Westport Water Tank Replacement Project - FAQs


Aquarion Water Company has an existing 1.5 million gallon (MG) water storage tank and pump station serving Westport, Connecticut on its property at 63-67 North Avenue in Westport.  The tank was built more than 60 years ago, and is no longer adequate to serve the everyday water needs or fire protection needs of the Town.  To address this issue, Aquarion plans to replace the single 1.5 MG tank with two 2.15 MG tanks, which have been sized to provide for the water needs of the Town.   

1. Why does Aquarion need to build new water storage tanks?

Water storage tanks hold water to serve a local communities’ daily needs and fire protection needs.  The existing tank is in poor condition, so it needs to be replaced.  Water usage in Westport has changed dramatically since the 1950s when the existing tank was built.  The existing tank is now too small to meet the needs of Westport – it needs to be replaced with larger and taller tanks.  

2. How much water storage does Aquarion need in Westport to satisfy the water demands of Westport customers?

To calculate the size for a new water storage tank, Aquarion uses the Connecticut Department of Public Health (DPH) Guidelines, which require water utilities to provide water storage equal to the everyday water usage of a community, plus water for fire protection (as well as other factors).  In the case of water storage for Westport, Aquarion sought and obtained DPH approval to also consider conservation savings when sizing new tanks.  

The table below summarizes how Aquarion determined that two 2.15 million gallons tanks were needed.  Most of the water storage volume is needed for provide for current everyday usage in the community – this amounts to 3.38 MG of water that flows through customers meters on an average day, plus about 340,000 gallons of unmetered usage in the community.  Since water demands are expected to increase over time, an increase in average day usage of 510,000 gallons was added to the current average day demands.  630,000 gallons of storage is needed to satisfy the firefighting needs of the community.  Offsetting these individual water storage needs are assumed conservation savings associated with improvement in plumbing fixtures and the recently implemented irrigation restrictions.  The end result is a need for 4.3 MG of water storage for Westport.

Description Storage Requirements (million gallons)
Average Daily Metered Consumption (2012 to 2016) 3.38
10% Adjustment for Unmetered Consumption 0.34
Fire Protection 0.63
Future Demands 0.51
Plumbing Code Water Savings (0.26)
Two Days a Week Watering (irrigation) Schedule Savings (0.31)
Subtotal 4.29
Proposed Total Storage Capacity 4.30


3. Do the proposed tanks have to be built at a certain elevation and with a certain height?

Anyone who has ever been SCUBA diving knows each foot of water increases the pressure felt by the diver.  It’s the same principle at work here.  The weight of the water in our storage tank provides water pressure to customers and fire hydrants.  If we were to place the water any lower, there would be insufficient pressure to push the water out and into the water mains connected to our customers’ homes.  By making the new tanks taller than the existing tank, we are boosting water pressure throughout the system.  This addresses low pressure for customers at higher elevations, but more importantly, increases fire flows.  The North Avenue tank site is connected to our transmission system and is at the correct elevation (it was designed for this purpose).     

4. What will the new tanks look like?

Aquarion has developed renderings of the proposed tank and landscaping to help the town, neighbors and residents understand what the site will look like after construction and after five years of growth of the proposed landscaping.  You can see the renderings of the proposed project by clicking on the links below.  The goal of the landscaping is to significantly conceal the tanks within five years after construction.  The landscaping plan includes 110 evergreen trees ranging in height from 10 to 26 feet, 8 American Hollies at 6 feet, 7 shade and understory trees, 42 evergreen shrubs, and 56 native deciduous shrubs. 

North Ave Tank South View as Planted

North Ave Tank North View in 5 Years

North Ave Tank South View in 5 Years

5. What is the height of the existing tank and proposed tanks?

Since the ground topography at the site is not level, the height of the tank above the ground varies. About 17 to 19 feet of the existing tank is above the ground level, as measured from the ground to the peak of the tank’s roof.  For the proposed new tanks, about 29-1/2 feet (to the peak) will be above the ground level on the north end of the site, and 39 feet 9 inches (to the peak) will be above grade on the south end of the site.

6. Will the proposed tanks increase the amount of water available for firefighting?

Yes.  Both the instantaneous flow of water at hydrants, as well as the total water volume available to fight fires will be greater with the new tanks. 

