deep well injection

November 29, 2023

SCS Engineers Environmental Outreach and Education USEPA
Outreach with all stakeholders, including community organizations, regulatory agencies, the public, and local environmental advocacy groups, about well-installation plans and the science behind them leads to smoother-running projects.


Since the 1980s, the USEPA and state regulatory agencies have made great strides to regulate wells and have a robust list of requirements that industrial, municipal, commercial, and manufacturing applicants must adhere to for installing and operating a deep injection well.

Despite the regulations, many communities fear injection wells, and who can blame them? Cutting through the misinformation and online “studies” makes understanding the facts and science difficult. The myriad of groundwater concerns making headlines can become overwhelming. This video, by our team of environmental and injection well experts, takes you through the critical elements and regulations when considering injection wells. And how they help create a safe well site acceptable to regulatory authorities, communities, and industry.

Kokil BansalOur presenter is Kokil Bansal, a licensed professional engineer with experience in landfill redevelopment site assessments, geologic sequestration, wastewater permitting, and advising her clients on proven sustainability practices. She holds a Bachelor’s in Chemical Engineering and a Master’s in Environmental Engineering. Ms. Bansal works on the SCS Engineers’ team of licensed engineers, geologists, hydrogeologists, and scientists dedicated to safe and sustainable environmental solutions for industry.

Ms. Bansal reviews the significance of the following factors for a USEPA “safe” deep injection well:

  1. Federal, State, and Local Regulations.
  2. The makeup of the potential sites’ rock formation (geology) and the relationship with the local and regional aquifers (hydrology). How geologists and hydrogeologists determine if there is a risk of induced seismicity from the injection well or any potential for groundwater pollution.
  3. Economic considerations and financial assurance for the design, implementation, and long-term operations and monitoring.
  4. Community engagement – explain and support with science every step taken to protect drinking water sources and cover any other potential environmental issues of concern. While Ms. Bansal covers engagement last, this should be a priority for everyone’s benefit. As she notes below:

Number one is proactive engagement; it is critical to talk to all stakeholders, including community organizations, the public, and local environmental advocacy groups, about the well installation plan covering the ‘how and where.’ Early involvement in the process leads to a better understanding of the benefits and factors you, as an applicant and local business, are implementing for the public. ~ Kokil Bansal


Watch the short video What Differentiates Safe and Unsafe Injection Wells? USEPA


Additional Resources




Posted by Diane Samuels at 6:00 am

July 12, 2023

SCS Engineers’ deep well injection expert, Monte Markley, is presenting at the 26th Annual EUEC conference, February 13-15, 2024, at the Irving Convention Center near Dallas, Texas.

The Energy Utility Environmental Conference (EUEC) attracts some 2000 attendees from around the globe and features over 300 speakers and 200 exhibitors.  This is the first live in-person event since the pandemic, and we are happy to be together again!

euec 2024
Monte Markley, VP/Project Director, SCS Engineers

SCS Vice President, Monte Markley, will present on “The Basics of Deep Well Injection as a Leachate Disposal Option”

Abstract: Deep well injection is a viable leachate management option in many parts of the United States, yet it is often screened out as a viable alternative due to a lack of understanding of the technology or gross misconceptions about its acceptance or applicability. The purpose of this paper is to present the basics of deep well injection as a technology and to present three key threshold criteria a facility should evaluate when considering the applicability of geologic sequestration of leachate.Technical criteria that will be discussed are potential disposal volumes, geologic suitability, chemical compatibility, pre-treatment requirements, and leachate chemistry. The economic considerations are evaluated based on the technical criteria noted above, management of public perception/relations, current leachate management expenditures, service life of the asset and risk to develop accurate capital, O&M costs, and return on investment. Regulatory considerations will include the role of state vs. federal primacy for each state, the general stance of regulatory acceptance in specific areas of the United States, and a discussion of the permitting process and typical reporting requirements.These key considerations are then integrated into an overall suitability evaluation that an owner can utilize to accurately determine if deep well injection is a viable option and, if so, how to educate other stakeholders and manage the process of implementation as a project moves forward.


Visit the EUEC 2024 website for abstract info, conference details, and registration information.

