Isn’t the use of deepwells to manage hazardous waste declining?
No, as a matter of fact the use of hazardous waste injection wells is increasing both in percentage of all generated waste and actual volume. According to EPA statistics, underground injection accounted for management of over 58% of all hazardous waste generated in the United States—which amounts to about nine billion gallons per year.
When will the well fill up, and you run out of space?
No time soon. Although the EPA 10,000 Year No Migration Petition that governs our well is more complex, we have an area of review which is about a radius of 2.5 miles. According to the models, our waste front is only about 1200 or 1300 feet out from the point of injection. We have injected over 1.5 billion gallons into the formation over the past 35 years, and based on the extremely large formation, it will take much more time to get even another 1300 feet.
What is your capacity?
Although we inject 60 to 70 million gallons per year, we can inject much more. Our permit capacity is about 236 million gallons per year. Our practical capacity based on the formation’s ability to accept flow is about 110 million gallons, or an addition 40 to 50 million gallons per year—which means we have the ability to manage both the growth of our customers’ business as well as very large projects.
Isn’t deepwell a larger risk to the environment than other technologies?
Pick your “yardstick.” Underground injection has no thermal or oxidation processes like incineration or water treatment, and thus no/low air emissions. Our technology has no or lower emissions of CO2, VOCs, or other Hazardous Air Pollutants (HAP) than incineration or water treatment. Underground injection also makes no chemical discharges to waterways. The purpose of EPA Underground Injection Control Regulations is to protect Underground Sources of Drinking Water (USDW), and the EPA has said that underground injection is “safer than virtually all other waste disposal practices.” (EPA Report 570/9-91-031)
How can you inject wastes and waters that have as much or more wastes codes than those of hazardous waste incinerators?
The EPA 10,000 Year No Migration Petition was established to remove hazardous chemicals from the environment and protect USDW. As an important part of this program, the No Migration petition permits injection of waters with constituents above land ban treatment standards.
How many groundwater monitoring wells do you have?
Zero. Having no groundwater monitoring wells is a testament to the cleanliness of a site that has managed hazardous waste for over 35 years. In contrast to other technologies, you might say that our pressurized annulus is a kind of continuous monitor of risk to groundwater. The pressure in the annulus assures than even in the event of a problem to the well, the injection fluid will be directed to the injection zone. If annulus pressure cannot be maintained, injection is ceased and the well problem is addressed before resuming operations.
How are your wells different from those injecting water from oil production and “fracing,” which have become associated with reported problems like induced seismicity?
To be able to obtain a No Migration Petition from the EPA, our wells undergo a much more rigorous review of geology than the Class II wells used in oil production. The geology into which we are injecting is well modeled, and there are about ten injection wells within about 10 miles—most of them operating for over 30 years. Our permits have a much more stringent requirements on geology and siting. The geology along the US Gulf Coast is ideal for injection, since it’s an area of very low seismic risk.
Aren’t there problems with reactions of acids with bases when they’re injected without adjusting pH?
We inject acids and bases in both wells. Typically one well is injecting 0 pH acid, while the other is injecting 12 to 14 pH bases. When we switch from injecting acids to injecting bases, we inject a large volume of water as a buffer. We also buffer between injection of other wastes, which may be incompatible for other reasons.