Proposed Wind Lake Alum Treatment - Contract for Alum SER 4_11

Purpose

The WLMD will contract with Sweetwater Technology to conduct an alum treatment of Wind Lake, Racine County, Wisconsin. WLMD will continue to annually contract with USGS to conduct baseline water quality monitoring. What: 200,000 gals of alum (aluminum sulfate) will be applied to all areas of Wind Lake greater than 5 feet deep ¿ 580 of the 960 acres. This equates to 345 gals/acre alum applied. Water quality monitoring includes nutrients including surface and bottom total phosphorus, temperature, and dissolved oxygen, conducted 6 times a year. When: The project is expected to take approximately 10 days in early May 2011, prior to aquatic plant growth. Where: Wind Lake is located in SE Wisconsin, in Racine County. Staging the project will be done at the Wind Lake Boat Launch on the SW end of the lake, and at Sportsmans Resort on the NE end of the lake. Alum will be applied to the 580 acres that are 5 feet and deeper. WBIC#: 0761700 in Town of Norway, T04N R20E S16 NW NE, Racine County, Wisconsin. Wind Lake Boat Launch: S Wind Lake Rd, Wind Lake, WI; Sportsmans Resort, 25313 W Loomis Rd, Wind Lake, WI How: The alum application equipment includes a barge fitted with surface application spray bars that apply the alum to a 60 foot path width. The barge is specially designed to compensate for the liquid carrying capacity required to ensure safe application. An onboard computer controls the process. The system can vary the application rate with the barge speed to maintain a specified dose. Depth and speed are monitored by the computer. Each of the systems controlled by computer have a backup, manual system, to allow the project to proceed without the computer. Three electronic systems are used to calculate the rate of chemical delivery and to warn of shallow water. The computer records the average water depth, path length, amount of material distributed and area treated. Tank trucks¿ discharge valves will be shut and locked when the equipment is unsupervised. Any spills will be hosed down with lake water immediately. The contractor will maintain all pumps and hoses to wash down the site. To prevent the spread of exotics, all equipment will be decontaminated before entering and leaving the area. Chlorine bleach will be used.

Objective

Nutrient inactivation is necessary to prevent phosphorus release from the bottom sediments during periods of anoxia. After conducting extensive management activities in the upstream and surrounding watershed, the largest single source of phosphorus in Wind Lake was determined to be the internal nutrient loading. Approximately 3200 lbs of phosphorus per year are generated by the lake sediments. The first alum treatment on Wind Lake was conducted in 1996 with an estimated life span of 7 years. The project proved much more successful that planned, lasting until severe flooding took place in 2008. Following the flooding, algae blooms again became a significant problem in the lake. A Lake Management Plan for Wind Lake, first written in 1989 and revised in 2008, recommended total phosphorus concentrations between 20 ¿30 mg/l. Project is fully outlined with supporting documentation in a March 1st, 2010 submittal to the Department. This document was submitted as part of a requirement for a May 1st, 2010 Lake Protection Grant application.

Outcome

Performance Measures: These are milestones that will be reported on in the Division Quarterly Report. Please estimate dates in a manner that encourages success. Number of sampling events associated with project: Six – spring and fall turnover, April, June, July, and August This will be conducted independently by the lake management district. NO COSTS to this EPA 319 grant. Sample collection will be complete by October 2011. Final report will be complete by October 2012. Data will be entered by October 2012.

Related Reports

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Targeted Monitoring
Competitive Project
SER_04_CMP11
2010
Inactive
 
Activities & Recommendations
APM Chemical Permit Request
Alum treatment to control phosphorus release.