Agency Pollution Control Agency

Contractor Saint Croix River Watershed Research Station - Sci

SWIFT Contract Number 140325

Project Name Myrtle Lake Core Sampling & Analysis

Project Number (if applicable) {Empty}

Summarize purpose of the contract, including why it was necessary: Myrtle Lake experiences frequent nuisance algae blooms and does not meet Minnesota state standards for total phosphorus and chlorophyll-a. This has led to questions whether the productivity and condition of the lake has changed over time, what the natural or historical condition of the lake was, what the current trajectory of the lake is, and how to set effective management goals. This project uses paleolimnological techniques and quantitative environmental reconstructions to estimate past conditions and natural variability, identify timing of ecological changes, and determine rates of change and recovery.

Paleolimnological analysis of a dated sediment core will reconstruct changes in the lake condition over the last 150 years using multiple lines of evidence including biogeochemistry, sediment accumulation, and algal and diatom remains as biological indicators of water quality. Diatom assemblages can be used to estimate quantitative environmental parameters and have been used as one line of evidence for developing nutrient criteria, lake-specific nutrient standards, and prioritizing management actions.

Historical and modern phosphorus dynamics in Myrtle Lake will also be analyzed. Total phosphorus and phosphorus fractions will be analyzed in the long core to understand the historical sources of phosphorus to the lake, the distribution of phosphorus and phosphorus fractions within the core, and to assess the relative capability of the lake to sequester phosphorus in its sediments. A spatial analysis of the sediment inventory of total phosphorus and phosphorus fractions across the basin will be done to identify potential hot spots of internal phosphorus sources in this lake and whole basin burial rates of phosphorus.

A high frequency buoy will be deployed to better understand the thermal and oxygen dynamics of the lake that could affect internal phosphorus loading. Core incubations under oxic and anoxic conditions will provide internal loading estimates.

Project Duration

Start Date Tue, 05/01/2018 - 00:00

Original end date Thu, 08/01/2019 - 00:00

Actual end date Thu, 08/01/2019 - 00:00

Did project finish on time? Yes

Total billable hours utilized (if applicable) {Empty}

Contract Amounts

Original contract: $52536.23

Amendments {Empty}

Contract total $52536.23

Did project finish within budget? Yes

What was the funding source? State

Is this a sole source contract? No

If this was a single source contract, explain why the agency determined there was only a single source for the services (if applicable) {Empty}

Evaluator Name Amy Mustonen

Evaluator Email Address Amy.mustonen@state.mn.us

Evaluate the contractor's timeliness Very Satisfied

Evaluate the contractor's quality Very Satisfied

Evaluate the contractor's cost Very Satisfied

Evaluate the contractor's overall performance Very Satisfied- Exceptional quality of work. Very pleased by the level of expertise as well as ability to communicate the results in the final report.

Would you engage the contractor's services again? Yes

Describe any negative action taken during the duration of this contract (i.e., termination, pursuit of suspension, etc.): {Empty}

Please rate the overall experience with the contractor 5 - very satisfied