NR 214.13(2)(a)(a) Ridge and furrow systems shall be constructed on sites with soils having 50% or more of the soil particles passing a No. 200 sieve, except that coarser textured soils may be approved on a case-by-case basis depending on system design and wastewater strength. Suitable soils shall extend at least 3 feet below the base grade of the furrow bottoms.
NR 214.13(2)(b)
(b) The system shall consist of at least 2 cells which can be alternately loaded and rested, unless there is sufficient storage or pretreatment to allow loading and resting of a single cell.
NR 214.13(2)(c)
(c) The system shall be sized and constructed in order to allow sufficient resting to allow soil conditions to become unsaturated and aerobic prior to being loaded.
NR 214.13(2)(d)
(d) The shape of each ridge and furrow cell within the system shall be such that a minimum of soil disturbance is necessary to form the system.
NR 214.13(2)(e)
(e) The wastewater distribution system shall be constructed so that individual cells within the system can be taken out of service for resting without interrupting the discharge to the remaining cells.
NR 214.13(2)(f)
(f) The ridge and furrow system shall be constructed in a manner which provides equal liquid distribution during loading of each cell. The header ditch shall be designed to allow complete drainage after each wastewater loading or lined to prevent wastewater seepage. The header ditch drainage and the grading of the furrows for equal liquid distribution shall be tested before seeding the ridges with grasses.
NR 214.13(2)(g)
(g) All outside embankments and dikes may not be steeper than 3 horizontal to one vertical. Inside embankments and dikes may not be steeper than 2 horizontal to one vertical. All embankments and dikes shall be properly seeded with perennial grasses to prevent erosion.
NR 214.13(2)(h)
(h) All ridge tops shall be a minimum of 6 feet wide to allow mechanical removal of grasses.
NR 214.13(2)(i)
(i) The furrows of the ridge and furrow system shall be one foot deep and one foot wide at the furrow bottom.
NR 214.13(2)(j)
(j) Furrow side slopes may not be steeper than one horizontal to 2 vertical.
NR 214.13(2)(k)
(k) All areas within a ridge and furrow system shall be accessible for maintenance equipment.
NR 214.13(2)(L)
(L) The system shall be constructed to prevent surface runoff from entering the system.
NR 214.13(2)(m)
(m) The ridges shall be seeded with perennial grasses which are suited to wet soil conditions. A nurse crop shall be used to seed new or modified systems. In addition, the grass cover shall be established to at least a 2-inch length before the system is used for wastewater treatment.
NR 214.13(2)(n)
(n) Precautions shall be taken during construction to minimize compaction of absorption areas to prevent a reduction in soil infiltration rate. Project specifications shall detail the specific precautions which will be taken.
NR 214.13(2)(o)
(o) Erosion control measures shall be taken during construction to prevent erosion of soil into a surface water.
NR 214.13(3)(a)
(a) The discharge to a ridge and furrow system may not exceed the hydraulic, organic, nitrogen, chloride or other limitations specified in a WPDES permit or plans developed pursuant to a permit requirement. In determining discharge limitations, the department shall consider past operating performance, the ability of the soils to treat the pollutants in the discharge, hydrogeologic characteristics of the site such as permeability and infiltration rates, and other relevant information.
NR 214.13(3)(b)
(b) The concentration of any wastewater parameter that may impact groundwater quality shall be limited at the point of discharge to a value that will minimize the concentration of the substance in the groundwater to the extent technically and economically feasible and will prevent exceedence of the preventive action limit (PAL) in the groundwater. This will be especially important for parameters, such as dissolved chloride, that do not receive significant treatment in the system.
NR 214.13(3)(c)
(c) The total pounds of nitrogen applied per acre per year shall be limited to the annual nitrogen need of the cover crop plus demonstrable nitrogen losses, such as from denitrification or ammonia volatilization occurring in the treatment system. Determination of the annual pounds of nitrogen applied to the land treatment system shall include the nitrogen supplied by the wastewater, organic nitrogen becoming available to plants and any supplemental fertilizers used.
NR 214.13(3)(d)
(d) The average hydraulic application rate may not exceed 10,000 gallons per acre per day for the system.
NR 214.13 Note
Note: Based upon the department's experience, the recommended range for the average hydraulic application rate for ridge and furrow systems is 2,000 to 5,000 gallons per acre per day.
