7 Del. Admin. Code § 7102-66.0

Current through Register Vol. 28, No. 3, September 1, 2024

Section 7102-66.0 - Operating, monitoring and reporting requirements for Major Class V Injection Wells, Class V Injection Wells that inject into a confined aquifer and all Class I Injection Wells

66.1 Operating requirements. Operating requirements shall, at a minimum, specify the following:

66.1.1 Except during stimulation, injection pressure at the wellhead shall not exceed a maximum, which shall be calculated, so as to assure that the pressure in the injection zone during injection does not initiate new fractures or propagate existing fractures in the injection zone. In no case shall injection pressure initiate fractures in the confining zone or cause the movement of injection or formation fluids into an underground source of drinking water.

66.1.2 Injection between the outermost casing protecting underground sources of drinking water and the well bore is prohibited.

66.1.3 For Class I injection wells, unless an alternative to a packer has been approved under Section 65.0, the annulus between the tubing and the long string of casings shall be filled with a fluid approved by the Department and a pressure, also approved by the Department, shall be maintained on the annulus.

66.2 Monitoring requirements for Major Class V Injection Wells, Class V that inject into a confined aquifer and all Class I Injection Wells. Monitoring requirements shall, at a minimum, include:

66.2.1 The analysis of the injected fluids with sufficient frequency to yield representative data of their characteristics;

66.2.2 Installation and use of continuous recording devices to monitor injection pressure, flow rate and volume, and the pressure on the annulus between the tubing and the long string of casing;

66.2.3 A demonstration of mechanical integrity pursuant to Section 61.0 at least once every three (3) years during the life of the well; and

66.2.4 The type, number and location of wells within the area of review to be used to monitor any migration of fluids into and pressure in the underground sources of drinking water, the parameters to be measured, and the frequency of monitoring.

66.2.5 Monitoring.

66.2.5.1 Monitoring of the injection zone: At a minimum, the permittee is required to monitor the pressure buildup in the injection zone annually, including at a minimum, a shut-down of the well for a time period sufficient to conduct a valid observation of the pressure fall-off curve.

66.2.5.2 Groundwater monitoring for Class I injection wells: When prescribing a monitoring system, the permittee shall also be required to monitor wells above the injection zone near the injection well, field or project.

66.2.5.2.1 The permittee shall be able to monitor the following:

66.2.5.2.1.1 The absence of fluid movement adjacent to the well bore, and;

66.2.5.2.1.2 The long-term effectiveness of the confining zone.

66.2.5.2.2 Monitor wells used to meet the requirements of subsection 66.2.5.2.1 shall be sampled periodically. The frequency of sampling and constituents to be analyzed shall be specified in the permit and shall be representative of the monitored activity.

66.2.5.2.3 Monitor wells used to meet the requirements of subsection 66.2.5.2.1.1 (above) shall be located within 150 feet of the injection well unless the applicant can demonstrate, through a hydro-geologic study, that a monitor well located at a greater distance will be capable of adequately monitoring fluid movement adjacent to the borehole.

66.2.5.2.4 For Class I wells, the permittee shall monitor a zone below the base of the underground source of drinking water, if a zone is available, and at least one zone within, and near the base of, the underground source of drinking water.

66.2.5.2.5 The Department may also require any of the following when needed to provide reasonable assurance that the requirements of subsection 66.2.5.2 are being met:

66.2.5.2.5.1 Continuous monitoring for pressure changes in the first aquifer overlying the confining zone.

66.2.5.2.5.2 Continuous monitoring for pressure changes in any monitor well constructed under subsection 66.2.5.2.5.1, above,

66.2.5.2.5.3 Periodic (minimum of quarterly) monitoring of groundwater quality in the first aquifer overlying the injection zone,

66.2.5.2.5.4 Periodic monitoring of groundwater quality in the lowermost underground source of drinking water.

66.2.5.2.5.5 Periodic additional monitoring to determine whether fluid movement caused by underground injection activity is occurring into or between underground sources of drinking water.

66.2.5.2.5.6 The use of indirect, geophysical techniques to determine the position of the waste front, the water quality in a formation designated by the Department, or to provide other site specific data.

66.2.5.2.5.7 Periodic monitoring of groundwater quality in the injection zone.

66.2.5.2.6 Any additional monitoring necessary to determine whether fluids are moving into or between USDWs.

66.3 Reporting requirements. Reporting requirements shall, at a minimum, include:

66.3.1 Quarterly reports to the Department describing:

66.3.1.1 The physical, chemical and other relevant characteristics of injection fluids;

66.3.1.2 Monthly average, maximum and minimum values for injection pressure, flow rate and volume, annular pressure; and

66.3.1.3 The results of monitoring prescribed under subsection 66.2.4.

66.3.2 The first quarterly report after the completion of the monitoring shall include the following (at a minimum):

66.3.2.1 Periodic tests of mechanical integrity;

66.3.2.2 Any other test of the injection well conducted by the permittee if required by the Department; and

66.3.2.3 Any well work/maintenance (including repairs).

7 Del. Admin. Code § 7102-66.0

21 DE Reg. 978 (6/1/2018) (Final)