Community Meets to Discuss Marsh Plan

On February 5, over 150 residents from Piermont and Palisades attended a meeting held at Piermont Village Hall where NYS DEC presented their plans to protect and restore portions of the Piermont Marsh. The DEC’s plan to use the herbicide “glyphosate” was met with great concern by nearly all attending, with several people speaking out forcefully about the known dangers to both humans and wildlife.

Several alternate options were brought up by the audience, as well as concerns regarding the long term cost, exposure to the herbicide, access to the area and viability of the entire project. In attendance were scientists from Lamont-Doherty who have experience with the marsh and its ecological impact on the river communities. A letter written by a group of concerned Lamont scientists regarding this project and the Piermont Marsh Alliance report on the meeting can be viewed on our website,

The meeting began at 7:00 pm and lasted well past its 9:00 pm expected end, with apparently no change to the DEC plans to proceed with the project beginning in the next few months. The communities will be notified and signs posted when the herbicide applications are to begin.

Below is the letter written by a number of Lamont-Doherty scientists in response to the DEC's plan.

Friday, Feb 2, 2018
LDEO Meeting Consensus (Dorothy Peteet, Jonathan Nichols, Nick Christie-Blick, Bill Menke, Maureen Raymo, Bob Newton, Paul Olsen, Tammo Reichgelt, Margie Turrin, Linda Heusser) after discussion of Draft Piermont Marsh Reserve Management Plan (DEC, 2017,

We agree that Piermont Marsh has value in storm protection, native plant communities, increased bird nesting sites, and resiliency monitoring. The issues we raise here are substantially the same as those we have raised in a variety of forums with DEC and PIPC scientists over the past four years, both in town meetings at LDEO since 2013.

Our concerns are as follows:

1) Glyphosate was defined by the World Health Organization in 2015 as a known carcinogen, and should not be used. The proposed 40-acre mowing and spraying with glyphosate (in Aqua-Pro) to increase plant diversity has major risks and recent discoveries show that it is accumulating in the environment with chronic low dose effects on animals and humans documented, as well as shifts in microbial and fungal communities, and is a possible driver for antibiotic resistance (van Brugen et al., 2018).

2) Phragmites would continue to re-colonize, and herbicide and/or mowing would have to be applied each year in perpetuity at a prohibitive cost. The Lower Hudson Valley region is so heavily invaded by Phragmites that seed source is prevalent and extremely viable due to high level of genetic diversity in the Hudson Valley (Stabile et al., 2016). A recent paper evaluating Phragmites management nationwide from 2005-2009 found that organizations spent >$4.6 million per year on P. australis management, and that 94 % used herbicide to treat a total area of ∼80,000 ha. Despite these high expenditures, few organizations accomplished their management objectives (Martin and Blossey, 2013).

3) Treatment separating the northern and southern areas of the marsh could result in an elevation decline, which might allow water to erode the marsh interior. Several studies have shown elevation decline with Phragmites removal (i.e., Hagen et al. (2007); students participating in the LDEO Secondary School Field Research Program have found this result in a test plot with black plastic coverage. Thus repeated mowing of Phragmites (coupled with removal of stems) would need to be monitored carefully for elevation change, and addition of clean sediment followed up with planting of native plants as needed.

4) Sea level is rising. The long-term history of Piermont Marsh (Pederson et al., 2005) reveals that average sedimentation rates since 1700 are about 1.1 inches/decade (2.9 mm/yr) but present sea level rise is regionally about 1.2 inches/decade (3.1 mm/yr) at the Battery, and projected to be 11-20 inches (279-508 mm) of sea level rise by 2050 (Horton et al., 2015). Attention should be given to possible sediment addition.
References: Hagen et al., 2007, Production of mummichog: response in marshes treated for common reed (Phragmites australis). Wetlands 27:54-67; Horton et al., 2015, NYC Panel on Climate Change 2015 report Ch.2: Sea level rise and coastal storms. Annals of the NY Academy of Sciences 1336:36-44; Martin, and Blossey, 2013. The Runaway Weed: costs and failures of Phragmites management in the USA. Estuaries and Coasts 36: 626-632. Pederson et al., 2005, Medieval warming, Little Ice Age, and European impact on the environment during the last Millennium in the Lower Hudson Valley, New York, USA Quaternary Research 63:238-249; Stabile et al., 2016, “Microsatellite DNA analysis of spatial and temporal population structuring of Phragmites australis along the Hudson River Estuary. Biological Invasions 18: 2517-2529; van Bruggen et al., 2018, Environmental and health effects of Glyphosate, Science of the Total Environment vol. 616-617:255-258.

The Piermont Marsh Alliance sent out the following summary of the February 5 meeting.

For those of you who were unable to attend Monday's meeting, we are providing the following summary. The room was full to capacity, primarily with Piermonters, but also with some residents of Palisades and other parts of Orangetown. Many attendees wore "No Herbicide - Protect Piermont Marsh" stickers. There were a number of scientists from Lamont and at least a dozen representatives of DEC and affiliates. Piermont Mayor Bruce Tucker opened the meeting, introducing Betsy Blair, who is Manager of HRNERR (Hudson River National Estuarine Research Reserve) and DEC Regional Marine Habitat Manager. Betsy restated the main points in the Draft Plan. The Plan can be accessed at:

DEC plans to eradicate Phragmites in the PIermont Marsh over a 40 acre area (approximately the size of 30 football fields) in the central portion of the Marsh, starting this winter with mowing, followed by application of herbicide in late summer. The project will be done in three phases: 10 acres (Phase 1 - 2018), then 15 acres (Phase 2 - 2021), then another 15 acres (Phase 3 - 2024). The DEC will proceed to the next phase only if the benchmarks of the prior phase are met, specifically maintaining surface elevation and increasing diversity of plant and animal communities.