NR 214.13(3)(e)
(e) Discharge to the system shall be limited so that the discharge volume combined with the precipitation from a 10-year frequency, 24-hour duration rainfall event does not overflow the boundary of the system.
NR 214.13(3)(f)
(f) The volume of discharge shall be limited to prevent inundation of the ridges except for temporary conditions following precipitation events.
NR 214.13(4)(a)(a) The discharge to each cell of the ridge and furrow system shall be monitored for total daily flow.
NR 214.13(4)(b)
(b) The department may require in a WPDES permit that the discharge be monitored for BOD
5, total suspended solids, forms of nitrogen, chloride, metals or any other pollutant that may be present. The department shall select the pollutants to be monitored and the required frequency of monitoring on a case-by-case basis by considering the potential public health impacts, probable environmental impact, soil and geologic conditions, past operating performance, concentrations and characteristics of pollutants in the discharge and other relevant information.
NR 214.13(4)(c)
(c) The department may require electronic or paper submittal of discharge monitoring reports and land application forms.
NR 214.13(5)(a)
(a) Each spring, the ridge top grasses shall be either cut and removed, or the grasses shall be burned. In addition, the grasses shall be cut and if possible removed at least once later in the growing season.
NR 214.13(5)(b)
(b) The discharge shall be alternately distributed to individual sections of the ridge and furrow system to allow sufficient resting periods to maintain the treatment capability of the soil.
NR 214.13(5)(c)
(c) The system shall be operated so that individual ridge and furrow sections have sufficient resting to allow soil conditions to become unsaturated and aerobic prior to being loaded.
NR 214.13(5)(d)
(d) The system may be used only when at least 5 feet of separation exists between the bottom of the furrows and the groundwater.
NR 214.13(5)(e)
(e) Management plan. The department shall require each ridge and furrow system owner or operator to submit a management plan for optimizing treatment system performance and demonstrating compliance with the requirements of this chapter. Following approval by the department, the treatment system shall be operated in conformance with the management plan. If the facility wishes to operate differently than specified in the approved plan, a written request shall be submitted to the department for approval to amend the management plan. The plan shall specify information on pretreatment processes, load and rest schedules, scheduled maintenance, vegetative cover control and removal, operational strategies for periods of adverse weather, monitoring procedures and any other pertinent information.
NR 214.13(6)
(6) Soil investigation and groundwater monitoring requirements. The soil investigation and groundwater monitoring requirements for ridge and furrow systems are specified in ss.
NR 214.20 and
214.21.
NR 214.13 History
History: Cr.
Register, June, 1990, No. 414, eff. 7-1-90;
CR 09-123: cr. (4) (c)
Register July 2010 No. 655, eff. 8-1-10.
NR 214.14
NR 214.14
Spray irrigation systems. NR 214.14(1)(a)(a) A spray irrigation system shall be located at least 1,000 feet from a well serving a community public water supply system and at least 250 feet from other potable water supply wells.
NR 214.14(1)(b)
(b) The nearest edge of wastewater spray shall be separated by at least 500 feet from the nearest inhabited dwelling, except that this distance may be reduced with the written consent of any affected owners and occupants. The department may require a greater distance depending on the type of distribution system and potential for aesthetic and public health impacts.
NR 214.14(1)(c)
(c) The ground surface of the system shall have a minimum separation distance to bedrock and groundwater of at least 5 feet.
NR 214.14(1)(d)
(d) A spray irrigation system may not be located in the floodway as specified in ch.
NR 116. Any system located in the floodplain shall conform to ch.
NR 116 and may not be operated when the floodplain is flooded.
NR 214.14(2)(a)(a) The spray application of wastewater to the land surface shall be designed to prevent ponding or runoff and to incorporate a load/rest cycle that optimizes wastewater treatment on the site. The wastewater application intensity shall be limited to the rate that can infiltrate into the soil surface as it is sprayed. The wastewater loading volume shall be designed so the wastewater will be absorbed and held in the top foot of the soil column for treatment. Following wastewater loading, the acreage shall be rested to provide time for soil organisms to biologically decompose organic pollutants in the wastewater, for organic solids on the ground surface to decompose and for the soil column to reaerate.
NR 214.14(2)(b)
(b) Table 1 provides values acceptable to the department for the intensity of wastewater spray and the wastewater application volumes for specific soil textures under optimum conditions. Alternate values that can be justified through soil testing results may be approved by the department. The volume applied and the intensity sprayed may be restricted by the department to values less than those listed in Table 1 if site conditions warrant.
