First Sonar herbicide treatment tomorrow Tuesday May 12th

Aquatechnex will be making the first of three aquatic herbicide treatments to areas of Lake Stevens tomorrow Tuesday May 12th.

Sonar herbicide is applied under a permit from the Washington Department of Ecology.  The permit requires that signs be posted on affected properties adjacent to the treatment area and for 400 feet in each direction.  The sign will inform you that there are no restrictions on using the water for potable or domestic use, there is no restriction on swimming, there is a irrigation precaution that Ecology makes us put on the sign we are required to post that says use precaution irrigating for 14 days.  The label allows irrigation of turf and ornamentals at the rate we are applying after seven days at high rates and 48 hours at the rates we are applying.  We are required to post this sign by the Ecology Permit.  This applies to water drawn from the treatment area in the lake, not other water sources.

Sonar is a slow acting granular herbicide, the pellets will be applied to the areas on this map.  Sonar Treatment Areas On Lake Stevens

Two more applications will be made at approximately 2 week intervals.  Questions please call 360-527-127, this goes to our answering service and they send us texts and emails quickly or

Sonar Herbicide Treatment to Start First Week in May

The Lake Stevens Aquatic Plant Management Program will be starting the first week in May.

There will be three potential components to this plan.  The program initially was focused on managing the invasive aquatic weed Eurasian Milfoil.  Previous work has been largely successful in this quest.  While milfoil has been largely removed from the lake, other nuisance aquatic weed species have started to impact residents on various parts of the lake.

While we have a number of herbicide tools that are selective for Eurasian Milfoil that are not subject to a fish timing window, we are more limited in terms of tools to deal with some of these other species.  Some herbicides can not be used until after July 15th because of permit conditions.

Sonar aquatic herbicide is not subject to a fish timing window and does have activity on many of the problem species present in the lake.  It is a fairly unique product in that it is very slow acting, requires more than one application and has to be applied to larger treatment sites to be effective.  We have mapped areas on the lake that where this product can work and these will be treated three times at about two week intervals.

Sonar has no real water use restrictions.  It can be applied to drinking water reservoirs and there are no swimming restriction.  We will be applying it at a rate that does not impact use of lake water for irrigation.

A map of the treatment sites is presented here Sonar Herbicide Treatment Map

Other work on the lake will include a Eurasian Milfoil survey in late May, potential treatment of areas found to have milfoil with ProcellaCOR herbicide in June and additional nuisance aquatic weed work as necessary after the July 15th fish timing window opens.

2020 Aquatic Weed Program planning has begun

For the past decade, Eurasian Milfoil and other nuisance aquatic weed growth has had an impact on the Lake Stevens Community.

Eurasian Milfoil has successfully be reduced to close to non problematic levels in the past few years via selective treatments.  Our team will be performing an survey for remaining plants and designing a treatment program as necessary in May of this year.

Other problem weed growth has begun to plague the lake however.  Many of the species present now do not respond to the milfoil herbicides and have to be treated differently.  In addition, many of the products that work on these species have a fish timing window that does not allow their application to the lake to occur until July 15th.

We do have one technology, Sonar Aquatic Herbicide, that is not subject to the fish timing window and we will begin to deploy it in select areas of the lake later this month (April).  Sonar is a very slow acting product and a few of the weeds present are a bit resistant to it, but it will provide relief and we will touch up as necessary on July 15th with others if necessary.  Sonar is also a product that is not very effective unless large contiguous areas are treated, it does not work well on narrow shoreline bands of plants, so we will be using it where it can be effective.  We will be posting treatment map shortly and those adjacent to treatment areas will be notified 10 days prior to starting.

If you have questions please contact us at 360-527-1271 or click here for email link


2019 Alum Treatment Ready to Go

Each fall Aquatechnex treats Lake Stevens with Aluminum Sulfate to capture and sequester phosphorus in the lake water column.  Lakes with higher levels of phosphorus can experience Harmful Algae Blooms, by using the technique to capture and tie up this nutrient we reduce the potential for this condition to occur.  This is a recognized lake management practice and is performed under a permit from the Washington Department of Ecology.

Our team will be on the water most of the week, we will be filling our application vessel at Wyatt Park and treating segments of the lake each day.  The plan was to treat starting at 7 am this morning and work till about Thursday Noon.

We are experiencing a delay at this point however as the delivery trucks are stuck in a major accident on I-5.  We expect to get going at some point this afternoon.

Check back for updates.

First Treatment Scheduled Next Week

While the previous years treatments targeting Eurasian Milfoil have been largely successful, there remains problem aquatic weed growth in some portions of the lake.  The City has asked us to target this nuisance growth where densities warrant application.

Aquatechnex staff will be posting signs on affected properties this coming Monday, July 22nd and will be treating areas on this map on Tuesday July 23rd.  We will be using two herbicides, Aquathol K and Littora.  Both are liquid herbicides and will be applied to the surface of the lake and in and around affected docks.

These herbicides do not have a federal swimming restriction, but the Washington Department of Ecology requires us to post 24 hour swimming restriction within the treatment areas and for 400 feet in both directions along the shoreline.

There is also a 48 hour irrigation restriction for anyone drawing water from the treatment area to irrigate.

A treatment map can be viewed at this link, Treatment Map

Survey work and Eurasian Milfoil Control for 2019

The Washington Department of Ecology has finally added the herbicide ProcellaCOR to the permit for use in our state.  This herbicide was approved by the US EPA in February of 2018 (article in the Waterline Newsletter at this link

ProcellaCOR is an extremely effective product for Eurasian Milfoil and should provide excellent and long term results.  In addition, this product can be applied with very minimal impact on lake use.  ProcellaCOR has been cleared for application to potable water supply reservoirs with no restrictions, there are  no restrictions on swimming in treatment areas the day of application, there is no restriction on using water from treatment area to irrigate turf, there is a short restriction on irrigating other plants such as ornamentals of 24 hours.

This product can be applied after July 5 with the permit becomes active.  We will be doing a survey of the lake to map treatment areas and posting that information here shortly.

There have also been increasing questions about other aquatic weeds in the lake.  Some areas of the lake have increasing growth of native species to the point where they are becoming problematic.  We will also be looking at these areas and working with the City to address this.  There is a fish timing window on the products used to target these species and that doesn’t open until July 15th.

Please check back for treatment maps and information as we approach the week of July 8th when the first ProcellaCOR applications are scheduled.

2019 Aquatic Plant Management Program kicks off first week in June

Lake Stevens has been subject to an infestation of Eurasian Milfoil, a invasive aquatic weed for a number of years.  A program was instituted about 6 years ago to manage this infestation.  The population has been managed effectively and the impact on the public has been reduced significantly.

This summer we have a new tool available to us, Procellacor herbicide is a new and extremely effective tool we will be using to target the remaining Eurasian Milfoil in the Lake Stevens system.  Survey work will be performed in June and the treatment will occur the second week in July about July 8th.  This is because the Washington Department of Ecology is completing it’s work to add this new product to the permit they manage to allow treatments.

ProcellaCOR can be used in potable water reservoirs with no impact on drinking water delivery, there are no swimming restrictions, no fishing restrictions and no restriction on using water from the treatment area to irrigate turf grass.  There are very short irrigation windows for other ornamental plants.

We will be posting survey results and a treatment map in mid June, please check back.