N.J. Admin. Code § 7:14A-8.15 - Specific operating criteria and construction standards applicable to Class III wells

(a) This section establishes operating criteria and construction standards for Class III wells.

(b) Construction requirements for Class III wells are as follows:

1. Class III wells shall, at a minimum, be constructed in accordance with the requirements and specifications set forth in N.J.A.C. 7:9D. More stringent requirements shall be imposed, based on an evaluation of the nature of the injection fluid and/or of geological conditions, or where the Department otherwise determines that it is appropriate, based on considering potential impacts on ground water quality.

2. All new Class III wells shall be cased and cemented to prevent the migration of fluids into or between underground sources of drinking water. The casing and cement used in the construction of each newly drilled well shall be designed for the life expectancy of the well. In determining and specifying casing and cementing requirements, the following factors shall be considered:

i. Depth to the injection zone;

ii. Injection pressure, external pressure, internal pressure, and axial loading;

iii. Hole size;

iv. Size and grade of all casing strings (wall thickness, diameter, nominal weight, length, joint specifications, and construction material);

v. Corrosiveness of injected fluid, formation fluids and temperatures;

vi. Lithology of injection and confining zones; and

vii. Type and grade of cement.

3. Appropriate logs and other tests shall be conducted during the drilling and construction of new Class III wells. A descriptive report interpreting the results of such logs and tests shall be prepared by a qualified log analyst and submitted to the Department. The logs and tests appropriate to each type of Class III well shall be determined based on the intended function, depth, construction and other characteristics of the well, availability of similar data in the area of the drilling site and the need for additional information that may arise from time to time as the construction of the well progresses. At a minimum, such logs and tests shall include deviation checks conducted on all holes where pilot holes and reaming are used, at sufficiently frequent intervals to ensure that vertical avenues for fluid migration in the form of diverging holes are not created during drilling.

4. Where the injection zone is a water-bearing formation, the following information concerning the injection zone shall be determined or calculated for new Class III wells:

i. Fluid pressure;

ii. Temperature;

iii. Fracture pressure;

iv. Other physical and chemical characteristics of the injection zone;

v. Physical and chemical characteristics of the formation fluids; and

vi. Compatibility of injected fluids with formation fluids.

5. Where the injection zone is not a waterbearing formation, the information in (b)4 above shall be determined or calculated and submitted to the Department.

6. Where injection is into a formation which contains water with less than 10,000 mg/l total dissolved solids (TDS), monitoring wells shall be completed into the injection zone and into any underground sources of drinking water above the injection zone which could be affected by the mining operation. These wells shall be located so as to detect any excursion of injection fluids, process by-products, or formation fluids outside the mining area or zone. If the operation may be affected by subsidence or catastrophic collapse, the monitoring wells shall be located so that they will not be physically affected.

7. Where injection is into a formation which does not contain water with less than 10,000 mg/l TDS, monitoring requirements may be less stringent.

8. Where the injection wells penetrate an underground source of drinking water (USDW) in an area subject to subsidence or catastrophic collapse monitoring wells shall be installed into the USDW in sufficient numbers to detect any movement of injected fluids, process by-products or formation fluids into the USDW. The monitoring wells shall be located outside the physical influence of the subsidence or catastrophic collapse.

9. In determining the number, location, construction and frequency of monitoring of the monitoring wells, the following criteria shall be considered:

i. The population relying on the USDW affected or potentially affected by the injection operation;

ii. The proximity of the injection operation to points of withdrawal of drinking water;

iii. The local geology and hydrology;

iv. The operating pressures and whether a negative pressure gradient is being maintained;

v. The nature and volume of the injected fluid, the formation water, and the process by-products; and

vi. The injection well density.

(c) Operating, monitoring, and reporting requirements for Class III wells are as follows:

1. Operating requirements shall, at a minimum, specify that:

i. Injection pressure at the wellhead shall not exceed a maximum which shall be calculated so as to ensure that the pressure in the injection zone during the injection does not initiate new fractures or propagate existing fractures in the injection zone, initiate fractures in the confining zone, or cause the migration of injection or formation fluids into an underground source of drinking water; and

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

2. Where appropriate, Class III wells may be monitored on a field or project basis rather than an individual well basis by manifold monitoring. Manifold monitoring may be used in cases of facilities consisting of more than one injection well, operating with a common manifold. Separate monitoring systems for each well are not required, provided the owner or operator demonstrates that manifold monitoring is comparable to individual well monitoring. Monitoring requirements shall, at a minimum, include:

i. Analyses of the injected fluids with sufficient frequency to yield data representative of the fluids' characteristics;

ii. Installation and use of continuous recording devices to monitor the injection pressure, flow rate and volume;

iii. A demonstration of mechanical integrity pursuant to 7:14A-8.12(c) at least once every five years during the life of the well;

iv. Weekly monitoring of fluid level and the parameters chosen to measure water quality in the injection zone; and

v. Quarterly monitoring of wells adjacent to the injection site to detect any migration from the injection zone into a USDW.

(d) Reporting requirements shall, at a minimum, include:

1. Quarterly reports to the Department on monitoring required;

2. Results of mechanical integrity, and any other periodic test required by the Department, reported with the first regular report after completion of the test; and

3. Monitoring may be reported on a project or field basis rather than on an individual well basis where manifold monitoring is used.

Notes

N.J. Admin. Code § 7:14A-8.15