Water Improvement
Agency: City of Alexandria, Louisiana
Project summary: The City of Alexandria is seeking funding to make critical enhancements to our utility system’s water infrastructure to make the system more resilient for storms, like the two major hurricanes that swept through Alexandria in 2020.
As the largest city in central Louisiana, Alexandria is an economic hub as well as the primary health care hub for the region. And, based on Alexandria’s location in the center of the state and the placement of the state’s Magashelter, Alexandria is typically the first choice for refugees fleeing hurricanes along the coast. As such, it is critical that Alexandria’s water system be able to withstand storms to be able to provide for the needs of local residents and the local hospitals and treatment centers, but also for the Megashelter, hotels and other sources of shelter for refugees.
The two projects outlined here would ensure the City is able to provide adequate water supplies and pressure during times of emergency to support the needs of our residents as well as those who are dislocated and seeking refuge in Alexandria.
Cost for Project A, Alexandria Well Replacement Highway 1 South Well Field is $3,526,000. Cost for Project B, Adams Pump Station Line Renovation, is $1,935,000. Total funding request is $5,461,000.
Project A
City of Alexandria Well Replacement Program
Proposed Hwy. 1 South Well Field – Phase 2
The Issue: The City’s water production capacity is expected to decline dramatically in the coming years unless a capacity replacement program is begun. All mechanical equipment has a finite lifespan. Depending on factors including construction techniques, material quality, and water and soil corrosivity, water wells typically have a useful life of between 35 and 60 years. Wells are abandoned due to age related structural failure, changes in water quality or environmental concerns. Additionally, well capacities normally decline over time due to water table depletion, screen clogging, sand consolidation and equipment wear. The average Alexandria water well is 42 years old.
City Wells: The City currently operates 45 wells with 31 being located in the Kisatchie Field and 14 located in‐town. Figure 1 is a complete listing of active City wells. Approximate production capacity is currently 23,000 gpm.
Kisatchie Field: Water providers typically construct new wells as the need arises. This results in a relatively uniform spacing of well ages. In Alexandria’s case, 39 wells were constructed in the Kisatchie well field in 1967 under an economic development grant. Of the original 39 Kisatchie wells, 15 (38%) have since been abandoned. Seven new wells were constructed between 1982 and 2000. The majority of the remaining wells are now 50 years old. It is expected that these wells will expire within a relatively short time span, resulting in a drastic reduction in the City’s production capacity. No new wells have been added in the Kisatchie since 2000.
In‐Town Well Field: In‐Town water production is also important to the City. Kisatchie water has been unavailable to the City in the recent past following ice storms, power outages and main breaks. During these periods, in‐town production has been critically important in maintaining water service. Three new In‐Town wells have been constructed in the past 22 years.
Historic Well Abandonment Age: The oldest City well for which records are available was drilled in 1921. While records have improved since state mandated abandonment reporting was instituted in the 1970’s, prior records are intermittent. A review of the historic abandonment age of City wells with reliable records indicates an average abandonment age of 36 years. As mentioned previously, wells are abandoned for a variety of reasons. Discounting declining water tables and poor construction techniques, a likely life of between 50 and 60 years is reasonable for the surviving wells.
Predicted Production Loss: Without a replacement program, Alexandria’s production capacity will likely decline to between 6,500 and 10,500 gpm within the next 8 to 13 years. This represents a capacity loss of between 16,000 and 12,000 gpm. It should be noted that these are 24 hour pumping rates and are included for illustration only. Best well management practice requires well runtimes not exceeding 10 to 12 hours daily.
Water Demand: Between 2013 and 2016, Alexandria’s 22,400 water customers used and average of 8 million gallons per day (mgd). While actual peak use numbers are unavailable, a peak of 21 mgd (14,580 gpm) is likely. Since a given percentage of any well field is normally down for maintenance at any given time, an allowance should be made for downtime.
