To the right is an example of the recommended treatment process that we will use at the water treatment campuses. You can click on the image to enlarge it. First, water is pumped from wells through a series of filtration units to remove sediment or solids that are sometimes found in groundwater. Next, the unregulated compounds treatment process begins with an ultraviolet advanced oxidation process using hydrogen peroxide (UV AOP - H2O2). This means that hydrogen peroxide goes into the water ahead of a UV light. Once this water mixed with hydrogen peroxide passes through the UV light, hydroxyl radicals are generated. These radicals react with and break down the 1,4-dioxane to create harmless molecules of carbon dioxide and hydrogen. After the UV AOP process, the water moves to vessels filled with granular activated carbon (GAC). These GAC filters will absorb the PFAs and any remaining hydrogen peroxide from the UA AOP process. Finally, the water will be disinfected using chlorine and pumped into the reservoir and then the main distribution system for our customers. These two processes together are the most common and proven technologies of treating for1,4-dioxane and PFAs.
The project is moving along during the February and March periods. Our engineering team, Carollo Engineering, continued with the preliminary design of the sites. While this continues, in mid-February, the Town began a two-step selection process to hire a Construction Manager who will work with the Town and Carollo to deliver the project. We are going to be using a Construction Manager at Risk method for the construction of the sites. The first step is for statements of qualifications to be submitted and reviewed by a selection committee made up of industry professionals. This was completed in early March. Upon review, we moved to the second step where the selection team will interview the highest ranking firms in mid-April.
The Construction Manager at Risk (CMAR) process is a collaborative project delivery method where the Owner (Marana Water) contracts a designer and a construction manager separately and they then work as a team to complete the project. Both the engineering designer and the contractor need to be engaged with a contract. We retained Carollo Engineering in January of 2019, and are in the middle of the process to secure a contractor. Typically, the Owner will select a Construction Manager when the engineering design is at approximately 30% completion to perform pre-construction services. These services include working directly with the Owner and the designer to perform constructability reviews, cost modeling, and value engineering during the design process.
There are many advantages to using a CMAR process for complex projects like this one. First, during the pre-construction phase, the Construction Manager, along with the Owner and the designer, can collectively identify potential opportunities to accelerate the project schedule. Some examples of this are identifying items that have a long lead time, or putting portions of the projects out to bid that are earliy in the project timeline. Secondly, the Construction manager will also be performing careful cost modelling of the project by obtaining bids and cost estimates for the project. The Construction Manager is required to deliver the project with a Guaranteed Maximum Price (GMP). Typically, when the project is at the 90% design completion phase, the Construction Manager will provide this GMP, which includes predetermined Owner allowances and contingencies. This is where the “at-risk” comes into play. Each bid packages has a GMP based on the efforts and due diligence of the Construction Manager during pre-construction. The Construction Manager is financially liable, or “at-risk,” should there be any necessary costs to complete construction above and beyond the GMP. This is another advantage, by providing cost security to the Owner.
On February 14, the EPA released their much anticipated “PFAS Action Plan.” According to the EPA, the PFAS Action Plan:
Demonstrates the agency’s critical national leadership by providing both short-term solutions and long-term strategies to address this important issue
Provides a multi-media, multi-program, national research, and risk communication plan to address this emerging environmental challenge
Responds to the extensive public input the agency has received over the past year during the PFAS National Leadership Summit, multiple communication engagements, and through the public docket.
To read a summary of the EPA’s Action Plan for PFAS, click here.
On January 22nd, the Water Infrastructure Finance Authority (AZWIFA) approved a loan to the Town of Marana for $15 million for the design and construction of two advanced water treatment facilities. Upon closure of the loan documents, the Marana Council approved the design engineering services contract for Carollo Engineering. Carollo will be working with the Town throughout the duration of the project, which includes final design, construction oversight, treatment plant start up, and post-construction activities. A design kick-off meeting took place the week of January 22nd with Marana Water staff. Carollo is a national engineering firm that specializes in water and wastewater infrastructure projects. The team working with the Town is from the local Tucson office.
AZWIFA is a governmental organization dedicated to protecting public health and promoting environmental quality through financial assistance for water and wastewater infrastructure. AZWIFA offers funding for drinkign water, wastewater, and stormwater projects designed to ensure safe, reliable drinking water and proper wastewater treatment. Over the last 25 years, AZWIFA as invested over $2 billion in Arizona communities. For more information, visit the AZWIFA website here.
On December 12th, the Water Infrastructure Finance Authority of Arizona (AZWIFA) approved the offer of a $15 million loan to the Town of Marana to address the issue of unregulated compounds. The final loan agreement documents with AZWIFA will be brought to the Marana Town council most likely in January 2019 for final acceptance.
Marana Water has selected and is currently negotiating a contract with a design engineering firm to begin the process of design for the two advanced water treatment plants. Each water system (Picture Rocks and Airline/Lambert) will have a treatment plant designed and constructed to significantly reduce or remove the discovered unregulated compounds (PFAs and 1,4-Dioxane).
Town of Marana has joined City of Tucson in a lawsuit filed Nov 8 in Pima County Superior Court as part of their ongoing effort to protect the public from any potential adverse health effects that could be caused by per- and polyfluoroalkyl substances (PFAs) that are present in portions of the groundwater supply.
Read the release.
Marana Town Manager Jamsheed Mehta wrote a letter to Town Council responding to questions about interim water consumption as the Town prepares to build two operational treatment plants for the Airline/Lambert and Picture Rocks water systems.
Read the letter.
Additionally, Arizona Department of Environmental Quality wrote a letter supporting Town of Marana’s efforts to address unregulated compounds in drinking water.
Town Council approved Resolution No. 2018-091 on Tuesday, September 25 authorizing the creation of the Picture Rocks water treatment campus capital project and the Airline/Lambert water treatment campus capital projects. The resolution also authorizes the transfer of up to two million dollars in budgeted expenditure authority, and authorizes the application for a clean water state revolving fund loan from the Water Infrastructure Finance Authority of Arizona (WIFA) to fund the construction.
Town Council Presentation Slides
Marana Resolution No. 2018-091
View the Sept 25 Council presentation video.
The Town of Marana Council made a unanimous decision on Tuesday, August 14, 2018 to pursue design and construction of a water treatment facility for each of the two impacted systems in Marana Water found to contain unregulated compounds. Additional information can be found at the links below.
August 15 Press Release
Town Council Presentation Slides
Video Recording of the August 14, 2018 Town Council Meetin