NR 811.856 Note Note: The department’s Public Water Supply Section located in Madison may be contacted to obtain a copy of DNR Application of DHS Radionuclide Wastewater Disposal Criteria for help in addressing Unity Equation issues.

NR 811.856 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (1) made under s. 13.92 (4) (b) 7., Stats., Register November 2010 No. 659; CR 22-074: r. and recr. (intro.), am. (2) (a) Register January 2024 No. 817, eff. 2-1-24.

NR 811.857 NR 811.857 Backwash wastewater from lime softening water treatment plants. Filter backwash wastewater from lime softening water treatment plants shall be disposed of by any of the following methods:

NR 811.857(1) (1) Recycle. Returned to the inlet end of the plant in accordance with the requirements of s. NR 811.862.

NR 811.857(2) (2) Discharge to a sanitary sewer. Lime softening backwash water may be discharged to a sanitary sewer system subject to the requirements under s. NR 811.85 (1) (a).

NR 811.857(3) (3) Discharge to a water of the state. Backwash wastewater from lime softening treatment plants may be discharged to a water of the state subject to the requirements under s. NR 811.85 (1) (b). Suspended solids shall be removed from the filter backwash wastewater prior to discharge by means of settling, and possibly coagulation. The pH shall be adjusted to within the range of 6.0 and 9.0 prior to surface water discharge.

NR 811.857 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: cr. (1) (title), am. (2), (3) Register January 2024 No. 817, eff. 2-1-24.

NR 811.858 NR 811.858 Lime softening sludge. Sludge from plants using lime to soften water will vary in quantity and in chemical characteristics depending on the softening process and the chemical characteristics of the water being softened. The department shall impose additional disposal requirements on a case-by-case basis for sludge from plants treating water containing radium-226, radium-228, uranium, or other radionuclides. These additional requirements shall modify the requirements for specific disposal methods. The requirements for specific disposal methods are as follows:

NR 811.858(1) (1) Lagoons. The design shall meet the following minimum requirements:

NR 811.858(1)(a) (a) Locations free from flooding, with grading or ditching to divert surface runoff.

NR 811.858(1)(b) (b) Minimum lagoon depth of 5 feet with interior and exterior slopes of 3:1.

NR 811.858(1)(c) (c) Two years solids storage volume for temporary lagoons and 8- to 10-years storage volume for permanent lagoons.

NR 811.858(1)(d) (d) A minimum of 2 cells to provide flexibility in operation. The inlet and outlet structures shall be designed so that the cells may be operated independently.

NR 811.858(1)(e) (e) Adjustable decanting devices.

NR 811.858(1)(f) (f) Means of convenient cleaning.

NR 811.858(1)(g) (g) Lagoons shall be designed to comply with ch. NR 213.

NR 811.858(1)(h) (h) Supernatant from lagoon thickening shall be discharged to a sanitary sewer, water of the state, or holding tank, under the applicable requirements of s. NR 811.85 (1). Lime softening sludge supernatant that is discharged to a water of the state shall meet the treatment requirements under s. NR 811.857 (3).

NR 811.858(2) (2) Application to agricultural land. The department may allow liquid sludge to be applied to agricultural land by tank truck. This method requires proper handling facilities, vehicles, and equipment to allow hauling and spreading that does not create dust, odors, or other nuisance conditions. Adequate sludge holding facilities are required for use during times that trucks cannot operate. Land application of sludge, including the radionuclide content, shall comply with s. NR 811.85 (1) (b).

NR 811.858 Note Note: Under s. NR 214.02 (3) (k), uncontaminated lime sludges from water supply treatment facilities shall follow the land spreading requirements under s. NR 518.04 (3). Uncontaminated lime sludges exclude any sludges containing radionuclide content that are regulated under a WPDES permit under ch. 283, Stats. The department’s wastewater program in the bureau of water quality is responsible for the issuance of WPDES permits for discharges from waterworks to a water of the state. Waterworks owners should contact the department’s district wastewater staff for WPDES permit application and compliance requirements.

NR 811.858(3) (3) Discharge to sanitary sewer. Discharge to sanitary sewer may be approved on a case-by-case basis if a study or experience has shown that problems will not occur in the sewage collection system or at the wastewater treatment plant. The discharge of lime softening sludge shall meet the requirements under s. NR 811.85 (1) (a). A water system owner shall submit plans to both the department’s wastewater section and public water engineering section for a new discharge or an increase in volume or percent solids of lime softening sludge to sanitary sewer for review and approval prior to initiation of the construction or operational change.

NR 811.858(4) (4) Mechanical dewatering. Mechanical dewatering may be utilized if approved by the department after review of the results of pilot testing. Supernatant from mechanical dewatering shall be discharged to a sanitary sewer, water of the state, or holding tank, pursuant to the applicable requirements under s. NR 811.85 (1). Effluent that is discharged to a surface water shall also meet the treatment requirements under s. NR 811.857 (3).

NR 811.858 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: am. (intro.), (1) (b), (d), (f), cr. (1) (g), (h), am. (2), (3), r. and recr. (4) Register January 2024 No. 817, eff. 2-1-24.

NR 811.859 NR 811.859 Spent media.

NR 811.859(1) (1) General. The department may require special handling and disposal for spent media from water treatment plants under any of the following circumstances:

NR 811.859(1)(a) (a) Granular activated carbon shall be evaluated when treating water with volatile organic compounds, radium, uranium, or radon gas.

NR 811.859(1)(b) (b) Filter sand, green sand, ion exchange media, membranes, support media, and other media that may retain radionuclide material shall be evaluated when treating water with radium-226, radium-228, or uranium.

NR 811.859(2) (2) Disposal approval. The water system owner shall contact the department for approval prior to disposal of the medias listed under sub. (1). The water system owner shall submit a written request indicating the type of media, the volume of media, the contaminants of concern and their concentration in the influent water and the media, the proposed method of transportation, and the proposed method of disposal. A landfill that accepts spent media from a water treatment facility that treated groundwater containing radium shall comply with the requirements under s. NR 506.12 prior to accepting the spent media waste for disposal.

NR 811.859 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: am. (1) (intro.), (a), (2) Register January 2024 No. 817, eff. 2-1-24.

NR 811.860 NR 811.860 Backwash wastewater from surface water treatment plants. Filter backwash wastewater from surface water treatment plants shall be disposed of by any of the following methods: