[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR146.23]

[Page 733-734]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 146_UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS
--Table of Contents
 
      Subpart C_Criteria and Standards Applicable to Class II Wells
 
Sec.  146.23  Operating, monitoring, and reporting requirements.

    (a) Operating requirements. Operating requirements shall, at a 
minimum, specify that:
    (1) Injection pressure at the wellhead shall not exceed a maximum 
which shall be calculated so as to assure that the pressure during 
injection does not initiate new fractures or propagate existing 
fractures in the confining zone adjacent to the USDWs. In no case shall 
injection pressure cause the movement of injection or formation fluids 
into an underground source of drinking water
    (2) Injection between the outermost casing protecting underground 
sources of drinking water and the well bore shall be prohibited.
    (b) Monitoring requirements. Monitoring requirements shall, at a 
minimum, include:
    (1) Monitoring of the nature of injected fluids at time intervals 
sufficiently frequent to yield data representative of their 
characteristics;
    (2) Observation of injection pressure, flow rate, and cumulative 
volume at least with the following frequencies:
    (i) Weekly for produced fluid disposal operations;
    (ii) Monthly for enhanced recovery operations;
    (iii) Daily during the injection of liquid hydrocarbons and 
injection for withdrawal of stored hydrocarbons; and
    (iv) Daily during the injection phase of cyclic steam operations

And recording of one observation of injection pressure, flow rate and 
cumulative volume at reasonable intervals no greater than 30 days.
    (3) A demonstration of mechanical integrity pursuant to Sec.  146.8 
at least once every five years during the life of the injection well;
    (4) Maintenance of the results of all monitoring until the next 
permit review (see 40 CFR 144.52(a)(5)); and
    (5) Hydrocarbon storage and enhanced recovery may be monitored on a 
field or project basis rather than on 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/operator demonstrates that manifold 
monitoring is comparable to individual well monitoring.
    (c) Reporting requirements. (1) Reporting requirements shall at a 
minimum include an annual report to the Director summarizing the results 
of monitoring required under paragraph (b) of this section. Such summary 
shall include monthly records of injected fluids, and any major changes 
in characteristics or sources of injected fluid. Previously submitted 
information may be included by reference.
    (2) Owners or operators of hydrocarbon storage and enhanced recovery 
projects may report on a field or project basis rather than an 
individual

[[Page 734]]

well basis where manifold monitoring is used.

(Clean Water Act, Safe Drinking Water Act, Clean Air Act, Resource 
Conservation and Recovery Act; 42 U.S.C. 6905, 6912, 6925, 6927, 6974)

[45 FR 42500, June 24, 1980, as amended at 46 FR 43162, Aug. 27, 1981; 
47 FR 5000, Feb. 3, 1982; 48 FR 14293, Apr. 1, 1983; 48 FR 31404, July 
8, 1983]