your kindness and generosity.  The funds are much needed to help pay the Herring Ponds Watershed Association portion of the Water Quality Plan that will tell us how to deal with reducing the nutrient input into the pond and hopefully preventing future blooms. (Donate here)

Keep your comments and suggestions coming!

Don Williams, President
Herring Ponds Watershed Association

July 21, 2020

Thanks to everyone for being so understanding during the current cyanobacteria bloom.  I went out yesterday in my boat around 1:30 PM and, despite the hot weather, no one was in the water, very few boats were out and even Three Rocks was empty. 

I have gotten a report that a dog that was swimming (and drinking the water) took ill but is recovering.  The evidence (even minus the needed testing) is pretty clear that this cyanobacteria bloom is toxic. 

I talked to David Gould, head of Plymouth’s Department of Marine and Environmental affairs, to clarify the status of the testing.  He confirmed that the identification of the cyanobacteria by the state was made based on photographs and that no other test had been done.  David had a sample taken yesterday and results should be available “in a couple of days.”  He said that since there are no public beaches on Great Herring Pond, Plymouth would not be able to pay for extensive testing.  He did, however, agree to have two initial samples taken at Plymouth expense.  The sample testing is expensive ($150 per test) and David is working in an emergency “1/12” budget situation because Town Meeting hasn’t met yet to pass a budget because of coronavirus concerns.  Town Meeting is scheduled for August 10.  In order to re-open Great Herring Pond (GHP), two successive weeks of testing with no cyanobacteria present will be necessary.  As you know from Hilary Snook’s input (Hilary is the regional EPA head and cyano expert), there is no way of knowing how long the bloom will last.  The good news is that GHP is flushed by river ingress (Carters River) and egress (Herring River).  The bad news is that the bloom is extensive and we still have most of the summer heat to contend with.  I have agreed to monitor the status of the bloom and, once it seems to have dissipated, take the necessary samples for testing so that the pond can re-open.  We cannot afford to pay for weekly testing and it makes no sense to test if cyanobacteria is still visible and extensive.

I have consulted with Hilary Snook and Hampton Watkins (Long Pond Association Water Quality Chair) about what might have caused this bloom.  It is the first on GHP for at least 80 years according to old timers who have never seen such a bloom.  It is clear that once blooms start on a pond, they are likely to continue (Snook).  It is therefore very important that we understand what drives these blooms and develop strategies to prevent their return.  The current bloom is certainly the result of a “perfect storm.”  The components of the cyanobacteria “perfect storm” are:  1) heat,  2) light, 3) nutrients and 4) “hydrologic conditions.”

We have had heat — weather has been hot lately and, due to a warm winter, the water temperature started off warmer this spring and has risen to 78 – 84 F (taken yesterday afternoon).  It also explains why Little Herring Pond (LHP) is still clean; temperatures in LHP range from 52.7 at the spring to 77.7 F (taken by Jim Smith and Lee Pulis yesterday late morning). 

We have had light — there has not been much rain in the area so there have not been many cloudy days.  Although we are not under severe drought conditions, rain has been relatively scarce.

We have had a couple of intense rainstorms the week of July 5 that could have easily provided the phosphorus nutrients via runoff.

Hilary got back to me about the “hydrologic conditions” that would be conducive to cyanobacteria blooms.  They include less snow melt (check), low rainfall (check) and additional storm water infrastructure (check – our 3 runoff remediations — ironic, yes?). 

So, where does this leave us?  We can hope that there will be no more “perfect storm” situations (possible but not a 100% chance at all).  We can hope that Mother Nature cooperates (not a good bet because all climate change effects are in the wrong direction). Or we can work on minimizing nutrient entrance into our ponds.  Of course, individually we can pump septic tanks religiously every 3 – 5 years, avoid phosphorus-containing fertilizers and refrain from throwing leaves and such into the pond, but the biggest contribution will undoubtedly be to reduce runoff.  The Herring Ponds Watershed Assoication is working with David Gould to fund an $80,000 study that will result in a Water Quality Plan that will both identify the likely sources (in order of importance) of nutrients and suggest ways to remediate this pollution. This will be considered at fall Town Meeting. We must raise $10,000 as the Herring Ponds Watershed Association contribution toward this study so be generous when asked to help out.  Moreover, if you live on or near GHP, please refrain from clear cutting your property down to the pond so that you can have a better view.  It leads to runoff and encourages others to do the same.

Hampton Watkins told me that there is always some cyanobacteria in the ponds in our area, waiting to bloom.  We just have to do our best to not give it everything it needs.  Control of nutrients is our best tactic.

We should have test results in “a couple of days” according to David Gould.  The results will confirm the presence of the cyanobacteria (probably a foregone conclusion) and the concentration.  Anything above 70,000 cells/milliliter is severe enough to shut down the pond.  We will let you know when we receive that information.

Also, I found out from Hampton Watkins that it is not safe to eat fish taken from GHP.  He asked if we’d seen evidence of fish kill yet.  We have not and that is a good sign but not one that we should take as an excuse to let down our guard.  Dogs and humans have already suffered from exposure.  Hampton also said that birds eating the contaminated fish are also at risk. 

I regret the length of this note but my experience as a scientist has taught me that the more people who know about the problem and the more that they know are keys to solving the problem.  Be well and thanks for your support, cooperation and kind words.

Don Williams, President
Herring Ponds Watershed Association