[Code of Federal Regulations]

[Title 40, Volume 24]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR258.23]



[Page 405-406]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 258_CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS--Table of Contents

 

                      Subpart C_Operating Criteria

 

Sec.  258.23  Explosive gases control.



    (a) Owners or operators of all MSWLF units must ensure that:

    (1) The concentration of methane gas generated by the facility does 

not exceed 25 percent of the lower explosive limit for methane in 

facility structures (excluding gas control or recovery system 

components); and

    (2) The concentration of methane gas does not exceed the lower 

explosive limit for methane at the facility property boundary.

    (b) Owners or operators of all MSWLF units must implement a routine 

methane monitoring program to ensure that the standards of paragraph (a) 

of this section are met.

    (1) The type and frequency of monitoring must be determined based on 

the following factors:

    (i) Soil conditions;

    (ii) The hydrogeologic conditions surrounding the facility;

    (iii) The hydraulic conditions surrounding the facility; and

    (iv) The location of facility structures and property boundaries.

    (2) The minimum frequency of monitoring shall be quarterly.

    (c) If methane gas levels exceeding the limits specified in 

paragraph (a) of this section are detected, the owner or operator must:

    (1) Immediately take all necessary steps to ensure protection of 

human health and notify the State Director;

    (2) Within seven days of detection, place in the operating record 

the methane gas levels detected and a description of the steps taken to 

protect human health; and

    (3) Within 60 days of detection, implement a remediation plan for 

the methane gas releases, place a copy of the plan in the operating 

record, and notify the State Director that the plan has been 

implemented. The plan shall describe the nature and extent of the 

problem and the proposed remedy.



[[Page 406]]



    (4) The Director of an approved State may establish alternative 

schedules for demonstrating compliance with paragraphs (c) (2) and (3) 

of this section.

    (d) For purposes of this section, lower explosive limit means the 

lowest percent by volume of a mixture of explosive gases in air that 

will propagate a flame at 25[deg] C and atmospheric pressure.

    (e) The Director of an approved State may establish alternative 

frequencies for the monitoring requirement of paragraph (b)(2) of this 

section, after public review and comment, for any owners or operators of 

MSWLFs that dispose of 20 tons of municipal solid waste per day or less, 

based on an annual average. Any alternative monitoring frequencies 

established under this paragraph must:

    (1) Consider the unique characteristics of small communities;

    (2) Take into account climatic and hydrogeologic conditions; and

    (3) Be protective of human health and the environment.



[56 FR 51016, Oct. 9, 1991, as amended at 62 FR 40713, July 29, 1997]