Unencapsulated Dock Foam alternatives

In the summer of 2019, GBF helped communities do 13 shoreline clean-ups. To quickly summarize, 112 volunteers picked up an astonishing 1369 pounds of trash. ( Full 2019 report here. )

Biggest Litter Issue: Polystyrene Foam

Polystyrene FOam Litter

Of the top 12 litter items, big and tiny pieces of foam were so abundant that they could not be counted, but were estimated at over 5000 pieces. A committee was set up in the fall of 2019 to staunch a major part of this pollution at source; essentially working with the community and partners to reduce and eliminate the uncovered/'open' dock foam that is helping many docks float. This foam pollution material is formally named unencapsulated expanded or extruded polystyrene foam.

2020 shoreline cleanups are being tallied, but volunteers report that this type of litter has unfortunately not disappeared at all. There are ways we can help. One strategy is to inform current dock owners about alternatives to unencapsulated polystyrene foam for docks. You can jump right to that, or read other information on effects and further potential actions to follow or join by clicking on menu titles below.
Polystyrene Foam Litter REport

For your new dock, avoid unencapsulated 'dock foam' ( polystyrene ) . It may seem cheaper, but it really isn't when you factor in the problems.

Find out why in GBF's New Report: Problems with Polystyrene Foam. Environmental fate and effects in the Great Lakes. The report was one of the objectives of the, Say 'NO' to Dock Foam committee that was set up in the Fall of 2019. The committee is also working to inform sellers, consumers, municipalities, and other stakeholders about the environmental impact of unencapsulated foam used to float docks, and encourage people to seek alternates as soon as they can. The committee is further engaged in pursuing the elimination of open foam used for docks in the future market place. Our deep appreciation goes to the Say "No” to Dock Foam Committee comprised of staff and volunteers. Thank you especially to volunteers: Peter Adams, Stella Juhāsz, Erika Kramer, Sue McPhedran, Brenda Royce, and Sandy Thompson. Thank you to GBF’s Brooke Harrison and Heather Sargeant, and the University of Toronto’s Lisa Erdle for their contributions to the committee. Thank you to JUNCTION59 for digitizing the report. A final thanks to all the sellers, and environmental managers who provided information when interviewed.

Some key points form the report:

Polystyrene Foam

      • More commonly known as Styrofoam®, polystyrene (PS) foam is widely available, cheap, and often used in food and beverage containers, building insulation, and floating docks


      • One way polystyrene foam pollutes the Great Lakes is through the fragmentation of expanded polystyrene (EPS) and extruded polystyrene (XPS) used in docks and floats.


      • When unencapsulated PS foam docks and floats come into contact with their surroundings – sun, wind, waves, ice, and burrowing animals – the foam can break apart and be released into the environment. Small foam pieces are microplastics(plastic <5mm), which are persistent in the environment and pose a risk to fish and wildlife.


      • PS foam can hurt wildlife by ingestion through physical damage, including blockage and abrasion, and through exposure to chemicals. PS foam can contain two types of chemicals: (1) additives and polymeric raw materials (e.g. monomers) originating from the plastics, and (2) chemicals adsorbed from the surrounding environment. Overtime, these chemicals can leach out of plastics and often these leachates can act as toxic or endocrine disrupting chemicals (Hermabessiere et al., 2017).


      • Laboratory experiments show negative impacts of PS on growth, survival, feeding and swimming behaviour, hepatosomatic index (HSI), and reproduction (Cole et al., 2015; Sussarellu et al., 2016; Qiang and Cheng 2019; Yu et al., 2018). Under certain conditions, PS foam leaches styrene, benzene, and ethylbenzene which have known toxic properties (Thaysen et al., 2018). The leaching of PS monomers is one of the reasons why there is greater concern with polystyrene relative to other types of plastic.


      • PS foam is one of the top items of debris found on shorelines, beaches, and surface water around the world, including the Great Lakes – St. Lawrence River basin
Important notice

This information is for suggestion only. It was compiled by volunteers. Although we do our best, it may not be complete and there may be mistakes. If you decide to purchase a dock, it is your responsibility to verify information yourself that works for you. There are also suggestions from the community using materails whose orginal intent is not for making docks, and have not been qualified by professionals or companies for dock-making and use, and therefore is greater risk for you to assume. We are also very interested in information you think needs correction, or if you have alternative ideas; and if you can share those, please email david.sweetnam@gbf.org.

