Section R. 299.4437 - Landfill operation; leak detection systemsRule 437.
(1) For unmonitorable units, the secondary collection system is also a leak detection system. To evaluate the performance of a leak detection system, the director shall establish a response flow rate for each landfill cell that contains a leak detection system in the operating license for the unit. The response flow rate for a leak detection system is determined by the following criteria: (a) By using a value of 200 gallons per acre per day for A landfill design that has a primary liner which uses 2 feet or more of compacted clay.This flow rate accounts for water from the consolidation of clay or natural groundwater.(b) By using a value of 25 gallons per acre per day for A landfill design which has A primary liner without 2 feet or more of compacted clay.(2) If the average daily flow rate removed from the sump of a leak detection system is more than the action flow rate for that cell specified in R 299.4432, the owner and operator shall evaluate the chemical characteristics of liquid in the leak detection system by sampling and analyzing the system in accordance with subrule (6) of this rule and evaluating for the presence of a leak by a statistical test under R 299.4908, a trend analysis, or other means. Before solid waste is placed in any new unit that has a leak detection system, the owner and operator may, at their discretion, establish a baseline concentration of constituents in the secondary collection system based on an analysis of representative samples from the system.(3) The owner and operator of a landfill shall conduct the response actions required under subrule (5) of this rule if monitoring of the leak detection system determines that both of the following apply to liquid that is removed from the system: (a) The average daily flow rate is more than the response flow rate that is established for the unit under subrule (1) of this rule.(b) The liquid contains hazardous substances indicative of leachate from the unit.(4) The owner and operator of a landfill that has a leak detection system that exceeds the response flow rate may demonstrate to the director that hazardous substance concentrations present are not above the baseline concentration established pursuant to subrule (2) of this rule or that the flow is due to construction or consolidation water from the primary liner and is not due to excessive leakage from the unit. The demonstration shall be certified by a registered professional engineer. Upon director approval of a demonstration, the owner and operator shall be exempt from the response action plan requirements of this rule.(5) An owner and operator who are required to conduct response actions pursuant to this rule shall take all of the following actions: (a) Within 7 days of a determination that the response flow rate has been exceeded, notify the director, in writing, that the response flow rate has been exceeded.(b) Submit a preliminary written assessment to the director within 14 days of a determination that the response flow rate has been exceeded. A preliminary written assessment shall include all of the following information for the landfill cell in which the response flow rate was exceeded:(i) The amount of liquids removed from the leak detection system.(ii) The likely sources of liquids, including the depth of leachate in the leachate collection system.(iii) The possible location, size, and cause of any leaks.(iv) The short-term actions taken and planned.(c) Determine, to the extent practicable, the location, size, and cause of any leak.(d) Determine whether waste receipt should cease or be curtailed, whether any waste should be removed from the landfill cell for inspection, repairs, or controls, and whether or not the unit should be closed.(e) Determine any other short-term and longer-term actions to be taken to mitigate or stop any leaks.(f) After a determination that the response flow rate has been exceeded, and for as long as the flow rate in the system exceeds the response flow rate, the owner or operator shall submit to the director, within 30 days of the end of the calendar quarter, a report that summarizes the results of any remedial actions taken and planned.(g) To make the leak or remediation determinations specified in this subrule, the owner or operator shall do all of the following:(i) Assess the source of liquids and amounts of liquids by source.(ii) Conduct a fingerprint, hazardous constituent, or other analysis of the liquids in the system to identify the source of liquids and possible location of any leaks and the hazard and mobility of the liquid.(iii) Assess the seriousness of any leaks in terms of potential for escaping into the environment or document why the assessments are not needed.(6) An owner or operator who is required to evaluate the chemical characteristics of a leak detection system under this rule shall sample and analyze for the constituents listed in R 299.4450 to R 299.4454 or the approved hydrogeological monitoring plan, quarterly during the active life and postclosure period, except as provided in subrule (7) of this rule, and shall submit the results of the monitoring and any required notifications and reports to the director not more than 30 days after the end of the calendar quarter.If none of the constituents or their breakdown products are detected in leachate at practical quantitation limits approved by the director for 2 consecutive sampling events, then the owner and operator may reduce the frequency of analysis of the constituents in the leak detection system to annually for as long as the constituents are not detected in the leachate.(7) The owner or operator of a landfill unit who initiates chemical characterization of a leak detection system or response actions after exceeding an action flow rate or response flow rate may discontinue the action if the average daily flow rate in a subsequent calendar month no longer exceeds the applicable flow rate that initiated the action.Mich. Admin. Code R. 299.4437