REQUEST FOR COUNCIL ACTION. Lake Augusta Alum Treatment Lower Mississippi Watershed Management Org. COMMENT:

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1 REQUEST FOR COUNCIL ACTION DATE: March 7, 2017 TO: FROM: SUBJECT: Mayor, City Council, and City Administrator Ryan Ruzek, P.E., Public Works Director Lake Augusta Alum Treatment Lower Mississippi Watershed Management Org. COMMENT: INTRODUCTION The Council is asked to authorize a Joint Powers Agreement (JPA) with the Lower Mississippi River Watershed Management Organization (LMRWMO) for an Alum treatment of Lake Augusta. BACKGROUND Mendota Heights is a member community of the LMRWMO. The WMO initiates studies that relate to water quality and protection of natural resources. Recently the WMO authorized a Watershed Restoration And Protection Strategy (WRAPS) plan for a number of lakes within the organization. Lake Augusta was chosen at it is listed as an impaired water in the State of Minnesota. The Minnesota Pollution Control Agency (MPCA) conducted the study and determined that the cause of impairment is due to an excessive phosphorus loading from the sediment in the lake bed. DISCUSSION The LMRWMO applied for a clean water funding grant and was selected to receive $88,000 towards an alum treatment application. The grant requires the city to provide matching funds of approximately 25% of the total project cost. The city has budgeted $35,000 towards this project. In addition to the matching funds from the city, the Augusta Shores Home Owners Association has provided a commitment of $2500 towards this project. BUDGET IMPACT Mendota Heights has budgeted $35,000 towards this project in the Storm Water Utility Fund. Preliminary estimates projected that the city share would not exceed this amount. The attached JPA would require the city to provide these funds to the LMRWMO for use on this project. If any additional funds remain after the project is complete they would be applied to the annual dues paid by the city. RECOMMENDATION Staff recommends Council approve the attached JPA and issue funds to the LMRWMO for the alum treatment of Lake Augusta. ACTION REQUIRED If Council concurs, it should pass a motion approving the JPA with the LMRWMO. This action requires a simple majority vote.

2 Lake Augusta Results of a Water Quality Study on Lake Augusta in Mendota Heights Sub-watershed Area: 400 acres Lake surface area: 44 acres Maximum lake depth: 33 feet Lake condition: Poor water quality due to excessive nutrients (phosphorus) that spur algae growth Sources of nutrients: Releases of phosphorus from the lake bottom and runoff from streets and yards in the watershed In 2012 and 2013, the Lower Mississippi River Watershed Management Organization (LMRWMO) studied five lakes, including Lake Augusta, to gain a better understanding of their water quality, sources of pollution, and the pollution reductions needed to improve the water quality and meet State standards. The Minnesota Pollution Control Agency funded the project through the Clean Water Land and Legacy Act. The project, called a Watershed Restoration and Protection Strategy (WRAPS) resulted in restoration plans for lakes with poor water quality, like Augusta, and protection plans for lakes with good water quality. Lake Augusta is located in the western side of Mendota Heights just southeast of the intersection of highways 55 and 110. Most of the drainage area (i.e. the watershed) of the lake lies to the east and northeast of the lake. Land use within the lake s watershed includes a large cemetery as well as commercial and low and high density residential areas. The lake is landlocked, meaning no water leaves the lake through a stream or outlet structure.

3 Lake Augusta has a maximum depth of 33 feet and therefore must meet Minnesota water quality standards for deep lakes: the average total phosphorus (TP) concentrations during the summer must be less than 40 micrograms per liter (µg/l); chlorophyll-a concentrations must be less than 14 µg/l; and Secchi depth transparency must be greater than 1.4 meters (4.6 feet). The lake was monitored through the Gun Club Lake Watershed Management Organization between 2007 and Secchi depth transparency measurements have been recorded between 1998 and The longterm average levels of all three criteria do not meet State water quality standards. Phosphorus is the plant nutrient that most often stimulates the growth of algae. A lake that is rich in phosphorus has the potential for abundant algal growth, which can reduce water clarity. Chlorophyll-a is the main photosynthetic pigment in algae. Too much chlorophyll - a indicates an abundance of algae in the lake. Lake Augusta Summer Average (June September) Water Quality Data Water clarity, or transparency, is often measured with a Secchi disk - a black and white disk that is lowered into the water until it disappears from view. The depth at which it is no longer visible is measured numerous times to get an average for the summer. Lake Augusta receives nutrients, like phosphorus, from a variety of sources. Monitoring and modeling results indicate the majority (87%) of the phosphorus in Augusta comes from the sediments at the bottom of the lake or internal loading. Internal phosphorus loading is a problem in many lakes because historic inputs of phosphorus get concentrated in the sediments. This phosphorus is recycled from the lake sediments into the overlying waters, primarily during summer periods, when it contributes to the growth of nuisance algal blooms. 315 lbs 87% 41 lbs 11% 7.5 lbs 2% Watershed Direct Atmosphere Internal Another 11% of the phosphorus comes from the surrounding watershed. Storm water and snowmelt running off residential and commercial areas carry grass clippings, fertilizers, and leaves into the lake through storm drains and pipes. Fertilizer in runoff feeds algae blooms directly. Leaves and grass breakdown in the water, also releasing nutrients to the water column and feeding algae.

