NR 110.24(7)(b)(b) Capacity.
NR 110.24(7)(b)1.1. Influent lines to all lagoon systems shall be sized in accordance with s. NR 110.13 (4).
NR 110.24(7)(b)2.2. Overflow structures and interconnecting piping for continuous flow lagoon systems shall be sized in accordance with s. NR 110.13 (4).
NR 110.24(7)(b)3.3. Overflow structures and interconnecting piping for controlled discharge lagoon systems shall be sized to handle the anticipated interlagoon flow rates during periods of discharge.
NR 110.24(7)(c)(c) Influent piping.
NR 110.24(7)(c)1.1. A manhole shall be installed at the end of the influent line or force main and shall be located as close to the dike as topography permits. Its invert shall be at least 15 centimeters (6 inches) above the maximum operating water level of the lagoon to provide sufficient hydraulic head without surcharging the manhole.
NR 110.24(7)(c)2.2. Influent lines shall be located such that the top of the pipe is at least 15 centimeters (6 inches) below the lower surface of the soil, bentonite, or synthetic liner.
NR 110.24(7)(c)3.3. For circular lagoons, the inlet shall terminate at the center of the lagoon. Influent lines to rectangular or square lagoons shall terminate in the first one third of the lagoon length. Influent and effluent piping shall be located to minimize short-circuiting within the lagoon.
NR 110.24(7)(c)4.4. The inlet line shall discharge either horizontally onto a concrete pad or by means of an upturned elbow terminating at least 30 centimeters (one foot) above the pond bottom.
NR 110.24(7)(d)(d) Overflow structures. An overflow structure shall be provided and shall consist of either a manhole or box equipped with multiple-valved pond drawoff lines or an adjustable overflow device. The overflow structure shall allow the liquid level of the lagoon to be adjusted to permit operation at depths ranging from 60 centimeters (2 feet) to the maximum design operating depth in stabilization ponds and from 1.2 meters (6 feet) to the maximum design operating depth in aerated lagoons. The department recommends that stop planks not be used in overflow structures to control operating depth.
NR 110.24 HistoryHistory: Cr. Register, November, 1974, No. 227, eff. 12-1-74; r. and recr. Register, February, 1983, No. 326, eff. 3-1-83, am. (3) (c) and (4) (b), r. and rec. (3) (d), Register, November, 1990, No. 419, eff. 12-1-90; CR 09-123: am (2) (b) 2., 3., (3) (d) 3., (4) (d) 1., 3. to 5., (6) (a), (b) 2., (c) 3. and 4. Register July 2010 No. 655, eff. 8-1-10.
NR 110.25NR 110.25General conditions required for all land disposal systems. The provisions of this section apply to all municipal and privately owned domestic sewage treatment works.
NR 110.25(1)(1)Applicability. Land disposal systems shall be reviewed and approved on a case-by-case basis.
NR 110.25(2)(2)Design report. A design report shall be submitted in accordance with s. NR 110.15 (1).
NR 110.25(3)(3)Treatment prior to disposal. All discharges to land disposal systems shall receive biological, chemical, physical or a combination of treatments necessary to meet effluent standards in ch. NR 206 and groundwater quality standards in ch. NR 140 as approved by the department. Industrial waste discharges tributary to the municipal system shall be in compliance with applicable pretreatment standards under s. NR 211.30.
NR 110.25(3m)(3m)Management plan.
NR 110.25(3m)(a)(a) A management plan shall be submitted with plans and specifications for all land disposal facilities.
NR 110.25(3m)(b)(b) The management plan shall contain specific information on pretreatment processes, scheduled maintenance, vegetative cover control and removal, load and rest schedules, application rates, operational strategies for periods of adverse weather, monitoring procedures and other pertinent information.
NR 110.25(4)(4)Design requirements.
NR 110.25(4)(a)(a) Application rates.
NR 110.25(4)(a)1.1. The application rate of wastewater may not exceed the long term infiltrative capacity of the soil.
NR 110.25(4)(a)2.2. The application rate of wastewater containing heavy metals may not exceed the soil capacity for preventing the movement of the heavy metals through the soil.
NR 110.25(4)(a)3.3. Multiple wastewater application areas shall be provided to allow load and rest cycles. The discharge shall be alternately distributed to individual cells of the disposal system in a manner to allow sufficient resting periods to maintain the absorptive capacity of the soil, and to allow soil conditions to become unsaturated and aerobic between loadings.
NR 110.25(4)(c)(c) Separation from water supplies.
NR 110.25(4)(c)1.1. Land disposal systems shall be separated from private water supply wells by a minimum horizontal distance of 76 meters (250 feet).
NR 110.25(4)(c)2.2. The minimum horizontal separation distance between a land disposal system and public water supply wells shall be determined during facilities planning in accordance with s. NR 110.09 (2) (p). In all cases the department recommends a minimum horizontal separation of 305 meters (1,000 feet) be maintained.
NR 110.25(4)(e)(e) Storage lagoons. Storage lagoons shall be provided for all land disposal systems which are adversely affected by winter conditions or wet weather. Storage lagoons shall be constructed in accordance with s. NR 110.24 (3) and (4).
NR 110.25(4)(f)(f) Load and rest cycles. Load and rest cycles for each system shall be determined based on hydrogeologic and other relevant site conditions such as soil permeability, texture, cation-exchange capacity, topography, depth to groundwater and bedrock and the wastewater characteristics.
NR 110.25(4)(g)(g) Construction precautions.