TITLE
Recommendation to authorize City Manager to execute all documents necessary with the Army Corps of Engineers to allow for the dredging, treatment and disposal of sediments from Colorado Lagoon; and to execute an Amendment to Agreement No. 30245 with Moffatt & Nichol in the amount of $62,388 to allow for additional post-construction monitoring required by the State Water Resources Control Board, and any amendments to the contract necessary to extend the term, amend the scope of work, or adjust the fee schedule of hourly rates for inflation in the extended term. (District 3)
DISCUSSION
The Colorado Lagoon (Lagoon) is a 28.3-acre tidal lagoon located in the middle of a suburban neighborhood (map attached). The lagoon serves three main functions: 1.) Hosting sensitive estuarine habitat; 2.) Providing public recreation (including swimming); and, 3.) Retaining and conveying storm flows. A Master Restoration Plan for Colorado Lagoon (Master Plan) has been developed and is currently being implemented.
On December 15, 2009, the City Council authorized the City Manager to execute a contract with ARB Inc., to begin major construction on the initial phase of the Master Plan. This initial construction effort will be completed by November 2010, and will help improve water quality and prevent the Lagoon’s recontamination by redirecting urban runoff into the sanitary sewer system. The next major phase of the construction effort involves the dredging and treatment of contaminated sediments. The dredging of Colorado Lagoon is being mandated by the Regional Water Quality Control Board through Total Maximum Daily Loads (TMDLs) that establish targets for water and sediment quality that must be achieved within seven years of their adoption.
The Army Corps of Engineers (ACOE) has agreed to assist the City with the transport of treated sediment to the Port of Long Beach. The ACOE will contribute approximately $1,000,000 in in-kind services to this project and manage its...
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