7. Will the proposed tanks increase water pressure for customers?

Yes.  Because of the increased height, customers will experience a pressure boost.  Because of the increased volume, the frequency and duration of periods of lower pressure will be reduced.  

8. Did Aquarion consider building the proposed tanks in other neighborhoods in Westport?

Yes. Aquarion identified and evaluated several potential locations for the proposed new tanks.

The tanks must be constructed at a certain elevation to ensure customers have adequate water pressure at their homes.  This is because water pressure is controlled by the elevation of the tanks.  Available sites at the correct elevation and of adequate size are limited. 

The first site that was evaluated was the location of Aquarion’s existing water storage tank in Westport on North Avenue.  This site has several advantages. First, Aquarion owns the site.  Second, Aquarion has had a tank and pump station located at the North Avenue tank site for many decades. Third, because the site already has a tank and pump station, the distribution system (i.e. water mains) has been designed and constructed with the necessary capacity to transmit large volumes of water to and from the site, which is necessary for a tank site.  

During the meetings with Planning and Zoning, an alternative site on Bayberry Lane was described to the Commission.  Constructing tanks at this site would cost millions more than construction tanks at the existing tank site on North Avenue.  Also, it would result in disruption to roads for the installation of large water mains, and disruption of another neighborhood in Westport.  

For later meetings with neighbors and Town officials, Aquarion prepared a report that outlined still more alternatives and the associated costs.  This report demonstrates that the construction of the two water storage tanks on the existing site is the best alternative – it provides the best technical solution with the least disruption and is the most cost effective.  A copy of the report can be reviewed by clicking on the link below.  

Alternative Analysis Report

9. Do state and local regulatory agencies have to review and approve the proposed tank project?

Yes, both the Connecticut Department of Public Health and Westport Planning & Zoning Commission needed to review and approve the project.

10. Has the Connecticut Department of Public Health (DPH) approved the project?

Yes. The Connecticut Department of Public Health is responsible for establishing guidelines and regulations to govern the activities of drinking water utilities. DPH has reviewed the storage (volume) calculations to ensure the proposed tanks meet the DPH guidelines for storage tank sizing, and has reviewed the tank drawings to ensure conformance with their standards for storage tank construction.  DPH has issued an Approval for Construction of the proposed tanks.  

11. Has the Westport Planning & Zoning (P&Z) Commission approved the project?

Yes.  Aquarion submitted an application for Special Permit and Site Plan to the Westport P&Z Commission.  The proposed tanks meet all the zoning requirements for the zone (i.e., height, lot coverage, setbacks).  The project did not require any variances.
During their review, the P&Z Commission requested that Aquarion evaluate whether the proposed tank size could be reduced.  Aquarion reviewed the water demand criteria, and by accounting for water conservation efforts (i.e. water savings from plumbing code changes and irrigation schedules), Aquarion was able to justify reducing the required storage capacity from 5 million gallons (MG) to 4.3 MG.  Also, the north tank was moved slightly south to be further from the nearest neighbor and allow more plantings.  The landscaping plan was enhanced to include more, taller trees. 
The application was approved by the P&Z Commission on September 14, 2017.  
As part of the permitting process, the following meetings were held with neighbors, the Town, and the P&Z Commission:
  • Neighborhood Meeting - June 26, 2017
  • Town Wide Informational Meeting - June 28, 2017
  • First Planning & Zoning Commission Public Hearing - July 20, 2017
  • Neighborhood Meeting - August 16, 2017
  • Second Planning & Zoning Commission Public Hearing - September 7, 2017

12. Has the project been reviewed by any other experts other than CT DPH and Westport P&Z?

Yes, in February 2018, the Town of Westport requested that a peer review be completed by a third party to validate that the proposed tank size (volume and height) are appropriate.  Aquarion agreed to pay for the Town to retain an engineering consulting firm to perform the review.  The peer review was completed in March 2018 and concluded that the size and height of the proposed tanks are reasonable, and have been determined using appropriate engineering methods.  A copy of the peer review report can be reviewed by clicking on the link below.

Peer Review

13. Has Aquarion worked with its neighbors to understand their interests and concerns about the project, and address these interests and concerns?

