Workshop Item: 2 - Robert Therres, Public Services Manager
Title
WELL SITING STUDY FOR WELLS 18 AND 19, IMPROVEMENT PROJECT NO. 11-08
Background
At the March 15, 2012 City Council meeting, Barr Engineering Co. was authorized to prepare a well siting study to assist the City in developing a plan for the northeast area well field starting with siting for wells 18 and 19. The study had five main goals:
· Determine sites for wells 18 and 19 so the City can begin the preparation of plans and construction of the wells.
· Provide a qualitative assessment of the total capacity of the well field to see if it can likely produce the desired amount of water for a future water treatment plant on the water tower 4 site.
· Identify potential sources of contamination that might affect siting of wells in this area.
· Estimate the impacts of the proposed wells and well field on nearby existing wells.
· Estimate the impact of the well field on water levels beneath nearby wetlands of concern.
Barr Engineering Co. has now completed the study and submitted to the City the "Wells 18 and 19 Siting Evaluation". As a part of doing this study, Barr Engineering Co. met with the Minnesota DNR to identify any specific issues or areas of concern they may have with the proposed well field. The DNR did indicate that there were significant new concerns relating to impacts on local surface waters and sensitive wetlands and that additional information, modeling and testing should be done by the City before the well field is put into service.
If these concerns are not addressed prior to the installation of wells 18 and 19, the City will run the risk of the DNR limiting the use of the new wells if impacts to local surface waters and wetlands were later found.
Brian LeMon from Barr Engineering Co. will provide further information on the results of the study and outline a series of steps for proceeding forward with the goal to reduce the risk and uncertainty of installing new wells that may later be severely limited in their use by the DNR.
Recommendation
Staff recommends that Council proceed forward with the additional study, done in steps, as outlined in the "Wells 18 and 19 Siting Evaluation" before proceeding forward with the well field design and construction. If Council wishes to proceed in this way, staff will bring forward a proposal to complete the necessary work at a future Council meeting.