Water Department

The city’s water department started up a new water treatment plant, which uses reverse osmosis and nano-filtration technologies, in 2018, increasing the city’s drinking water quality and production capacity.

The city sources water from the Jordan and Silurian aquifers, and the new plant will remove more of the minerals associated with these underground water sources that, while not harmful, affect water’s taste and scent.

The new plant also brings online two new wells and raw water mains, and replaces a plant built in 1977 and expanded in 2001 to produce about 1.6 million gallons of water per day. The new plant nearly doubles the system’s production to 3 million gallons per day and is built to serve a population of 30,000.  North Liberty water customers use an average of about 1.4 million gallons of water a day, and use has peaked as high as 2.2 million gallons in a day.

The new plant has been under construction since 2016, and its design allows for a future second phase that would bring daily production to 6 million gallons.

Well Supply

North Liberty gets its water from four Silurian aquifer wells and from three Jordan aquifer wells. Approximately 75% of the water is produced from the Jordan aquifers. We pump approximately 750 gallons per minute from our two Jordan wells. On average the Jordan wells run 8.4 hours per day. The Silurian wells can pump from 100 to 175 depending on which well is operating. The four Silurian wells are alternated daily with the Jordan wells for blending purposes.

Our third Jordan aquifer well is an 39-million-gallon aquifer storage recovery, or ASR, well. It allow us to operate at full capacity and store excess water during low-use periods. We can then recover about 800 gallons of per minute during peak usage.

Water Towers

Two variable-speed (high service) pumps replenish the water towers on demand. These pumps were part of a recent plant upgrade and are capable of producing over 1,000 gallons per minute. The pumps are alternated on a weekly basis so only one runs at a time.

The two water towers can hold 1.4 million gallons of water when full. A 400,000-gallon tower is located on 240th Street, with a 1-million-gallon tower located on Kansas Avenue.

Backflow Prevention and Potable Water Protection Policy

Iowa code requires cities with a population of 15,000 or greater to enact a backflow prevention program with a containment system. (Backflow is defined as the unwanted reversal of flow in a drinking water system.) The purpose of a containment system is to protect the quality of drinking water from the time it leaves the water treatment plant  until it reaches the consumers.

City Requirement

City of North Liberty has implemented a policy and adopted a plumbing code to safeguard its water distribution system against contamination or pollution by water or other substance flowing into its system from a customer’s system. Our internal policy meets or exceeds the standards set forth in Iowa Administration Code for Backflow Prevention with Containment.

Backflow Prevention

City of North Liberty’s backflow prevention program is designed to protect our community’s drinking water from accidental contamination that can occur due to cross- connections. A cross-connection is any point where contaminants can “backflow” from the customer’s point of use into the public water supply. The Building Inspection Department is authority of jurisdiction and shall determine the type of backflow prevention assembly required for containment based on the degree of hazard as specified in the plumbing code.

Backflow prevention assemblies must be tested when they are installed and at least once each year after that. A certified backflow prevention assembly technician must complete testing to ensure that the backflow device is working properly. Test results are required to be uploaded to a third party tracking company called Track My Backflow.

Iowa Registered Backflow Assembly Testers

A list of registered certified backflow testers is available from Track My Backflow. The Iowa Department of Public Health keeps a complete list of registered backflow prevention testers by county.

New Water Service
Commercial & Industrial

The Building Inspection Department is authorized to require an approved reduced pressure zone backflow prevention assembly to be installed immediately downstream from the water meter and before any plumbing fixture or equipment. The plumbing code does require additional backflow protection at every cross connection hazard.


An approved reduced pressure zone backflow prevention assembly for isolation must be installed on branch piping serving a boiler, swimming pool, or in-ground lawn irrigation system.

Existing Water Service

Commercial & Industrial

Upgrades of existing water services shall be treated as new water services for the purpose of this section.

On premises survey may be conducted by the Building Inspection Department to ensure required backflow protection devices are installed and being maintained properly.

The Building Inspection Department shall determine the type of backflow prevention assembly required for containment based on the degree of hazard, as determined from information gathered through on premises investigations or surveys.


An approved reduced pressure zone backflow prevention assembly for isolation must be installed on branch piping serving a boiler, swimming pool, or in-ground lawn irrigation system.

Fire Protection Systems
An approved backflow prevention assembly must be installed and maintained on all new and existing fire protection systems.

Permit Requirement

Permit must be obtained from the Building Inspection Department to install or replace a backflow preventer.

Water Quality Reports

We monitor daily for water quality at the Water Treatment Plant as well as have our water analyzed on a regular basis through the University of Iowa Hygienic Laboratory. Water quality is our first priority.


Water Quality Report 2019

Water Quality Report 2018

Water Quality Report 2017

Water Quality Report 2016

Water Quality Report 2015

Water Quality Report 2014

Water Quality Report 2013

Water Quality Report 2012

Water Quality Report 2011

Water Quality Report 2010

Water Quality Report 2009

Water Quality Report 2008

Water Quality Report 2007

Water Quality Report 2006

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