Title
SUPPLEMENTAL AGREEMENT WITH CH2M FOR WATER SUPPLY REVIEW PHASE II FEASIBILITY STUDY
COUNCIL INITIATIVE ADDRESSED:
Provide sustainable water quality & environmental infrastructure
CITY ATTORNEY REVIEW: N/A
SUMMARY STATEMENT:
On August 27, 2015, the City Council considered the recommendation of the Water Supply Review Customer Advisory Committee (CAC) to develop a new water source on the Cowlitz River utilizing Ranney collector wells, and directed staff to prepare a contract amendment to further evaluate the feasibility of developing a new water source. CH2M has developed a feasibility study scope of work to assess potential siting, capacity, water quality and treatment requirements of a future Ranney well water supply.
The scope of work includes several components with each ensuing activity based on the results of the prior activity to incrementally develop site specific information while controlling costs. Major components of work include:
• Exploratory Test Drilling (three potential sites)
• Detailed Aquifer Testing (one preferred site)
• Engineering Analysis
• Community Outreach
• Project Management
• Option for detailed aquifer analysis at a second site
Site investigation will focus on the following three locations: North Lexington (Riverside Park); South Lexington (near Rocky Point); and the Fishers Lane WTP. The potential fourth site south of the Hall of Justice was dropped from consideration due to its proximity to and potential to negatively influence Kelso’s Ranney well on the opposite bank. At each site, a small diameter test well will be drilled, followed by short duration stepped rate pumping tests and analysis of water samples to characterize the basic hydrogeology and assess general water quality.
Based on the findings of the initial site investigation, one preferred site will be identified and further evaluated to determine specific aquifer properties and more detailed water quality. A larger diameter test well will be installed along with several monitoring wells to determine productivity, drawdown, river effects, and other factors which ultimately control the size, depth, spacing and number of collector wells and laterals needed. Additional laboratory testing will be conducted to determine water quality and water chemistry and identify treatment requirements and transitional distribution system impacts.
For each site, numerous agreements and permits must be obtained prior to the start of testing and in order to discharge water back to the Cowlitz River during extended pump testing. The ability to obtain these permits and permissions in a timely fashion will determine the overall project schedule:
• Temporary Right of Entry and Construction Agreements (each property owner)
• Shorelines permits (City of Longview and Cowlitz County)
• Well drilling start card (Dept of Ecology)
• Hydraulic Project Approval (Dept of Fish and Wildlife)
• Water Quality Certification (Dept of Ecology)
• Encroachment Permit (CDID#1 and Corps of Engineers joint review)
The results of the intitial site investigation and detailed aquifer testing will be evaluated and reported separately to provide decision points for moving ahead with the feasibility study. CH2M will also re-engage the CAC to help disseminate information to the public and encourage the community to participate in the decision making process. The proposed scope includes a continuation of public outreach activities to provide information gathering, education, and community input opportunities.
If the results of the first detailed aquifer test prove unfavorable, an optional task is identified to perform detailed aquifer testing at a second site. If all sites prove unfavorable, installation and testing of exploratory test wells at additional sites would incur additional costs to remobilize the drilling contractor and conduct the additional testing.
Copies of the proposed scope of work and anticipated schedule are attached for review. Major milestones identified in the schedule include:
• Oct 14, 2015 - Notice to Proceed
• Nov 02, 2015 - Begin drilling exploratory test wells
• Dec 22, 2015 - Publish Exploratory Well Report
• Jan 5, 2016 - CAC Meeting 1
• Jan 28, 2016 - City Council Update
• Feb 11, 2016 - Begin detailed aquifer testing
• Apr 20, 2016 - Publish Aquifer Test Report
• Apr 27, 2016 - CAC Meeting 2
• May 04, 2016 - Open House
• May 19, 2016 - Joint Council / BHWSD Workshop
• June 9, 2016 - City Council Decision
FINANCIAL SUMMARY:
The cost of the proposed contract amendment is $327,550, not including optional tasks. Sufficient funds remain in the Regional Water Supply Project budget to pay for this work.
RECOMMENDED ACTION:
Motion authorizing the City Manager to execute an amendment with CH2M for Phase II of the water supply review project.
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