City of Ankeny Aquifer Storage and Recovery Well, Ankeny, Polk County, Iowa – Fact Sheet, March 2023

Proposed Decision to Issue UIC Permit

Introduction

The U.S. Environmental Protection Agency (EPA) Region 7 invites the public to review and comment on its proposed decision to issue an Underground Injection Control (UIC) permit for the operation of an aquifer storage and recovery well to the City of Ankeny, located in the city of Ankeny, Polk County, Iowa. The permit, if issued, would authorize the injection of treated drinking water by the city, as part of their aquifer storage and recovery operations at this site, for five years from the date of issuance.

Background

The City of Ankeny has requested an Underground Injection Control (UIC) permit for the operation of an aquifer storage and recovery well in the city of Ankeny, Iowa. The permit, if issued, would allow the use of the well to inject water that has been treated to drinking water standards by the city into the Cambrian-Ordovician Jordan Aquifer (St. Lawrence Formation, Jordan Sandstone, and Prairie du Chien Group), which is approximately 2,072 feet below ground surface. The treated drinking water injected for storage would be recovered later for use in the public water system during periods of high demand. Prior to distribution, the recovered water would undergo testing and receive the necessary treatment to make sure it meets drinking water standards.

Prior to this permit request, EPA has issued seven permits for both pilot and full-scale projects in Iowa that use the Cambrian-Ordovician Jordan Aquifer System as a storage and recovery zone. The results of these projects have shown that the Cambrian-Ordovician Jordan Aquifer can successfully be used as a storage and recovery zone for drinking water.

This operation would allow the city to provide treated drinking water during periods of peak demand and allow for an emergency backup supply during times of drought or flood, without the need to develop additional drinking water treatment plants. Any expansion to this project would require an additional EPA permit to cover the conversion or construction of additional wells.

A draft permit has been developed by EPA that specifies conditions for the operation, monitoring, reporting, and abandonment of the injection well. This project has already received approval from the Iowa Department of Natural Resources (IDNR), but a federal permit is required for the injection portion of this process to meet the provisions of the EPA-administered UIC program in Iowa.

Permit Issuance Process

As part of the permitting process, the applicant conducted a search to identify the location of all known wells (including public or private drinking water supply wells) located within a ¼-mile radius of the aquifer storage and recovery well location that penetrate either the confining layer or the injection interval of the aquifer. The search did not identify any public drinking water supply wells. One private well was located; however, it is approximately 420 feet deep and does not penetrate the confining layer of the proposed injection formation. No other wells were located within the search area. The nearest well on file that goes into or through the proposed injection zone is owned and operated by the city and is located approximately 2 miles away; it should not have any affect or be affected by this operation.

The applicant identified the depth of all underground sources of drinking water (USDWs) above the injection zone and any confining zones that occur. Based on this information and additional information available from IDNR and the Iowa Geologic Survey, it appears that there is sufficient isolation of the proposed injection zone. Additionally, the permit specifies a maximum injection rate, maximum injection pressure, and maximum total storage volumes, which will prevent the movement of injection fluids or geologic formation fluids into any USDW located above the injection zone or to any zone outside the injection interval specified in the permit application.

Proposed Permit Issuance

EPA proposes to issue a permit for the operation of an aquifer storage and recovery well to the City of Ankeny. The permit would require that the permittee, or their agent, operate the injection well as described in the permit, and in a manner that will only allow the injection of treated drinking water into the approved injection zone. Any modifications to these requirements are subject to EPA approval. The proposed permit also includes additional conditions for the operation, monitoring, reporting, and plugging of the injection wells. The conditions specific to this project are:

The injection rate for this well is limited to a maximum rate of 1,750 gallons per minute at a maximum injection pressure of 128 pounds per square inch at the wellhead, and a total storage volume of 325 million gallons.
The injected fluids shall be analyzed prior to commencing an injection event and/or whenever changes are made to the injection fluid.
The recovered fluids shall be analyzed at specific intervals during a recovery cycle. Samples will be analyzed for general chemical, radiological, and biological characteristics to determine if any contaminants were mobilized in the subsurface, and to ensure the water is of drinking water quality prior to distribution.
The permittee will be required to notify EPA of any National Primary Drinking Water standard with a maximum contaminant level (MCL) exceedance within 15 days of discovery.
A demonstration of mechanical integrity shall be conducted, in accordance with 40 Code of Federal Regulations (CFR) Section 146.8, through performance of tests specified in the permit or alternative mechanical integrity tests that have been approved by EPA.
The permittee is required to report to EPA within 24 hours any noncompliance that may endanger public health or the environment.
The permittee is required to submit an annual report to EPA, summarizing the results of the monitoring required by the permit.
The facility has an approved plugging and abandonment plan that will result in an appropriate well closure.
The permittee has demonstrated a financial responsibility that indicates adequate resources will be maintained for an appropriate well closure.

Public Hearing and Public Comments

EPA will hold a public hearing if significant interest is expressed. Written requests for a public hearing should state the nature of the issues proposed, and must be submitted no later than April 26, 2023, to the EPA contact listed below.

EPA is also soliciting written comments on the proposed permit for this facility. The Administrative Record for this action will remain open for public comment until April 26, 2023. Written comments must be submitted no later than that date to the EPA contact listed below.

The Administrative Record, which includes the proposed permit, permit application, and all relevant documents and correspondence related to this permitting action, is available for review and copying at the EPA Regional Office in Lenexa, Kansas; or is available electronically upon request using the contact information below.

UIC Program Office
Groundwater and Drinking Water Branch
Water Division
EPA Region 7
11201 Renner Blvd.
Lenexa, KS 66219

If you have questions or need additional information, please contact:

Ben Meissner
EPA Region 7 (WD/GAD/UIC)
11201 Renner Blvd.
Lenexa, KS 66219
Email: [email protected]