Ms. Blair stated that the overall scope of the restoration has been significantly reduced from the wording in the original Permit of "up to 200 acres," but later stated that the DEC had never intended to treat the full 200 acres. She stated that Piermont Marsh is a national long-term sentinel study site for NOAA (National Oceanic and Atmospheric Administration) to see if this restoration will work and if the Marsh can survive projected sea level rise and accompanying increased salinity. DEC will be installing surface elevation tables in both reference and restoration areas.

Ms. Blair also stated that the Draft Plan recognizes the important role of Phragmites in storm protection by locating the eradication area in the center portion of the Marsh, at approximately half a mile distance from both Piermont and Sneden's Landing. Additionally, the DEC is supporting a study by Peter Sheng of the University of Florida designed to quantify the effect of Piermont Marsh vegetation on storm surges.

Ms. Blair presented DEC's decision to use herbicide, stating that they had reviewed alternatives and believe this to be the only effective method. She said the urgency to move forward is not due to an expiration date for the funds, but rather DEC's view that, if nothing is done, the opportunity to restore the "native marsh communities" could be lost.

The Draft Plan includes monitoring of herbicide levels before, during, and after treatment in air, water, and soil. There was a question as to where they will measure the herbicide, and the answer was "close to, but not in the Village." When asked about how much herbicide would be used, Ms. Blair did not know. The plan states that initial spraying will occur on one to three days in late summer.

Ed McGowan of the Palisades Interstate Parks Commission reported on the restoration at Iona Marsh, which in their view has been successful. This was done using glyphosate, and does involve long-term maintenance via targeted herbicide applications. In response to audience questions, he acknowledged that Iona Marsh differs from Piermont Marsh, in that it is much smaller, enclosed by both natural features and railroad tracks, and is not near any residential communities. In response to audience comments, he also acknowledged that Iona is not likely to have the same degree of nitrogen rich runoff as Piermont Marsh, again due to the absence of human proximity.

In response to questions about method of eradication, Ed stated that they had experimented with flooding to kill Phragmites at Iona, but it was not successful. It was explained the herbicide, when applied, is aimed at the tops of the plants after they have been mowed the prior winter, so that it will be absorbed by the Phragmites and not the shorter plants.

DEC's pesticide compliance manager stated that they oversee the contractors hired to apply herbicide. A question was raised about notification of recreational users of the Marsh and Tallman Park and DEC stated they would post signage to dissuade boaters and hikers from entering the treatment area. The spraying will be done via amphibian vehicles entering through Tallman Park. Maintenance spraying will employ backpack sprayers.

The preponderance of the audience's comments and questions expressed concerns about and opposition to the use of herbicide. A brief review of the comments:

One audience member pointed out that the budget, which adds up to almost $850,000, is almost entirely allocated to Phragmites eradication and related monitoring, with only small amounts for other projects. Additionally, the resident expressed concern that homes which flood get both large amounts of water and sediment (which could potentially be contaminated) and that the spraying would take place during hurricane season.

Many comments were made objecting to the use of glyphosate. There was discussion of its health effects on human, plant, and animal life, and the trustworthiness of various sources regarding its carcinogenicity. Glyphosate's "half life" was discussed, with some disagreement (14 days? 91 days?). Audience members reported that other countries had banned glyphosate as a carcinogen.

Some residents brought up aesthetic concerns, particularly relating to the use of black geotextile (25 feet wide) around some boundaries and the degraded appearance of the treatment area for a number of years.

Dorothy Peteet, a scientist at Lamont-Doherty who studies the Marsh, stated that ten scientists from Lamont had met together and were in agreement as to their objections to the Plan. They object to the use of herbicide, they believe that Phragmites will re-colonize based on the hardiness of its seeds, and they are very concerned about elevation decline in the Marsh with removal of Phragmites, and the prediction that the Marsh will disappear on its own due to sea level rise. They pointed out that the experiment with small-scale application of geotextile by high school students has resulted in loss of elevation. Betsy Blair stated she was not aware of this and would look into it.

Piermont resident and geoscientist Klaus Jacob's concerns were presented, specifically that, with the eradication of a central portion of the Marsh, the Marsh could effectively be split in two and this could lead to unforeseen consequences.

One community member pleaded with the DEC to consider an initial trial of eradication without using herbicide.

The original Permit to build the bridge included a requirement to enhance the quality of the water in the Sparkill Creek. A question was raised as to why this is not addressed in the Draft Plan, in light of the extraordinarily high levels of pollution in the Creek. Betsy stated that this requirement was met by a green infrastructure project, specifically the installation of a rain garden at Tappan Zee High School, and that DEC would not divert funds from the eradication for this purpose.

A couple of residents spoke in favor of the Plan to restore the "native Marsh plants." One person commented on the pervasiveness of herbicide pollution in our food supply and our environment; another commented on all of the sewage present in the Creek and the Marsh. They both expressed the view that spraying glyphosate would not make a significant difference.

A question was raised regarding herbicide use in the Village of Piermont; a resident from the Landing responded that Piermont Landing does not use herbicide or other chemicals for landscape maintenance and that, in general, the use of these appears not to be prevalent in Piermont.

Overall, the great majority of the attendees expressed strong objections, specifically to the use of herbicide. At the very end of the meeting, one resident asked, "Is there anything we can do to change your minds about using herbicide?" The moderator turned that question back to the audience - "Is there anything we can do to change your minds?"

WRITTEN COMMENTS ARE BEING ACCEPTED UNTIL MARCH 1, 2018, AND WILL BE RECORDED IN AN APPENDIX TO THE PLAN. Comments can be sent by mail to NYS DEC, PO Box 315, Staatsburg, NY 12580 or by e-mail to

Marthe for the PMA Steering Committee