We hope to see you there!



Posted by Laura Dorn at 11:48 am

February 21, 2023

Meet SCS Engineers’ carbon sequestration and deep well injection experts at BOOTH 729 at the 39th annual International Fuel Ethanol Workshop (FEW) & Expo, June 12-14, in Omaha, Nebraska.

The FEW provides cutting-edge content and unparalleled networking opportunities to the global ethanol industry within a dynamic business-to-business environment. It is the largest, longest running ethanol conference in the world—and is powered by Ethanol Producer Magazine.

The FEW delivers timely presentations with a strong focus on commercial-scale ethanol production – from quality control and yield maximization to regulatory compliance and fiscal management. The FEW is also the ethanol industry’s premier forum for unveiling new technologies and research findings. The program extensively covers cellulosic ethanol while remaining committed to optimizing existing grain ethanol operations.

We invite you to attend the presentation by SCS expert, Kacey Garber, on “Applications of Solution Storage Efficiency via Multiphase Flow Modeling to Carbon Dioxide Storage Project Scoping”
[Carbon Capture & Storage Summit, Wednesday, June 14, Track 2, 8:30 -10:00 am]

Abstract: Carbon Capture and Storage (CCS) is becoming increasingly attractive due to growing climate change concerns as well as tax incentives related to conducting CO2 capture. Facilities that capture CO2 may consider storing captured CO2 via geologic sequestration (GS). GS at a given location requires a Class VI Underground Injection Control (UIC) permit for a Class VI UIC well(s) to inject supercritical CO2. These permits require multiphase flow modeling to delineate both the extent of the supercritical CO2 plume and areas that exceed a critical pressure threshold as a result of injection. We have found numerical modeling is also valuable during project scoping to provide a sense of what the total CO2 storage capacity may be for a given project. To determine long-term storage capacity, CO2 trapping (storage) mechanisms must be considered, including structural/stratigraphic, capillary, solution, and mineral trapping (depending on geochemistry). Solubility trapping appears to be the ultimate trapping mechanism for injected CO2 under most geochemical conditions; therefore, solution storage efficiency will be a key metric for project scoping. Solubility trapping occurs when the CO2 dissolves from its separate, buoyant phase into formation pore water. If the total available pore space for the project and the solubility limit of CO2 can be estimated, then the total solution storage capacity can also be estimated. Then numerical modeling can be used to estimate design and operational parameters to quickly examine under what conditions the most efficient use of pore space occurs. In this example, we investigated what factors may promote solution storage efficiency using a multiphase flow model. This includes how supercritical CO2 injection rate, duration, and location(s) affect solution storage efficiency. This simplified study concluded that injection rate, duration, and location(s) all affect solution storage efficiency. Project-specific considerations need to be incorporated into the model in order to determine the conditions ideal for maximizing solution storage efficiency.

The 2023 FEW program has four concurrent tracks and three additional events:

  • Track 1: Production and Operations – Biological Processes
  • Track 2: Production and Operations – Mechanical Processes and Plant Control
  • Track 3: Coproducts and Product Diversification
  • Track 4: Leadership and Financial Management
  • Co-located: Biodiesel & Renewable Diesel Summit
  • Preconference: Carbon Capture & Storage Summit (June 12), topics will include:
    • Tax Policy
    • Impact on Carbon Intensity of Fuel
    • Required Plant Infrastructure
    • Environmental Permitting
    • Pipeline Requirements and Construction
    • Low Carbon Fuel Markets and Mandates
  • Preconference: Ethanol 101 Summit

The FEW typically draws industry professionals from all 50 states and more than 30 countries. Upwards of 550 biofuels producers from 209 facilities all over the world attend each year.

The 2023 FEW proudly visits Omaha, NE. We look forward to seeing you there!

Click for more information as speakers and topics are announced.  Early Bird Registration ends May 3.


