M&A helps a municipal water provider augment its supplies.
Client: City of Glendale / CH2M Hill - Time frame: 2007–2009
- Location: Maricopa County, Arizona
The City of Glendale’s Oasis Water Treatment Plant was constructed in 2007 to supply to its Zone 4 distribution area. This phased project will eventually serve up to 30 mgd at full buildout in 2025. Under Phase 1, which was completed in 2007, facilities were constructed to treat about 10 mgd of surface water that is delivered to the plant via the Arizona Canal. Completed in 2011, Phase 2 was implemented to increase plant capacity by 10 mgd and ensure a reliable supply during canal dry-ups and periods of surface water shortage. It required augmenting supplies with groundwater.
This project received an ACEC award for Engineering Excellence in October 2011 for "...demonstrating a high degree of achievement, value, and ingenuity."
M&A served on a multidisciplinary team led by CH2M Hill to develop this groundwater supply. We began by evaluating and ranking 11 existing City wells that could potentially be used to supply this water; ranking criteria included distance from the treatment plant, registered production capacity, site dimensions, and anticipated configuration and condition. We then conducted field investigations at the four most viable wells to assess their physical condition, potential yield, site-specific aquifer properties, and logistical factors.
M&A also assessed options for using these wells to supply the treatment plant, considering factors such as capacity, capital and O&M costs, risk, logistical issues, and water quality. We found that replacing the wells would incur the highest initial cost but offered the highest production potential, lowest O&M cost, and lowest overall risk. We ultimately developed specifications for three replacement wells and oversaw their drilling, installation, and development.
- Used the results of reconnaissance investigations, downhole video surveys, and various analyses to prioritize wells for further field investigations
- Identified sensitive well site issues (historic preservation areas, noise, and inconvenience to commercial, residential, and adjacent city service areas) and coordinated mitigation plans
- Corrected the registered capacities for five “pre-code” wells, increasing their permitted annual yield
- Developed and ranked alternatives for activating the Zone 4 wellfield based on several factors, including relative capital and O&M costs
- Prepared a report with recommendations for wellfield activation, and presented the results to City decision makers
- Prepared technical specifications for drilling, constructing, developing, and testing the new supply wells
- Prepared submittals for well and de minimus discharge permits
- Evaluated downhole video surveys and borehole geophysical logs
- Prepared a construction report for the replacement wells
-
Modeled the potential impacts of pumping on nearby wells to help site potential new wells
- Designed three high-capacity replacement wells up to about 1,700 feet in depth based on the zonal test results, lithologic descriptions and sieve analysis of drill cuttings, and borehole geophysical logs
- Provided field oversight for well construction
- Selected intervals for zonal testing in the pilot borehole, monitored water quality parameters, and collected samples for lab analyses
- Specified procedures for decommissioning selected old wells; oversaw and approved decommissioning
- Managed contractors who installed and operated test pumps, conducted video surveys, and performed minor well rehabilitation
Acronyms & Abbreviations