Also, any references to any particular retailer or seller are not an endorsement, it is simply as a reference to information that could not be gleaned from an unbranded source at this time . Georgian Bay Forever has no materially interest in any manufacturer or seller mentioned.

An important point: there is NO dock that does not have an impact on the environment. However, there are options that are better than unencapsulated polystyrene foam which fragments, littering widely and never going away - just breaking down into microplastics.

In terms of pricing, alternates are generally more expensive, but tend to last longer. Looking at one version of alternates - unencapsulated dock foam floats with cedar top vs. HDPE cubes floats with cedar top, the alternates HDPE depending on size were 10 to 31% more expensive (bigger sizes had less of a gap).

These suggestions are in no particular order. A dock choice is based a variety of factors that work for your unique situation.

1) Modular Docks (cubes) made with High Density Polyethylene (HDPE)/Hard Plastics.

CAUTIONARY UPDATE - April 2022. This Spring, one volunteer noted to me that their module had cracked. The particular module seemed to then emit small balls of polsystyrene foam...a disaster. We do not know how widespread that is (is this a very rare occurence etc.?) This kind of emission from a rupture is very bad. Therefore if you can avoid "filled modules" and go for air ones or see the other options - pontoons for example - that's a better/good precaution. If you have to go here - inquire how they are filled (is it a solid closed cell filling in one fused body which is better or just air blown polystyrene bits and balls and not fused and therefore something to be avoided). And, if you can inquire about their encapsualtion thickness, we don't know for sure - but it could be that .125 inches is not enough for Georgian Bay - look for thicker. Also, if you do have modules that are filled, take them out in the winter and store them carefully. We are going to keep investigating. CLOSE ON THE UPDATE.

Air filled OR filled with extruded (closed cell) polystyrene OR filled with closed cell polyethylene foam in one fused body inside ( encapsulated by the wall of High Density Polyethylene). If you need a foam fill, which are more expensive - look for the filling foam to be closed cell with a fused body inside. Foam filled ones can have longer guarantees and are suggested to be more stable, but also use more plastic material, and if they rupture are a concern.

Thickness of walls of plastic. Looking at the thickness of the walls of the hard plastic surrounding your foam or air (even better) will be important. However, we do not know what an appopriate thickness should be, but if anyone has some comments based on their experince, please email heather.sargeant@gbf. org. Most seem to be at a minimum of .125 of an inch or greater (Reference Techstar). Some air-filled cubes have walls that are .3753 inches thick. Logic would seem to indicate, if your dock or raft gets battered around by boats and wave action - the thicker the walls are the better.

Benefits: Estimated to last 30 to 50 years (if offered, warranties are often quite a bit less). Modular, come in squares about 36.5 x 48.5 x 48.5 cm (expand as you wish) adn rectangles, but there are many other sizes and types. Easy to put together and store - lock in place and carry separate pieces. If it is foam-filled, they will be heavier. Comes in lots of colours.

There are options that sometimes allow them to be covered with wood planking, to give that more traditional look. There are also aluminum framing options. Some manufacturers use recycled plastic in the manufacturing of the cubes helping reduce plastic going into landfills.

ADDED NEW APRIL 2022Ruptures - GBF has had one report of a rupture of the encapsulation of a "filled" module . This is a problem if they are filled with loose polystyrene as there will be significant emissions of tiny balls of polystyrene. A huge, huge litter problem. We do not know if this is what all "filled" modules are like. As above: If you have to go here, either try air only or inquire how they are filled (is it a solid closed cell filling in one fused body which is better or just air blown polystyrene bits and balls and not fused which should be avoided). And, if you can inquire about their encapsulation thickness, we don't know for sure - but it could be that .125 inches is not enough for Georgian Bay. Also, if you do have modules that are filled, take them out in the winter and store them carefully. We are going to keep investigating.

Some pollution risk - thick plastic floats can leach over time, but they are not going to fragment and disperse to the degree of unencapsulated dock foam through the forces of nature and animals burrowing into them.

They are floating and modular - so when the waves roll – they undulate more (less stability); choosing systems with larger modules can offset to some degree.