Function Gallons per Minute
Projected Peak Use 14,580
Maintenance Downtime (10%) 1,460 Leak/unmetered water allowance (20%) 2,920 Necessary Peak Day Production Capacity 18,960
A total well field capacity of 18,960 gpm would meet peak requirements and also allow a well runtime slightly over 9 hours per day during average use.
Production Goals: The predicted post‐decline well field capacity (6,500 to 10,500 gpm) will leave a 8,500 to 12,500 gpm production shortfall.
Necessary Peak Day Production Capacity | 18,960 gpm | 18,960 gpm |
Projected Post Decline Capacity Range | ‐ 6,500 gpm | ‐10,500 gpm |
Capacity Shortfall | 12,460 gpm | 8,460 gpm |
The average in‐town well produces 435 gpm; the average Kisatchie well delivers 540 gpm. The goal of the Well Replacement Program is to recover the projected shrinkage over a 10-year period. To accomplish this goal, the City must construct replacement wells at a rate of approximately 3 per year. Wells will be constructed in both well fields with an initial emphasis on in‐town capacity.
Purpose of the Program: Depending on multiple factors, including well depth and site requirements, the replacement cost for individual City wells will range from $450,000 to $1,400,000 per well with an average cost around $650,000. Best well field management practices dictate that well replacements should be completed over a number of years to prevent a future near‐simultaneous loss of production capacity.
Scope of Proposed Project: This project is to develop a new well field site in a previously undeveloped property owned by the City. The production sands at this site were discovered in the City’s 2017 Water Well Test Hole Program. The original well, constructed in 2020 in this proposed new well field (R1643), is 340 feet deep and increased the City’s in‐town production capacity by adding an 850 gpm production well.
The proposed project would install a 1,000,000 gallon ground storage tank, booster station as well as the ancillary items required to operate the site, including all weather access drives, fencing, electrical, standby generator, communications, chemical addition, and a water main to connect to the City’s existing transmission main. This project would allow the City to further develop the well field with a planned expansion of up to 4 wells in the same production sands as the prior well with exploration for further production sands on the remainder of the well field.
The overall estimated project budget is as follows: Highway 1 South Well Field Phase 2 ‐ $3,526,000
Project B
City of Alexandria
Adams Pump Station Line Renovation
The Issue: The City’s existing distribution manifold at the Adam’s pumping station is beyond repair and in need of replacement. The Adam’s pumping station is on the primary main feeding water to the City from the Kisatchie Well Field, which contains approximately 75 percent of the City’s total water production capacity. The Adam’s pumping station provides a critical role in providing the potable water necessary to supply the City’s peak demands.
History: The City developed the Kisatchie Well Field in 1967 under an economic development grant to supply water to the Pineville Kraft Corporation. As part of this project, the City constructed 39 wells, 2 – 1.5 million gallon ground storage tanks in Kisatchie, and a 42” main from these tanks to the Adams Pumping Station and 2.5 million gallon standpipe at that site. The water was then re-pumped through a 36” main to the paper mill across the Red River. The City also included several interconnections to its existing distribution system such that the majority of the water consumed by the City travels through the Adams pumping station.
Corrosion Issues: Beginning in 1969 shortly after installation, the City began experiencing outages along the route from the Kisatchie Well Field to the Adams station. The majority of problems in the line initially were located at blowoffs and air release valves as the result of low electrical resistivity and attendant corrosiveness of the soil causing failure in the bolts at these fittings. As these failure-prone fittings were removed from service, the more recent failures have been within the pipe itself which is beginning to show signs of corrosion within the pipe section. Likewise, the Adam’s pumping station distribution pipe manifold has had several issues in recent years with leaks in the piping segments such that patching and repairs are no longer feasible. The manifold is in need of replacement.
Scope of Proposed Project: This scope of this proposed project is to replace the existing distribution manifold and related piping at the Adam’s pumping station. The piping would be replaced with new cement mortar lined ductile iron piping and the exterior of the piping would be coated to prevent corrosion from the elements.
The overall estimated project budget is as follows: Adams Pump Station Line Renovation - $1,935,000