R 299.4432 Type II landfill operation; leachate and secondary collection system monitoring; leachate treatment, storage, and disposal.

Rule 432. (1) The owner and operator of a type II landfill shall remove leachate from a disposal unit as frequently as necessary to ensure that the leachate depth on the liner, excluding the sump, is not more than 1 foot, except after a significant storm event. The leachate depth on the liner shall not be more than 1 foot for more than 7 days after a significant storm event. A significant storm event is a storm that generates 0.1 inches or more of rainfall in 24 hours. (2) The owner and operator shall monitor the leachate collection system and record all of the following: (a) Leachate depths on a schedule that assures compliance with this subrule. (b) The monthly volume of leachate pumped from all units. (c) The quality of leachate generated from the landfill by sampling and analyzing for both of the following: (i) The primary inorganic indicators listed in R 299.4450 and primary volatile organics listed in R 299.4453 on a quarterly basis during the active life and on an annual basis during the postclosure period. (ii) Other constituents listed in R 299.4451, R 299.4452, and R 299.4454 on an annual basis during the active life and postclosure period. (3) The owner and operator of a sanitary landfill that contains a secondary collection system shall do all of the following: (a) Remove pumpable liquids in the secondary collection system sumps on a frequency that is sufficient to minimize the head on the bottom liner. (b) During the active life, do both of the following: (i) Record in the operating record the amount of liquid removed from each system sump at least weekly. (ii) Calculate and record in the operating record the average daily flow rate, monthly. (c) During the postclosure period, do both of the following: (i) Record in the operating record the amount of liquids removed from each secondary collection system sump, at least monthly. If the liquid level in the sump stays below the pump operating level for 2 consecutive months, the amount of liquids in the sumps may be recorded quarterly. If the liquid level in the sump stays below the pump operating level for 2 consecutive quarters, the amounts of liquids in the sumps may be recorded semiannually. If at any time during the postclosure care period the pump operating level is exceeded at units on quarterly or semiannual recording schedules, the owner or operator shall return to the monthly recording of amounts of liquids removed from each sump until the liquid level again stays below the pump operating level for 2 consecutive months. (ii) Calculate and record in the operating record the average daily flow rate, monthly, unless the owner and operator are on a reduced frequency for recording flow under subparagraph (i) of this paragraph. An owner and operator who qualify for recording flow on a reduced frequency are exempt from calculating an average daily flow rate. (d) If the average daily flow rate removed from the sump of a secondary collection system during any month averages more than the action flow rates specified in subrule (4) of this rule, do one of the following within 30 days of the end of the month in which the exceedance occurred: (i) Initiate a liquids management plan to reduce the flow in the secondary collection system and the potential impact of this flow and place this plan in the operating record, and for unmonitorable units, comply with the leak detection requirements of R 299.4437. A liquids management plan may provide for increasing the frequency or rate of leachate removal, the suspension of leachate reintroduction, the application of interim cover to reduce leachate generation, or other actions which are appropriate to reduce the flow rate in the secondary collection system. The owner and operator may discontinue actions under a liquids management plan if the average daily flow rate in a subsequent month no longer exceeds the action flow rate which initiated the action. (ii) Demonstrate to the director that the flow in the secondary collection system is due to construction or consolidation water from the primary liner and not by excessive leakage from the landfill cell. The demonstration shall be certified by a registered professional engineer. In the event the director denies this demonstration, the owner and operator shall initiate a liquids management plan within 30 days of the denial. (iii) For monitorable units which have a natural soil barrier or equivalent geologic protection below the secondary collection system which meets the criteria of R 299.4422(2), continue to remove pumpable liquids on a frequency which minimizes the head on the bottom liner. Landfill cells which meet this criteria are exempt from the liquids management plan requirements of this paragraph. (4) In order to evaluate the performance of a secondary collection system, the director shall establish an action flow rate for each landfill cell containing such a system in the operating license. For purposes of this rule and R 299.4437, a "landfill cell" means a portion of a landfill unit which contains a separate secondary collection system and sump. The action flow rate shall be equal to the following: (a) A value of 5 gallons per acre per day, for unmonitorable units with less than 2 feet of compacted clay in the primary liner. (b) A value of 25 gallons per acre per day, for monitorable units with less than 2 feet of clay in the primary liner. (c) A value of 50 gallons per acre per day, for unmonitorable units with at least 2 feet of compacted clay in the primary liner. (d) A value of 200 gallons per acre per day, for monitorable units with at least 2 feet of compacted clay in the primary liner. (5) The owner and operator of a type II landfill shall inspect all leachate collection pipes on a schedule that assures the proper operation of the leachate collection system. All pipes shall be cleaned or flushed as necessary to assure proper operation. (6) The owner and operator of a type II landfill shall ensure that all leachate that is generated by the landfill is disposed of in compliance with part 31 of the act. To do so, the owner and operator shall provide for 1 of the following: (a) On-site treatment and discharge by a facility that is permitted under part 31 of the act or is otherwise approved by the director. (b) Discharge, by sewer or pipeline, to an off-site publicly owned treatment works or other facility that is permitted under part 31 of the act or is otherwise approved by the director. (c) Discharge, by pump and haul, to an off-site publicly owned treatment works or other facility that is permitted under part 31 of the act or is otherwise approved by the director. (7) The owner and operator of a type II landfill that discharges to an off-site publicly owned treatment works or other facility that is permitted under part 31 of the act shall do all of the following: (a) Secure written permission to discharge to the facility before discharge. (b) Meet any applicable pretreatment requirements. (c) If the discharge is by pump and haul, provide, for hauling a volume necessary to comply with subrule (1) of this rule. (8) The owner and operator may recirculate leachate, liquid from the secondary collection system, or gas condensate back to a disposal unit if the director approves a plan for the recirculation in an operating license.