2) Pontoon Based Docks made with High Density Polyethylene (HDPE)/Hard Plastics.

Estimated to last 30-50 years or even more (if offered, warranties are often quite a bit less). More stable as less modular. Topped with wood planking, to give that more traditional look (the wood would likely not last as long).

Some manufacturers may use recycled plastic in the manufacturing of the pontoons helping reduce plastic going into landfills.

Thickness of walls of plastic. Looking at the thickness of the walls of the hard plastic surrounding the pontoon will be important. However, we do not know what an appropriate thickness should be, but one seller (NYDock) notes the most common thickness is 5/8”, although there are other thicknesses.

Same as above- some pollution risk - plastic floats can leach over time, but they are not going to fragment and disperse to the degree of unencapsulated dock foam through the forces of nature and animals burrowing into them. WE assume these are not filled - but good to ask. It they are filled with loose foam - becasue if they rupture - that is an emissions disaster.

3) Pontoon Based Docks made with Steel Pontoons

Durable. More stable as not really modular. Topped with wood planking, to give that more traditional look. Epoxy is applied to the steel to keep from rusting.

Some pollution risk - epoxy is plastic based and chemicals could possibly flake into the water over time. The epoxy may need to be replaced over time to keep the pontoons from rusting. ( GBF Asked a manufactuer/seller to verify, no response, but this point was noted by someone who recently bought this alternate. If you ask the question and find out, please email heather.sargeant@gbf.org)

Printable takeaway: Click HERE for a printable form from a committee member of these 2 above options.
4) A do-it-yourself - potentially lower cost option: Barrel Docks

Please remember, barrel materials are NOT intended for docks, so these are not qualified by professionals and companies for this specific use, but community members have used this as an option successfully.


Less upfront cost.


Stability may be an issue. There are instances of how to make these on YOUTUBE if you search for it.

Heavy-duty plastic barrels are the base 'float' materials, and they have the some leaching environmental risk over time. If it is a used barrel, that's great from a re-purposing POV; but ensure it is very clean.

5) If your dock has Unencapsulated foam, some Temporary Mitigation Suggestions to Minmimize the Spread of Foam Litter Until You Can Properly Encapsulate.

There are some helpful practices here to prevent some litter in the downloadable document, but note:

Concerns: Ontario Law 228 comes into force in May 2023. The Retrofitting suggestions may be a lot of work, and then might not be legal after that. It may/probably would be more beneficial to explore and plan for the other options for your dock with better alternatives that work more towards zero emissions of foam. Note the law says "A person who constructs or reconstructs a floating dock, floating platform or buoy shall ensure that any expanded or extruded polystyrene in the dock, platform or buoy is fully encapsulated."

Click here for a download of the temporary mitigation measures.
Some helpful hints on Barrel Docks from a volunteer from Bayfield-Nares Islanders' Assocation

As can easily be seen, there are three sets of barrels at each dock side - which is usual, two at each end, and either one or two in the middle, depending on length of dock. The width should be a minimum of eight feet, better at ten or twelve, to provide a good firm surface, with lots of support.

There are two sizes of barrels commercially available. The larger ones are of roughly 23 inch diameter and 35 inch length. They are easily transported - and one site where they can be purchased is at Tay Rd., just off the 400, north of Waubaushene. Take the exit at the first bridge after W., go around and over that bridge, turn right, or north, and the site is on the curve that the 400 makes going to Pt. Severn. Check the barrels to see that there are no faults, and that the bungs are installed. Last year (2019) they cost under $35 each. Other possible sites will have lower prices.

barell dock picture

For construction, just make the dock accessible to whatever size of barrels that have been supplied, and they rest inside, under the floorboards. They need a box-like "pen" to hold them in place - the underpinnings of the dock can easily be made to accommodate this. They will last quite a while, and it is easy to tell when they have lost their buoyancy, as they will thump on the underside of the dock, letting anyone who walks on it know which barrel needs replacing.

For replacement, if there is access to a hoist, that is the easiest way, as the dock can be lifted by the hoist, and the barrels removed and replaced with no problem. If no hoist is available, the removal of the floorboards of the dock is in order, over the sinking barrel. Slip in the new one, replace the boards, and all is well. One additional "trick" is to try to have the barrel rotated so the bung is above the water. A further hint is to keep the dock away from rocks, as the barrels are easily damaged by rubbing along the shore, having relatively thin skins. As well as relative low costs, ease of insertion and removal, and effectiveness, the fact that the part under water is an arc enables the ice to lift the dock, unlike a rectangular shape, where the support might be crushed. These docks can easily provide great service for many years.

