Condition of the Pond Committee's 1981 Report

This is a report prepared by a Foster's Pond Corporation committee of Pond residents. The Committee canvassed all of the available alternatives for dealing with the weed problem, ultimately recommending the purchase of a weed harvester.

TO: Rebecca Backman, Pres. Fosters Pond Corporation
SUBJECT: Condition of the Pond Committee, Meeting Report

On 8/19/81 a meeting of the Condition of the Pond Committee was held at my home on Willard Circle. All Committee members and alternates were present except for Janet Kenney and Pat Phillips.

Prior to the meeting, Mr. Gerry Smith, an Aquatic Biologist from Aquatic Control Technology, Inc. Wayland, Mass. surveyed the Pond by boat with David Brown and me. He identified many species of weeds and algae present in the pond. The predominant species were:

Dispersed Algae: Blue-green (type unknown)

Filamentous Algae (Mats): Anabaena

Attached Weeds:

- Cabomba (heavy growth in channel)
- Coontail
- Allidia
- Bladderwart
- Tapegrass
- Pond Weed

Mr. Smith discussed the control strategies available to us for treatment of the identified weeds and algae:

Chemical Weed Control. Applied once a year affective for most types of weeds. Nutrients in weed will be released back into the water within 30 to 60 days creating a problem later. Reduction of the weeds will encourage a larger growth of algae. Standard treatment chemicals won't control the Cabomba which would eventually take over the entire prolific growth area of the pond. Cost approximately $150/acre or perhaps $5,000 for 30 to 40 acres.

Lower Water Level. With our dam the water could be lowered approximately 3 feet. If done correctly winter kill would help control some of the weeds in the shallow areas at minimal cost. Most effective if exposed areas were cleaned of weeds during the draindown. Won't kill several of the weeds we have and won't affect the algae. Won't remove nutrients. May be very difficult to get necessary permits and neighborhood consensus, etc.

Wet Dredging. Involves pumping of bottom muck in a slurry from a barge to another "large" holding pond. Would take a year or more to complete. Cost $1/2 million for 30 to 40 acres.

Chemical Algae Control. Can be very effective at holding algae in check. Cheapest and most effective is copper sulfate. Would be applied to entire pond 2 or 3 times a season. Would not control weeds and may actually encourage their growth. A license to apply would be required. Cost $1,000 per treatment.

Reduce nutrient Input to Pond. Phosphates of major concern. Come from fertilizers, household detergents and human wastes. Suggested a program to eliminate the use of phosphated laundry detergents. Was not aware of any non-phosphate dishwashing detergents. [Editor's note: Since this report was written, phosphate-free dishwashing detergents have become widely available.]

Light Screening. By covering bottom with a sun screening material weed growth can be controlled. Mr. Smith brought a piece of literature on a product called Aquascreen. This material is very expensive and therefore should be considered for small areas only.

Mechanical Weed Harvesting. Using the specialized harvesting equipment available this is an effective means for weed and algae mat removal (see attached comments for Mechanical Harvesting). Weeds are good as garden mulch and animal feed additive. Can be done on contract or by purchasing a harvester. Contract cost $300 to 350/acre per treatment. For one or two treatments/year - Net Cost $6,000 to 25,000/year. The cost to purchase the smallest harvester would be about $20,000 plus the annual cost of maintenance and a skilled operator ($2,000 to $3,000). Mr. Smith mentioned that he has a used harvester that could be purchased for $10,500.

With our thanks to Mr. Smith, we adjourned (late) and will soon reconvene to continue the discussion.

STEVE E. ELLIS
Chairman
Condition of the Pond Committee