Yes.  Aquarion has been working with Westport officials, state legislators, interested residents and neighbors since October 2017.  This work has included numerous phone calls and informal meetings as well as formal workshop sessions.  A summary of the formal meetings and workshop sessions are outlined below.
  • Neighborhood Meeting – December 13, 2017
  • Neighbors Work Group Meeting – January 11,2018
  • Neighbors Work Group Meeting – February 27, 2018
  • Neighbors Work Group Meeting – March 29, 2018
  • Neighbors Work Group Conference Call – June 8, 2018
Following the Planning & Zoning approval, Aquarion staff and consultants invested significant time and resources to prepare for, attend, and discuss the project with the town, neighbors and residents.  This investment has included at least 650 hours of Aquarion staff time and 1100 hours of consultant time to prepare documents, reports, graphics, etc.
Aquarion paid $15,000 for the Town to retain an engineer to perform a peer review of the proposed tank project, as noted above. 
Aquarion offered to pay for a consultant of the neighbors’ choosing to prepare their own renderings of the proposed tanks and landscaping.

14. What is the proposed material of construction for the tanks?

Water utilities construct large water storage tanks of steel or concrete. The proposed water storage tanks in Westport will be constructed of concrete.  Use of concrete allows the tanks to be partially buried and provides a favorable lifecycle cost.  Aquarion considered the construction of steel tanks, but opted against this choice as the tanks would have to be fully exposed (i.e. not partially buried) and thus would require the construction of retaining walls, which would increase the overall impact on the site.
Neighbors requested that Aquarion consider fiberglass or carbon fiber construction.  Aquarion reviewed each option and noted the following to the town, residents and neighbors at the workshop meetings.
Fiberglass: Aquarion spoke with Mr. Owen Stevens from FTC Inc. about the ability of a fiberglass paneled tank from FTC Inc. to meet the requirements for the project.  Based on discussions and review of the requirements for the project, Mr. Stevens and Aquarion concluded that a fiberglass tank would not work for the project for the following reasons:
  • Height – Reinforced fiberglass tanks have a height limit of 16 feet.  The proposed tanks must be taller than 16 feet to provide the required volume and height.
  • Wetlands: If shorter tanks were feasible, in order to provide the necessary volume of water storage, the tanks would have to be a larger diameter, which would necessitate encroaching on the wetland setback on the property. 
  • Retaining Walls – Fiberglass tanks cannot be buried and would require an extensive retaining wall surrounding the two tanks, which would require additional clearing of the site, beyond what the proposed project requires.

Carbon Fiber:  There is no requisite water industry standard to allow for the use of carbon fiber for the construction of potable water storage tanks. 

15.  How long will the proposed tank project take to construct?

The estimated duration of construction activity at the site is 2 years.

16.  Why is Aquarion proposing two tanks instead of one?

With two tanks, in the future, Aquarion will be able to remove one tank from service for maintenance or repairs without impacting service to customers.  The ability to take a tank out of service for maintenance or repairs is important to maintain the sanitary condition of the tanks and to maximize the service life of each tank.  If Aquarion were to build one very large tank instead of two tanks, Aquarion would not be able to remove the tank from service for maintenance or repairs without disrupting service to customers.

17.  Has Aquarion evaluated whether it could build shorter tanks?

Lowering the height of the tanks would reduce the benefits of volume and pressure.  Aquarion evaluated other improvements that could compensate for shorter tanks, such as larger water mains.  That analysis indicated that to make up for just a five foot reduction in the tank height would require more than a mile of transmission main in Long Lots Road at an added cost of more than $5,000,000.  Clearly, maximizing the tank height within the limits allowed by the zoning regulations is the preferred alternative to spending an additional $5,000,000 to provide improved water service to Westport customers.

To review the graphic showing the proposed transmission improvements click on the link below.

Water Main Improvement Alternative

18. Will traffic be impacted during the construction process?

Aquarion will meet with the Westport Police Department and school officials to review and discuss traffic control during construction.  All construction work will take place on Aquarion property and not in the roadway.  As with any construction project, it can be inconvenient for residents, but Aquarion will work diligently to communicate project information to the public.