Chapter NR 664

NR 664.0221(4) (4) The department may approve alternative design or operating practices to those specified in sub. (3) if the owner or operator demonstrates to the department that the design and operating practices, together with location characteristics, will do both of the following:

NR 664.0221(4)(a) (a) Prevent the migration of any hazardous constituent into the groundwater or surface water at least as effectively as the liners and leachate collection and removal system specified in sub. (3).

NR 664.0221(4)(b) (b) Allow detection of leaks of hazardous constituents through the top liner at least as effectively.

NR 664.0221(5) (5) The double liner requirement in sub. (3) may be waived by the department for any monofill, if the requirements of pars. (a) and (b) 1. or 2. are met:

NR 664.0221(5)(a) (a) The monofill contains only hazardous wastes from foundry furnace emission controls or metal casting molding sand, and the wastes do not contain constituents which would render the wastes hazardous for reasons other than the toxicity characteristic in s. NR 661.0024.

NR 664.0221(5)(b) (b)

NR 664.0221(5)(b)1. 1. All of the following:

NR 664.0221(5)(b)1.a. a. The monofill has at least one liner for which there is no evidence that the liner is leaking. For the purposes of this subsection, the term “liner” means a liner designed, constructed, installed and operated to prevent hazardous waste from passing into the liner at any time during the active life of the facility, or a liner designed, constructed, installed and operated to prevent hazardous waste from migrating beyond the liner to adjacent subsurface soil, groundwater or surface water at any time during the active life of the facility. In the case of any surface impoundment which has been exempted from the requirements of sub. (3) on the basis of a liner designed, constructed, installed and operated to prevent hazardous waste from passing beyond the liner, at the closure of the impoundment, the owner or operator shall remove or decontaminate all waste residues, all contaminated liner material and contaminated soil to the extent practicable. If all contaminated soil is not removed or decontaminated, the owner or operator of the impoundment will comply with appropriate long-term care requirements, including but not limited to groundwater monitoring and corrective action.

NR 664.0221(5)(b)1.b. b. The monofill is located more than one-quarter mile from an underground source of drinking water (as that term is defined in 40 CFR 144.3).

NR 664.0221(5)(b)1.c. c. The monofill is in compliance with generally applicable groundwater monitoring requirements for facilities with operating licenses under s. 291.25, Stats.

NR 664.0221(5)(b)2. 2. The owner or operator demonstrates that the monofill is located, designed and operated so as to assure that there will be no migration of any hazardous constituent into groundwater or surface water at any future time.

NR 664.0221(6) (6) The owner or operator of any replacement surface impoundment unit is exempt from sub. (3) if both of the following apply:

NR 664.0221(6)(a) (a) The existing unit was constructed in compliance with the design standards of 42 USC 6924(o)(1)(A)(i) and (5).

NR 664.0221(6)(b) (b) There is no reason to believe that the liner is not functioning as designed.

NR 664.0221(7) (7) A surface impoundment shall be designed, constructed, maintained and operated to prevent overtopping resulting from normal or abnormal operations; overfilling; wind and wave action; rainfall; run-on; malfunctions of level controllers, alarms and other equipment and human error.

NR 664.0221(8) (8) A surface impoundment shall have dikes that are designed, constructed and maintained with sufficient structural integrity to prevent massive failure of the dikes. In ensuring structural integrity, it may not be presumed that the liner system will function without leakage during the active life of the unit.

NR 664.0221(9) (9) The department shall specify in the operating license all design and operating practices that are necessary to ensure that the requirements of this section are satisfied.

NR 664.0221 History History: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06; CR 19-082: am. (5) (a) Register August 2020 No 776, eff. 9-1-20.

NR 664.0222 NR 664.0222 Action leakage rate.

NR 664.0222(1) (1) The department shall approve an action leakage rate for surface impoundment units subject to s. NR 664.0221 (3) or (4). The action leakage rate is the maximum design flow rate that the leak detection system can remove without the fluid head on the bottom liner exceeding one foot. The action leakage rate shall include an adequate safety margin to allow for uncertainties in the design (e.g., slope, hydraulic conductivity, thickness of drainage material), construction, operation and location of the leak detection system, waste and leachate characteristics, likelihood and amounts of other sources of liquids in the leak detection system and proposed response actions (e.g., the action leakage rate shall consider decreases in the flow capacity of the system over time resulting from siltation and clogging, rib layover and creep of synthetic components of the system, overburden pressures, etc.).

NR 664.0222(2) (2) To determine if the action leakage rate has been exceeded, the owner or operator shall convert the weekly or monthly flow rate from the monitoring data obtained under s. NR 664.0226 (4) to an average daily flow rate (gallons per acre per day) for each sump. Unless the department approves a different calculation, the average daily flow rate for each sump shall be calculated weekly during the active life and closure period, and if the unit is closed in accordance with s. NR 664.0228 (2), monthly during the long-term care period when monthly monitoring is required under s. NR 664.0226 (4).