4 The WRAPS report and restoration plan for Lake Augusta indicates that a 78% reduction of phosphorus from internal sources is needed to improve water quality, reduce algae growth and meet State standards. This will in turn allow sunlight to reach more of the lake bottom, improving rooted aquatic plant growth, habitat, and lake oxygen levels. In order to reduce internal sources that significantly, an in-lake alum treatment of the lake sediments is recommended. Watershed residents can further improve water quality by reducing the amount of nutrients reaching the lake in storm water (see below). We all live in a watershed. Sometimes it s obvious our property drains to a particular body of water; sometimes it s not. Those in the Lake Augusta watershed may not be aware their property eventually drains through storm sewers and into the lake (see map on front). Even if you live several blocks or miles from the lake, runoff from your property drains to the lake through stormsewer pipes under your street essentially turning every curb into a shoreline. Stormsewer systems are different from the sanitary sewer systems in which water used inside your home is treated at a wastewater treatment plant before being discharged to a waterbody. Outside your home, stormsewers collect rainwater and snowmelt leaving your property and convey them to the lake without treatment. A storm drain funnels rain and snowmelt into stormwater pipes to prevent flooding. But, they also carry pollutants (like oil, deicers, and fertilizers) along with leaves and grass clippings into nearby lakes, streams, or wetlands. Pollutants carried in runoff include lawn fertilizers, nutrients from decaying grass clippings and leaves, pesticides, toxins from coal-tar driveway sealants, oil from leaking cars, pet waste, and salt, sand and other deicers. In the lake, these pollutants result in poor water quality effecting aesthetics and recreational enjoyment of the lake as well as fish, bugs, birds, and their habitats. You can be part of the solution by using some easy practices at home. Sweep up grass clippings, fertilizer, leaves, and extra sand and salt before they get into the storm drain (compost grass and leaves; save fertilizer, sand and salt for reuse) Install a raingarden to capture runoff from your roof or driveway and let it soak into the ground (visit for information on Blue Thumb classes) Clean up after your pet (put waste in trash) Install a rain barrel to collect rainwater for use in gardens Keep your car in good repair to avoid leaks Use asphalt-based driveway sealants (or if using a service, ask the company to use them) Wash your car at a carwash rather than on the driveway

5 JOINT POWER AGREEMENT AGREEMENT made this day of, 2017, by and between the Lower Mississippi River Watershed Management Organization ( LMRWMO ) and the City of Mendota Heights ( City ), a Minnesota Municipal Corporation. RECITALS A. This Agreement is made pursuant to the authority conferred upon the parties by Minn. Stat. Sections ; and B. The LMRWMO has received a grant from the Minnesota Board of Water and Soil Resources of One Hundred Ninety-Six Thousand Dollars ($196,000.00) ( Grant ) for WRAPS Internal Phosphorus Loading Control: Lake Augusta and Sunfish Lake ( Project ); and C. The Grant requires a cash match from local funds towards implementation of the project and the City is willing to provide the matching funds because the Project will benefit the City. NOW, THEREFORE, THE PARTIES AGREE AS FOLLOWS: 1. Upon execution of this Agreement, the City will pay the LMRWMO Thirty-five Thousand Dollars ($35,000.00) which the LMRWMO will use as matching funds for the Project. 2. Upon completion of the Projects and payment of all Project costs, unspent matchings funds, if any, shall be remitted to the City. IN WITNESS THEREOF, the parties have caused this Agreement to be executed by their duly authorized officials. Dated:, CITY OF MENDOTA HEIGHTS BY: Neil Garlock, Mayor AND Lorri Smith, City Clerk Dated:, LOWER MISSISSIPPI RIVER WATERSHED MANAGEMENT ORGANIZATION BY: Current Chair AND Secretary/Treasurer v1