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See PDF for table 
NR 214.14(2)(c)
(c) The spray irrigation equipment shall be capable of isolating individual sections of the treatment system for resting without interrupting discharge to acreage scheduled to be loaded with wastewater.
NR 214.14(2)(d)
(d) The spray nozzles shall be arranged so that the wastewater will be evenly distributed over the acreage being loaded.
NR 214.14(2)(e)
(e) The spray nozzle openings shall be sized to prevent plugging and located as near to the ground surface as practical to minimize wind drift of the wastewater.
NR 214.14(2)(f)
(f) The spray irrigation system shall be seeded with a mixture of perennial grasses, such as reed canary grass, tall fescue and orchard grass. New seedings shall also contain a nurse crop. The department may approve the use of other types of cover crops but will restrict the use of such sites to times when the cover crop is actively growing. There shall be sufficient land area with a grass cover crop to adequately treat wastewater flows during wet weather conditions.
NR 214.14(2)(g)
(g) The department may require reduced hydraulic application rates or grass buffer strips, or both around the perimeter of the site to absorb runoff during rainfall events.
NR 214.14(3)(a)
(a) The discharge to a spray irrigation system may not exceed the hydraulic, organic, nitrogen, chloride or other limitations specified in a WPDES permit or plans developed pursuant to a permit requirement. In determining discharge limitations, the department shall consider past operating performance, the ability of the soils to treat pollutants in the discharge, the ability of the vegetative cover to take up nutrients, hydrogeologic characteristics of the site such as permeability and infiltration rates, and other relevant information.
NR 214.14(3)(b)
(b) The concentration of any wastewater parameter that may impact groundwater quality shall be limited at the point of discharge to a value that will minimize the concentration of the substance in the groundwater to the extent technically and economically feasible and will prevent exceedence of the preventive action limit (PAL) in the groundwater. This will be especially important for parameters, such as dissolved chloride, that do not receive significant treatment in the system.
NR 214.14(3)(c)
(c) The total pounds of nitrogen applied per acre per year shall be limited to the annual nitrogen need of the cover crop plus demonstrable nitrogen losses, such as from denitrification or ammonia volatilization occurring in the treatment system. Determination of the annual pounds of nitrogen applied to the land treatment system shall include the nitrogen supplied by the wastewater, organic nitrogen becoming available to plants and any supplemental fertilizers used.
NR 214.14(3)(d)
(d) The hydraulic application rate for each system shall be based on topography, cover crop, wastewater characteristics, hydrogeologic conditions, and soil texture, permeability and cation exchange capacity. The average hydraulic application rate may not exceed 10,000 gallons per acre per day.
NR 214.14 Note
Note: Based upon the department's experience, the recommended range for a spray irrigation system average hydraulic application rate is 2,000 to 7,000 gallons per acre per day.
NR 214.14(3)(e)
(e) The intensity of irrigation spray shall be limited on a day-to-day basis to prevent ponding, except for temporary conditions following rainfall events.
NR 214.14(3)(f)
(f) Wastewater spraying shall be limited to prevent the runoff of any wastewater mixed with rainwater. Wastewater may not be sprayed during any rainfall event that causes runoff from the site. Uncontaminated storm water may be allowed to drain from a spray irrigation field.
NR 214.14(3)(g)
(g) The department may restrict spray irrigation during times of the year when the cover crop is dormant or not actively taking up water and nutrients.
NR 214.14(3)(h)
(h) The department may limit the fecal coliform bacteria in the discharge from meat and poultry processing operations to protect human and animal health.
NR 214.14(4)(a)(a) The discharge to spray irrigation systems shall be monitored for total daily flow.
NR 214.14(4)(b)
(b) The department may require in a WPDES permit that the discharge be monitored for BOD
5, total suspended solids, forms of nitrogen, chloride, metals or any other pollutant that may be present. The department shall select the pollutants to be monitored and the required frequency of monitoring on a case-by-case basis by considering the potential public health impacts, probable environmental impact, soil and geologic conditions, past operating performance, concentrations and characteristics of pollutants in the discharge and other relevant information.
NR 214.14(4)(c)
(c) The department may require electronic or paper submittal of discharge monitoring reports and land application forms.