NR 664.0222 History History: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06.

NR 664.0223 NR 664.0223 Response actions.

NR 664.0223(1) (1) The owner or operator of surface impoundment units subject to s. NR 664.0221 (3) or (4) shall have an approved response action plan before receipt of waste. The response action plan shall set forth the actions to be taken if the action leakage rate has been exceeded. At a minimum, the response action plan shall describe the actions specified in sub. (2).

NR 664.0223(2) (2) If the flow rate into the leak detection system exceeds the action leakage rate for any sump, the owner or operator shall do all of the following:

NR 664.0223(2)(a) (a) Notify the department in writing of the exceedence within 7 days of the determination.

NR 664.0223(2)(b) (b) Submit a preliminary written assessment to the department within 14 days of the determination, as to the amount of liquids, likely sources of liquids, possible location, size and cause of any leaks and short-term actions taken and planned.

NR 664.0223(2)(c) (c) Determine to the extent practicable the location, size and cause of any leak.

NR 664.0223(2)(d) (d) Determine whether waste receipt should cease or be curtailed, whether any waste should be removed from the unit for inspection, repairs or controls and whether or not the unit should be closed.

NR 664.0223(2)(e) (e) Determine any other short-term and longer-term actions to be taken to mitigate or stop any leaks.

NR 664.0223(2)(f) (f) Within 30 days after the notification that the action leakage rate has been exceeded, submit to the department the results of the analyses specified in pars. (c), (d) and (e), the results of actions taken and actions planned. Monthly thereafter, as long as the flow rate in the leak detection system exceeds the action leakage rate, the owner or operator shall submit to the department a report summarizing the results of any remedial actions taken and actions planned.

NR 664.0223(3) (3) To make the leak and remediation determinations in sub. (2) (c), (d) and (e), the owner or operator shall comply with par. (a) or (b):

NR 664.0223(3)(a) (a) Do all of the following:

NR 664.0223(3)(a)1. 1. Assess the source of liquids and amounts of liquids by source.

NR 664.0223(3)(a)2. 2. Conduct a fingerprint, hazardous constituent or other analyses of the liquids in the leak detection system to identify the source of liquids and possible location of any leaks, and the hazard and mobility of the liquid.

NR 664.0223(3)(a)3. 3. Assess the seriousness of any leaks in terms of potential for escaping into the environment.

NR 664.0223(3)(b) (b) Document why the assessments are not needed.

NR 664.0223 History History: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06.

NR 664.0226 NR 664.0226 Monitoring and inspection.

NR 664.0226(1) (1) During construction and installation, liners (except in the case of existing portions of surface impoundments exempt from s. NR 664.0221 (1)) and cover systems (e.g., membranes, sheets or coatings) shall be inspected for uniformity, damage and imperfections (e.g., holes, cracks, thin spots or foreign materials). Both of the following inspections are required immediately after construction or installation:

NR 664.0226(1)(a) (a) Synthetic liners and covers shall be inspected, to ensure tight seams and joints and the absence of tears, punctures or blisters.

NR 664.0226(1)(b) (b) Soil-based and admixed liners and covers shall be inspected for imperfections including lenses, cracks, channels, root holes or other structural non-uniformities that may cause an increase in the permeability of the liner or cover.

NR 664.0226(2) (2) While a surface impoundment is in operation, it shall be inspected weekly and after storms to detect evidence of any of the following:

NR 664.0226(2)(a) (a) Deterioration, malfunctions or improper operation of overtopping control systems.

NR 664.0226(2)(b) (b) Sudden drops in the level of the impoundment’s contents.

NR 664.0226(2)(c) (c) Severe erosion or other signs of deterioration in dikes or other containment devices.

NR 664.0226(3) (3) Prior to the issuance of an operating license, and after any extended period of time (at least 6 months) during which the impoundment was not in service, the owner or operator shall obtain a certification from a qualified engineer that the impoundment’s dike, including that portion of any dike which provides freeboard, has structural integrity. The certification shall establish, in particular, that the dike will do both of the following:

NR 664.0226(3)(a) (a) Withstand the stress of the pressure exerted by the types and amounts of wastes to be placed in the impoundment.

NR 664.0226(3)(b) (b) Not fail due to scouring or piping, without dependence on any liner system included in the surface impoundment construction.

NR 664.0226(4) (4) 

NR 664.0226(4)(a) (a) An owner or operator required to have a leak detection system under s. NR 664.0221 (3) or (4) shall record the amount of liquids removed from each leak detection system sump at least once each week during the active life and closure period.

NR 664.0226(4)(b) (b) After the final cover is installed, the amount of liquids removed from each leak detection system sump shall be recorded 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 shall be recorded at least quarterly. If the liquid level in the sump stays below the pump operating level for 2 consecutive quarters, the amount of liquids in the sumps shall be recorded at least semi-annually. If at any time during the long-term care period the pump operating level is exceeded at units on quarterly or semi- annual recording schedules, the owner or operator shall return to 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.