Posted by Laura Dorn at 9:39 am

November 10, 2022

SCS Engineers Environmental Consulting and Contracting
Glenn (far left) is a Geologist and Senior Project Professional with SCS’s Carbon Sequestration and Deep Well Injection practice. Pictured here with part of his class, he is graduating as a Third Class Petty Officer from the Coast Guard’s Marine Science Technician A-School. Congratulations to All! Glenn’s mates recognized him as a Master of Arms in his class for being inspirational. We are pretty darn proud of him and all who serve our nation.


Glenn Haave has had a close relationship with protecting our environment for years, ever since his days working on the ocean towing ships in and out of ports. He figured his deep appreciation of his natural surroundings and desire to protect them might carry into his chosen career path, especially after earning a Bachelor of Science in Geology. But when he came to SCS Engineers as a high-spirited, new graduate, he had no idea of the opportunities that would come his way— both at SCS and serving in the U.S. Coast Guard Reserves.

“Both SCS and the Coast Guard hold you accountable to rise to the occasion and get the job done. With that trust and delegation of responsibilities, I am challenged to become a leader, which gives me a sense of duty and confidence,” Haave says.


Combining Geology, Hands-On Experience, and Teamwork

Starting at SCS doing groundwater and soil sampling and helping remediate landfills for redevelopment, Haave proved to be a fast learner. Quickly building on his skills, he was presented with a unique proposition– to join one of only a few multidisciplinary teams in the country that design and install deep well injection infrastructure. EPA-approved injection wells are safe for placing fluids underground into porous geologic formations. These underground formations may range from deep sandstone or limestone to a shallow soil layer. Injected fluids may include water, wastewater, brine (salt water), or water mixed with chemicals.

Planning, permitting, and executing these projects is a multifaceted undertaking encompassing geologic consulting, reservoir engineering, and deep drilling, with environmental protections and sustainability as core goals.

“Few geologists ever get to work on this type of job. These projects require a lot of capital, time, and very specialized expertise. I was fortunate to be working at SCS’s Miami office at the right time, able, and willing,” says Haave, drawn to complex tasks calling for a razor-sharp eye for detail, focus, and discipline.

Drawing on his experience supporting the Miami-Dade Water and Sewer Department Ocean Outfall Legislation Injection Well Program, where he saw 11 wells constructed in a demanding, high-profile project, he is now on a multidisciplinary team of SCS professionals.


Innovations in Carbon Sequestration – Protecting Our Environment

Now, he takes on a new charge: working on a type of deep injection well called a Class VI well. This sophisticated infrastructure directs carbon dioxide (CO2) liquids and gases into the ground for long-term storage. A fairly new, EPA-approved carbon sequestration technique, it is proven effective at substantially reducing CO2 emissions to the atmosphere.

“Class VI wells are an exciting evolution as the world looks to decarbonize the economy. I feel like I am part of an extraordinarily innovative solution where I am using my background to support a global effort to impact our climate positively,” Haave says.

“I feel a sense of purpose in that we are helping mitigate exponential global warming. At least as important, I am comforted that what we do brings hope that my son, daughter, and their generation will grow up on a healthy, safe planet.”


Another Dimension – U.S. Coast Guard A School

As he embraces this unique opportunity to help the environment, he celebrates another milestone: graduating from U.S. Coast Guard A School and advancing in rank to Marine Science Technician Petty Officer Third Class. His calling will be responding to pollution incidents to protect U.S. waters and inspecting facilities and container vessels that transfer hazardous materials to and from land.

Getting into the Reserves is not easy, nor are the next steps. Making it into A school after boot camp is typically a two-year journey: the waiting list of accomplished graduates is long.

Haave finished three intensive months of classroom work; mock training in the field, morale-building exercises to keep spirits high while away from family and friends, and a battery of testing.

Through these rigorous trials, he took on the honorary role of Master at Arms, leading and mentoring his shipmates and serving as a liaison between the crew and captain.

“Becoming a Coast Guardsman was like a dream come true. It was something I had wanted to do since I was 19. But I needed time to mature. I did a lot of soul searching before I could fully realize what was entailed in living up to Coast Guard expectations; to truly embrace that it’s about a sense of duty to country and family, and to deliver on that conviction,” says Haave, now 37, and nominated as a most inspirational person by his shipmates and instructors.

When he shared his long-envisioned, materialized aspiration with his SCS supervisors, he was unsure what they would think; he was taking on another big commitment.

