NR 110.255(1)(a)10.c.c. Soil pH may not be less that 6.5.
NR 110.255(1)(a)11.11. A minimum separation distance of 10 feet shall be maintained between the bottom of the absorption pond and bedrock.
NR 110.255(1)(b)(b) Discharge limitations for absorption pond systems. Effluent limitations are as specified in s. NR 206.08 (1) (b).
NR 110.255(2)(2)Spray irrigation systems.
NR 110.255(2)(a)(a) Design and construction criteria for spray irrigation systems.
NR 110.255(2)(a)1.1. All spray irrigation systems shall be designed with a wastewater distribution system capable of loading and resting various portions of the site to optimize wastewater treatment within the soil and crop growth.
NR 110.255(2)(a)2.2. Spray irrigation onto frozen ground is prohibited. The department may restrict loadings during times of the year when the cover crop is not actively growing.
NR 110.255(2)(a)3.3. Application of wastewater to the spray irrigation system shall incorporate a rest/load cycle and application intensity such that the soil moisture holding capacity in the top foot of the soil column is not exceeded and ponding or runoff do not occur. Following wastewater application to a portion of the field, that portion shall be rested. Table 8 provides values for the maximum volume of wastewater that may be applied per load cycle and the maximum intensity of wastewater application for specific soil textures. The values in Table 8 are the maximum amount approvable unless greater values can be justified through soil testing and are 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 8 if site conditions warrant.
Table 8
- See PDF for table PDF
NR 110.255(2)(a)4.4. The spray nozzle openings shall be sized to prevent plugging and shall be located as near to the ground surface as practical to minimize wind drift of the wastewater.
NR 110.255(2)(a)5.5. The spray nozzles shall be arranged so that the wastewater will be evenly distributed over the entire area under irrigation.
NR 110.255(2)(a)6.6. The spray irrigation system shall be arranged so that individual sections within the system can be taken out of service for resting without interrupting discharge to the remaining sections.
NR 110.255(2)(a)7.7. The spray irrigation system shall be seeded with perennial grasses such as reed canary grass, tall fescue and orchard grass. The cover crop shall be a crop which is not used for direct human consumption. New seedings shall also contain a nurse crop. The cover crop shall be maintained by cutting and removing the grass a minimum of twice per growing season. The department may approve the use of other types of cover crops such as corn but will restrict the use of such sites to times when the cover crop is actively growing. The department may also require reduced hydraulic application rates, grass buffer strips or both around the perimeter of the site to prevent wastewater runoff during rainfall events.
NR 110.255(2)(a)8.8. The ground surface of the spray irrigation system shall have a minimum separation distance to bedrock of at least 5 feet.
NR 110.255(2)(a)9.9. A minimum separation distance of 5 feet shall be maintained between the land surface elevation of the spray irrigation field and the highest anticipated groundwater elevation. The department may on a case-by-case basis allow this distance to be reduced if the permittee can show, based on hydrogeologic and other relevant site factors, that the groundwater will be adequately protected.
NR 110.255(2)(a)10.10. The department may require disinfection of effluent to spray irrigation systems if there is a potential risk to public health.
NR 110.255(2)(b)(b) Discharge limitations for spray irrigation systems. Effluent limitations are as specified in s. NR 206.08 (2) (b).
NR 110.255(3)(3)Ridge and furrow systems.
NR 110.255(3)(a)(a) Design and construction criteria for ridge and furrow systems.
NR 110.255(3)(a)1.1. The shape of each cell within the ridge and furrow system shall be such that a minimum of soil disturbance is necessary to form the system.
NR 110.255(3)(a)2.2. A ridge and furrow system may not be constructed on a site at which less that 50% of the soil particles pass a no. 200 sieve. 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 110.255(3)(a)3.3. The furrows of the ridge and furrow system shall be one foot deep and one foot wide at the furrow bottom.
NR 110.255(3)(a)4.4. Furrow side slopes may not be steeper than one horizontal to 2 vertical.
NR 110.255(3)(a)5.5. The system shall be sized and constructed in order to allow sufficient resting to allow soil conditions to become unsaturated and aerobic prior to any wastewater being reapplied.
NR 110.255(3)(a)6.6. The system shall be constructed in a manner which provides equal liquid distribution during loading of each cell. The header ditch shall be sealed in order to allow complete drainage and to prevent wastewater seepage. The drainage of the header ditch and the grading of the furrows for equal liquid distribution shall be tested with water before seeding the ridges with grasses.
NR 110.255(3)(a)7.7. The system shall consist of at least 2 cells which can be alternately loaded and rested.
NR 110.255(3)(a)8.8. The wastewater distribution system shall be arranged so that individual cells within the ridge and furrow system can be taken out of service for resting without interrupting discharge to the remaining cells.
NR 110.255(3)(a)9.9. The bottom of the ridge and furrow system may not be closer than 5 feet to the highest anticipated groundwater elevation. The department may allow this distance to be reduced on a case-by-case basis if the permittee can show, based on hydrogeologic and other relevant site factors, that the groundwater will be adequately protected.