NR 664.0226(4)(c) (c) “Pump operating level” is a liquid level proposed by the owner or operator and approved by the department based on pump activation level, sump dimensions and level that avoids backup into the drainage layer and minimizes head in the sump.

NR 664.0226 History History: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06.

NR 664.0227 NR 664.0227 Emergency repairs; contingency plans.

NR 664.0227(1) (1) A surface impoundment shall be removed from service in accordance with sub. (2) when either of the following occurs:

NR 664.0227(1)(a) (a) The level of liquids in the impoundment suddenly drops and the drop is not known to be caused by changes in the flows into or out of the impoundment.

NR 664.0227(1)(b) (b) The dike leaks.

NR 664.0227(2) (2) When a surface impoundment must be removed from service as required by sub. (1), the owner or operator shall do all of the following:

NR 664.0227(2)(a) (a) Immediately shut off the flow or stop the addition of wastes into the impoundment.

NR 664.0227(2)(b) (b) Immediately contain any surface leakage which has occurred or is occurring.

NR 664.0227(2)(c) (c) Immediately stop the leak.

NR 664.0227(2)(d) (d) Take any other necessary steps to stop or prevent catastrophic failure.

NR 664.0227(2)(e) (e) If a leak cannot be stopped by any other means, empty the impoundment.

NR 664.0227(2)(f) (f) Notify the department of the problem in writing within 7 days after detecting the problem.

NR 664.0227(3) (3) As part of the contingency plan required in subch. D, the owner or operator shall specify a procedure for complying with the requirements of sub. (2).

NR 664.0227(4) (4) No surface impoundment that has been removed from service in accordance with the requirements of this section may be restored to service unless the portion of the impoundment which was failing is repaired and the following steps are taken:

NR 664.0227(4)(a) (a) If the impoundment was removed from service as the result of actual or imminent dike failure, the dike’s structural integrity shall be recertified in accordance with s. NR 664.0226 (3).

NR 664.0227(4)(b) (b) If the impoundment was removed from service as the result of a sudden drop in the liquid level, then both of the following apply:

NR 664.0227(4)(b)1. 1. For any existing portion of the impoundment, a liner shall be installed in compliance with s. NR 664.0221 (1).

NR 664.0227(4)(b)2. 2. For any other portion of the impoundment, the repaired liner system shall be certified by a qualified engineer as meeting the design specifications approved in the operating license.

NR 664.0227(5) (5) A surface impoundment that has been removed from service in accordance with the requirements of this section and that is not being repaired shall be closed in accordance with the provisions of s. NR 664.0228.

NR 664.0227 History History: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06.

NR 664.0228 NR 664.0228 Closure and long-term care.

NR 664.0228(1) (1) At closure, the owner or operator shall comply with either par. (a) or (b):

NR 664.0228(1)(a) (a) Remove or decontaminate all waste residues, contaminated containment system components (liners, etc.), contaminated subsoils and structures and equipment contaminated with waste and leachate, and manage them as hazardous waste unless s. NR 661.0003 (4) applies.

NR 664.0228(1)(b) (b) Do all of the following:

NR 664.0228(1)(b)1. 1. Eliminate free liquids by removing liquid wastes or solidifying the remaining wastes and waste residues.

NR 664.0228(1)(b)2. 2. Stabilize remaining wastes to a bearing capacity sufficient to support final cover.

NR 664.0228(1)(b)3. 3. Cover the surface impoundment with a final cover designed and constructed to do all of the following:

NR 664.0228(1)(b)3.a. a. Provide long-term minimization of the migration of liquids through the closed impoundment.

NR 664.0228(1)(b)3.b. b. Function with minimum maintenance.

NR 664.0228(1)(b)3.c. c. Promote drainage and minimize erosion or abrasion of the final cover.

NR 664.0228(1)(b)3.d. d. Accommodate settling and subsidence so that the cover’s integrity is maintained.

NR 664.0228(1)(b)3.e. e. Have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present.

NR 664.0228(2) (2) If some waste residues or contaminated materials are left in place at final closure, the owner or operator shall comply with all long-term care requirements contained in ss. NR 664.0117 to 664.0120, including maintenance and monitoring throughout the long-term care period (specified in the operating license under s. NR 664.0117). The owner or operator shall do all of the following:

NR 664.0228(2)(a) (a) Maintain the integrity and effectiveness of the final cover, including making repairs to the cap as necessary to correct the effects of settling, subsidence, erosion or other events.

NR 664.0228(2)(b) (b) Maintain and monitor the leak detection system in accordance with ss. NR 664.0221 (3) (b) 4. and (c) and 664.0226 (4), and comply with all other applicable leak detection system requirements of this chapter.

NR 664.0228(2)(c) (c) Maintain and monitor the groundwater monitoring system and comply with all other applicable requirements of subch. F.