Injection Wells & Underground Injection Control (UIC)

UIC Regulatory Background

The United States Environmental Protection Agency (USEPA) has defined a well as “a bored, drilled, or driven shaft whose depth is greater than the largest surface dimension; or, a dug hole whose depth is greater than the largest surface dimension; or, a subsurface fluid distribution system”. An injection well is used to place fluid underground into porous geologic formations.

The use of injection wells dates to the 1930’s when they were widely used for the disposal of produced water generated during oil production. In the 1950s chemical companies began injecting industrial wastes into deep injection wells.

With the passage of the Safe Drinking Water Act (SDWA) in 1974 congress required the USEPA to among other things “develop minimum federal requirements for injection practices that protect public health and prevent contamination of underground sources of drinking water”. The USEPA accomplished this through the Underground Injection Control (UIC) Program and developed minimum requirements for 6 classes of UIC wells. 

Classes of UIC Wells

  • Class I Industrial and Municipal Waste 
  • Disposal Wells
  • Class II Oil and Gas Related Injection Wells
  • Class III Solution Mining Wells
  • Class IV Shallow Hazardous and Radioactive Waste Injection Wells
  • Class V Wells for Injection of Non-hazardous Fluids into or Above Underground Sources of Drinking Water
  • Class VI Geologic Sequestration Wells

Managing & Maintaining Your UIC Wells

Injection well design, permitting and operation are overseen by either a state or tribal agency if their respective programs meet minimum federal UIC requirements and USEPA has granted primacy.  If not, USEPA implements the program directly through one of its regional offices.

What Strata Can Do For You

If you own, operate or are considering an injection well let Strata provide the technical and regulatory services necessary to navigate the maze of regulations.

The Strata team have completed underground injection control (UIC) permits and have provided field activity supervision for facilities throughout the country. We have experience in all aspects of deep wells ranging from feasibility studies and well design, installation, maintenance, and testing. Strata staff are experienced with permitting issues for both new and existing deep wells related to facility operations throughout the region. The Strata team personnel have experience working with local and regional governmental agencies, waste disposal facilities, and the USEPA.

Our clients list includes midstream pipeline and storage facilities, and solution mining companies, which utilize UIC Class I injection for disposal of process water and/or the production of brine for cavern development in solution mining operations. Others include oil and gas and industrial clients utilizing porosity for natural gas storage in UIC Class II wells. 

Strata Capabilities

Our team has years of combined downhole well experience and are familiar with state and federal regulators throughout the country. Strata offers engineering and geology services where licensed. Our staff provides technical consulting and field services regarding a wide variety of issues to ensure the continued operation of all classes of injection wells including solution mining of salt and fluid waste injection.

  • Well Feasibility and Risk Assessment
  • Permitting for all UIC Well Classes includes:
    • Geologic Characterization and Reservoir Evaluation
    • Area of Review Evaluations
    • Fluid Containment Evaluation
    • Facility Operation Plans
    • Drilling Prognosis
    • Coring and Testing Programs
    • Well and Casing Design
    • Surface Operations Design
    • Design of Instrumentation and Control Systems
    • Chemical Compatibility Studies
    • Waste Characterization
    • Plugging and Abandonment Plans
  • Drilling and Completion includes:
    • Well Site Management
    • Geologic Supervision
    • Execution of Well Surveys and Testing Programs
    • Well Stimulation
  • Regulatory Compliance includes:
    • Maximum Authorized Operating Pressure (MAOP) Reporting
    • Emergency Response
    • Mechanical Integrity Tests (MIT)
    • Pressure Fall-off Tests—Planning, Execution, and Analysis
    • Static Fluid Measurements
    • Step-rate Testing and Analysis
    • 3-Dimensional Mapping (SONAR) Analysis
    • Well Workovers, Maintenance and Repair
    • State/Federal Monitoring Reports
    • Well Closure (Plugging and Abandonment)
  • GIS and CAD Mapping


  • Class I Permitting, Natural Gas Storage Facility, Kansas (2009): Strata was a key in the permitting of two Class I non-hazardous disposal wells at a proposed Class III natural gas storage facility.
  • Class I Well Site Evaluation, Ector County, TX:  Mr. Zook of Strata conducted a geologic and regulatory feasibility (fatal flaw) analysis of installing a UIC Class I well in Ector County, Texas. The analysis showed that conditions were favorable for a low volume, high pressure disposal well could be installed.

  • Class I Non-Hazardous Injection Well Siting Study, Refinery Company, near Santa Maria, California: Mr. Zook of Strata oversaw a study to evaluate the practical merits of using a Class I well for disposal of mineralized waste water. The evaluation encompassed local and regional geologic conditions capable of accepting injected waste water in a regulatory acceptable manner established by the Environmental Protection Agency (EPA), Region IX. Conclusions determined by the feasibility analysis determined that conditions were favorable for installation of a UIC Class I well.

  • Class I Non-Hazardous Injection Well, Coal Mining Operation, Southern Illinois: Mr. Zook of Strata oversaw the regulatory compliance testing of a new UIC Class I well for a coal mining operation in southern Illinois. The testing included; pressure fall-off test, mechanical integrity test, and step-rate testing. Analysis and final reports were submitted to the Illinois EPA. The results allowed startup operations of the well to proceed.

  • Class I and III Permitting, Evaporation Facility, Kansas: Strata has permitted and re-permitted Class I and III wells at this active salt solution mining facility. 

  • Class  I Well Compliance Testing (fall off testing and MIT), multiple clients across Kansas (ongoing since 2004): Strata has overseen Class I pressure fall-off testing and Mechanical Integrity Test (MIT) for clients in the salt solution mining, natural gas, and natural gas liquids industries since 2004.  Strata has been successfully and reliably performing compliance testing and analysis for over 13 years in Kansas, Oklahoma, Iowa, and Utah.

  • Class I Well Workover, multiple clients and locations: Strata has performed Class I well workovers including removal and replacement of well tubing and packer for clients in the salt solution mining, natural gas, and natural gas liquids industries for over a decade. These projects include plan and report submittals to State regulatory agencies and the execution of field activities with field oversight and problem solving provided by experienced staff of experts.

  • Class III Compliance, Kansas Evaporation Facility, Kansas (ongoing since 2004): Strata has completed regulatory compliance tasks for many Class III salt solution wells at an active salt solution mining facility since 2004. Tasks include the preparation of work plans and reports for well workovers, gamma, and, SONAR logging. Strata has also provided field oversight of these activities. Strata has developed 3-dimensional evaluation techniques of UIC Class III well assessment, which provide an analysis on cavern growth to more effectively determine management strategies for salt production.

  • Class III Compliance, Compass Minerals, Lyons, Kansas Evaporation Facility: Strata has completed MIT’s for a number of Class III salt solution well workovers at an active salt solution mining facility. Tasks include pressure testing well casings for regulatory compliance. Strata has provided field oversight of these activities. These activities require plans and report required by regulatory agency.

  • Horizontal Porosity Storage Well Installation, Iowa: Strata put together a highly-qualified team of experts to install the first horizontal well for porosity storage in Iowa.  Strata geologists performed stratagraphic analysis, supervised vertical and horizontal drilling, logging, completion, cementing, perforation and acidizing of the 3,045 foot well.  Strata worked around the clock to install the first endeavor of its kind in Iowa.