18 AAC 60.805 - Landfill gas monitoring

(a) If the department determines that a potential landfill gas hazard exists at a landfill facility due to the waste disposed in the landfill or conditions present at the facility, the owner or operator of the landfill shall implement a landfill gas monitoring program in compliance with this section. Gas monitoring required under this section must comply with applicable levels and conditions established by the department on a site-specific basis to protect the public health, safety, and welfare, and is subject to the requirements of (e) - (h) of this section. At a minimum, every Class I or Class IIMSWLF must implement a program for monitoring methane. Through a facility-specific analysis, the department will determine which other gases each Class I and Class II MSWLF must monitor.

(b) Monitoring under this section must be conducted at least quarterly and in compliance with a written plan approved by the department.

(c) A landfill gas monitoring program under this section must detect and measure gases likely to be generated in the landfill based on the type of waste disposed in the landfill.

(d) A methane monitoring program must ensure that the concentration of methane gas generated by the facility does not exceed

(1) 25 percent of the lower explosive limit for methane in facility structures, excluding gas control or recovery system components; and

(2) the lower explosive limit for methane at the facility property boundary or alternate location approved during the permitting process.

(e) A landfill gas monitoring program must utilize both

(1) monitoring devices in facility structures; and

(2) unless otherwise approved by the department during the permitting process, subsurface probes at

(A) the facility boundary; or

(B) an alternate location approved by the department during the permitting process.

(f) The locations selected for

(1) monitoring the subsurface must be based on

(A) soil conditions;

(B) the hydro geologic conditions underlying the facility and adjacent property;

(C) the hydraulic conditions underlying the facility and adjacent property; and

(D) the proximity of facility structures and property boundaries to the waste mass; and

(2) monitoring within facility structures must consider the presence and location of

(A) crawl spaces, basements, closets, and other enclosed spaces in which gases can be trapped; and

(B) electrical boxes and conduit, plumbing drains and water supply lines, and other pathways through which gases can enter the structures.

(g) If methane levels exceeding the limits set in (d) of this section are detected, or another landfill gas exceeds the applicable level or condition established by the department under (a) of this section, the owner or operator shall immediately notify the department by telephone and in writing, and shall take all necessary steps to reduce or dissipate the concentrations of methane or other landfill gas, as applicable, to protect the public health, safety, and welfare.

(h) Not later than 30 days after detection under (g) of this section, the owner or operator shall submit to the department a long-term remediation plan for the landfill gas release. Not later than 60 days after the detection under (g) of this section, or upon approval of the plan, whichever is sooner, the owner or operator shall initiate remediation efforts under the long-term remediation plan and submit written notification to the department that remediation under the plan has been initiated. Upon approval of the plan by the department, the owner or operator shall place a copy of the plan in the operating record and implement the approved plan.

Notes

18 AAC 60.805

Eff. 2/25/2022, Register 241, April 2022

Authority:AS 44.46.020

AS 46.03.010

AS 46.03.020

AS 46.03.100

AS 46.03.110

AS 46.03.810