Keeping an eye on Platte Lake is a never-ending job. The lake will always be vulnerable to whatever flows into it from the upper Platte River, or swims into it from Lake Michigan. The Lake and watershed are sampled every two weeks, weather and ice conditions permitting. Where the water is deepest, off Birch Point and at the 90 foot hole in the northwest basin of the lake, water is triplicate sampled at 8 different depths. These samples are analyzed at the lab at the Hatchery (in parallel with analysis of hatchery water quality) for phosphorus content and other relevant parameters and the results provided to the PLIA along with the results from sampling key Platte River tributaries.
Because of the Settlement Agreement, between 2000 and 2015 98% of the cost for this sampling and analysis has been paid by the MDNR; 2% by the PLIA. But, as of January 1, 2015 the Fish Hatchery had been in compliance with its mandated phosphorus discharge limit for the past five years, So MDNR is no longer be required to fund the lake sampling. The PLIA now has full responsibility for lake sampling, analysis and monitoring. All other provisions of the settlement agreement remain in effect.
But the risk to Platte Lake from increased nutrient loads from other sources in the watershed continues. The PLIA must continue sampling the lake, river and major river tributaries and will has assumed 100% of the cost. We’ve seen this change coming and have been developing strategies for continuing the sampling and keeping Platte Lake clean.
Our first step was to find ways to reduce the cost of the sampling process, without compromising our ability to safeguard the lake. Platte Lake has been sampled and monitored for many years and PLIA has court-ordered sampling data that goes back to 1990. This data have been analyzed by experts in environmental sampling design at Virginia Tech University. They have made recommendations to the PLIA on what would be the ideal sampling model for Platte Lake and the Platte River. The PLIA is hopeful that it will be able to maintain the same level of surveillance of the lake at a reduced cost by modifying the sampling methodology.