“They were not only accommodating, but they are proud. SCS Engineers is a military-friendly organization. They are always supportive, flexible, and believe in me.”

In the Coast Guard, he had a choice from a far-encompassing list of specialty areas, given his high military school entrance score. He chose marine science technology because it tied in with his civilian work – navigating and ensuring adherence to federal regulations and being a steward of the environment.


Looking Forward

Gazing back at how far he’s advanced in just the last few years, then looking forward, Haave says, “You know, I’m just 37 years old. I feel like I have a lot more in my gas tank –the amazing experiences I have been fortunate to have are just the beginning. I see more opportunities to advance as a leader and to become an even more rounded geologist, able to approach every project comprehensively and deeply.”


We thank all of our veterans and appreciate Glenn Haave for his service to the U.S. Coast Guard and his commitment to protecting our environment with SCS Engineers by advancing sustainable environmental practices and solutions.


Find out more about carbon sequestration and greenhouse gases:

Video: Building a Well

Information: Deep Well Injection and Sequestration Wells

Video: Carbon Sequestration for Landfills and GHG Tutorial


Safe engineering takes discipline and teamwork –qualities that have always served SCS and our clients with innovative, proven solutions for running operations more efficiently and greener. For a rewarding career, consider SCS Engineers, where all employee-owners have a vested interest in every solution.





Posted by Diane Samuels at 10:32 am

October 20, 2022

SCS Engineers Environmental Consulting and Contracting
Kacey Garber is a groundwater protection project manager involved in maintaining the safety of our planet’s water supply.


Kacey Garber wanted to be a storm chaser when she grew up, trained to detect and alert others of brewing severe weather. But then she found geology and went on to earn graduate and postgraduate degrees in this discipline, which brought the summa cum laude scholar to SCS Engineers. Her charge is groundwater protection, an area where she aspires to grow her expertise further.

The young professional (YP) is already moving quickly along that trajectory, beginning by supporting landfills and utilities and now applying her strong skill set in a highly specialized, fast-evolving arena – deep-well injection.

A common thread binds Garber’s main interests – groundwater protection, geology, and meteorology/trained weather spotter, which she still does in her spare time.

“What draws me to these niches is the thrill of being part of the scientific community collecting and interpreting compelling data to figure out solutions. And not just any solutions but those with the promise of helping protect people and the environment. That’s where I want to have an impact,” she says.

She’s heard of climate change almost her whole life and has thought for almost as long that someday she would play some problem-solving role to help mitigate its effects.

Garber splits her time at SCS between several areas. She monitors and tests groundwater for landfills, closely following both active and closed sites, and helping landfills prepare for post-closure. She supports electric utilities with groundwater issues potentially related to their closed coal ash ponds and disposal sites. And now, she is leading groundwater protection tasks for class VI deep-well injection projects as part of a dedicated team that permits and builds these wells.

The cutting-edge, EPA-regulated technology injects and stores carbon dioxide underground safely, preventing this potent greenhouse gas from releasing into the atmosphere.

Garber’s on-the-job experience in the field is paramount to her new, added role. Her studies in geology focused on sedimentary basins are also proving important.

“Sedimentary basins [where large bodies of rock occur] are ideal spots for carbon sequestration. But first, you must understand the geologic characteristics of the basin and each rock formation and determine exactly which locations within the basin are best for injecting and storing carbon dioxide. That’s a big part of what I do to ensure efficiency and safety,” she says.

In her eyes, Garber lives and works in the best of two worlds in that she can concentrate on different but related interests.

“Joining our deep-well injection team brings me back to my roots in traditional geology. But it also enables me to stay on the groundwater monitoring track, which is meaningful as I aim to position myself as a national expert who can do this important work. Ensuring water quality is critical to protecting the environment and communities, as a large part of our country relies on groundwater for its water supply.”

As she grows her reach into deep-well injection, she grows her relationships too. The multidisciplinary team—all new colleagues to her a year ago are her newest work family addition.

