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Plan Review Procedures for Large Septage Storage Facilities

In accordance with s. NR 113.12, Wis. Adm. Code, the use of a septage storage facility with a total storage capacity greater than 50,000 gallons requires a DNR plan approval to ensure compliance with ch. NR 110, Wis. Adm. Code. A WPDES (Wisconsin Pollutant Discharge Elimination System) operating permit is required if a septage storage facility’s capacity exceeds 550,000 gallons.

"Septage" is defined as the wastewater or contents of septic or holding tanks, dosing chambers, grease interceptors, seepage beds, seepage pits, seepage trenches, privies or portable restrooms.

This guidance addresses the construction plan approval requirements of NR 110. For information concerning specific WPDES permits, contact the applicable WPDES permit staff. The WPDES permit would be processed separately from the construction plan review and would be issued after the plan approval.

For a proposed storage facility, construction plans and specifications with the stamp or seal of a Wisconsin Professional Engineer should be submitted to:

Jason Knutson
Wastewater Section Manager
Wisconsin DNR - WQ/3
PO Box 7921
Madison, WI 53707-7921

The submittal should include three sets of the plans and specifications and two copies of the design report or other supplemental information. The content and format of the plans and specifications should generally conform to the requirements of s. NR 108.04, Wis. Adm. Code. The submittal should be from, or submitted on behalf of, the person, corporation or other entity that will be the legal owner of the storage facility after it is constructed.

If the use of an existing tank or structure were proposed, then a Wisconsin Professional Engineer would need to be retained to inspect and evaluate the structural integrity of the structure proposed for use. This engineer should then submit plans and information to verify conformance with the requirements of s. NR 110.26(10). In some instances, a tank leakage test may be required. If any additional new piping, pumps or mixers will be proposed as part of the permanent installation, design information and plans and specifications for these items should also be included.

Septage storage facilities must comply with the requirements of s. NR 110.26(10) for sludge storage facilities. If the septage storage structure will be a lagoon, it must also comply with s. NR 110.24. The plan submittal should include a design report that describes the basis for design and provides site information. Site maps should be provided demonstrating adequate separation distances from water supply wells, residential and commercial buildings, bedrock and high groundwater. Farm outbuildings, such as a barn, would not be considered as a residential or commercial building. The design report should also describe the expected operations of the proposed storage facility. For example, describing the types of wastes to be received, septage receiving and unloading procedures, and ultimate disposal.

The department also highly recommends that local officials and neighbors be notified of the proposed storage facility prior to the submittal of plans. Local zoning issues must be dealt with at the local level.

The submittal must also include the following information describing the environmental impacts of the proposed facility and its operation.

  1. Description of existing land use and resource features (e.g., wetlands, lakes, streams, floodplains, groundwater) that may be affected by the proposed project.
  2. Impacts on flora and fauna (the potential existence of endangered or threatened resources should be identified).
  3. Impacts on prime agricultural land.
  4. If the proposed site is undisturbed, the potential existence of archaeological and historic resources should be checked.
  5. Description of impacts associated with facility operation, including truck traffic, odor generation and other potential nuisance conditions.
  6. Description of mitigative measures, if applicable, to be employed to address identified adverse impacts.

With regard to items 2 and 4, if the area affected by construction is previously disturbed cropland, a lawn or some other area where it may be obvious that there are no endangered species or archaeological resources, then no further information may be needed. Where there is a reasonable possibility for the occurrence of these resources, then additional information should be sought through the department's Endangered Resources Review Program.

For archaeological resource information, contact Richard Kubicek, DNR archaeologist.

Information relating to agricultural land impacts should be described but an Agricultural Impact Statement (AIS) prepared by the Department of Agriculture, Trade and Consumer Protection would not normally be required. Agricultural Impact Statements are only applicable to projects for public entities that may acquire property by condemnation as identified under Chapter 32, Wis. Stats.

After it is determined that the proposal complies with applicable rules and will not result in significant adverse environmental impacts, the department will issue a news release to the local media. The news release will describe the proposed facility location and operation and allow a two-week time period for receiving public comments. After public comments are evaluated, the department will either confirm a decision to approve the proposal, or will request additional information or project revisions to address issues identified by public comments. The department will issue a plan approval to the legal owner of the proposed structure. Construction cannot commence prior to the DNR issuance of the plan approval.