As noted above, we can always learn more from you.

There are lots of different kinds of docks for different purposes. This is by no means a comprehensive list. We hope that if you have one major takeaway, it is - unencapsulated foam is huge source of shoreline litter; consider and research alternates to that.

We are very open to receiving information from you about other alternates to look into, or your own experiences and learnings with working towards more environmentally friendly choices for docks. Please email david.sweetnam@gbf.org.

Other sources of informational sources about dock choices for your interest:
2017 Cottage Life Article - (https://cottagelife.com/design-diy/modular-docks-one-piece-at-a-time/)
Connecticut River Conservancy - Swap your dock information (https://www.ctriver.org/our-work/source-to-sea-cleanup/swap-your-dock/)
AND Connecticut River Conservancy - Swap your dock information (https://www.ctriver.org/wp-content/uploads/CRC-30yr-Floatation-Comparison-Final.pdf)
Dismantling old docks. A volunteer for the Say 'No' to Dock Committee has put together these tips to help you figure out how to dismantle your old dock. Please note: Your safety is your own responsibility.

Click here for tips on how to dismantle your old dock

Unencapsulated foam that doesn't end up as litter on the shorelines and in the water - seems to go straight into the bins for landfill.

Sad and frustrating especially given that Ontario is rapidly running out of landfill space, with seemingly little known about where new landfills will go. We need to use materials that last a lot longer and can be re-used for a long-time. Another good reason that if you are replacing your dock, to NOT use new unencapsulated foam with its estimated lifespan of maybe 10 years and all the fragmented litter pollution that into the waters and shores all around.

TIP abour cleaning up fragments: A GBF donor suggested using a wet/dry vac on shore if there are many fragments, say for exmaple after a storm, or if you are taking a part an old dock. (using appropriate safety precautions as recomended by the wet/dry vac manufacturer).

To extend the life-use of this product if you can, consider this innovative use volunteered from a Georgian Bayer:

  • 1. Archery targets - if you are an archer, this old foam is a great place to put your target sheets on. Thank you Andrew Kolody.
  • 2. Use as "base" blocks for holding up boats during winter storage. "Winter boat storage as boats are kept off the ground on the billet pieces. They are lighter than using 6"x6" PT (Pressure Treated Pine) pieces for the same purpose and easier on the hull." Thank you Andrew Kolody and Ted Simmonds.
  • 3. Your suggestion...please email david.sweetnam@gbf.org with a suggestion on how to re-purpose.

That being said - it is better this already used foam go in landfill than scattered as litter in the water where it will continue to breakdown into microplastics and risk getting into the stomachs of aquatic and other wildlife.

Why is unencapsulated polystyrene foam used in docks difficult to recycle?

Generally, according to the research GBF has read and put in the report Problems with Polystyrene Foam, "While there are some efforts to recycle used PS foam floats, these materials have a low recycling rate. Recycling of EPS and XPS [types of poystyrene foam] is possible, although due to high costs of transport and its low value, PS foam is often not recycled (Ragan, 2007). Dock foam can be especially expensive to transport and dispose of since used dock foam is often waterlogged (Missouri Department of Natural Resources, 2006). In some areas, recycling programs have been developed as an effort to recover the material where dock foam has been banned (Missouri Department of Natural Resources, 2006). However, these programs have seen limited success due to costly landfill tipping fees for waterlogged foam and no commercial market for PS dock foam (Missouri Department of Natural Resources, 2006; “Sheltered workshop recycling dock foam,” 2016)."

Futher details:

The Township of The Archipelago (TOA) has clarified to GBF that foam from docks go into landfills. If you are a resident, and take your polystryrene foam from docks, there is no charge to despose of it at a waste trasfer station, but it must be in a "manageable" size. It would go into the household waste bin.

Township of Georgian Bay, District of Muskoka. I am waiting for this information to be clarified by the District of Muskoka (Georgian Bay Township).

