1. (a) Leachate collection and removal systems shall be required at all lined landfills, to prevent leachate discharges and to collect and remove leachate contained within each liner system in conformance with Env-Sw 806.05.
2. (b) Leachate collection and removal systems shall be designed to be hydraulically separate from the stormwater management system(s).
3. (c) Leachate collection and removal systems located outside the waste deposition area shall be leak tight and accessible for leak testing, inspection, cleaning, and repair.
4. (d) Leachate collection and removal systems shall be designed to function effectively during freezing and frozen-ground conditions.
5. (e) Leachate collection and removal systems shall be designed to function effectively during both the active life of the landfill and the landfill closure and post-closure care period. Therefore, for the purpose of sizing the system(s) components and specifying materials with an appropriate design life expectancy, the leachate generation rates, volumes, chemical composition, and temperatures for the above specified time period shall be considered.
6. (f) Leachate collection and removal systems shall be designed to maintain one foot or less of hydraulic head on all portions of the liner, excluding the leachate collection sumps if any, during routine leachate flows plus the 50-year/24-hour storm event.

7. (g) Leachate collection and removal systems shall be designed to manage the quantity of leachate to be generated by the 100-year/24-hour storm event, in a manner which shall:

   1. (1) Not allow a hydraulic head greater than one-foot to exist on any portion of the liner system, excluding the leachate collection sumps, if any, for longer than 7 days;
   2. (2) Provide storage and removal capabilities determined in accordance with (h) below if for a facility not directly connected to a permitted wastewater treatment facility or in accordance with (i) below if for a facility directly connected to a permitted wastewater treatment facility; and
   3. (3) Not rely on leachate recirculation as a factor in determining the required storage and removal capabilities, even if leachate recirculation will be a routine operating procedure at the facility.

8. (h) Leachate collection and removal systems which are not directly connected to a permitted wastewater treatment facility shall provide capacity for storing leachate as follows:

   1. (1) At least 15% of the 100-year storm event storage volume as specified by (g) above shall be provided in primary storage units located outside the waste deposition area or in sumps located within the waste deposition area;
   2. (2) The number of walls or liners in leachate storage units shall be no less than the number of liners within the landfill; and

   3. (3) Containment for the volume of leachate produced by the 100-year storm event which exceeds the volume of the primary storage units shall be provided:

      1. a. Within contingency storage units located outside the waste deposition area; and

      2. b. On the uppermost liner within a waste deposition area provided that:

         1. 1. Storage on the liner in excess of one-foot of hydraulic head shall be limited to a period of 7 days or less, based on procedures identified in the leachate management plan provided pursuant to Env-Sw 806.05, including the pumping and removal rates required to reduce the hydraulic head to one foot or less within 7 days and the specifications for the equipment required to do so; and
         2. 2. Systems relying on valve closure to initiate storage on the liner shall be fully equipped with automated notification alarms and dialers to minimize the potential for overflow, in accordance with (q) below.

9. (i) Leachate collection and removal systems which are directly connected to a permitted wastewater treatment facility shall be designed as follows:

   1. (1) The system shall provide leachate storage units outside the waste deposition area as necessary to meet the requirements of (g) above based on the allowable discharge rate of leachate to the wastewater treatment facility, pump capabilities, and other such factors which limit the rate at which leachate removal can occur;
   2. (2) Compatible pumping and removal rates shall be provided as a component of the facility’s leachate management plan, pursuant to Env-Sw 806.05; and
   3. (3) Systems relying on valve closure to initiate storage shall be fully equipped with automated notification alarms and dialers to minimize the potential for overflow, in accordance with (q) below.

10. (j) The various components of a leachate collection and removal system shall:

    1. (1) Be chemically compatible with the anticipated waste and leachate characteristics;
    2. (2) Provide access for monitoring flow, monitoring hydraulic head in the uppermost liner system, controlling flow, conducting inspections, and cleaning;
    3. (3) Maintain integrity under both dynamic and static loading events for all phases of landfill development;
    4. (4) Specify geotextiles based on calculations which incorporate the leachate generation and flow rates anticipated to occur during the operating and post-closure care phases of the landfill; and
    5. (5) Be designed to prevent the passage of fine particulates into the leachate collection and piping systems as well as mitigate against or eliminate the effects of any material capable of reducing the hydraulic flow capacity of the leachate collection and piping systems.
11. (k) Pipes which require solvent welding shall only be used in leachate vaults equipped with a high-water alarm, a backup high-water alarm, and automatic dialer.

12. (l) The granular soil drainage materials in the liner system shall:

    1. (1) Be designed to meet the requirements of (f) and (g) above; and
    2. (2) Contain no more than 15% calcium carbonate to prevent deposition and clogging and otherwise be of a quality that shall not result in clogging of the leachate collection and removal system(s).
13. (m) A facility shall not be designed to rely solely on managing leachate by recirculation methods.
14. (n) Recirculation of leachate, if practiced, shall proceed only in accordance with the provisions of a leachate recirculation plan approved by the department as part of the facility’s operating plan pursuant to Env-Sw 1105 based on the criteria in Env-Sw 806.05.
15. (o) Leachate collection and removal systems which depend on routine pumping, rather than gravity operating methods, shall only be used at facilities where a full-time operator shall be present during normal operating hours and where auxiliary power and pumping equipment shall be available.

16. (p) Pump stations located outside the waste deposition area shall be designed to provide the following:

    1. (1) Backup pumping capacity;
    2. (2) Backup power supply;
    3. (3) High-water alarm;
    4. (4) Backup high-water alarm;
    5. (5) Alarms to automatic dialer; and
    6. (6) Efficient operation during both average and peak flows.
17. (q) Tanks, sumps, and other storage units associated with leachate collection and removal systems shall be equipped with high-water alarms, backup high-water alarms, and automatic dialers.
18. (r) Automatic dialers shall be equipped with a backup power supply and designed to continue dialing, sending messages, or otherwise attempting to reach a person at least once every ten minutes until the automatic dialer is turned off or otherwise reset at the site.

19. (s) Pipes, tanks, sumps, and other conveyance or storage units associated with leachate collection and removal systems outside the waste deposition area shall have secondary containment or be double-walled except for underground pipes, manholes, and other buried leachate conveyance or storage systems existing prior to the 2024 readoption of this chapter unless existing systems:

    1. (1) Are undersized;
    2. (2) Have failed;
    3. (3) Have reached the end of their service life; or
    4. (4) Are required to be upgraded or replaced for reasons other than the lack of a double-wall or secondary containment.

20. (t) A leachate transfer area shall be designed to contain releases during leachate transfer and constructed of a concrete pad or other impermeable surface that is of sufficient size for:

    1. (1) All connection points to be situated over the impermeable area when leachate is being transferred; and
    2. (2) The entire tank portion of the cargo truck or railcar being filled to be situated over the impermeable area when leachate is being transferred.

Source. #5172, eff 7-1-91; ss by #6535, INTERIM, eff 7-1-97, EXPIRES: 10-29-97; ss by #6619-B, eff 10-29-97; (See Revision Note at chapter heading for Env-Sw 800); ss by #8459, eff 10-28-05 (formerly Env-Wm 2505.06); ss by #10597, eff 7-1-14; ss by #14156, eff 12-21-24