“It’s humbling to partner with so many incredibly smart people, each with their respective areas of expertise. We’ve come to trust each other’s judgment as we solve issues together. And as it turns out, we have a lot in common, especially our love of nature—the joy we find in being outdoors, camping, and hiking.”

Getting a foot in the door of a nationwide environmental firm has been good. Especially one that welcomes YPs and is vested in their career development, something she found uncommon among companies with as great a geographical reach and breadth of expertise.

She seized the opportunity.

“I saw it as a way to gain visibility early in my career. And to become well-rounded in my discipline. We perform groundwater monitoring for many project types, and there are parallels in how it’s done in each; I can support and learn from all of them.”

At the same time, she explores other specialized areas.

“There are designated experts here at SCS in many professions and industries dedicated to caring for the environment. They are great resources to learn from.”

Where she would land one day was unknown for a while. Garber thought she’d become a professor or researcher at one time. But that changed when she interned with the United States Geological Survey, venturing beyond the classroom and lab to assess land use impacts on water quality and floodplains.

“I liked solving problems out in the field and decided pretty quickly that’s where I wanted to be,” she says.

The desire to teach is still in her, though. She travels state to state, presenting to regulators, technology experts, and other seasoned professionals and decision-makers on groundwater modeling, monitoring, and testing.

She also reaches out to ambitious geology students, visiting them on campus to tell them about deep-well injection and carbon sequestration and that the company she works for does these projects around the country. Their curriculum rarely includes an introduction to this specialized niche.

Remembering herself as one of them, Garber says, “I didn’t know of this work in college. I first learned as a newcomer to SCS.

It intrigued me, and I was excited to hear that the deep-well injection group needed a team member with a strong monitoring background. Later I thought, how cool it would be for students to discover this potential career path early.”

How else does she fill her days? Besides watching for and reporting developing storms to weather bureaus– she called in a funnel cloud once out in the field—she plays guitar in a local band.

Sometimes she goes solo and has played and sung at a nearby rehabilitation center and nursing home.

“I love playing music. It makes me happy. But what really feels good is to play for folks, especially those who may be more limited in what they can do and where they can go. For them, listening to music and dancing seems to be the highlight of their day. It makes me happy to see them happy.”


SCS Engineers Environmental Consulting and Contracting
Kacey presenting at the 2022 Groundwater Protection Council’s Annual Conference.
SCS Engineers Environmental Consulting and Contracting
Geoscientists love their rocks! Kacey hiking Mt. Lemmon for the view and the geology.

Ensuring a safe, healthy environment and a better world for everyone is about a commitment to people, community, and hard work. Thank you, Kacey Garber, for your dedication to keeping our groundwater safe, for helping execute innovative solutions to advance sustainability, and for bringing a lift to others along the way. 


You, can make a difference in your life, your work, and your community!





Posted by Diane Samuels at 6:00 am

January 25, 2022

class i injection wells
The deep well setup varies by the type of well and its purpose. Shown here is a simple gravity well.


The technology of safe wastewater sequestration into deep formations has been in use for more than 60 years. As deep well injection is gaining interest for the management of industrial wastewater, one of the more frequently asked questions is whether an injection well is feasible in a specific location.

Detailed feasibility studies dive deep into the many considerations that are the basis for a preliminary deep well injection system design, estimated costs to drill and operate, determination of a return on investment, and project schedule. But first, you’ll want to gather enough information to move forward confidently with an investigation.


Find the Fatal Flaws First

The diagram below illustrates a high-level process for identifying obstacles that may represent a fatal flaw to Class I injection well construction and operation in a particular location.

deep well injection diagram
Fatal Flaw Evaluation Sequence Diagram – SCS Engineers


We’ll walk through this evaluation sequence to determine whether additional resources are justified to study injection well technologies for your facility by answering two questions:

  1. Does a local regulatory program support deep well injection?
  2. Is the local geology sufficient for an injection well?


Does Your Local Regulatory Program Support Deep Well Injection?

The U.S. Environmental Protection Agency (USEPA) regulates injection wells under the 1974 Safe Drinking Water Act with stringent criteria governing the construction and operation of injection wells for industrial wastewater. There are six defined classes of injection well types, each based on the type of disposal activity. Class I wells are useful to inject non-hazardous or hazardous industrial process fluids into deep, isolated rock formations.

