First Loon Lake Treatment for 2020

Aquatechnex biologists are going to target Eurasian Milfoil in a few spots on the lake that were not infested or treated this past year this week.  The probable date is Thursday and signs will be posted on affected properties prior to application.

We will be using Procellacor herbicide, there are no swimming or potable water restrictions on the water in the treatment area, there is a 24 hour restriction on drawing water to irrigate ornamental plants.

This treatment will not affect the majority of the homes on the lake, we will also be doing an extensive survey and will be determining if and when additional treatments are necessary.

A map of treatment areas can be accessed here Treatment Map

Loon Lake Procellacor Treatment July 9th

Aquatechnex biologists will be posting affected areas of the lake on Monday July 8th and treating areas on the treatment map on Tuesday July 9th.  The treatment map can be viewed at this link, Treatment map, click here

ProcellaCOR is a new aquatic herbicide that is extremely effective on milfoil and hybrid forms of milfoil present in Loon Lake.  As part of a DOE grant, our team tested it against plants from the lake in a concentration exposure time study conducted last year.  ProcellaCOR was added to the Ecology permit effective July 5th.

ProcellaCOR treated areas can be used for swimming and fishing with no restriction just after application.  ProcellaCOR can be used in potable water reservoirs with no restriction on delivery for potable use so there are no drinking water restrictions if anyone draws from the treatment area for this purpose.  There is no restriction on irrigating turf grass from the treatment area, there is a 24 hour restriction on using water from the treatment area to irrigate other ornamental plants.

Questions?  Call 360-527-1271 and our operator will get us a message and we will get right back to you.

Loon Lake Milfoil Surveys this week

Aquatechnex biologists will be performing the first Eurasian Milfoil survey of the year this week on Sunday and Monday.  This will involve our boats collecting hydro-acoustic data to map shape and location of aquatic plant beds, and visiting those sites to determine species composition.  We will also be hosting a tour of the lake with the Steering Committee members Monday afternoon and reporting to their meeting Monday evening.

The Washington Department of Ecology has issued a new permit to utilize the new aquatic herbicide Procellacor with treatments allowed after July 5th.  It is our objective to have Loon Lake treated early the following week.  This product places no restrictions on water use for drinking supply, swimming or fishing.  You can use the lake water to irrigate turf grass with no restriction.  There is a 24 hour restriction on using water from treatment areas to irrigation other plant species.


2019 Invasive Aquatic Weed Management Program kicks off first week in June

Aquatechnex biologists will be starting this year’s aquatic plant management work with a detailed survey of Loon Lake the first week in June.  This effort will involve hydro-acoustic mapping of the plant beds and a detailed examination of the plant community species make up.  Loon Lake has seen infestations of Eurasian and Hybrid forms of milfoil and Curly Leaf Pondweed.  Both species are detrimental to the health of the lake and beneficial uses.

Hybrid milfoil poses the major problem in the lake at the end of 2018.  The Loon Lake LMD through Stevens County have received a grant to develop treatment strategies to confront this problem plant.  This involved the collection of plants from the lake, DNA testing to determine hybrid strain, shipping plants to the Aquatic Plant Control Research Program at North Carolina State University and subjecting them to a concentration exposure time study with a number of herbicides.  We will be using this information to start operational control work this summer.

The new herbicide Procellacor performed very well in these laboratory experiments and will be used in Loon Lake soon after it is approve for addition to the Washington State Department of Ecology permit in early July.  This technology should provide long term control in Loon Lake.

We will update this with maps of the treatment areas as the survey is completed.  If you have any questions please address them to

First Eurasian Milfoil and Curly Leaf Pondweed Treatment Scheduled Week of June 25

Aquatechnex biologists will be treating the invasive aquatic weeds in Loon Lake early the week of June 25th.  The plan is to get the lake posted with shoreline signs as required on Monday June 25 and treatments will start early morning on the 26th with anticipated completion by noon.