NR 214.14(5)(a)
(a) Spray irrigation systems shall be operated in a load/rest cycle that will provide time for the soil organisms to biologically decompose the organic pollutants in the wastewater, for organic solids on the ground surface to decompose and for the soil column to reaerate.
NR 214.14(5)(b)
(b) The spray irrigation system cover crop shall be cut and removed at least twice a year to stimulate growth of vegetation and removal of nutrients from the system. Corn or other crops may be harvested only once as long as the applied nutrients are limited accordingly.
NR 214.14(5)(c)
(c) The soil at each individual spray irrigation field shall be tested annually for available nitrogen, available phosphorus, available potassium and pH. The results of these analyses shall be submitted to the department and used to determine if the nutrients applied to the site are meeting the agronomic needs of the cover crop.
NR 214.14(5)(d)
(d) Management plan. The department shall require each spray irrigation system owner or operator to submit a management plan for optimizing treatment system performance and demonstrating compliance with the requirements of this chapter. Following approval by the department, the treatment system shall be operated in conformance with the management plan. If the facility wishes to operate differently than specified in the approved plan, a written request shall be submitted to the department for approval to amend the management plan. The plan shall specify information on pretreatment processes, load and rest schedules, scheduled maintenance, vegetative cover management and removal, scheduling of annual soil nutrient testing, operational strategies for periods of adverse weather, monitoring procedures and any other pertinent information.
NR 214.14(6)
(6) Soil investigation and groundwater monitoring requirements. The soil investigation and groundwater monitoring requirements for spray irrigation systems are specified in ss.
NR 214.20 and
214.21.
NR 214.14 History
History: Cr.
Register, June, 1990, No. 414, eff. 7-1-90;
CR 09-123: cr. (4) (c)
Register July 2010 No. 655, eff. 8-1-10.
NR 214.15(1)(a)(a) An overland flow system shall be located at least 500 feet from the nearest inhabited dwelling, except that this distance may be reduced with the written consent of any affected owners and occupants. The department may require a greater distance depending on the type of system and potential for aesthetic and public health impacts.
NR 214.15(1)(b)
(b) An overland flow system shall be located at least 1,000 feet from a well serving a community public water supply system and at least 250 feet from other potable water supply wells.
NR 214.15(1)(c)
(c) The ground surface of the system shall have a minimum separation distance to bedrock and groundwater of at least 5 feet.
NR 214.15(1)(d)
(d) The system may not be located in the floodway as specified in ch.
NR 116. Any system located in the floodplain shall conform to ch.
NR 116 and may not be operated when the floodplain is flooded.
NR 214.15(2)(a)(a) Overland flow systems shall be underlain by at least one foot of heavy textured soils such as clays or clay loams to retard leakage through the base.
NR 214.15(2)(b)
(b) The downslope flow distance shall be 100 feet or greater.
NR 214.15(2)(c)
(c) The downslope gradient for the overland flow fields shall be between 2% and 8%.
NR 214.15(2)(d)
(d) The system shall consist of at least 2 cells of approximately equal area which can be alternately loaded and rested. Where self-propelled equipment which operates on a continuous basis is installed and division into identifiable cells is impossible, its movement shall be regulated to provide alternate loading and resting of the soil.
NR 214.15 Note
Note: It is recommended that an overland flow cell be rested for at least one third of the total time in the load/rest cycle.
NR 214.15(2)(e)
(e) The overland flow treatment system design shall evaluate the interaction between the primary factors influencing system performance and efficiency, such as temperature, downslope flow distance, wastewater hydraulic application rate and the rest period, to optimize treatment on the site.
NR 214.15(2)(f)
(f) The overland flow system shall be arranged so that individual cells within the system can be taken out of service for resting without interrupting the discharge to the remaining cells.
NR 214.15(2)(g)
(g) The distribution equipment shall be arranged so that the wastewater will be evenly distributed over the entire area of an overland flow cell and the wastewater travels down the slope in non-channelized flow.
NR 214.15(2)(h)
(h) The wastewater distribution equipment shall be located at or near the ground level.
NR 214.15 Note
Note: A pressurized distribution system is recommended for ease of operation.
NR 214.15(2)(i)
(i) The wastewater distribution system shall be designed to allow easy cleaning of the distribution orifices. Flexibility to adjust the flow from individual orifices shall be provided to allow the system to be hydraulically balanced to minimize flow channeling.