Abandoned Docks

These docks can often be a source of litter as they can be made with unencapsulated polystyrene foam, and seem to be more prevolent with wilder stroms and higher water.

It can be a challenge for community associations who are striving to help with shoreline litter to tackle this issue with their community volunteers.

The Township of The Archipelago (TOA) is working with community associations within its jursidiction to determine the scope of how and where abandoned docks might be, in order to see if TOA can assist in some way. If your community is within TOA, and you know of an abandoned dock, please contact your local community association to help identify it or contact david.sweetnam@gbf.org.

Ted Simmonds from Bayfield-Nares Islanders' Association is an inspiration. He worked to dismantle about 20 docks in his community. If you can find a Ted(s) in your community, those volunteer efforts are an amazing contribution that helps stop pollution. Click on the picture below to learn about what Ted did.

picture of Ted
The Township of The Archipelago (TOA) and MPP Miller, Parry Sound-Muskoka

  • UPDATE: MPP Miller tabled a Private Member's Bill 228: Keeping Polystyrene Out of Ontario's Lakes and Rivers Act which is designed to reduce polystyrene pollution by requiring any polystyrene foam used in the constructions of docks and rafts to be fully encapsulated. Status: It has had its first reading. Find the Act and status here: Bill 228.
    BILL 228 HAS PASSED THIRD READING (May 13, 2021) AND WILL BECOME LAW. IT should come into force within about 2 years of passing.
  • Earlier and other efforts: TOA organized a delegation to the Honourable Jeff Yurek, Minister of the Environment, Conservation and Parks on the dock foam litter issue at the August 2019 Association of Municipalities (AMO) Conference to ask for a ban on unencapusulated dock foam. TOA asked GBF to present the context (eg.GBF's 2019 shoreline cleanups report) and the effects of this pollution (from the GBF comminssioned report of peer-reveiwed science papers, Problems with Polystyrene Foam: Environmental fate and effects in the Great Lakes.
  • Thank you TOA. In 2020 and 2021, TOA provided support to this effort, which falls under GBF's larger project - Divert and Capture: The fight to keep microplastics out of our water.

The Township of Georgian Bay (GBT).
    GBF and the the Say No to dock committee talked to GBT in 2019 and 2020, and they have have agreed to share educational materials. GBT shared an article about swapping out dock foam in its July 2019 newsletter. See page 6. Additionally, GBT has provided financial support to GBF for plastic mitigation efforts in 2021.
  • Share information with your friends and family about unencapsulated polystyrene, and encourage them to look and see what is making their dock float. If you want GBF to present to a group of 25 or more about this issue, please email heather.sargeant@gbf.org.
  • Donate to GBF. We're a charity that works so hard to make every one of your dollars count towards protecting the water. Please donate today.
  • If you have any information about alternatives to unencapsulated dock foam, or wish to share your experiences around swapping out your dock that can benefit others, please email heather.sargeant@gbf.org.
  • If you have any ideas on extending the life of dock foam that is just going into landfill, please email heather.sargeant@gbf.org.
  • Please notify of us of sellers of unencapsulated dock foam in docks. Our committee will send them educational informtaion about the littering effects of this product. Email heather.sargeant@gbf.org.


Georgian Bay Forever thanks these funders for their contributions to mitigating polystyrene foam pollution, part of GBF’s Divert and Capture project.

This project was undertaken with the financial support of the Government of Canada through the federal Department of Environment and Climate Change, Ce projet a été realisé avec l’appui financier du gouvernement du Canada agissant par l’entremise du ministère fédéral de l’Environnement et du Changement climatique, the RBC Foundation, Patagonia, J.P. Bickell Foundation, The W. Garfield Weston Foundation, LUSH, The LeVan Family Foundation, The Charles H. Ivey Foundation, the Township of The Archipelago and GBF’s many passionate donors.

We want to thank these volunteers from the Say'No' to DOck Foam Committee comprised of staff and volunteers. Thank you especially to volunteers: Peter Adams, Stella Juhāsz, Erika Kramer, Sue McPhedran, Brenda Royce, Sandy Thompson, Katherine Denune. Thank you to GBF's Brooke Harrison and Heather Sargeant, and the University of Toronto’s Lisa Erdle for their contributions. A final thanks to all the sellers, and environmental managers who provided information when interviewed.