A treatment map can be viewed by clicking on this link.  June 2018 Treatment Map and Water Use Restriction Zones

There are water use restrictions that will be in place.  Ecology recommends a 24 hour swimming restriction within the treatment areas (does not apply anywhere else in the lake, see map), 2 days for drawing water for irrigation from treatment zone.  Please observe the signs on you property for further information.

2018 Efforts to Manage Invasive Aquatic Weeds Underway

Aquatechnex has been working with the Loon Lake LMD to develop a treatment program to deal with the Hybrid Milfoil present in Loon Lake, and to target a new invader, Curly Leaf Pondweed.

The Hybrid Milfoil problem is being addressed by a operational research program funded by the LMD and the Washington Department of Ecology.  In the fall of 2017, milfoil plants were collected and shipped to a research lab that specializes in management of invasive aquatic weeds at North Carolina State University.  These plants were established and grown out, separated into study tanks and treated with multiple rates of different aquatic herbicides.  This research will allow us to pick the best combination of herbicides and rates to target this growth in the coming year.

In the shorter term, our intention is to treat the growth present with Diquat, a contact herbicide that will provide rapid relief and knock down the problem vegetation in the littoral areas of the lake.

We will be mailing the required public notice to shoreline homeowners this week, and scheduling treatment either the week of the 18th of June or early the week of the 25th.

We will be posting the exact dates and a treatment map at this site closer to the date of treatment so please check back.

Summer of 2017

This past year, Aquatechnex biologists discovered that Loon Lake was subject to a infestation of Hybrid Milfoil, this plant is a cross between Eurasian Milfoil and native northern Milfoil.  We discovered this when this plant did not respond as rapidly to a systemic herbicide treatment in June of last year as it should have.  We then treated with an second herbicide in September of last year.

This year we are working with your LMD to develop treatment strategies to address hybrid milfoil.  This work is partially funded by a grant that we helped your LMD obtain from the Washington Department of Ecology.  The plan is to collect plants, do additional DNA analysis, perform herbicide studies to optimize a recommendation then provide control.

At this point it appears that the combination of both herbicide treatments last summer has suppressed much of the problem growth in the lake.  We plan to evaluate this in the coming week and start the process of sampling and making treatment decisions.  This is primarily based on member of your LMD doing survey work and not locating problem growth in the lake to this point.  Should that change we will address the situation.

Hybrid Milfoil Discovery and Treatment Update

Aquatechnex was hired by your LMD to implement our proposal submitted two years ago to target and control Eurasian Milfoil in June of this year.  We mapped milfoil present in June and performed an application to target Eurasian Milfoil in late June.  The results have been monitored and have been found to be lacking.

One condition that has been appearing in some Pacific Northwest Lakes, especially in North Idaho, is a hybrid milfoil which is a cross between Eurasian and Native milfoil species.  This can happen over time when 2,4-D treatments have been used extensively and aggressively.  The only way to really confirm this is through DNA testing.

In late August our team collected and shipped nine samples from a number of sites in Loon Lake to GenPASS, a lab that specializes in aquatic plant DNA testing.  All nine samples came back today as hybrid.

We will be posting Loon Lake today and treating tomorrow with Diquat herbicide.  Diquat is a contact herbicide that will kill all of the milfoil plants in the water column and provide relief from the problem posed.  Diquat is not a systemic herbicide, but we will work with your LMD board over the winter to develop a treatment strategy to target this new threat to the lake.

For more information,

A treatment map will be posed later today after discussion with LMD members.

Update July 23rd

We have received a question regarding upcoming.  The way the Washington Department of Ecology permit is developed, we are required to provide residents notice of treatments and we generally create a few different treatment windows so we don’t have expend your funds to notify people a number of times over the summer.

There is no treatment scheduled for the week of August 1st.  We plan to do survey work on the lake during this week to review conditions, the results of the first treatment, any need for touch up etc and will be in communication with your board in this regard after that has occurred.