Thirty-one states and three territories are the permitting authorities, with primacy delegated to its regulatory program that meets or exceeds the minimum standards established by the USEPA. One of ten regional USEPA offices issues permits and regulates Class I injection wells in the nation’s balance where authority remains with the USEPA. Most USEPA regions, states, and territories have a favorable outlook on the construction and operation of injection wells. Although permitting hazardous injection wells in some states is permissible, you can expect a more robust permitting effort and additional costs for financial assurance.

Following a determination that injection wells are permissible at a specific location, it’s important to identify whether active or plugged Class I injection wells exist within the respective state. The technology of wastewater sequestration into deep formations has been in use for many decades, so the absence of active or abandoned injection wells in an area where regulatory support is present may raise flags related to permitting hurdles or the sufficiency of the local geology.

We’ve prepared a table containing Class I industrial injection wells’ permissibility and existence by state, current at this publication. It is a compilation of various USEPA regions, states, and territories program websites. Since the concentration of total dissolved solids defines protected aquifers, those with 10,000 mg/L or less are considered potential underground sources of drinking water and are therefore strictly prohibited from injected fluids.



Is Your Local Geology Sufficient for an Injection Well?

Considerations for suitable geologic conditions include rock formations that provide sufficient capacity for injected fluids while preventing the upward migration of injected fluids into protected drinking water aquifers. You’ll find regional and local geological information through public sources like the U.S. Geological Survey, state geological surveys, local oil and gas associations, universities, and private clearinghouses.

A sufficient injection zone consists of formation(s) with adequate thickness, high porosity and permeability that can accept the fluids at the proposed injection rate and pressure required to handle the anticipated disposal volumes. These are typically high porosity limestone, dolomites or sandstones at depths exceeding 3,000 feet.

Shale, low permeability limestone, or a sequence of rock types low in porosity and permeability act as “caprocks,” creating a confining zone. These are typically 200 to 1,000 feet above the injection zone but below the base of the protected underground drinking water sources.

Artificial penetrations may consist of oil and gas wells and mining and exploration boreholes. A lack of artificial penetrations within approximately two miles of the desired injection well reduces the potential for artificial vertical migration pathways for injected fluids to reach the protected drinking water aquifers. In some cases, wells or boreholes may penetrate the top of the designated confining zone. In these cases, it is important to obtain abandonment records to demonstrate the occurrence of proper plugging so that the injected fluids stay in the injection zone.

A continuous gentle subsurface geologic structure, lacking faulting and folding, is ideal for reducing the potential for injection-induced seismicity. Complex geologic structures, such as major faults, may act as natural vertical migration pathways for injected fluids to reach the protected drinking water aquifers. Some faults may have the potential to respond to the injection of fluids through seismic action. Although all jurisdictions don’t require an evaluation of the induced seismicity component, it may have local implications in areas with dense oil and gas production.

This two-component evaluation helps identify high-level obstacles that may represent a fatal flaw to the installation or operation of an injection well. A detailed feasibility study may be the logical next step if your facility passes such an evaluation. Feasibility studies build upon the evaluation to provide you with specific information and requirements, including:

  • Permitting with anticipated timeframes
  • Public participation
  • Siting and construction
  • Monitoring and testing
  • Reporting and record-keeping
  • Financial assurance and closure
  • Project schedule from permitting to operation
  • Preliminary well design
  • Budgetary level estimates

SCS’ injection well practice is available to address your questions on whether this disposal technology is appropriate for your facility.


Additional Resources

Video: Leachate and Other Industrial Fluid Injections

Paper: Managing Industrial Liquids

Paper: Deep Disposal Well Considerations for Leachate Management


About the Author:

Stephanie HillStephanie Hill is a Professional Geologist licensed in Florida, Kentucky, Illinois, and Texas and is a key member of the Deep Well and Underground Injection Control practice. Her experience includes permitting and regulatory compliance for underground injection control and coal mining, hydrologic investigations, and identifying large-scale environmental impacts to surface and groundwater resources from various industry practices.





