Item #03
Date: July 18, 2023
To: Mayor and City Council
From: Jim Schaad, City Manager
Subject: Approve a Consulting Agreement with IGServices Recommendation:
Pass a Motion to approve a consulting agreement with IGServices in the amount not to exceed $35,000 to develop an Ellis Lake water quality implementation plan.
Rationale for Recommendation:
The City desires to improve amenities at Ellis Lake in order to develop a regional recreation and tourism venue, provide residents with high quality outdoor recreation activities, and promote development/ redevelopment in the area. Staff recommends development of a water quality implementation plan to determine the cost and feasibility of alternatives to circulate clean, phosphate-free water into the lake.
Details of this effort are outlined in the scope of work of the attached consulting agreement.
Background:
Ellis Lake is a prominent 40-acre recreational feature with significant historical value to the City of Marysville. Unfortunately, the lake has suffered from poor water quality, causing the lake to be unattractive, unhealthy, and less than desirable for outdoor recreation activities. The City Council has considered the redevelopment/rehabilitation of Ellis Lake a priority, with improvements listed as goals in the last several year’s budget and strategic planning discussions.
In fiscal year 2021/23 the Yuba Water Agency provided $142,300 in funding for the application of a phosphorous sequestration agent and removal of non-native carp from Ellis Lake in an initial attempt to improve lake water to a cleaner and healthier condition. The carp removal and phosphate reduction treatment had positive effect in reducing phosphates in the short-term, but the efficacy of the phosphate treatment lasted for a shorter than expected duration, requiring a second treatment to curb algae blooms. Though long-term effectiveness of treatment was less than anticipated, valuable information was gleaned in the process, including:
• Phosphate levels were significantly higher in summer months while winter months had relatively low readings, particularly when heavy rainfall allowed replacement of existing water with new fresh rainwater. The City now lowers the lake levels before and during significant rain events to capture as much phosphate free rain water as possible and circulate more water through the lake.
The lake is visibly clearer as a result of this replenishment method.
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• Phosphate levels climb during the summer months and the City hypothesizes that additional phosphates are introduced into the lake from the ground water well to replace evaporated water.
The evaporation process does not remove any phosphates from the lake and results in increased phosphate levels. There is also minimal circulation of the water through the lake in summer months. Higher phosphate levels and warm, stagnant water promote algae blooms and decrease water clarity.
• In the summer months immediately following the phosphate reduction treatment significant aquatic plant growth occurred. This growth had not been seen in previous summer seasons and was likely due to improved clarity of the lake water which allowed more sunlight to penetrate to the lake bottom, promoting aquatic plant growth.
City staff completed the activities contained in the grant scope at a cost of $112,343.95, well under the estimated $142,300, leaving a balance of $29,956.05. The Yuba Water Agency has approved use of this funding balance to complete a water quality implementation plan. Additionally, a motion to appropriate an additional $150,000 for activities related to this effort was approved in the City’s FY2023/2024 budget proceedings.
Discussion & Analysis:
City Staff would like to continue efforts to improve lake water quality. City staff feel that an important next step is to determine the cost and feasibility of alternatives to circulate clean, phosphate-free water into the lake. The City proposes that the remaining grant funding be utilized to complete a water quality improvement alternatives analysis and recommended implementation plan. The scope of this analysis is provided in a proposal from IGServices (attachment A). The analysis will look at alternatives for providing water to the lake with minimal phosphate levels and adequate circulation of water to control nutrient levels and minimize harmful algae blooms.
Alternatives include:
1) Pump water from existing well and treat with EutroSORB or similar product to remove phosphates prior to releasing to the lake. Pump only enough water to replace that lost through evaporation.
2) Pump water from existing well and treat with EutroSORB or similar product to remove phosphates prior to releasing to the lake. Pump enough water actively circulate water through the lake from south end to north end.
3) Pump low phosphate water from Yuba River. Pump only enough water to replace that lost through evaporation. This alternative would look at sub-alternatives of using existing storm drain pipe or a new dedicated line. It would also look at a sub-alternative to move the pump/fish screen further downstream on the Yuba River.
4) Pump low phosphate water from Yuba River. Pump only enough water to replace that lost through evaporation. Pump enough water actively circulate water through the lake from south end to north end at a determined turnover rate (based on best practices). . This alternative would look at sub-alternatives of using existing storm drain pipe or a new dedicated line. It would also look at a sub-alternative to move the pump/fish screen further downstream on the Yuba River.
5) A combination or hybrid approach where both river water and well water is used.
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Activities:
• Working with product suppliers and City Engineer, determine a design at the schematic level to treat water at the existing well. From this design, develop basic components, design costs, capital costs to install and ongoing costs to manage water quality. • Working with City Engineer as well as other consultants, contractors, agencies determine a design approach at the schematic level to import water from the Yuba River. From this design, develop basic components, design costs, capital costs to install and ongoing costs to manage water quality.
• Research and document recommended best practices for lake water management from similar size and composition lakes.
• Research and determine permitting steps from multiple agencies exercising authority over the activities related to implementing any of the listed alternatives. • Determine if lake will need to be drained as part of implementation/construction. • Develop high level timelines for implementing the alternatives. • Provide recommendations on short-term/long term and ongoing actions that should be taken to improve water quality, including capital investments, appropriate permitting, pumping/circulation amounts, lake water turnover, water testing, treatment, maintenance activities, etc.
• Provide a written report and presentation to City Council and possibly present to other agencies (Yuba Water Agency, Yuba County).
Environmental Review:
This activity is not considered a project for the purposes of CEQA.
Fiscal Analysis:
The majority of the cost for this analysis will be funded from remaining Yuba Water Agency grant funds.
Any additional costs beyond the grant funding balance of $29,956.05 would be funded by the City (approximately $5,000). Funding for this activity has been included in the FY2023/2024 budget.
Attachments:
1) Consulting Agreement – IGServices
2) Consultant’s proposal