Item #10
Date: February 1, 2022
To: Mayor and City Council
From: Jim Schaad, City Manager
Subject: Carp Removal and Phoslock Application to Ellis Lake Recommendation:
Pass a Motion to 1) authorize the City Manager, or designee, to execute a grant agreement with the Yuba Water Agency, in the amount of $142,300, 2) approve entering into a Professional Services Agreement for $71,700 with HDR Engineering, Inc., to remove common carp from Ellis Lake, 3) approve entering into a contract for $53,250 with Aquatechnex Inc. for application of a phosphorous sequestration agent (Phoslock) into Ellis Lake and 4) authorize the Finance Director to make a supplemental appropriation of $142,300 to account number 10-160-5200 (Repairs & Maintenance – Buildings and Grounds).
Rationale for Recommendation:
The application of a phosphorous sequestration agent and removal of non-native carp from Ellis Lake is a two component plan to remediate high levels of Phosphates from the Lake’s water column. Phosphates are introduced into the lake’s water column via various sources, including phosphate laden well water used to replace water lost through evaporation and percolation. High phosphate levels contribute to excessive algae growth/blooms in the summer months which in turn negatively affects water quality.
Additionally, carp aggressively stir up phosphate laden silt at the bottom of the lake, re-introducing it to the water column.
Background:
Council has expressed to improve the water quality of Ellis Lake, a man-made reservoir, located in central Marysville. The lake has historically served dual functions - storm drainage basin and a recreational facility. In recent years lake water quality has diminished to levels that are visually displeasing, odorous and unhealthy. Because of this the Yuba Water Agency and the City commissioned a year-long study performed by HDR Inc., to determine the cause(s) for poor lake water quality. The conclusion of the study was that high phosphate levels within the lake were contributing to excessive algae blooms in summer months, leading to the poor water conditions. Among recommendations from the study were various long and short-term methods for managing constituent water chemicals/minerals. Phosphate sequestration and carp removal were deemed an effective short-term strategy for reducing the main cause of detrimental algae growth/blooms until a long-term solution could be identified and funded.
Discussion & Analysis:
Since Yuba Water Agency utilized HDR to perform the initial study and fisheries sampling, staff negotiated scope terms and cost to perform carp removal with HDR and recommends utilizing them to perform the service for a cost not to exceed $71,700.
Item #10
Because the majority of the cost for application of phosphate sequestration is the product (Phoslock), staff solicited competitive bids per City procurement policy. A request for bids was initiated on December 22, 2021 with a bid opening date of January 13, 2022. The City received one bid $53,250 from Aquatechnex LLC of Santa Ana California. Staff has determined the bid to be fair and reasonable and recommends award to Aquatechnex LLC.
Fiscal Analysis:
The cost of mitigation will be funded through a grant provided by the Yuba Water Agency to reimburse the City for the two contracts. Staff is recommending authorizing the Finance Director to make a supplemental appropriation of $142,300 to account number 10-160-5200 (Repairs & Maintenance – Building and Grounds).
Attachments:
1) Yuba Water Agency Grant Agreement
2) HDR Professional Services Agreement
3) Aquatechnex bid proposal