Even before the Working Group (WG) was formed in 2021, the DSLPOA Lake Stewardship Committee had begun its program to understand and control the growth of Eurasian Watermilfoil. Lake Steward Bert Bicknell and a small group of volunteers worked for the first time with a commercial dive team in 2020, deploying mats and hand harvesting at the first four confirmed EWM sites. Each year since then the WG has considered the full range of available control options and chosen those best suited to our growth structure and budget. Each year the team has reported identification, monitoring, control and financial results to DSLPOA members and others via the AGM and association communications. Most control methods have remained unchanged until recently with the approval of two aquatic herbicides, Reward and procellaCOR FX, for use in Canada under very strict guidelines and oversight.
The WG had previously ruled out using Reward. Some property owner interest in using procellaCOR started in 2023 with its Canadian approval. The interest level increased last year with the circulation of infomercials produced by SePRO Corporation, who makes the herbicide and certifies exterminators. In late 2025 the WG commissioned U-Links to conduct an independent review of published research, manufacturer’s information and anecdotal reports regarding both herbicides for two reasons. One, to provide property owners with balanced information about the two herbicides that could legally be released into their lake. Two, to provide the WG with up to date information about aquatic herbicides that will inform future control measure decisions.
The WG’s decision for 2026 is to continue using benthic matting and hand harvesting, starting at sites 1 and 4, followed by other priorities identified before July 13. The U-Links report details a number of pluses and minuses for Reward and procellaCOR. The WG has chosen to avoid using Reward because it does not kill plant roots, meaning a program of repeat applications would be required. The WG has chosen to avoid using procellaCOR in 2026 for a number of reasons, outlined below, and will continue to monitor future research reports as more field experience with its use becomes available.
- The first stated goal of the DSLPOA is “To protect the environment of the Lakes”. To that end the WG will always need to balance the impact of EWM growth and the harm caused by herbicides.
- Long term degradation in the environment, meets most requirements of a forever chemical.
- Collateral damage to other plant species and life forms near site.
- Resistance formed by EWM following repeated usage.
- Long term toxicity is not yet known due to short time of use in the field.
- Studies regarding impact on pregnant or lactating women not yet available.
- Safe use of water for domestic or drinking purposes cannot be guaranteed since filtration and UV exposure do not remove procellaCOR.
The full text of the U-Links report is available here - https://www.dragandsprucelakes.ca/wp-content/uploads/2026/07/6443-Evaluating-EWM-Herbicide-Applications-for-DSLPOA.pdf
There will be an opportunity to ask questions before and during the upcoming DSLPOA AGM. Please join us there on Sunday, July 12.