Posted by Diane Samuels at 6:00 am

June 10, 2020

There are many methods and actions businesses, industries, and consumers are taking to mitigate the generation of carbon emissions, such as recycling, composting, and moving to hydrogen-power vehicles, to name a few. There is no one-size-fits-all solution, the answer to cleaner air, water, and soil vary widely and work differently, but all aim to achieve the same goal. We, as environmental engineers, have the benefit of helping our communities and industries move forward using a variety of new technologies that support the lowering of carbon emissions and are sustainable.

SCS Engineers works behind the scene with many clients and thought we’d share some of their new technologies and processes that are expected to help lower greenhouse gases in the future. We kick off this series with Charm Industrial’s new method that captures atmospheric CO₂ in biomass, then converts it to a liquid and injects it into rock formations that have stored crude oil for hundreds of millions of years. While recycling and low emission vehicles lower the generation of CO₂, this one is engineered to extract existing gases and remove them.

You can learn more on the Charm Industrial website or visit SCS’s Liquids Management page for more environmental solutions.






Posted by Diane Samuels at 6:00 am

June 17, 2019

Understanding the entire range of wastewater management and disposal alternatives can be a daunting task, particularly as increasingly stringent surface water discharge standards take effect or as zero discharge facilities find the management of their waste liquid needs changing over time. Former solutions are no longer options or may be too costly. One alternative that is rapidly gaining traction is deep injection wells.

Deep well injection is a viable leachate management option in many parts of the United States, yet it is often screened out as a possible alternative due to a lack of understanding of the technology or gross misconceptions about its acceptance or applicability. The purpose of the Monte Markley’s paper The Basics of Deep Well Injection as a Leachate Disposal Option  is to present the basic technical, economic and regulatory considerations of deep well injection as a technology a facility should evaluate when considering the applicability of geologic sequestration of leachate.

Technical criteria discussed are potential disposal volumes, geologic suitability, chemical compatibility, pre-treatment requirements, and leachate chemistry. The economic considerations are evaluated based on the technical criteria noted above, management of public perception/relations, current leachate management expenditures, the service life of the asset and risk to develop accurate capital, O&M costs, and return on investment. Regulatory considerations include the role of state vs. federal primacy for each state, the general stance of regulatory acceptance in specific areas of the United States,  and a discussion of the permitting process and typical reporting requirements.

These key considerations are then integrated into an overall suitability evaluation that an owner can utilize to accurately determine if deep well injection is a viable option and, if so, how to educate other stakeholders and manage the process of implementation as a project moves forward.

About the Author: Monte Markley, PG, SCS Engineers




Posted by Diane Samuels at 6:01 am

January 22, 2018

High-pressure injection of liquids can be challenging in Class I wells where depths exceed 10,000 feet and extreme temperature variations occur between injection and shut-in conditions. Elevated downhole temperatures at these depths create a high-temperature differential between the injectate and annular fluid resulting in significant swings of annulus pressure and surface seal pot volumes. One-way micro tubing leaks at joints have also occurred due to these conditions.

The injectate cools the annular fluid resulting in contraction of the annular liquid and lowering of the seal pot volume, which requires the addition of fluid into the annulus. Once the wells are shut in, annular pressures rise as the annulus fluid is warmed by the native formation fluid, creating an increased pressure differential on the downhole components and increasing the seal pot volume and potentially creating high-pressure situations in the annulus. In addition to the labor-intensive operation of having to add and remove liquid from the annular space, greater downhole pressure differentials may affect long-term integrity of the injection tubing and protective casing.

Maintenance of an annulus pressure that is less than the injection pressure, similar to the operation of more shallow Class I wells, is impractical under the operating scenario for deeper wells. It also creates the potential for fluid migration from the tubing into the annular space in the event of a leak.

Monte Markley, P.G., and Stephanie Hill will present this and more at the 2018 Underground Injection Control (UIC) Conference. The presentation will focus on the design and implementation of an innovative high-pressure annulus monitoring system that mitigates the presence of micro tubing leaks in joints, and pressure and temperature swings of the annulus.

Learn more about DIW here.

Posted by Diane Samuels at 6:01 am