< 2012 Proposal for Implementation of weevils in Six Mile lake | Six Mile Lake Association

2012 Proposal for Implementation of weevils in Six Mile lake

Project Description
The Six Mile Lake Association

2012 Proposal for Implementation of EnviroScience’s

at Six Mile Lake, Charlevoix and Antrim Counties, Michigan

Prepared by:

EnviroScience, Inc.
3781 Darrow Rd.
Stow, OH 44224-4035

During the past three years, the Six Mile Lake Association implemented a Milfoil Solution® (formerly MiddFoil®) program in Six Mile Lake, which lies in Antrim and Charlevoix counties, Michigan. EnviroScience’s Milfoil Solution® utilizes the Eurasian watermilfoil (milfoil) weevil, Euhrychiopsis lecontei, to provide long-term control of the growth and spread of milfoil. Six thousand milfoil weevils were stocked in areas with dense milfoil about halfway along the eastern shore of Six Mile Lake in 2009 and 12,000 were stocked in 2010. This year, the milfoil and weevil densities were monitored for the first time and 16,000 weevils were stocked in three sites.

Results from 2011 showed an overall decrease in the milfoil density and a very healthy weevil population. EnviroScience biologists found both adult weevils and various life stages in all the stocking sites this year. In addition, the milfoil at all three sites was observed to be one to three feet below the surface of the water. These factors are attributed to a program that is progressing at an acceptable rate considering the lower numbers stocked in the initial year of this program. EnviroScience recommends continued monitoring and additional stocking in 2012 and 2013 to achieve desired lake-wide control of the milfoil.

EnviroScience’s customized Milfoil Solution® includes stocking milfoil weevils into a lake, pond, or river over the course of two of more years, depending on the size of the lake and the milfoil infestation. Although every lake responds somewhat differently, experience has demonstrated that the length of time needed for the weevils to achieve lake-wide control depends total number of weevils stocked. Faster results and lower management costs in subsequent years are expected if the milfoil infestation is addressed more aggressively in the first year or two.

In most cases, noticeable weevil activity during the first stocking season may be limited and will be usually restricted to the immediate stocking areas. Over the course of the next two to three years the weevils will move from the stocking areas and spread out around the lake, ultimately reaching the density required to sustainably control the milfoil within three to five years. Biological control is a gradual management strategy therefore a Milfoil Solution® program requires stocking weevils over multiple years. This minimizes seasonal variability, allows for annual adjustments to the program based on survey data, and spreads the cost over time.

Expected control of MILFOIL utilizing the Milfoil Solution® program includes:
 reduction in the density of the milfoil (stems/m2),
 an increase in healthy native plants that serve to outcompete the milfoil,
 open areas and increased distance between milfoil stems that lead to elimination of the milfoil in the bed, and
 maintenance of the milfoil below the lake surface at a non-nuisance level

Monitoring the progress of the program through surveys is a key component in designing the most effective management strategy. Data collected during the surveys provide the information necessary to make recommendations and adjustments to the program. It also provides the client with an annual report detailing the status of the Milfoil Solution® program.

At the request of the Six Mile Lake Association, EnviroScience has prepared the following proposal, which involves establishing baseline conditions and charting the progress of the project through field surveys and laboratory analysis.


Milfoil Solution® includes three general tasks each year as outlined below. In addition to stocking milfoil weevils, baseline and post-stocking surveys allow for the continuous monitoring of the Milfoil Solution® program and the evaluation of its progress. The information collected assists in planning for any necessary adjustments for the subsequent year. Finally, an annual report provides the association with the year’s accomplishments and plans or recommendations for the next year.

Below is a detailed description of each task performed yearly as part of the Six Mile Lake program.

Task 1: Site selection, mapping and initial survey, and weevil stocking
Project sites are selected, in part, by input from the client, and in part by the presence of conditions in and around the site that would contribute to a successful propagation of the weevil population. At the time of the initial annual visit, EnviroScience biologists will tour the lake to determine potential stocking locations. Selected sites will be marked using Global Positioning System (GPS) technology. A survey of the MILFOIL bed will be conducted followed by stocking of E. lecontei weevils. The same protocol is used for each survey to allow our biologists to track the progress of the weevils. This includes taking random plant samples back to our laboratory for our technicians to look for adult weevils and its life stages – egg, larvae, and pupae – and determine the population density. At the lake, our biologists will determine the density of the milfoil and record the presence of any native plants in and around the stocking sites. Tracking the native plant community is a key component of the success of the program. The native plants will start to out-compete the MILFOIL and fill-in areas once dominated by MILFOIL. Additionally, native plants provide a food source and habitat for other aquatic life which is important for biodiversity and ensuring a healthy, balanced ecosystem. In addition to stocked sites, one or more monitoring sites not stocked with weevils, can be established to gauge the progress of the program in other parts of the lake.

Task 2: Follow-up Survey
An EnviroScience team will return 5-8 weeks after the weevil stocking to survey the stocking areas using the same protocol as the initial survey. The data from initial and follow-up survey will be used to track the progress of the program over the summer and from year to year. The final year of the Milfoil Solution® program includes one visit between July and early September to assess the overall effects of the multiple-year program.

Task 3: Reporting
A report summarizing the progress of the Milfoil Solution® program is generated at the end of each stocking year (September – December) and pursuant to the final follow-up survey. The reports include the evaluation of the data collected from the surveys, a detailed map of the project sites, and recommendations for the subsequent year’s management.

2012-2014 Pricing for Six Mile Lake

The following table indicates the total costs by year. Expenses include two annual surveys at each site, stocking, reporting, as well as travel, per diem, and equipment costs by year.

Year Total Weevils Cost for Weevils Surveys, Stocking, Report Expenses Total
2012 30,000*** $15,000 $2,600 $17,500
2013 20,000*** $10,000 $2,700 $12,700
2014 $1,500 $ 1,500
Totals 135,000 $121,500 $20,375 $31,700

*** The total weevil amount includes the two-for-the-price-of-one discount offered by EnviroScience.

Note: EnviroScience determines the expected budgets based on over 12 years of experience and the initial milfoil infestation. Each year, our biologists will re-evaluate the progress and adapt the number of weevils only if necessary.

Incentive for Multiple Year Program: Because our clients experience the best results when weevils are stocked over multiple years, we offer our program at the same 2011 price structure for subsequent years.

Terms and Agreement

EnviroScience, Inc. will provide services and organisms for application of Milfoil Solution® to Six Mile Lake as outlined in the attached proposal. The following paragraphs outline terms of payment.

Payment- Payments for each year’s costs are due in accordance with the following schedule:
-20% of the first year’s cost is due at the time of contract submittal.
-80% (remaining balance of annual cost) is due at the time of the initial stocking or survey each year.

Should the project be cancelled, delayed or otherwise postponed after May 1st of any year due to factors outside of the control of EnviroScience, Inc., 20% of the annual project cost for the year in question will be kept as a cancellation fee to defray costs associated with start up of the laboratory cultures. Any additional balance will be retained and applied to the project costs for the following year. Factors beyond EnviroScience’s control may include, but are not limited to adverse weather, high water level, and actions of outside contractors hired by the client.

Please note: Stocking priority is determined by the date we receive a signed contract and deposit. The price in this proposal is valid for 120 days from the date of issuance.

Respectfully submitted by:

Rebecca McMenamin
Sales Representative
EnviroScience, Inc.

Accepted and Authorized to Proceed:

Signature Date

Send invoices to:

Name, Address or Email

©2024 Six Mile Lake Association

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